Need Advice - Reloading/Group Shape

[CMH]

I have been trying to work up a load for my 700 SPS tactical I got a couple of months ago. Just now getting around to working on it. Last weekend worked up loads for a ladder test. Shooting Varget, Nosler prepped brass, CCI BR2 Primers, 168 SMK. Found a sweet spot at 42.5-44. Loaded groups of 5 at 42.1, 42.4, 42.7, 43.0, 43.3, 43.6, 43.9, 44.2. Went to range today and shot them. Best group was 42.7 gr. at 0.8" C to C at 100 yards. All other 5 shot reload groups right around 1.0-1.2". However a number of my groups showed the same pattern - two groups - one group of three and another seperate group of two - almost perfectly oriented hoprizontally. Shot some FGM at shot a 0.4" group, and a 10 shot group right under an inch with no 3/2 pattern readily identifiable.

At first I thought it might be something I was doing. Conditions were not the best (temp in the 20's with variable wind), and I was shooting from a crappy platform (Card table). So in all honesty I can't rule me out. However, I got markedly better results with the FGM.

So I am planning on doing some more load development. I was thinking about going to 175 SMK's or 178 AMAX anyhow, so this seems like a good time to make the move. I had some 168 SMK's laying around so they were my first go 'round with the gun to start builing some familiarity. Beyond that though - does the pretty consistent three and two grouping point to anything else I should be wokring on (Reloading, rifle, shooter, or otherwise)?

Thanks,

Casey

 

[clmayfield]

Re: Need Advice - Reloading/Group Shape

If these were shot in consistent wind, it could be trigger control problems. A load issue won't orient itself horizontally. Vertically or all over (round), but horizontal shows an issue with the shooter (or just a shifty wind).

You might just be fixating on some random events as well... sometimes shots just stack up funny fro no real reason.

You also might try experimenting some with seating depth to see if you can get the group size down. I don't know that SMK's show as much of a difference with varying seating depth as some other bullets, but it can make a difference.

 

[CMH]

Re: Need Advice - Reloading/Group Shape

Thanks Carter. It could be either trigger control or wind - I am not perfect and the wind was variable, and cold - messing some with my form and fundamentals. I have heard of horizontal stringing due to shooter problems - just never seen the 3/2 pattern. Maybe I am erratic with my mistakes, but repeatable when they occur.

I am still thinking about going to 175 or 178, but not necessarily to fix this particular issue - if there even is one with the load - sounds at this point like it is something else.

I have these seated about as far out as I can get them and still feed in mag - 2.825 if I remeber correctly. My 700 is 2.925 (seems typical of the newer lawyer-age stuff), so I can get nonwhere near that and still mag-feed. My rationale was to seat them as close as possible - hence the 2.825. Were you thinking like 2.800 or something else?

Thanks,

Casey

 

[Headgear]

Re: Need Advice - Reloading/Group Shape

Your loads seen pretty light. I don't believe that you said what caliber but I'm guessing 308. If it is, look at Hogdon's load data. For 308 with Varget the maximum is 46 grains. I have much better results between 45 and 45.6 but all guns are different.

If you are going to be shooting long range, you may want to heat those up a little. Be careful though and watch for pressure as you go.

 

[LRS_Ranger]

Re: Need Advice - Reloading/Group Shape

I had a similar experience with horizontal stringing. Even when I heated my loads up to where they were dead even horizontally, they would still make separate groups. I have a crappy cheap scope with no parallex adjustment on it, and I was thinking that maybe taking my cheek off the gun I put it back down with a slightly different weld. One of these day's I'll bolt on a better scope to see if that's the issue. I didn't really pursue it because I was getting about 1.3 at 100, and for now that's good enough since it's not a precision rig. I'll be interested to see what ideas come up here though..

 

[shoot4fun]

Re: Need Advice - Reloading/Group Shape

"Shot some FGM at shot a 0.4" group, and a 10 shot group right under an inch with no 3/2 pattern readily identifiable. "

So, do you have a chrono? IMHO If so, you need to tailor your loads to the FGM it would seem. The FGM is trying to tell you what distance from the lands your gun likes and what velocity your accuracy node is. They load FGM w/ SMK bullets, don't they?

 

[Tripwire]

Re: Need Advice - Reloading/Group Shape

Has anyone ever wondered why FGM is so successful in so many rifles?

It's because they hit an optimal charge weight with a very efficient propellant that covers most barrel lengths and contours.

The OP's load isn't in a node........

 

[CMH]

Re: Need Advice - Reloading/Group Shape

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tripwire</div><div class="ubbcode-body">
The OP's load isn't in a node........ </div></div>

How do you know for sure? Just because FGM is outshooting my loads? Ladder test showed two localized nodes in this area. Maybe this is as good as it gets with this loading combo? Can you explain where you are coming from here?

 

[CMH]

Re: Need Advice - Reloading/Group Shape

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: shoot4fun</div><div class="ubbcode-body"> "Shot some FGM at shot a 0.4" group, and a 10 shot group right under an inch with no 3/2 pattern readily identifiable. "

So, do you have a chrono? IMHO If so, you need to tailor your loads to the FGM it would seem. The FGM is trying to tell you what distance from the lands your gun likes and what velocity your accuracy node is. They load FGM w/ SMK bullets, don't they?
</div></div>

I don't have a chrono or access to one right now. FGM I have is old stuff, but still appears to be SMK. After reading your post, I went and mic'd a couple. Mine are 2.800 right on the nuts. I would have to seat even deeper and further away from lands that are nearly out of sight already. Because of the huge jump I have already, I wouldn't have thought this was the culprit, but I guess anything is possible.

 

[CMH]

Re: Need Advice - Reloading/Group Shape

Headgear - it is a 308. Did a ladder test up to 45.5 which were starting to show light signs of pressure. Variances on ladder test were wild above 44.5, so I decided to try to go with accuracy rather than speed.

 

[Tripwire]

Re: Need Advice - Reloading/Group Shape

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CMH</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tripwire</div><div class="ubbcode-body">
The OP's load isn't in a node........ </div></div>

How do you know for sure? Just because FGM is outshooting my loads? Ladder test showed two localized nodes in this area. Maybe this is as good as it gets with this loading combo? Can you explain where you are coming from here?
</div></div>

WAG.........

Please define exactly for me/us the criterea that caused you to determine you were in a "localized node".....whatever that means.

 

[BamaLoaded]

Re: Need Advice - Reloading/Group Shape

The high OCW node for Varget and 168 SMK's is 46 gr. Always work up looking for pressure signs. If your gun will handle the pressure @ 46 gr. then play with the distance to the lands to dial it in.
The low OCW node is somewhere right around 44.0 gr. and will be about 100 fps. slower than the high node.

The high node for 175 SMK's and Varget is 45.0 gr. and the low node is right around 43.0 gr.

If your not in the node, your either coming into, or going out of a scatter node, so fliers would not be unusual.

I'm not sure how the Nosler brass will affect these nodes. The nodes I mention above are with Win. brass and CCI primers.

 

[sermonator]

Re: Need Advice - Reloading/Group Shape

I've seen similar things happen with runout issues, too. Albeit, it's more often 3 or 4 in a group and then strays.

 

[CMH]

Re: Need Advice - Reloading/Group Shape

First off, let me state I am just learning about nodes, etc. So some of what I post may be completely erroneous, wrong, or just plain stupid. If I am wrong, please let me know where so I can set things right. If I am stupid, please feel free to make fun of me and then set me straight.

Tripwire - I shot a ladder test from 40.5 gr to 45.5 gr in 0.5 grain increments last weekend. I thought the point of this was to identify areas where changes in charge minimuzed the vertical change between shots. I did not keep my target, but I looked at it pretty closely last weekend after shooting. If I started at 41.0 grians and figured the vertical distance to each immediately preceeding shot, I would have a record of vertical changes per 0.5 gr powder change. I.e. 41.0-40.5, 41.5-41.0, etc. As I said, I do not have those exact values, but the general magnitudes, etc. are correct on the attached chart:

If the goal is to look for loads that minimized vertical change, one would be looking for local minimums on the chart - that was where I came up with that terminology (actually I pilfered it from calculus classes, but the idea is correct). In my case it was the 42.5-42.0 and 44.0-43.5 differences (highlighted by red and purple circles, respectively)that were the smallest. As such, I targeted in on loads around those areas to try to shoot 5-shot groups with in smaller charge increments. I assumed that those local minimums were nodes, or the nodes were very near them.

I did not shoot up to 46.0 gr becasue the two minimums I shot above were two rounds through the same small hole, and I was starting to see real minimal primer flattening at 45.5. I could probably go to 46.0 but I didn't see a reason to at the time with the start of pressure signs and two good areas to concentrate on.

Bama Loaded - I thought nodes were unique to each setup - i.e. load, brass, gun, etc. Are those numbers you quoted for your gun? PRetty common? Happen everytime be definition?

So, how far off base am I with all of this?

Edit - after looking through my chart again, I realized that I would have like 5.25" of total vertical spread, which is not correct - it was more like 2.75"-3", so keep in mind the actual vertical spread values are probably not correct, but the shape of the curve and their relatiuonship to each other is still correct.

 

[BamaLoaded]

Re: Need Advice - Reloading/Group Shape

From what I'm finding out these nodes are mostly repeatable in different guns and even with different barrel lengths to some extent(20" to "24"). The one thing that will skew the results is the brass since the neck tension and capacity of various brass will give different results. Lapua or Win. brass seem to be predictable and repeatable. The lower nodes don't seem to be as accurate as the high nodes. Be sure to always work up to your nodes checking for pressure signs. Results can vary, but usually by .2 gr or .4 gr max.

 

[Tripwire]

Re: Need Advice - Reloading/Group Shape

Look for a one-ish grain "zone" almost near the max charge for YOUR case capacity that gives you the same point of impact with the same point of aim.

Shoot your work up in .2 or .3 grain increments to more clearly define that "node". Point five is too wide of a gap and you can overshoot (pun not intended) what you are trying to see on the paper.

What you want is (for example) X.3 grains, X.5 grains, X.8 grains, Y.1 grains, and Y.4 grains, to all shoot into the same neat little "group" if fired at the same POI. When you find that it means the barrel occilation at the muzzle (which flys back and forth from chamber to muzzle several times before the bullet exits) is at a minimum, which imparts a minimum of influence on the exiting bullet, which means you're shooting in an accuracy node.

Yeah that means little or no verticle dispersion but you can't readily define the node with .5 grain jumps in charge weight. All you are doing is what everyone else does who hasn't a clue about barrel harmonics, only you are adding more words to it, and more headache....and finding skewed results as your reward.

What's the status of your brass?

Runout was mentioned and certainly bad bullet runout could cause you trouble, but if you are running good gear, and good loading practices, bullet runout is usually a non-issue. I ask about your brass because casehead runout can be a factor also. Below is a pic of two five round groups fired at 200 yards with the 6mm 85gr TSX, load worked up via OCW to 3250 in a 20" tube. The one on the left is .001" or less bullet runout and less than .002" case head runout. The one on the right was .001" or less bullet runout and casehead runouts of .005", .006", .007", .007" and .007". Yes the three on the same horizontal plane are the .007" runout. The group on the left measures .780" and the one on the right measures 1.470". Is casehead runout the reason? I believe it's a contributing factor because with all else equal it shows a difference on paper and there's the fact I've repeated this more than once. To grasp the full concept of this the Lapua brass used in this test suffered two fireformings to get a fully blown out AI shoulder, and a third full load firing to get a minimum of casehead runout...under these circumstances with this rifle. Yes, for the innahnet gurus, this bolt face/action is square/true.

Just an FYI, FWIW, based on MHE, that....my initial speculative opinion is that you need to find a better node.

 

[Headgear]

Re: Need Advice - Reloading/Group Shape

I read your original post again and I think you really need to have a do-over.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">At first I thought it might be something I was doing. Conditions were not the best (temp in the 20's with variable wind), and I was shooting from a crappy platform (Card table). So in all honesty I can't rule me out. However, I got markedly better results with the FGM. </div></div>

Conditions and crappy platform equal crappy results unless you are really good. Also do the ladder several times. Maybe you did but I didn't get that from your OP. You will be surprised and probably a little frustrated at the results. You are probably the weakest link so repeating the test will help you find more of an averaged result.

I also like a little more distance to show the separation a little better and it helps to eliminate some over lap problems. Have you read this? http://www.6mmbr.com/laddertest.html

I'm not saying to test at a 1000 but you may get a better read at 300 to 500. I got different brass recently and retested my loads and only had a 2.5 to 3" vertical spread between 44.4 and 46 grains with 168 Amax's at 300 yards. I do have a full custom rig and reload on an arbor press with Wilson dies and separate my rounds by seating pressure, run out and a lot of other anal procedures. I'm sure all of that helps the consistency and severity of the spread and maybe your rig and loads may not keep them as tight yet but I think more distance will give you a better look at what is happening. Just MHO.

I like to shoot three ladders and shoot them round robin to get a more averaged effect from the conditions, barrel heat and how dirty the barrel gets during the test. If you shot those FGMM's last, it could be that you were getting more comfortable and/or the conditions were getting better also.

Try to do the test over on a day with better conditions, get on a good bench and try a three ladder test, round robin style and see if you don't get better results. BTW, when I shoot 3/2 splits, it's all me but then I don't know where your reloading skill is at. Splits could be caused by a combination of many things. Just be very careful about mounting your weapon. It has to happen the exact same way every time or all the test procedures in the world will be useless.

Good Luck

 

[gunslinger686]

Re: Need Advice - Reloading/Group Shape

can you even do a ladder test at 100 yrd,think you need to be at least 4-600 yards

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1713419&nt=8&page=1

 

[CMH]

Re: Need Advice - Reloading/Group Shape

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: gunslinger686</div><div class="ubbcode-body">can you even do a ladder test at 100 yrd,think you need to be at least 4-600 yards

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1713419&nt=8&page=1 </div></div>

There was a definite pattern to it - much more spread than I would have thought ????

 

[CMH]

Re: Need Advice - Reloading/Group Shape

I am going to 175 gr. bullets, so I am going to have the perfect opportunity to do this again. Hopefully this time I don't half-ass it and will have some more research and advice under my belt. Thanks to everyone who posted advice and pointed out where I went wrong. It will probably be a couple of weeks before I get back to this. I will try to post results if interesting and/or still unclear to me. Thanks for the help.

Casey

 

[CMH]

Re: Need Advice - Reloading/Group Shape

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tripwire</div><div class="ubbcode-body">
What's the status of your brass?

Runout was mentioned and certainly bad bullet runout could cause you trouble, but if you are running good gear, and good loading practices, bullet runout is usually a non-issue. </div></div>

Brass is once fired Nosler (fired in this gun). I checked necks when it was new and it was surpsingly concentric in my external neck trimmer, so I quit working on it (unlike some new Winchester stuff I recently loaded in another caliber - all over the map virgin + once fired). No idea about bullet runout. I had heard bullet runout was less of an issue with boat tail bullets, but I am not sure. I am loading with standard RCBS dies (FL size + regular seating die). I do not have the tool that measures runout. Did not figure it made that much difference outside of the BR crowd.

Casey

 

[tatemarb]

Re: Need Advice - Reloading/Group Shape

One note on the ladder. You need very good technique when shooting it and you need the most distance you can get to shoot it at. If you could, use a good bag for the front and rear supports instead of the bipod unless you have very good technique and can load the bipod properly (can't on a card table I imagine).

Also, I have heard at least one bechrest guru say that when shooting ladders or competitions they don't magazine feed rounds. The issue is creating runout if the bullet comes into contact with anything while being chambered. This is also more of an issue when loading beyond SAMMI spec COAL also (since feed ramps, magazines, and chambers are designed around spec COAL).

Good luck!

tater
good luck

 

[tatemarb]

Re: Need Advice - Reloading/Group Shape

If you don't think runout can cause repeatable misses or second groupings, think about this. If you take a round with zero runnout and run it through a magazine and chamber which introduces runout, it will be introduced in the same direction for each round that is affected. This round would enter the chamber in the same orientation each time (repeatability) and then you fire at the same target distance as before (repeatability) it is possible that you get a consistently inconsistent POI. In the case of staggered feed magazines, one side might introduce runout and the other not. giving a pattern described above relative to impact position.

Just thinking out loud, might not be right. Try making ten rounds that are identical in case capacity, charge weight, bullet dimensions/weight. Also load them to the same seating depth (don't adjust the seating die while loading them, the bullet tips introduce the differences in COAL). shoot five by single loading then five by magazine feeding as usual and see what happens. If they both do the 3/2 stuff then you can forget the theory above.

tater

 

[CMH]

Re: Need Advice - Reloading/Group Shape

tater -

An interesting theory. Theese were all fed in groups of five from magazine - whihc could lead to 3/2 staggering. Things that make you go hmmmmm..... I will have to try the test you suggested.

Casey

 

[vman]

Re: Need Advice - Reloading/Group Shape

I havnt read every single post in this thread, but will comment on what i have read so far.

- Establish max charge before you do a ladder (yes i know it sucks, wasted range trip but stop whining and do it)
- Perform ladders out far 300 yards +
- Avoid the low end nodes and go for something a little faster
- I think you could push a 168SMK faster than 42.5-44 varget. Just my 0.02 but most remingtons seem to smash out 175SMK at 45.0gr varget easily, and 168s obviously a little higher. Yours may vary but try higher.
- Jump can sometimes be culprit, especially if runout is high.