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I am wondering what would cause the case(s) to bulge on the end of the rim-fire ammo on this 17HMR ammo? (I hope you can see the few rounds that have bulged ends in the picts.). It happened with a few different rounds from a couple different manufacturers, and different types of loads.
The Winchester rounds were the only rounds that split. The Winchester rounds did not bulge. The CCI and Hornady did NOT split but they had bulged ends.
I am guessing that the only way this can happen is from the pressure inside the barrel, between the back of the case and the bullet as, as the bullet is travelling down the barrel. Once the bullet leaves the end of the barrel the pressure drops to near zero almost instantaneously (at least within a fraction of a second).
I shot a total of [maybe] 20 various 17HMR rounds. These 10 (or so rounds) are the only ones with "issues". I was at ecstatic to see that none of them had the back end blown off (or ripped off during ejection).
These are being shot out of a semi auto pistol. 6 inch barrel. Stainless steel - NO PLASTIC or POLYMER on it except for the grips.
Anyone with more knowledge of ballistics and the way things work, please chime in. I am working on a project and would like to know if I can eliminate this from happening.
I am thinking a stiffer recoil spring to keep the slide against the back of the shell longer? Until full action to eject the shell?
While shooting, it did not seem "violent" when the slide was working on ejection and loading the next round. If it were "violent" I would assume that the gun was being beat up and a stiffer spring would be a must. This wasn't the case, and everything felt normal.
Any help is appreciated.
I am going to be getting a chrono from Santa this year. I can't compare printed velocities with what I am actually shooting from my gun, yet, but I will be able to after Christmas. I would assume that higher pressures (in my gun) would show higher velocities than printed on the ammo boxes?
The Winchester rounds were the only rounds that split. The Winchester rounds did not bulge. The CCI and Hornady did NOT split but they had bulged ends.
I am guessing that the only way this can happen is from the pressure inside the barrel, between the back of the case and the bullet as, as the bullet is travelling down the barrel. Once the bullet leaves the end of the barrel the pressure drops to near zero almost instantaneously (at least within a fraction of a second).
I shot a total of [maybe] 20 various 17HMR rounds. These 10 (or so rounds) are the only ones with "issues". I was at ecstatic to see that none of them had the back end blown off (or ripped off during ejection).
These are being shot out of a semi auto pistol. 6 inch barrel. Stainless steel - NO PLASTIC or POLYMER on it except for the grips.
Anyone with more knowledge of ballistics and the way things work, please chime in. I am working on a project and would like to know if I can eliminate this from happening.
I am thinking a stiffer recoil spring to keep the slide against the back of the shell longer? Until full action to eject the shell?
While shooting, it did not seem "violent" when the slide was working on ejection and loading the next round. If it were "violent" I would assume that the gun was being beat up and a stiffer spring would be a must. This wasn't the case, and everything felt normal.
Any help is appreciated.
I am going to be getting a chrono from Santa this year. I can't compare printed velocities with what I am actually shooting from my gun, yet, but I will be able to after Christmas. I would assume that higher pressures (in my gun) would show higher velocities than printed on the ammo boxes?