Page 1 of 1

Question: 7 mm Mausers, worn bores, and powder coating jacketed bullets

Posted: Sun Apr 14, 2019 9:11 pm
by professrh
All of my 7x57 Mausers slug at .287 (groove diameter). Two of them (the Venezuelan Heartbreaker and the Loewe m1916) shoot badly with .284 jacketed bullets--even the 175-grain RNSP.

Buffalo Arms sells .287 jacketed bullets (Hornady bullets, they tell me, swaged up from .284). The worn rifles in question shoot these fatter bullets quite well.

Sadly, I'm not inclined to fully trust these "adjusted" bullets in the field (read: I'm not interested in shooting a big river-swamp hog with a bullet that may disintegrate on impact.)

I've read of folks powder coating jacketed bullets to make them shoot better in big-for-caliber or worn bores. But internet lore . . . is what it is.

Do any of you guys (whom I am inclined to trust, because I've been around here for a while and kind of know you) have any experience with this process? If you've tried it, how did it work for you? (If you're sure it won't work, why?) I'm not set up for powder coating at present, but if I can turn a couple of paper-puncher rifles into reliable field guns, I'll probably go for it.

Thanks for your help!

Re: Question: 7 mm Mausers, worn bores, and powder coating jacketed bullets

Posted: Sun Apr 14, 2019 10:13 pm
by ammolab
I can’t see how a bump up size operation of .003” would make a jacketed bullet any less trustworthy in the integrity department.

Re: Question: 7 mm Mausers, worn bores, and powder coating jacketed bullets

Posted: Mon Apr 15, 2019 9:39 am
by Rapidrob
I routinely bump .323 bullets up to .329 and have had no problems with accuracy. Your concerns about a bullet failing upon impact is valid. The jacket may have been thinned enough to cause problems at high speed. A round nosed bullet may be a better path to take. Round nose bullets would be my first choice for shooting hogs nothing penetrates like a long round nose bullet.
Another option would be to Paper-Patch the bullet. Easy to do and works very well once you get the hang of it.

Re: Question: 7 mm Mausers, worn bores, and powder coating jacketed bullets

Posted: Mon Apr 15, 2019 8:31 pm
by ammolab
Rapidrob wrote:
Mon Apr 15, 2019 9:39 am
I routinely bump .323 bullets up to .329 and have had no problems with accuracy. Your concerns about a bullet failing upon impact is valid. The jacket may have been thinned enough to cause problems at high speed. A round nosed bullet may be a better path to take. Round nose bullets would be my first choice for shooting hogs nothing penetrates like a long round nose bullet.
Another option would be to Paper-Patch the bullet. Easy to do and works very well once you get the hang of it.
As the bullet is bumped up to enlarge it...wouldn’t the bullet be shortened and the jacket be thickened?

Re: Question: 7 mm Mausers, worn bores, and powder coating jacketed bullets

Posted: Tue Apr 16, 2019 2:15 pm
by professrh
ammolab wrote:
Mon Apr 15, 2019 8:31 pm
As the bullet is bumped up to enlarge it...wouldn’t the bullet be shortened and the jacket be thickened?
That sounds legit. You may be right. RapidRob's theory also sounds legit; he may be right. Maybe both of you, depending on the bullet and the, I don't know, amount of torque applied? Or. . . ?

Anyway, when I called Buffalo Arms last year or so, I was told the guys in the back were pretty sure there shouldn't be any problems hunting with the plumped-up bullets. When I pressed, the rep allowed that it might be wise to test from a stand or a shooting house the first time out.

So I figure, why go there.

I may try to learn how to paper patch jacketed bullets. I have a number of different bullet styles and weights, including 175-grain RNSPs.

I may try powder coating, especially if I can get some first-hand input into how well it works, how much diameter I can add that way, and what if any are the downsides.

I appreciate your comments and hope folks will keep 'em coming.