Interesting results

long-shot

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Long story short is I made a target to test MOA accuracy of my centerfire rifles and thought it might be fun to try my rimfire using the same target but closer ranges.

The target was made to be MOA from 100-500 and I have another for 600-800 yards.

I shot this today using 2 shots at 50, 75, 100, 125, and 150 yards. I actually thought this was going to be too close for this target, but it showed some interesting results.

50, 75, and 100 were tight (or as tight as 2 shots shows) but check out 125 and 150.

MOAChallenge100-500target-1.jpg


IMG00132-20110405-1230.jpg


Shot using Wolf Match in an Annie 64 MPR.
 

NUTT

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Re: Interesting results

My first thought is that the larger center circles on the 125 & 150 yard targets are giving you fits. You might try a center dot in the larger targets to give you a better aiming reference and re-shoot.

If you are certain that your aiming point was correct it shows quite a bit of vertical stringing at those distances (and maybe a wind push at 125). I'm just starting to shoot rimfire at distances more than 50 yards and haven't had a chance to test this yet.
 

RicosRevenge

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Re: Interesting results

Was is windy? Was the wind swirling?

Sure looks like wind to me... look at your 50, 75 and 100 targets... everything is at 7:00 on the target - your first shot at 125 is also 7:00 then pushes to low 5:00. This is exaggerated more at the 150 and everything goes right.

Where is your zero on a calm day? If your gun shoot tight (like it seems with 50, 75 and 100) then it needs to be better zeroed.

Would like to see 5 or 10 shot groups though instead of 2. It would tell you more; but actually, not too bad shooting! Hope you had a blast!
 

long-shot

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Re: Interesting results

Rico,

Yeah my zero was a bit "OFF" and the wind really picked up as I went back, but 125 and 150 really showed me where the mythical vertical spread takes over. My rifle at 100 isn't centerfire accurate, but good enough for training feedback. At 50 it's likely the most accurate rifle I own. Beyond 100... Well, maybe not.
 

long-shot

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Re: Interesting results

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rpk762</div><div class="ubbcode-body">Would an average wind cause vertical like that? </div></div>

Seriously doubt it!
 

RicosRevenge

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Re: Interesting results

^^ I agree. Try a few 5 or 10 shot groups at 125 or 150... interested to see the result. I'm really wondering if maybe that ammo out of your gun destabilizes between 100 and 125 yards. Your 100 pair looks tight.
 

Greg Langelius *

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Re: Interesting results

Two shots demonstrate very little.

Bipod, rest, sling?

Usually; when I see vertical, I think about breathing.

Then, depending on the ammo, there could be a transonic issue at or beyond 100yd.

Also, I agree about all the "aiming white". Just try using a reasonably visible marker and put an "X" in center to give a more concise aimpoint reference.

Greg
 

long-shot

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Re: Interesting results

Greg,

It was shot using a bipod and rear bag. I can't say I had perfect follow through, but it should have been good enough. I'll shoot some groups at 125 and 150 and post the results.

I never thought about destabilizing. I kind of thought these were subsonic to begin with, but this does look possible.

jeff
 

D_TROS

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Re: Interesting results

I would say good shooting, but the ES of the ammo, variable bullet speed causeing flyers, becomes more apparent at long distances. That is why such bullet prep is required for accurate shooting at/around 1k with centerfires. Rimfires are more finicky because there is no bullet prep (some sorting, but overrated unless you want benchrest accuracy) just good ammo. also, if you shoot more shots per group, this spread might work itself out to a avg.

cool tho. what was your dope from 50 to 100 to 150?

crazy the groups just opened up tho...almost linearly with distance...hmmm
 

mrjimsfc

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Re: Interesting results

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: long-shot</div><div class="ubbcode-body">I kind of thought these were subsonic to begin with, but this does look possible.</div></div>
Sub-sonic is dependent on not only elevation, but weather (temperature and changes in barometric pressure) as well. If your breach temperatures were high (because the sun is shining) it would cause the powder to burn more rapidly and cause a slightly higher velocity out of the barrel. With the right conditions, you may have a MACH I at 1090 ft/sec and a muzzle velocity of over 1100 ft/sec. Just enough to cause a problem. Check with a chronograph!
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