.375 Winchester BP loads

[omgb]

I've been wring out a new BB94 in 375 Winchester. I'm using a couple of different cast bullets and none of the loads are very steller. IMR 4198 has proven the best so far provided I use an RCBS 250 grain GC bullet. This bullet of course, does not like to feed from the magazine. now the Lyman 260 grain PB bullet feeds like a house afire but it leads and won't group. I tried RL7 and got bupkis. So, I decided to give BP a try. I used WW cases, Win LR primers 4.5 grns of RL7 and 45 grains by volume of GOEX 2f BP. For lube, I stuck with White Lightning. I slugged the bhore and came up with .377. Unfortunately, my die is also .377. However, with BP no need to worry, the round will "slug-up". So, I loaded up 40 or the RCBS GC bullets in the above load. The attached jpeg. is the result. Over the chrony I got 1218/1221/1226/1229/1226/1222/1219/1225/1222/1223/1221

Smokeless loads did not group as well and ran 1722/1683/1614/1647/1677/1696/1700/1678 using 25.0 grains of IMR 4189.

[26Charlie]

Never tried BP in the .375. Those results are encouraging. May try it with a plain-base bullet.
With smokeless, I have had good results with a slightly slower powder, 3031 - with both the RCBS 37-250 and the Lyman 375449 sized .378 I use about all the 3031 you can cram in the case. The load is 35 gr. or 36 gr. , I think the lower load is with the Lyman because it takes up more room in the case, and both bullets group well in the 3 different rifles I have for this caliber - a bigbore M94, a Marlin M375 (what they call their M336 in this caliber) and a Ruger #3 with scope on it.
Recently picked up a mould for the 375297 GC and cast up some, but haven't had a chance to try them yet.

[Harry O]

I have been loading BP in a .375 Winchester for some time. Sort of a faux 38-55. A little bit different from your load, though. I started out with a .375 Winchester BB. My wife was looking for a BP cartridge rifle, so I figured, why not use the .375 Win. I cast up some soft cast, plain-base Lee 250gr bullets, sized it for .377" and lubed it with SPG. Then I filled the case with Swiss FFFg BP (some compression when seating the bullet). As stated above, it is only 35 or 36gr.

Not enough lube in a rifle. I later added a couple of fiber discs with a lube wad between them (set between the bullet and the BP. This cut the BP a couple of grains. Anyway, it is accurate and very low recoil and my wife loves it. I have not crono'ed them because there is no point. I later got her a Ruger No. 3, put peep sights on it and shot them in it. She loves that one even better, so I have my Winchester back.

[chromecrow]

I have had good luck using 3031 in my .375 BB. It has a large (.381) bore so I make 'em as fat as I can. I used dacron as a filler but had some unburned powder left in the bore. In my 38-55 I have had good results using AA1680/w dacron and 5744 w/no filler. I am anxiously awating the .375GB boolit.

[McLintock]

Ken Waters did a Pet Loads article for the 375 Winchester levergun for the January-February 1978 issue of Handloader Magazine. His top accuracy load was 18 gr IMR 4227 with an Ideal 231 375248 bullet, and top full power cast bullet load was 34.0 gr of 3031 with a Lyman 375449 gas check bullet. I've used the first one in my 38-55 single shot, but with 245 gr plain base bullets, and it is very accurate and consistent for me. It zips along at about 1450 fps. I've also used a load of 31.0 of 3031 with the same bullet Water did (375449), and it is top notch all the way out to 500 yards. I'm using cases that are shorter even than the 375 cases, and .380 or .381 bullets in a .376 bore.
So far as black powder is concerned, I use the Lyman 375449 gas check, with no wad and 41-2 gr of Swiss 1.5 in my Winchester lever 38-55. I'm not using a duplexed load like yours but I'm getting better results than with any plain base bullet I've tried. It seems to carry enough lube for a 26" barrel, so that I don't have to use a grease cookie, at least in my gun. I regularly use it in Cowboy Action matches where I have to shoot ten shots as fast as I can get off, so there's no blow tubing or cleaning during the string. It does well at up to 200 yards.
McLintock