Bullet Drop Variance

[skatz11]

What are the major factors that effect rimfire barrels? I was shooting my Spikes dedicated .22 upper yesterday and it was shooting with approx 1 MOA less drop than my CZ452 normally does. I was expecting to have to dial some more elevation compared to the bolt gun. I didn't have the CZ with me yesterday, but its been constant all summer.

Wolf Match Target @ 100 yards
CZ452 Varmint - 7.25 MOA
ST22 ( 16" LW barrel) - 6 MOA

The ST22 was shooting very well, holding about 2" for 10-15 round groups. I can't wait to take it out again and shoot it some more.

 

[TOP PREDATOR]

Re: Bullet Drop Variance

harmonics and barrel whip, (there was just a good post about it, damned if i could find it now)about what part of the "whip" the bullet leaves the barrel. the different lengths could be putting them out at a different part of the whip cycle.

heat is another factor, along with any torque put on the barrel.

most rimfire barrels are unique even within the same model, which is another factor.

barrel length was another recent topic of discussion causing the bullet to drag through the barrel when the powder is burnt up.

i don't know if it'll apply to your situation, but the line of sight through the optic vs. bullet path thing. maybe not as i guess drop is drop.

that's the charm of rimfires, what makes sense usually doesn't apply and what's odd usually works.

found it..
http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=2030102#Post2030102

 

[Hellbender]

Re: Bullet Drop Variance

Just guessing, but I bet your scope is at least 3/4" higher over the bore on the AR.

If you have the same zero on both guns, say 50 yards, the angle the bullet is intersecting the line of sight (50 yards) is at a higher angle on the AR, thus solving your conundrum.

The closer the zero range, the more this will be evident.

 

[skatz11]

Re: Bullet Drop Variance

Thanks for the replies! Makes sense now that I think about it.