(Scope Shim?) 182 grain bullets shooting higher than 150 grain from Mosin

[cowboycraig]

182 grain bullets shooting higher than 150 grain from Mosin. Guess this question would be the same with any rifle.

With 150 grain bullets at 100 yards rifle (with bore sighted scope) is shooting high. Have scope adjusted all the way to be center black. Don't think that is healthy for the scope and I should shim it.

Always get confused if I need to raise the front of back of scope to compensate for this? If the rifle is shooting high the scope should be tilted which way?

182 grain bullets (both 150 and 180 are PPU) rifle is shooting WAY HIGHER. like 12 inches. Is that common with different grains?

Specific bullets I am speaking of.
150
http://www.midwayusa.com/product/773893/prvi-partizan-ammunition-762x54mm-rimmed-russian-762x53mm-rimmed-150-grain-soft-point-box-of-20?cm_vc=OBv1442368

182
http://www.midwayusa.com/product/442368/prvi-partizan-ammunition-762x54mm-rimmed-russian-182-full-metal-jacket-box-of-20?cm_vc=subv1773893

Thanks!
Craig

[Steve C]

You will find this not uncommon.  The heavier bullet is slower and therefore has more barrel time than a lighter faster load.  The longer it is in the barrel the more time the effect of recoil has to force the barrel upwards.  There is consequently more time for all aspects of barrel harmonics to effect the bullet behavior of a heavier, slower load.

[cowboycraig]

Using a "brass stacker" Mosin 91/30 scope mount and have a feeling it can "nudge". Feels totally secure and used loctite. Did find that the stock was coming loose and need to use some loctite on the two screws that secure it. Might be exaggerating a bit with 12 inches. But it is something like that. Need to spend more time at the range and get it figured out.

Have gotten feedback that the larger slower bullet may very well shoot higher since it is the barrel longer and is effected my recoil and barrel harmonics more.

Ended up having to move the scope about 2 inches further down the barrel. The pistol sight is actually really nice. Have gone deer hunting with the rifle and think "not" having the scope "all up in my grill" gives a better view for hunting.


https://dl.dropboxusercontent.com/u/7668504/published/Pictures/ThisIsMyMosin-1.jpg

Rifle is based on the setup on a video by Nutnfancy
"Scope Your Mosin!: The Brass Stacker mount" by Nutnfancy
http://youtu.be/dOmqUdhJm_8

Installed a Timney trigger and it is "amazing"!
http://www.midwayusa.com/product/559350 ... roductLink

This scope
http://www.midwayusa.com/product/353309 ... roductLink

Brass Stacker scope mount. What I like about these is the rifle needs no tapping etc, and the iron sights are still usable
http://brassstacker.com/mosin-nagant/Mo ... Mount.html

Was planning on shimming the scope with these mounts
http://www.midwayusa.com/product/332743 ... oss-medium
shim pack
http://www.midwayusa.com/product/712472 ... 10-and-020

[j_h_nimrod]

I don't know about 12" difference being explained by the extra few hundred thousandths of a second the bullet is in the barrel. I know it does have an effect  but not 12". What kind of groups are you getting?  A 30-06 is similar yet every one I have groups pretty close (1-2" difference usually low but not always). The Mosin I used to have was erratic (most likely because the barrel was in terrible shape) but did not display this difference either. I do also remember it kicked like a mule and had tremendous muzzle blast so a flinch is always a possibility.

If you are still shooting high with scope adjusted to its lowest stop shim the front.  Scopes are supposed to work the best when they are near the center of their range but have never found it to make a noticeable difference.

[762Armo]

Is that the same scope that brassstacker is advertising with their mount? And same one as in the nutnfancy video?
My Mosin was shooting way high with the brassstacker mount and a Simmons pistol scope I had on it. Scope I had couldn't even adjust all the way down to hit anywhere close to the middle of the target.

[cowboycraig]

I don't know about 12" difference being explained by the extra few hundred thousandths of a second the bullet is in the barrel. I know it does have an effect  but not 12". What kind of groups are you getting?  A 30-06 is similar yet every one I have groups pretty close (1-2" difference usually low but not always). The Mosin I used to have was erratic (most likely because the barrel was in terrible shape) but did not display this difference either. I do also remember it kicked like a mule and had tremendous muzzle blast so a flinch is always a possibility.

If you are still shooting high with scope adjusted to its lowest stop shim the front.  Scopes are supposed to work the best when they are near the center of their range but have never found it to make a noticeable difference.

My groups with 150 were about 2-3 inch groups. Mostly within 2 inches. This was at 100 yards.

I need to get back to the range and check my 12 inch estimate. It sounds a little crazy. I could not really get them on paper and was in a rush. Could tell I was shooting high, and it seemed like 12 inches. Let me get back out there and report back.

And for sure I have my scope all but one click left to compensate for how high the 150 grains are shooting. Thinking shim is needed and another trip to the range.

Thanks for the info!
Craig

[cowboycraig]

Is that the same scope that brassstacker is advertising with their mount? And same one as in the nutnfancy video?
My Mosin was shooting way high with the brassstacker mount and a Simmons pistol scope I had on it. Scope I had couldn't even adjust all the way down to hit anywhere close to the middle of the target.

This is the exact scope nutnfancy used and recommended. Great scope!

What you are saying is interesting. The Brass Stacker was level with barrel when installed and I don't think has moved. Maybe Brass Stackers just shoot a big high even if level? Hard to tell. Since the mount seems to be secure and level will get new scope rings that shim. Odd thing is the barrel did bore sight right on.

150 grains are on at 100 yards, but the scope is only one click from maxed out to get on target (was shooting high).
208 grains are someplace over the target at 100 yards.

Craig

[cowboycraig]

Is that the same scope that brassstacker is advertising with their mount? And same one as in the nutnfancy video?
My Mosin was shooting way high with the brassstacker mount and a Simmons pistol scope I had on it. Scope I had couldn't even adjust all the way down to hit anywhere close to the middle of the target.

Did you ever get it sorted out?

[762Armo]

No, I was gonna buy same scope as nutn but kinda forgot about it. Now I know it might not work. I feel like I need to use a level, make sure it is leveled before securing the mount. Also thinking brassstacker just sits too high. Even if zero'd at 100, it might be more off at 200 or 300, then a "regular" rifle with low mounts, because of the downward angle of the scope. Hope this makes sense, I don't always do a good job of conveying the thought in my mind into paper, or an online forum in this case. :-)