7mm Brazilian ammo question

[dualsport]

Here I go again. I'd like to duplicate military issue ammo for a 1908 Brazilian 7x57. I want to be able to use the issue sight settings, which go from 300 to 2000. Did they use a 175 roundnose or the newer spitzer type?

[mooman76]

Even if you duplicate the load, the older military rifles typically shot high by their sites. You may be better off just developing your own load that works into it.

[koehn,jim]

They used the 175 gr roundnose cupra nickle jacket. but I agree with mooman you are better off making your own try about 145 gr cast with 24 grains of i 4895 shoots nicely in mine.

[MtGun44]

I load enough H4831SC under a Hornady 175 Rn to make 2400 fps. It shoots really
well and too the sights in all my 7x57 milsurps, plus has a really excellent record by me
and my friends on game in US and Africa (plains game). I highly recommend this
load. Difficult to recover a bullet as the great majority exit. We are talking deer,
black bear, kudu, blesbok, blue wildebeest, zebra, moose, red hartebeest, impala,
and more - first hand and by a female hunter friend with a Ruger 77. All one shot
kills, amazingly. Only recovered two ever, perfect mushrooms. Very accurate in my
Ruger 77 and hers, and decent to excellent in the milsurps. SHe always puts them in
the right spot, and so far - so have I.

Bill

[dualsport]

Thanks guys. I'll try two loads, the 175 SP /4831(I have at least 500 of these from a gunshow deal), and the Lyman 285308 with a good dose of a slow powder. The object will be a 500m silhouette load. My only other 7mm mold is a Lee soup can, probably too light for the rams. MG44, you are a huntin' son of a gun, I'm jealous. I want to go to Africa for a varmint hunt, no big game.

[Bret4207]

A lot of people scorn the old style Hornady RN in 175x7mm or 160x6.5 but the old timers down home swore by those rounds.

[Calamity Jake]

RCBS 7MM-168 does real good in my 1909 Brazilian.

[atr]

YES !!!.....175 gr RN loaded with IMR 4350....as Bill said one shot kills are normal
the 175 Gr Rn was the original load for the 7x57

another very good load is the 140 or 145 gr. spitzer

[dualsport]

A 7x57 side note. Long ago when I knew even less I loaded up some Speer MagTips for my Ruger 77 7x57. Mistake. That bullet was way too tough, more like a fmj. Got a average buck in the am, never did find him, 'til he came down the mountain on some guys pony. I switched to 154 RNs and never had that problem again. The RN will shoot plenty flat for 'far enough'. I'm a hunter anyway, not a sniper.

[Buckshot]

...............From my M98/08 Brazilian 29" bbl, and Rem 175gr Core-Lokts a casefull of surplus WC860 or 872 will provide original ballistics @ 2400 fps. Very accurate and also clean burning. Using the RCBS 7mm-168, 42.0 grs of either will get you about 1750 fps. Wanno go faster, add more powder :-) I haven't checked availability or prices on milsurp powder in ages, so the above info may be worthless.

................Buckshot

[Larry Gibson]

Brazil and Columbia also used a 139 gr FMJBT at a velocity of 2950 fps (29+" barrels).

A recent pressure/velocity test I conducted of some old 7x57 using my M95 Chilean (22" barrel) showed the South American Cavim 84 load using the 139 gr FMJBT to give 2590 fps and 45,700 psi(M43).

I also had some very old ('20) 7x57 that was not corroded and the powder appeared in good condition. However, I was leary of attempting to fire it as I didn't know if the cases had become brittle or not. I have had what is called an "M" split on old ammo before and it lets a lot of gas back into the action. I pulled 5 bullets and powder and put them into WW cases with WLR primers. I then attempted to fire the 5 '21 primed cases and none fired anyway. The RNFMJ cupro-nickel bullets weighed 172 gr and the powder charge averaged 36 gr. The powder was the usual irregular cut flake european type. The velocity was 2295 fps and the MAP pressure was 54,500 psi(M43). The ES/SD of the fps and MAP were within normal spreads.

CIP PMAP is 57,000 psi so both types of ammo were within current spec.

I duplicate the 139 service load with a 139 gr Hornady BTSP over 52 gr H4831SC in WW cases. Velocity is 2600 fps (22" barrel) with 48,700 psi(M43). Accuracy is excellent.

I duplicate the old milsurp 172 gr RNFMJ with a 175 gr Hornady over 48 gr of H4831SC in WW cases. The velocity is 2310 fps (22" barrel) at 48,600 psi(M43). Accuracy is also excellent.

Larry Gibson

[dualsport]

860 it is. I have 16 lbs. or so and more 5010 if worse comes to worse. On british.com they give an accuracy load for the .303 with ww860 and a 200 gr. cb. I've also read about 860 being used in the 6.5 Swede. Maybe buying that very slow powder wasn't so dumb afterall. A bigger problem is having enough brass for everything. I'm finding that each milsurp needs it's own cases, sharing them between guns is counterproductive, i.e. the 1908 chamber isn't that close to a Remington RB or a modern commercial chamber. Now I'm orienting the brass in each gun and barely neck sizing, with a Lee collet die when I have one. EDIT: Larry, we were typing at the same time, I'll load some up with 4831 for comparison. I got a gallon can of old 4831 left. I used to have a bunch of that Cavim, now just a couple boxes. I think it's boxer, IIRC. I also read in an old article today that all that old surplus 4831 was originally for 20mm cannon powder, somehow I always thought it was 30-06 powder.

[Larry Gibson]

"I also read in an old article today that all that old surplus 4831 was originally for 20mm cannon powder, somehow I always thought it was 30-06 powder.

That's what it is/was alright, the 20mm cannon powder. I still have about 6 - 7 lbs left myself. Other than loading density there's just the usual lot to lot variation between the old 4831 and the new H4831. Always safer to work up the load though.

Larry Gibson

[MtGun44]

You can do a packaged deal hunt in South Africa for much less than you may think.

Try looking at www.cruisersafaris.com

Believe everything on the site. I was there and everything was exactly as stated.
Esp spend time on their newsletters, really accurate info on the individual hunt
results for various groups. No connection except that I and my friends (a year apart)
were both very satisfied and felt like we really go our money's worth.

Bill

[blastit37]

A question for Larry Gibson: Mr Gibson, did you happen to measure or do you know what the diameter of those old 7mm bullets was/is? Its my understanding that the old ones were .266". Thanks

[Buckshot]

A question for Larry Gibson: Mr Gibson, did you happen to measure or do you know what the diameter of those old 7mm bullets was/is? Its my understanding that the old ones were .266". Thanks

............I'm not Larry so I surely can't say that the bullets mic'd, but I'd doubt they were anywhere near .266". A 7mm barrel would run ~ .285" x .276 (give or take the odd thousandth here and there. A slug of .266" would kinda rattle around some on it's trip down the barrel.

.............Buckshot

[blastit37]

You are correct, I meant .286; I guess I have too many Swede's.

[Larry Gibson]

A question for Larry Gibson: Mr Gibson, did you happen to measure or do you know what the diameter of those old 7mm bullets was/is? Its my understanding that the old ones were .266". Thanks

They ranged from .2842 to .2874". The older 172 gr RNFMJs were the largest at .2874".

Larry Gibson

[blastit37]

Thank you sir. I wonder when the change to .284ish sized bullets occured? I have a couple of 7x57 FN replacement barrels which were unfired and they slug .2865". The proofs date to the 1960's so I assume they were still using the larger bullets then. Guess I will have to go to cast to get the proper size as .264's will only shoot 2-3" in my rifles even with the new barrels.

[Larry Gibson]

My only current 7x57 is a semi sporter M95 Chilean in excellent condition. I boght it not quite finished and disassembeled in a box for a good price. I shoots j bullets extremely well all of which ar .284. I picked up 5 boxes of old Herters 139 HPs and it really likes those. The groove depth on it is .286. I have minimally used an older semi-Lovern style RCBS 28-168-FN in it. Cast of WWs + 2% tin they drop at .287 and I use a .287 sizer to seat the GC and just lube them. I've not really wrung it out yet so can't give any real idea how it will shoot with cast but it looks like it will shoot well.

Photo's show rifle, some of the ammo tested and the RCBS mould

Larry Gibson