7mm military = .284 or .286

[SSE]

Hi Guys
I just got a nice 1908 7mm mauser in and was going to load up some rds. to punch some paper with and was digging around to find some old surplus bullets that I knew I had somewhere from 20 or 30 years ago. When I finally found them they turned out to be 163 grain FMJ but they mic. .286
All the 7mm commercial bullets I have mic..284 I do not think I have any milsurp 7mm ammo anymore. So my question is, do any of you have any 7mm mil-surp ammo that you can pull the bullet and mic. it for me ?

 

[Robert Richardson]

.285 bullet diameter for 7x57 Mauser.

 

[SSE]

.285 bullet diameter for 7x57 Mauser.

Thanks RR
Do you know what country made that ammo? I have not come across .285 before.
What does your mic. give for dia. of Sierra 30 cal. 168 bthp? or some other slug we both might have

 

[AmmoManAaron]

Mil-surp 7mm bullets and ammo often run .286" while commercial 7mm bullets and ammo often use .284". With jacketed bullets in your surplus rifle, the bullet fit really isn't a big deal if you work up your load from at or near start (as you normally should). A person might get into trouble trying to use those .286" bullets in something like a 7mm Rem. Mag., but you aren't doing that. Just for punching paper or plinking, I would load the .286" you have on hand and not worry about it. With .284" commercial, even though potentially undersized for your surplus bore, they will probably give better accuracy because they hold a tighter weight tolerance. I'll bet if you weigh several of your .286" bullets, they will vary plus or minus a few grains. FWIW, my surplus 7mm Mauser rifles seem to like just about anything when using IMR-4320 powder, but it's a very easy cartridge to load and I haven't had my rifles particularly dislike any powder or bullet combination using powders from IMR-3031 on the fast side through IMR-4831 on the slow end. The one thing that will probably help accuracy the most is picking a load that puts the cartridge OAL on the long side of the specification range - military Mausers tend to have a long throat. Hope this helps and good luck! Let us know if you have any other questions.

 

[bigedp51]

Its that stupid metric conversion thingy, that's why they put KPH below your MPH readings on your speedometer to confuse you.

Slug your bore, I had a well used 1943 03-A3 30-06, the throat was .311, mid-bore was .309 and the muzzle was .312

And softer lead core 30-30 Hornady 170 grain bullets gave very good accuracy. The softer lead core 30-30 bullets when kicked in the seat of the pants would expand to bore diameter.

 

[SSE]

Its that stupid metric conversion thingy, that's why they put KPH below your MPH readings on your speedometer to confuse you.

Slug your bore, I had a well used 1943 03-A3 30-06, the throat was .311, mid-bore was .309 and the muzzle was .312

And softer lead core 30-30 Hornady 170 grain bullets gave very good accuracy. The softer lead core 30-30 bullets when kicked in the seat of the pants would expand to bore diameter.

Yeah, I have used the 30-30 170 gr. in my Argentine mausers with great success.

 

[Robert Richardson]

Mil-surp 7mm bullets and ammo often run .286" while commercial 7mm bullets and ammo often use .284". With jacketed bullets in your surplus rifle, the bullet fit really isn't a big deal if you work up your load from at or near start (as you normally should). A person might get into trouble trying to use those .286" bullets in something like a 7mm Rem. Mag., but you aren't doing that. Just for punching paper or plinking, I would load the .286" you have on hand and not worry about it. With .284" commercial, even though potentially undersized for your surplus bore, they will probably give better accuracy because they hold a tighter weight tolerance. I'll bet if you weigh several of your .286" bullets, they will vary plus or minus a few grains. FWIW, my surplus 7mm Mauser rifles seem to like just about anything when using IMR-4320 powder, but it's a very easy cartridge to load and I haven't had my rifles particularly dislike any powder or bullet combination using powders from IMR-3031 on the fast side through IMR-4831 on the slow end. The one thing that will probably help accuracy the most is picking a load that puts the cartridge OAL on the long side of the specification range - military Mausers tend to have a long throat. Hope this helps and good luck! Let us know if you have any other questions.

This^^^^^