This little blurb is about ongoing testing with the .300 Whisper, but the info. may be useful to anyone, who goes where others may not have been with small cases and fast burning powders. The test rifle is a 700 S.A. with Gaillard barrel, action squared, trued, etc.....Weaver 36X scope,etc. The 1-13" twist,1 1/2 degree throating that I prefer, pointed to best accuracy by increasing loads above the subsonic level. Until now, experimentation has been only subsonic with heavy cast bullets. Accuracy in testing was proceeding along quite well until we tried a bore riding bullet that needed to be seated slightly deeper into the case to allow it to chamber. The load was using Lil' gun powder and was gleaned from the 'net, and was used in an AR-15 with success.
Well,first shot, powder blowback in face and stuck bolt!! The ruptured case was removed and the rest of that ammo set aside. Seems that the load that was safe with other bullets of that weight, turned ugly due to a small diff. of internal case cap.,caused by just a slightly deeper seated bullet.
The .300 Whisper was designed for use with very heavy(240gr.) .30 cal. bullets, however if the throating or barrel dimensions do not allow the long bullet to be seated out so it is not below the shoulder, others could be in for the same treatment. This is esp. magnified by the very small case. The problem is easily fixable by sizing the front 2/3 of the bullet to better fit the bore(.301"). The fix is not so easy with the long jacketed bullets.
I hope this may shed some light on possible problems reloading very small cases with fast burning powders, cases such as the Whisper family.
Well,first shot, powder blowback in face and stuck bolt!! The ruptured case was removed and the rest of that ammo set aside. Seems that the load that was safe with other bullets of that weight, turned ugly due to a small diff. of internal case cap.,caused by just a slightly deeper seated bullet.
The .300 Whisper was designed for use with very heavy(240gr.) .30 cal. bullets, however if the throating or barrel dimensions do not allow the long bullet to be seated out so it is not below the shoulder, others could be in for the same treatment. This is esp. magnified by the very small case. The problem is easily fixable by sizing the front 2/3 of the bullet to better fit the bore(.301"). The fix is not so easy with the long jacketed bullets.
I hope this may shed some light on possible problems reloading very small cases with fast burning powders, cases such as the Whisper family.
