I'm not familiar w/ the concept of a non-concentric bore. I need to read up on that. Having said that, there a large number of things that contribute to gun accuracy. May just be internet lore, but supposedly it was happenstance that lead to Browning's development of the "BOSS." Supposedly the gunsmiths at Browning who worked on guns sent back to the factory found out that a large number of them became more accurate by bobbing off a small amount of the barrel at the muzzle. They thought that bobbing the barrel altered the barrel harmonics and helped the accuracy of many guns. The BOSS was developed so the shooter could adjust the barrel harmonics w/ repeatability.

Your most recent graph shows a good representation of the barrel (bore axis) and scope (line of sight) and how the two work together to produce mid-range trajectory. For many years I found the concept of mid-range trajectory very confusing.

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Posted by weagle99

Member since Nov 2011

35893 posts

Posted on 9/17/14 at 9:09 pm to H.M. Murdock

quote:
Some rifles/pistols in the past have a bore that is drilled at an angel in the barrel, is this one?

Tis not.

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Posted by TigerOnThe Hill

Springhill, LA

Member since Sep 2008

6811 posts

Posted on 9/17/14 at 9:14 pm to Hu_Flung_Pu

HFP,

quote:
I think there has to be a correct ratio for the muzzle flip to affect point of impact. Weight of gun (absorb recoil), shooters grip (absorb recoil), barrel length (time bullet has to escape), velocity of bullet (time bullet has to escape). I believe there is a ratio that once passed, will result in the bullet landing higher or lower.

I agree that there are a number of confounding factors, just like you mentioned.

I didn't think about it until last PM, but evaluating this phenomenon would make a good science fair project. (Sorry, but when my kids were growing up we did a total of 20-30 science fair projects.) One could easily find at what muzzle velocity does the slower velocity round no longer hit higher than the higher velocity round. Load rounds in 50 fps increments from 800-1200 fps. Shoot them from the same gun w/ the same sight settings. Post the targets lowest velocity to highest velocity. At some point, the point of impact of the lower velocity rounds will start hitting lower on the target.