.338 300gr SMKS - MOA vs. Range?

[vh20]

Man, am I having a devil of a time dialing in a load for this .338LM rifle! This is my first experience with these long-range specialty-type bullets. I'm getting inconsistent results from day to day. I have been doing my main load testing at 100 yds. like I normally would, but I remembered reading that these super-long bullets may take about 300 yds. to stabilize. I found it hard to believe that you could actually shoot a significantly smaller MOA at 300+ yds than you could at 100, so I asked the Sierra tech folks and they seemed to confirm that it isn't uncommon. Still, with no experience to draw from in this area, I'm wondering just how much smaller?

For instance, in a recent session, I shot three 3-shot groups at 100 yds with an overall average of 1.71 MOA - absolutely sickening, disheartening, makes me question if I forgot how to shoot, you name it. But then for the heck of it I backed off to 300 and fired another 3-shot group…0.54 MOA. Really?! Can there be that much of an improvement by increasing the range, or did I just get lucky on that last group at longer range? That was the end of my session for that day, so I came back the next day with the same load, expecting to zero the rifle at 200, then do some more experimenting at 300 and farther to see if the performance could be duplicated. Instead I ended up chasing the zero around (which has NOT been a problem at all until now). I never got past 200 yds, and fired three 3-shot groups that averaged 1.26 MOA (which is between my 100 yd avg., and my one 300 yd group). So, here's my real question:

You guys that are shooting 1/2 MOA groups using 300gr SMK out of your .338LMs (especially if it's a Savage 110 FCP or BA) - At what kind of yardage are you getting that performance? Is it consistent, or does range make that big of a difference? I'm starting to wonder if I don't need a totally different approach. Thanks!

 

[JLR]

I can't speak for anything about the guns in question, but in my experience with the 300smk and a .338Edge, it shoots just as good at 100yds as it does anywhere else.

 

[jfseaman]

I have not finished my 338 Edge but I was told by a more experienced shooter/competitor that sometimes shower can be better.

My usual 260 load is seriously sub moa at 700 yards but at 100 it can be a little wobbly.

Other than that, follow standard procedures, I'm sure you know the drill but...
Check your bedding
Check your barrel clearance (more may be better)
Check your action screws torque
Check your scope mounting system, rail screws, ring torque, rings..
Check your scope.
Neck tension consistency
Velocity consistency
etc....

 

[D_TROS]

Whats your load? There shouldnt be a large enough vel diff even at 300 yards to effect groups any.

I shoot my 338LM with 92 gr of H1000 and its shoots lights out at all distances. The SMK's are great for not being super sensitive to seating depth so that leaves you or the rifle.

what the seaman said above, check ALL of your screws on rifle and scope. A torque wrench is advised. If you dont have one get one as you will find you use it for everything.

I know people like savages because the barrel is easy to switch out, maybe its still loose??

My buddy is having same probs with a Rem 308, and Sometime it shoots, sometimes it dont.

AFter you check all the bolts and nuts (including the one behind the rifle ) you may need a smith to check it out. Before you do that, have someone you know to be a consistant shot to take a try at it. Might be you after all. Might not.

Good luck man,
DT

 

[vh20]

Thanks! I do really appreciate the advice you guys are coming up with. I'll answer to some of the specifics you mentioned/asked about when I get a moment later where I can get free (at work now). If you guys are willing to bear with me a little longer, I'll also post some target pics to see if some more experienced eyes can spot something I'm missing.

 

[Longshot38]

Alright I'm going to start with the most common cause of such problems, and understand this is not meant to be insulting in any way. It is just that I don't know you or your expereice level. But the most common causes of these issues are either the shooter or a bad scope. On the shooters end it could be anything from improper form to recoil sensativity. So what kind of LR shooting experence do you have? Have you had anyone (knowledgeable) watch you shoot and anaylize your form? As for the scope, have you box tested it? If not, do so and see what turns up.

On the ammunition end it could be a great number things. Tell us more about your groups. Are you seeing vertical stringing, horizonal devations, both? Vertical stringing is a result of velocity devations. Horizonial can be anything from the shooter to enviromental. Tell us more about your reloading process. Is it new brass or fired brass? Are you neck turning? How far are you setting the shoulder back? What is your seating depth and are you jumping the bullet?

 

[ChrisGarrett]

You're never going to get a 100yd load that averages 1.71moa on a consistent basis to then make 300yds at 3 inches. It's not physically possible for those bullets that are spreading out to 1.71moa at 100yds to then magically bend back in at 300yds and form a tighter group.

This isn't the movie WANTED, where people can bend bullets in mid-flight, to their will.

At best, you can keep a 1" group at 100yds, a 3" group at 300yds.

Chris

 

[vh20]

You're never going to get a 100yd load that averages 1.71moa on a consistent basis to then make 300yds at 3 inches. It's not physically possible for those bullets that are spreading out to 1.71moa at 100yds to then magically bend back in at 300yds and form a tighter group.

This isn't the movie WANTED, where people can bend bullets in mid-flight, to their will.

At best, you can keep a 1" group at 100yds, a 3" group at 300yds.

Chris

THIS has been my belief all along. I cannot for the life of me imagine how a bullet can "know" where to return to the centerline of a group once it has deviated from it (over-simplifying a bit here). I have never experienced that with any kind of bullet in the past, but I'm new to these super-long bullets and there are those who are claiming it happens. It was even confirmed to me on two separate calls to Sierra. They refer to it as "the bullet going to sleep." However no one ever mentioned the magnitude of improvement that supposedly can occur, thus my question here. I just don't believe it really occurs, and the discussion here seems to confirm it. I will answer more of the questions that have been asked as soon as I can this afternoon. Thanks.

 

[ChrisGarrett]

THIS has been my belief all along. I cannot for the life of me imagine how a bullet can "know" where to return to the centerline of a group once it has deviated from it (over-simplifying a bit here). I have never experienced that with any kind of bullet in the past, but I'm new to these super-long bullets and there are those who are claiming it happens. It was even confirmed to me on two separate calls to Sierra. They refer to it as "the bullet going to sleep." However no one ever mentioned the magnitude of improvement that supposedly can occur, thus my question here. I just don't believe it really occurs, and the discussion here seems to confirm it. I will answer more of the questions that have been asked as soon as I can this afternoon. Thanks.

You can have a load that shoots 1moa at 100yds, NOT shoot 1moa at 300yds, due to a bullet not being stable from 100-300yds, in essence...it's awake and not 'asleep'. This is probably what they're talking about. Things can get worse after 100yds, but they can't get better, is how I understand it, but my degree covers English Literature and Communications, not 'physics'.

Chris

 

[vh20]

OK, I'm going to post my targets from the past 3 sessions. All loads have the same bullet (300gr SMK), brass (Lapua), and charge (Retumbo, 91.0gr). The only variables are primer substitutions and bullet seating depths as noted (and also target distance as noted). Up to this point I had been using -.020 off the lands as my standard seating depth. On this 100 yd session (see Target 1) I compared three different primers with bullets at -.020, and also played with the seating depth on the CCI primer load. I thought I was on to something, since the CCI load seemed to show a response by seating at -.010. Also the Fed. and Win. primered loads were showing some promise even at -.020. No groups hitting .5 MOA yet, but several in the .7 range.
Center bull is two foulers, plus a 3-shot group with CCI/-.020. Bottom left bull is CCI/-.030. Bottom right is CCI/-.010. Upper right is WLRM/-.020, and upper left is Fed GMM215/-.020. Based on this, I figured my next session should start with the Fed. and Win. primer loads, but seated -.010 to see if they would tighten up like the CCI load did. I was expecting progress...

 

[vh20]

My next session picked up where I left off. I tested the same load as before with CCI, Fed, and Win. primers, and seating at -.010. Instead of tightening, my groups went to crap. I couldn't even get the CCI load to repeat anywhere near it previous performance. In fact, my best group at this session didn't even match my worst group of the previous one. It was at this point that in desperation I backed off to 300 yds and fired a group with the CCI/-.010 load and got - a 0.54 MOA group! Seriously confused now...

For reference, the corner bulls are all 100 yds. Bottom left is 2 foulers, bottom right is WLRM/-.010, top right is Fed GMM215/-.010, and top left is CCI/-.010. The 300 yd group is low-right of the center bull (didn't dial in enough elev.). What looks like 3 holes touching at the bottom of the group is only 2 with a piece of paper missing between them. The third hole is slightly high/right, making for a 1.7 in. group. At this point I decided next session I would re-zero my rifle with this load @ 200 yds. and then experiment with it at 300+. As you will see, that didn't work out too well, either.

 

[vh20]

My last session. I was going to take my CCI/-.010 load, zero my scope at 200, then go out and see if I could better performance at longer range to test this "bullet goes to sleep" theory that I found hard to believe. Every round on this target is identical. Also, I didn't start with a clean barrel this time - it had 14 rounds from the previous session through it since cleaning. The first group is bottom left. The first shot was the high one, then I put two low right together which made me think I pulled the first shot. So, I fired a fourth shot which also landed right with the low ones. I figured I pulled one shot but otherwise had gotten a .54 MOA group. I expected to make some zero adjustments to the scope and be on my way. I dialed in the corrections (3 clicks UP and 1 LEFT) and shot the next group at bottom right bull. Ugh - my zero didn't move UP at all, and my windage was over-corrected. Group size getting worse, too. I gave it 3 more clicks UP and went back 1 RIGHT and then fired another group at the top right bull. Now my elevation jumped double and the windage is back about where it should be. Group size getting horrible. Finally, 2 clicks DOWN, moved to the top left bull and first two shots looked great, then that last one blew it. Went home dejected and ready to send the rifle to a watery grave.

I've got to run, but I'll be back shortly and answer some of the questions you guys have asked. Thanks SO much for listening!

 

[vh20]

To answer some of the questions asked:

Jfseaman: The rifle has been epoxy-bedded in its factory HS Precision stock. Barrel clearance is generous, action screws are torqued 60 in. lbs. front and rear (but trigger guard screw is just snug), Farrell scope rail and rings all torqued to Farrell's spec (can't remember the values), rings were pushed hard-forward in the slots when torqued. I do not have a way to check neck tension, but have never had this kind of problem before. Velocities have been consistent-enough, but got weird at last session (more later, but suspect a chrono problem).

D-Tros - The current load info is listed with the targets above, but centers around 91.0 gr of Retumbo, and I've tried 3 different primers and experimented a bit with seating depths from -.010 to -.030. I do own and use a torque wrench as advised. I don't know about the barrel tightness, but it is a brand-new rifle.

Longshot38 - You are quite right to suspect me as a cause, and I cannot guarantee I'm not it. I cannot say if I'm capable of .5 MOA shooting because I don't think I've ever owned a rifle capable of it (although I think this one should be). However, I own a bone-stock Browning A-Bolt in .30-06 that I can routinely shoot .7 MOA with using a load I developed for it, despite it not having any of the accuracy-improving features of the Savage .338. It also has more recoil than the .338 and I have never had much trouble with it. I don't consider myself to be recoil sensitive at all. This .338 is pretty much painless to shoot, but there still could be a technique deficiency I'm not aware of. I don't have anyone to watch me shoot.

The groups are posted for your opinions. Brass has been all virgin (but full-length sized) up until the last session. The last session I started in on the second firing, bumped shoulders back .002. Oddly, velocities jumped about 100 fps, but I am suspecting a chrono problem (Shooting Chrony).

I hope some of this will help you guys figure out how to set me straight! Thanks so much for your help.

 

[Longshot38]

So a couple things that might help. First off is the human element. You say you have no one to watch you shoot. That is alright, an alternative exist. Just setup a video camera on yourself then after you get done review the footage. On the reloading end a great number of things might help. Try not doing a FL resize, rather just neck size until the your rounds start getting tight in the chamber. Also check for run out in your rounds. This can and has cause issues. You might also consider measuring your chamber to see how much freebore exist in order to find the best seating depth for your bullet. And lastly try a different bullet. Rifles are like women, you won't know what all they like until you take them out a few times and try some different things.

 

[sib1948]

My 338 LM shoots consistently under 0.6 MOA at 100 yds with S&B 250 gr. BTHP. Just starting hand loading this month and getting my bench organized. Your groups should be much better, which leaves you, the gun or your ammo as the problem. Do you have anyone else who could shoot your gun or your ammo in another gun ? You might get some answers that way.

 

[Desert Fox]

If you're confident with your ability, then the only thing left is the equipment.

What kind of scope you have on that rifle. A braked 338 Lapua need a robust scope.

 

[ChrisGarrett]

Maybe the rifle doesn't like 300gr SMKs? Try some 250gr Scenars, or SMKs, or try the 300gr Bergers and/or Scenars.

Pick a primer, pick seating depth and play with your charge weights.

Shoot 5 shot groups, too. Frank hates 3 shot groups, even at 200yds.

Go back to the basics and fiddle with one variable at a time.

Taking one combo and shooting only 3 shots, is too small a sample size to get any concrete idea on what works and what doesn't.

Chris

 

[vh20]

Desert Fox - a Vortex Viper PST, 6-24x, FFP. The scope recently (possibly between Sessions 1 and 2 above) developed a "flake" of debris of some kind on the reticle. It looks like a paint chip or something in the upper left quadrant, and in perfect focus with the crosshairs/reticle (i.e. same focal plane which to me indicates that is where it is stuck). A call to Vortex today suggested two things - 1) The debris is not related to any problem I'm having, but they'll be happy to fix it under warranty, and 2) He thought my scope ring torque was too high, which could cause erector tube binding. I torqued to Farrell's spec, which I THINK was 20 in. lbs., but Vortex said anything above 15-17 is excessive and could cause erector tube binding (rear ring too tight) and/or parallax adjustment binding (front ring too tight). He suggested there shouldn't be any permanent damage, and re-torquing to the lower value should be curative (IF that is happening). I will re-torque them as suggested, but I don't expect that to fix my overall problem.

 

[vh20]

Maybe the rifle doesn't like 300gr SMKs? Try some 250gr Scenars, or SMKs, or try the 300gr Bergers and/or Scenars.

Pick a primer, pick seating depth and play with your charge weights.

Shoot 5 shot groups, too. Frank hates 3 shot groups, even at 200yds.

Chris

Lord, I hope that's not the case. I've got a bunch of them on hand! Plus, they seem to make fairly good hunting bullets compared to the Scenars. I DO have 100 of the Scenars on the shelf if it comes to it, though.

Do any of you have any experience with the Caldwell Lead Sleds? I really want to eliminate me as a variable, and there's really not anyone around here whom I know to be a better shot than myself (not saying much there but I just don't know many "serious" riflemen). I've never used one, but was looking at the DFT model. I wonder if they can take everything away (shooter-error) but the rifle/load, and also if they are likely to cause any damage (there's not much "give" to them, so all the recoil is concentrated into the stock). The 200.00+ price is within reason if they do the job, but too much to waste on something if it only half-works. Any experiences?

 

[ChrisGarrett]

Lord, I hope that's not the case. I've got a bunch of them on hand! Plus, they seem to make fairly good hunting bullets compared to the Scenars. I DO have 100 of the Scenars on the shelf if it comes to it, though.

Do any of you have any experience with the Caldwell Lead Sleds? I really want to eliminate me as a variable, and there's really not anyone around here whom I know to be a better shot than myself (not saying much there but I just don't know many "serious" riflemen). I've never used one, but was looking at the DFT model. I wonder if they can take everything away (shooter-error) but the rifle/load, and also if they are likely to cause any damage (there's not much "give" to them, so all the recoil is concentrated into the stock). The 200.00+ price is within reason if they do the job, but too much to waste on something if it only half-works. Any experiences?

My buddy has one and while I can see its purpose, much like a Ransom rest, I think of it as a crutch and cheating in a way.

5 shot groups, take your time. Change only one variable at a time and practice.

You'll get better, but don't waste your barrel on the SMKs, was my point. At some point, it's time to pack up shop and move on.

Chris

 

[timelinex]

I think the 100yd vs 300yd myth has been proven more to be an operator error type thing rather than the system. The bullet stabilizes within a couple yards, if not right out the barrel, so there is not stablilazation that goes on between 100yds and 300yds.

 

[vh20]

Chris,
Does it do the job and take the shooter out of the equation? I'm not looking for a crutch or to cheat, I'm looking to isolate the problem, if you follow me. If it shoots lights-out on a sled, then I'm wasting the barrel on any further load development work. I just have never used one to know if they are very effective.

 

[ChrisGarrett]

Chris,
Does it do the job and take the shooter out of the equation? I'm not looking for a crutch or to cheat, I'm looking to isolate the problem, if you follow me. If it shoots lights-out on a sled, then I'm wasting the barrel on any further load development work. I just have never used one to know if they are very effective.

It's pretty stable, no doubt. I think he moved to one of those Sinclair front adjustable rests and a rear sandbag, but when he started getting into precision shooting, he felt the way you do and went out and got one.

Chris

 

[ChrisGarrett]

I think the 100yd vs 300yd myth has been proven more to be an operator error type thing rather than the system. The bullet stabilizes within a couple yards, if not right out the barrel, so there is not stablilazation that goes on between 100yds and 300yds.

It's true, but it's not really predictable, so it gets used as a crutch.

Chris

 

[vh20]

I guess my question about sleds has always been, by restraining the rifle so tightly, can you introduce more problems - like recoil feeding back into the barrel oscillations and creating accuracy problems of its own. I honestly never heard anything about them good or bad, so I'm just thinking out loud (in print?), so to speak. Thanks.

 

[D_TROS]

After looking everything over, my 2 guess would be scope and trigger.

Trigger control is the culprit the majority of the time for horizontal stringing. Most of your groups (except 1) show at least a little horizontal stringing, and most of your groups would have been really good if the horizontal stringing was cut in half. Unless the wind is REALLY howling, it will not affect the flight at 100 yds. I would reccommend a lot of dry-fire practice, not only at night time, but also before you shoot groups to get your mind/finger on the same page. Also an aftermarket adjustable trigger is never a bad idea, or have your trigger worked over.

Scope might be binding and "jumping" loose on recoil. Def do a box test. I have found that when quality scopes are dialed, the shot moves exactly where it was dialed to. Cheaper scopes and faulty ones will be inconsistant when dialed.

Good luck
DT

 

[vh20]

D-TROS - Thank you for your thoughtful analysis. I typically dry-fire 4-5 times between each shot while waiting for the barrel to cool. I have noticed this gun has a fairly strong main spring and apparently the mechanism and firing pin have significant mass as well, because it is a fairly substantial POP!! when it is dry-fired. I have had a problem with a slight shift of the aim point when it is fired - not much, only about one bullet-diameter at 100 yds, and it happens about once every 4-5 shots (dry-firing). It is only visible if the scope is cranked to to 24x. I have been working diligently to eliminate this slight movement when dry-fired, but have had varying degrees of success. Whether using bipod and rear bag, front rest and rear bag, hold tight, hold loose, don't hold the rifle at all and just pinch the trigger against the trigger guard with thumb and forefinger, I still get an occasional shift when it releases. I've tried different trigger finger positions, made 100% certain that the pull is perfectly straight, but no real change has happened. One bullet diameter shift at 100 yds is about a 0.3 MOA error, so it doesn't account for all of my problem, but it could be a contributing factor. Yesterday afternoon I was having pretty good success dry-firing by putting a heavy sandbag in front of the bipod legs and using it as a dead-weight to load the bipod against. I was able to hold the crosshairs on the seed-pods (about 1 in. dia.) of a Sweet Gum tree about 300 yds away with no discernible shift when dry-fired (I had not tried a weight in front of the bipod yet). If you have any further suggestions for this issue I'd love to hear them. I've never noticed this problem with any of my other rifles before, but this is the first time I've owned a scope with such high magnification that makes it apparent.

Another factor I haven't mentioned is that about the time I started getting really inconsistent results, a piece of debris showed up on the reticle of my scope. It is about 2x the size of a mil-dot, and is in sharp focus (i.e. same focal plane as the crosshairs). My scope had tracked as I expected it to before, but since this thing showed up I've had two instances where the point of impact didn't seem to follow the turret adjustments I had dialed in (these are the only two times I've moved it since the flake appeared). Vortex will fix the debris issue with no questions asked, so I have decided to send it in for that issue under warranty and while they have it get them to check the tracking and stability of the erector tube and reticle. They seem to think the debris issue is just that - a small piece of debris and not indicative of any internal problem with the scope, but at least I can get them to eliminate the scope as a variable in the equation.

 

[Aimsmall55]

Your going to get your scope back. Maybe even a new one. I hate to be the bearer of bad news.... But it's just gonna do the same thing. Only reason I say this is cause it's happened to me 3 times. Two words : muzzle brake. Instead of blowing the concussive forces away (you gotta have a muzzle brake) the concussive forces are being blown sideways and in cramped areas sometimes back at you. It puts so much pressure on the etching that it just fails. Had a thruster brake on my .300 win mag and it gave me 1 repair job and 2 new scopes. My suggestion... Get a little bit more rugged scope if you are financially able. Or maybe trade it out with a scope on another rifle you may have. But I'm telling ya, it's going to keep reoccurring. Sorry to be a downer

 

[vh20]

Aimsmall - Are you saying you had problems with a Vortex Viper PST not being rugged enough? Can you describe what was happening, and did it affect accuracy or was it just a visual defect?

Thanks

 

[Aimsmall55]

It would start visually then I noticed my poi would shift. Also the turrets weren't dialing in correctly. I contacted Vortex and talked with Scott I beleive and he told me about the brake issue. You see little flakes correct?? What I did was change that scope out with another. A NF will take a beating. It's still on a .300 win mag (viper pst) but one that isn't braked like the other one. Meaning it has little bitty holes ..... A lot of them. And the concussive forces aren't as concentrated. Where as the other brake just had 3 ports on each side and would blow your buddy's hat off if he were 10 feet to your right or left. Hope this gives a little clarity as to what I mean.....

 

[George63]

2 other things, not mentioned, that can contribute to this "shoots better at distance" fallacy:

seeing the impact at 100yds, then chasing the shot

imperfect adjusting/ checking the AO to eliminate parallax error ( just because the target appears in focus, does not mean the AO is set right)



and a lead sled can also ruin a good scope - a little google searching should find you testament to this

 

[vh20]

Aimsmall - Yes, that is exactly what happened with me. I can't say for sure that my POI shifted, but I suspect it since my group sizes keep getting bigger, not smaller despite fine-tuning. After the flake appeared on the reticle, I only tried moving the turret twice (once when I went from 100 to 300 yds, and on another session when I tried to re-zero with a new load at 200). In neither instance did the reticle move exactly as I expected. When I was zeroing at 200 my first elevation correction of about .3 mils (3-clicks) went unchanged on the next group. Three more clicks UP and the next group jumped up the equivalent of 6 clicks (as if the first correction was held in a bind until released by the second correction, where they added together).

I really appreciate your response, as it sounds exactly like what is happening to me, with same equipment, same symptoms, etc. FedEx is picking up the scope this AM, and I'll see what Vortex says about it. If they find a problem like you had, I will consider selling the replacement and looking for a better option. I'm disappointed to hear that about the Viper PST - they seemed to get such good reviews from everyone. I did a lot of research before I decided on that one.

Thanks from your neighbor over here in AL.

 

[vh20]

George63 - thanks for the input. I have never fired from a lead sled, but was more concerned about damaging the stock/bedding, and whether or not it might affect accuracy due to reflected vibrations, etc. I hadn't considered the scope, but that is also a good point.

 

[Aimsmall55]

Aimsmall - Yes, that is exactly what happened with me. I can't say for sure that my POI shifted, but I suspect it since my group sizes keep getting bigger, not smaller despite fine-tuning. After the flake appeared on the reticle, I only tried moving the turret twice (once when I went from 100 to 300 yds, and on another session when I tried to re-zero with a new load at 200). In neither instance did the reticle move exactly as I expected. When I was zeroing at 200 my first elevation correction of about .3 mils (3-clicks) went unchanged on the next group. Three more clicks UP and the next group jumped up the equivalent of 6 clicks (as if the first correction was held in a bind until released by the second correction, where they added together).

I really appreciate your response, as it sounds exactly like what is happening to me, with same equipment, same symptoms, etc. FedEx is picking up the scope this AM, and I'll see what Vortex says about it. If they find a problem like you had, I will consider selling the replacement and looking for a better option. I'm disappointed to hear that about the Viper PST - they seemed to get such good reviews from everyone. I did a lot of research before I decided on that one.

Thanks from your neighbor over here in AL.

No problem. Vortex will take care of you and you'll have it back real quick. It's not that they aren't good scopes, it's just that they DO have their limitations on what kind of ass kicking they can take. For something like a 6.5 creedmor or a .308 they are better suited. I will say this... I put it on a .300 win mag 5r with a different style brake and have not had an issue yet. I'm sorry to have to relay the message but you deserve to know that it will keep on happening. Not a matter of if but when. Some of mine lasted longer than others. But eventually they all failed. If you don't have another combo with a tougher scope I would definetly look into selling it and saving yourself a lot of head ache

 

[timelinex]

There's absolutely no way the PST is not rugged enough..... All their higher line scopes are rated for the 50 bmg and they stand behind that. The flake you are experiencing is a 'common' problem they had, and it doesn't effect accuracy. I think its the paint chipping off on the inside. Not sure why, but I know I've read this has happened to a few people. I run a PST on my 110BA and it does just fine.

I'm wondering... How did you come up with 91gr? what kind of load development did you do?

I had some accuracy problems initially with my 110ba and I found that the higher grains of retumbo I used, the more accurate it started becoming. First I settled on 92.6gr of retumbo, behind 300 gr bergers. Recently I changed that to 92gr, it's still in my accuracy node, only 15fps slower and will be a bit easier on the brass. Don't be scared to go above published maxes, all rifles are different. As long as you slowly work your way up and watch for pressure, its not a problem.

Last question, how often do you clean your rifle, and what kind of procedure do you use?

 

[Aimsmall55]

There's absolutely no way the PST is not rugged enough..... All their higher line scopes are rated for the 50 bmg and they stand behind that. The flake you are experiencing is a 'common' problem they had, and it doesn't effect accuracy. I think its the paint chipping off on the inside. Not sure why, but I know I've read this has happened to a few people. I run a PST on my 110BA and it does just fine.

I'm wondering... How did you come up with 91gr? what kind of load development did you do?

I had some accuracy problems initially with my 110ba and I found that the higher grains of retumbo I used, the more accurate it started becoming. First I settled on 92.6gr of retumbo, behind 300 gr bergers. Recently I changed that to 92gr, it's still in my accuracy node, only 15fps slower and will be a bit easier on the brass. Don't be scared to go above published maxes, all rifles are different. As long as you slowly work your way up and watch for pressure, its not a problem.

Last question, how often do you clean your rifle, and what kind of procedure do you use?

You must have got a good one. It may be rated for a .50 cal. But you can't deny the fact that they fail a lot as it appears due to muzzle brakes. Shit, I just posted that I've had to send mine back 3 times.

 

[Aimsmall55]

I asked what was wrong the very last time Response. "Your muzzle brake is apparently too much for the glass etching on this scope". "That's why your groups are moving and the turrets aren't matching your adjustments at distance". Like I said they are good scopes, but they can't take a lot of concussion wo messing up or breaking the etching. One time I sent it back and before I did I put it in a gun vice and tapped the end of the bell. The whole damn reticle would slightly move

 

[timelinex]

I asked what was wrong the very last time Response. "Your muzzle brake is apparently too much for the glass etching on this scope". "That's why your groups are moving and the turrets aren't matching your adjustments at distance". Like I said they are good scopes, but they can't take a lot of concussion wo messing up or breaking the etching. One time I sent it back and before I did I put it in a gun vice and tapped the end of the bell. The whole damn reticle would slightly move

Wow, I dont know what to say. I actually just checked and my pst is on my 308 and I actually have my SWFA hd on the 338. Both have muzzle breaks however. This is the first time that I have heard of muzzle breaks destroying quality glass.

Its definitely unacceptable for the reticle to move for any reason, especially with something like a tap. I'm guessing they are currently going through some quality control issues with their latest batch or something, as that is NOT normal.

 

[Aimsmall55]

Wow, I dont know what to say. I actually just checked and my pst is on my 308 and I actually have my SWFA hd on the 338. Both have muzzle breaks however. This is the first time that I have heard of muzzle breaks destroying quality glass.

Its definitely unacceptable for the reticle to move for any reason, especially with something like a tap. I'm guessing they are currently going through some quality control issues with their latest batch or something, as that is NOT normal.

Yeah I know. Btw... How do you like your swfa?? What's the specs on that scope. Maybe the op can look into one of those. How much$ if you don't mind me asking ??

 

[vh20]

FedEx'd my scope back to Vortex this AM with instructions to check zero-stability and tracking as well as fixing the flake. That should reveal whether there's a scope problem or not.

Timelinex - I have chronicled my load development previously in the threads linked below. I am not settled on 91.0 gr. for sure just yet, but it was starting to show some promise when all of a sudden things started going backwards. I realized that was about the same time as when the flake appeared on the reticle, but dismissed the two as being related. Then when the scope didn't follow my turret adjustments when I re-zeroed last session I became suspicious. It was tracking perfectly when I first mounted and sighted it in back in December.

Cleaning (using a bore guide) has been a wet patch of Hoppe's 9, followed by a bronze brush with more Hoppe's (10 strokes, very slow and easy, especially at the crown), then dry patches until clean. Then a wet patch or two of Butch's Bore Shine, a dry one or two, and then repeat wet/dry/dry once more. I never get the blue to completely go away, but I quit when it starts to diminish. I have found that it takes about 5 shots from a clean bore for it to start grouping again. I do not know how many shots before the accuracy starts to suffer again because I've started to have this new problem where everything is inconsistent.

I'd appreciate hearing about some of what you learned developing the load for yours. If it's OK, I'll PM you later.

Thanks!

http://www.snipershide.com/shooting/showthread.php?t=165935&p=2253223#post2253223

http://www.snipershide.com/shooting/showthread.php?t=167912&p=2273174#post2273174

http://www.snipershide.com/shooting/showthread.php?t=169524&p=2289158#post2289158

 

[GUNZ n AMMO]

+1 on the scope breaking. Also check your scope ring tightness, base and action screws. My action screw was at 25"lbs from the factory, the base came loose twice, so it's nice to have a torque screwdriver...

 

[vh20]

Aimsmall - MAN, DID Y0U EVER CALL THAT ONE RIGHT!! I just heard from Vortex this AM. They found problems with the tracking, and the reticle was "canted", in addition to the debris being stuck on it. I got a call from a nice lady who gave me the general story, but not specific details. What she DID say is that they are replacing the scope with a new one, and it is on its way out to me this AM. I sent it out FedEx on Tues, they received it two days later and sent out the replacement the very next day. Even though the scope was a disappointment, you've got to admire Customer Service like that. Thanks, Vortex.

With that said, I have decided not to keep this scope. I have wasted too much time, barrel life and components to risk going through this again. I have decided to go with another scope - most likely a Nightforce NXS 5.5-20x50, but I sure hate to give up FFP. I also am considering a Leupold Mk 4 E/RT which does have FFP, but no illumination. Decisions, decisions! Any guidance from you guys would be appreciated. The good news is that since I'm getting a brand new scope, the retailer I purchased it from has agreed to take it back and give full credit towards the purchase of the Nightforce (or whatever). Again - can't beat that kind of service.

I never thought I'd be so happy to find out I had a defective 1000.00 scope! The bizarre behavior with target grouping while trying to do load development was really getting to me. It would have been obvious if I had already worked out a good load with known performance, but when you're starting from scratch with everything new, it's not so clear where the problem is. You don't really expect a brand new scope with a great reputation to be at fault. Thanks, everyone!

 

[ChrisGarrett]

Unless you have to range quickly, FFP might be something you can live without, if you find other features more enduring.

Good to know it was a scope issue, as you were all over the map.

Everybody makes a stinker, even Schmidt Bender, from time to time, so maybe you should just mount up the replacement and see what you see?

Good luck, Chris

 

[Aimsmall55]

Thank the dear Lord I was right. You Vortex guys would have my head

 

[vh20]

Everybody makes a stinker, even Schmidt Bender, from time to time, so maybe you should just mount up the replacement and see what you see?

Good luck, Chris

I know exactly what you mean, Chris, and I agree. But I have to admit that after all the frustration, wasted effort, and expense I've been through I'm a bit gun-shy (pun intended), and would feel more confident by going in a different direction with the scope. Plus, if I mount the replacement scope I can't return it to the retailer for credit. My only chance to get out of this scope without it costing me anything is right now. I think I'm pretty lucky to get that chance since I bought it in December.

I'm sure from all I've read that Vortex makes good stuff. I gave them a try and it didn't work out. They stood behind their product in a most honorable way, and perhaps I'll try them again in the future. Certainly the CS I received from them cannot be beat. But for now, however, I need to go with a maker that is more of a known-quantity. If I could afford S-B I'd go that route, but for now NF or Leupold is as close as I can get.

 

[vh20]

I have noticed this gun has a fairly strong main spring and apparently the mechanism and firing pin have significant mass as well, because it is a fairly substantial POP!! when it is dry-fired. I have had a problem with a slight shift of the aim point when it is fired - not much, only about one bullet-diameter at 100 yds, and it happens about once every 4-5 shots (dry-firing). It is only visible if the scope is cranked to to 24x. I have been working diligently to eliminate this slight movement when dry-fired, but have had varying degrees of success. Whether using bipod and rear bag, front rest and rear bag, hold tight, hold loose, don't hold the rifle at all and just pinch the trigger against the trigger guard with thumb and forefinger, I still get an occasional shift when it releases. I've tried different trigger finger positions, made 100% certain that the pull is perfectly straight, but no real change has happened. One bullet diameter shift at 100 yds is about a 0.3 MOA error, so it doesn't account for all of my problem, but it could be a contributing factor.

Yeah, well it turns out what I was actually seeing was the reticle shifting inside the scope. That's why nothing I tried would stop it. I played around with dry firing another rifle on my front rest and rear bag this afternoon and the reticle never shifted by any visible amount. If the reticle on the Viper PST was shifting visibly on just dry firing, I can't imagine what it was really doing under recoil.

 

[Tarheelpwr]

I know exactly what you mean, Chris, and I agree. But I have to admit that after all the frustration, wasted effort, and expense I've been through I'm a bit gun-shy (pun intended), and would feel more confident by going in a different direction with the scope. Plus, if I mount the replacement scope I can't return it to the retailer for credit. My only chance to get out of this scope without it costing me anything is right now. I think I'm pretty lucky to get that chance since I bought it in December.

I'm sure from all I've read that Vortex makes good stuff. I gave them a try and it didn't work out. They stood behind their product in a most honorable way, and perhaps I'll try them again in the future. Certainly the CS I received from them cannot be beat. But for now, however, I need to go with a maker that is more of a known-quantity. If I could afford S-B I'd go that route, but for now NF or Leupold is as close as I can get.

If you're looking in the $2k range, why not look into the Vortex Razor HD 5-20? That is their scope line designed like a tank. That or the SS 5-20 HD, but the illum version is out of stock currently. The non-illum was in stock as of a couple days ago when I spoke with Skylar. They seem to be the best "bang for the buck".

 

[vh20]

Thanks for the suggestion, Tarheel. I would like to try that SS scope because it seems to have a very good reputation. However, since my retailer agreed to allow me to return my replacement Viper for full credit towards an exchange, I had to pick something he carries (no SS). I ended up going with a Nightforce 5.5-20x50 MLR/MRAD. It will be here tomorrow!

 

[Tarheelpwr]

It would start visually then I noticed my poi would shift. Also the turrets weren't dialing in correctly. I contacted Vortex and talked with Scott I beleive and he told me about the brake issue. You see little flakes correct?? What I did was change that scope out with another. A NF will take a beating. It's still on a .300 win mag (viper pst) but one that isn't braked like the other one. Meaning it has little bitty holes ..... A lot of them. And the concussive forces aren't as concentrated. Where as the other brake just had 3 ports on each side and would blow your buddy's hat off if he were 10 feet to your right or left. Hope this gives a little clarity as to what I mean.....

I just wanted to add to this: I have been talking to Scott and Jimmy about getting a PST 6-24 for my 338 Lapua. They also told me that the PST is rated for up to .50 BMG (and last I checked, I've NEVER seen a .50 without a muzzle brake; usually pretty aggressive). I asked them about the issue of muzzle brakes destroying PST's and they told me to "take the internet with a grain of salt". This issue was not acknowledged by Vortex.

I'm not trying to step on any toes, just pass on info that was relayed to me from the source.