Just got a viper pst 4-16 ffp and it is mounted on a Weaver 20 moa base. This is my first "long distance build" so this may be a stupid questions but anyways... So first thing I did was find mechanical zero on the optic. (The last scope I bought was not centered so I figured it wouldnt hurt to do). I then mounted it and bore sighted. Looking at the turrets they seem to be half way up their available travel. IS this an issue? One of the reasons I went with this optic/ base set up was for the larger amount of adjustable travel. In my mind it seems that the turret should be closer to the lower limit of its adjustment especially with the 20 moa base.
Rifle Scopes zeroing a pst ffp
- Thread starter mzvarner
- Start date
How far away did you bore sight it. I'd go zero it at the range, then check it.
Yea do what he said.
Thanks for the advice. I will try to shoot it in the next couple days. Mine is an MOA scope, does that matter much from mil? Idk what the conversion is.
Ok well you need to zero it with ammo. The bore sighter will only get you on paper, there will still be drop. Remember the bullet is going to travel in an arc and bisect your line of sight (where the optic is zeroed) twice, in other words there will be intersection with the line of sight and the bullets trajectory. At long distances (where the bullet really starts to arc) the 20MOA base will add extra MOA to your optics capabilities.
Just zero it at 100 yards for now. This is a great place to start.
I dont know why you're quoting me? What do you think I meant when I said zero it at the range? Of course I meant zero it with ammo why would I suggest going to the range if he wasn't going to actually shoot it. I don't see the need for bore sighting,especially if done to close. With matching reticle/turrets it's quick and easy to zero a scope, usually 3 shots and a couple to confirm.
I use a bore sight to get it on the paper for the first shot.
Then hit the range. One or two shots at 50 yards just to get it close, then out to 100 for the zero.
My Viper PST 6-24 with a 20 MOA base is about 75-80% of the travel when zeroed at 100 (.308).
Then hit the range. One or two shots at 50 yards just to get it close, then out to 100 for the zero.
My Viper PST 6-24 with a 20 MOA base is about 75-80% of the travel when zeroed at 100 (.308).
Hey, I'm just agreeing with your comment. And I'm not replying to you but the OP. We are all friends here.
Thanks
I frequently use 20 MOA rings and on some rifles the best I can do is an inch or two high at 100 yards with the elevation turret at the bottom of travel. Others will still zero dead on at 100 yards. My guess is that you'll be high at 100 at first based on where you said the turret is sitting.
I have the same problem. Except I have the 6x24 and zeroed at 100 yards I only have 8.9 mils up to play with. The scope has a total of 20.6 mils of elevation. I too have a 20 moa base and thought that I would at least be closer to the bottom. I think my problem is that my receiver may not be level, I had to bed the rail to make it sit flat and lost most of the 20 moa that should be there. I measured the rail from the receiver to the top front and rear and there is not much of a difference. Or it could be the scope because mine travels 5.5 mils below the zero mark on the turret. I called Vortex and they said that they usually only go a couple tenths past zero and mine must be marked wrong. I don't know if I believe that or not. I don't know much about the internals of a scope but it seems that the lenses may not be centered. When I get some time I may send it in to have it checked out. What kind of rifle is it on?
It may sound silly, but make sure you mounted your base correctly for the 20MOA. I have read a couple of threads where guys put them on the receiver backwards... I got a used NF 20 MOA unimount and had to look up which end was front/back when I mounted my 2.5-10x44 PST on my AR.
Also, if you bed the mount, bed the REAR pad only. When you bed, the front screws should be tight and the rear ones not installed or VERY loose.
And make sure you actually have a 20 MOA base. Mine is visibly thicker mounting pad at the rear versus the front.
If you scope goes down 5.5 mils in a Viper PST after zeroing, did you install the zero stop shims? You remove the elevation turret and install the shims (in a bag in the box) until you fill the space between the top of the body and the bottom of the bulge of the elevation piece.
My Viper PST on a 20 MOA base has 15 mils of up available, out of 19.x mils of total travel. It goes about 0.6 mils below my 100 yard zero to the stop.
And make sure you actually have a 20 MOA base. Mine is visibly thicker mounting pad at the rear versus the front.
If you scope goes down 5.5 mils in a Viper PST after zeroing, did you install the zero stop shims? You remove the elevation turret and install the shims (in a bag in the box) until you fill the space between the top of the body and the bottom of the bulge of the elevation piece.
My Viper PST on a 20 MOA base has 15 mils of up available, out of 19.x mils of total travel. It goes about 0.6 mils below my 100 yard zero to the stop.
The mount has a recoil lug on it so I could only mount it one direction. And I have not used the shims yet, it goes 5.5 mils past the 0 on the turret shroud not my 100 yard zero. I had to bed the front because if I tightened the front screws down without the bedding it would cause the mount to bend in the middle, I used a ruler to verify it. I kind of think it may be a combination of the receiver not being straight and possibly the scope lenses not centered, but I really don't know. The rifle is a Savage and I know that some of the receivers are not the straightest. I just got it back from them the other day after they had it for over 2 months, and they said that everything was within their standards. So I don't know what else to do. Thanks for the advice, if you have any more ideas it would be appreciated.
Never heard of such a thing. If you tightened the front screws down and had a gap in the back then beded it that way, you should be good to go. You have done something wrong, if you needed to bed the front, there is your problem. Make sure you are using the correct Base for the weapon you have. Several have spent days trying to make the wrong parts work. What kind of base and what is the part #?
Watch this video
http://www.youtube.com/watch?v=aoW5bHQqgis
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The owner's manual that came with my USO included a section on centering the reticle.
What difference would that make... what a bunch of hogwash!
Mount it, boresight it, sight it in at the range.
If too much erector travel (elevation) is used up zeroing, and as a result there's not enough left to dial to your intended longest shot, you need more cant.
OTOH I have a Spuhr 13 mil (44.4 MOA) mount that I have had several optics on (S&B PM II 5-25, Bushnell XRS, currently Steiner 5-25) and I knew before mounting them that I would just get a 100 yard zero in there with almost all the elevation left to dial, because all those scopes have around 30 mils (or more) of erector travel.
Simple math.
Joe
What difference would that make... what a bunch of hogwash!
Mount it, boresight it, sight it in at the range.
If too much erector travel (elevation) is used up zeroing, and as a result there's not enough left to dial to your intended longest shot, you need more cant.
OTOH I have a Spuhr 13 mil (44.4 MOA) mount that I have had several optics on (S&B PM II 5-25, Bushnell XRS, currently Steiner 5-25) and I knew before mounting them that I would just get a 100 yard zero in there with almost all the elevation left to dial, because all those scopes have around 30 mils (or more) of erector travel.
Simple math.
Joe
You need to zero the rifle first. Then see how much travel you have. If you have too much, then you might need a 25 MOA base.
But I also cannot see how tightening the front screws on the mount could cause it to bend in the middle.
But I also cannot see how tightening the front screws on the mount could cause it to bend in the middle.
Its a Seekins I'm not sure what the part number is but I know its a 20 moa. I don't even think they build anything less for my rifle. I thought it was strange to have to bed the front as well, but I didn't want the rail to bend like it was. Oh I also tried a EGW 20 moa and I had problems fitting that one as well so I sent it back. Maybe its just the gun, but it shoots too well to replace it.
So did you watch the video and is that how you tested your base to see what needed bedded? Please post the results of your test and what exactly you did to correct the result of the test. If you did not test it like the video, please explain the procedure used so we can help you find where this went wrong.
What model of savage? Seekins only makes bases for a 10FP. I wonder if its really for all round recievers 10 - 16, kinda weird that they say for the 10fp
What model of savage? Seekins only makes bases for a 10FP. I wonder if its really for all round recievers 10 - 16, kinda weird that they say for the 10fp
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That was the same video I used to bed the rail. Its a 10 FCP HS 5r. I may take it off grind the bedding off and do it again this weekend. I called and spoke to some one about it saying 10FP and they told me that it is the same thing. I also test fit an EGW base as well and it looked to be about the same gap in the front. I'm starting to think that the top of the receiver is not a true as it should be but I may have to live with it cause Savage couldn't find anything wrong with it. Or I can just put a 30 moa rail on it. I don't know I hardly shoot past 600 yards anyways. It's just irritating to me.
Oh my, are you sure you watched the video?
Ok so you are doing it backwards. You should be tightening down the front and putting no screws in the back and looking at the gap in back, not the front. Then bed the back and tourqe the front screws. Jezz...louizze...Watch the video again....
Oh my, are you sure you watched the video?
Watch the video again....
Well actually at about 4:00 he test to see if he needed to bed the front by installing the rear screws. In his situation he didn't have to. Unlike mine where the front of the receiver sits lower than the rear. If I install the front screws first and tighten them down it causes the rail to bend in the middle because the rear is higher than the front. Sorry if I'm misunderstanding his video but that's what I got out of it. I thought you had to bed the lower portion so the front and rear of the receiver is on the same liner plain.
I would get a weaver base and see how it sits on your weapon. I have never had a problem with them.
http://www.midwayusa.com/product/31...e-10-series-short-action-matte?cm_vc=wishList
Think this is the right one.
http://www.midwayusa.com/product/31...e-10-series-short-action-matte?cm_vc=wishList
Think this is the right one.
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OK, NOW I understand. And yes, in your case, you need to bed the front.
Although I would wrap some sandpaper around the rear mount area, with the grit OUT, and shape the rear area of the mount to fit the front tight without bedding. And this will give you more slant to the mount.
Although I would wrap some sandpaper around the rear mount area, with the grit OUT, and shape the rear area of the mount to fit the front tight without bedding. And this will give you more slant to the mount.
Good advise, I would rather work on the rear mount rather than bed the front if I were to keep this base, well I guess I would really rather find a base that fits better.
Just a strange situation altogether. It can make you pull your hair out for sure.
If you have verified the mount is straight, why not bed the front and rear with the mount tipped down so it's touching the front... picture a wedge shaped layer of bedding between the rail and receiver front and rear.
This will give you even more cant than the rail has built in.
In your situation that's what I'd be trying.
Joe
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This will give you even more cant than the rail has built in.
In your situation that's what I'd be trying.
Joe
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