38-40 Marlin ideas?

[NorthMoccasin]

I am planning on getting my 1894 MARLIN 38-40 out of the safe and back in action. In the past I have used an old ohaus 180gr swc mold with mixed results. 5 to 7 gr 700x gives the best accuracy with that bullet, about 2" at 50 yd, but is painfully slow. I have tried the similar RCBS mold with similar results. Faster loads are 4"+. I notice Accurate has several RNFP molds in the 160 to 200gr range and wondered If anyone has any experience with them. 180 Remingtons over 22.0 4227 do about 2" or a little less at 50yd but my supply of them is limited.

[SvenLindquist]

2 MOA is decent for a 38-40. My #1 Lyman book shows 175 PB W/ 17GR 2400 1340 fps or 15.5 4759 1415 fps or 8 Unique 1350 fps. TrailBoss would also work fine.

[9.3X62AL]

2 MOA with any levergun in most calibers would make me ecstatic.

[enfield]

the Lee 40 cal truncated cone bullet works well.

[NorthMoccasin]

thanks for the input guys, but I am interested in a bullet with a crimp grove that will function in a lever and give decent accuracy. Accurate offers some that look good but i wondered if anyone had any experience with them.

[Texas by God]

Have you tried Unique with your existing moulds? What range are you grouping 2" at? If you say 100 yds- then I'd suggest that you quit crying[emoji3]

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[9.3X62AL]

I agree with the O/P's thrust concerning the desire for a crimp groove. Such a bullet design expands the powder choices GREATLY for a tube-fed levergun. Original Lyman moulds for these hyphenated Winchester calibers are greatly biased toward black powder usage--they cast undersized for smokeless powder, and presume that the bullet will seat upon a compressed column of black powder to guard against bullet setback as the cartridge shunts down the mag tube. E.g., Lymans #311008 and #427098 are entirely lacking in crimp grooves. They are meant to rest on the powder column, and a crimp around the ogive's origin area wraps the package up. In 44/40 WCF, I opted for the SAECO #446 design that cast large enough for my rifle's throat (a few tenths under .429") and includes a crimp groove. I get it.

[woody1]

Going back a step. Have you checked your throat and groove diameter? My old Marlin '89 has a huge (.406) groove diameter.

[Outpost75]

Accurate 40-182H is my design for .40 S&W and 10mm Ruger Blackhawk. It should work well in .38-40 and has a crimp groove. Have not tried in a rifle, but I get 1079 fps from 5" revolver with 5 grains of Bullseye with grouping better than factory 180 JHPs.

[NorthMoccasin]

Thanks for the input guys. I misspoke about group sizes (old timers brain fart) Groups mentioned in 1st post were NOT MOA but inches at 50 yards. The original post has been corrected. To clarify, only one load, 5.5gr 700x under a rcbs 170gr swc will stay in 2" at 50 yds. heavier loads and other powders 3" to 4". J words consistently 1.5 to 2" at 50 yds. Groove diameter is .400, bullets are .401. I have tried Unique, 2400, 4227, 5744, Universal, red dot and probably others over the years. Thanks again. I guess I could by a cannalure tool to put a crimp groove in 40 cal pistol bullets.

[Thin Man]

If you posted this procedure I missed it reading this column, but you may benefit from water dropping your cast boolits to make them harder. It sounds as if your rifle requires a harder projectile to grip the rifling, and water dropping can provide just that. Hope this helps.

[NorthMoccasin]

Thanks Thin Man, I hadn't thought of that. I'll give that a try. If that doesn't work out, I suppose I'll just have to pick one of Accurate's molds and hope for the best, since no one seems to have any experience with them in a 38-40.

[44magLeo]

Perhaps some of the people that suggest good boolits in their rifle could send 50 or so to you to try. Then if they work, buy a mold .
Leo

[yeahbub]

If the rifle is of modern manufacture, have you slugged the barrel to determine if you have a reverse taper in the bore, tight at the breech, loose at the muzzle? If it's button rifled and a round contoured barrel, it's a good possibility. Octagonal barrels exhibit this problem less because no steel is removed after they are rifled, but round barrel contours are cut after rifling and unresolved stresses are released where the most steel is removed. If you've tried a number of different loads and boolits with no particular difference in results, this may be the case. Usually the difference is less than .001 or so from end to end, but cast boolit accuracy is definitely affected when they start to leak as they move down the bore. A bit of pressure lapping repairs this pretty easily, usually in less than 30 rounds.

[NorthMoccasin]

Thanks yeahbub, it's an original 1984 with an octagon bbl. I will slug both ends when I get back to rifle.

[pull the trigger]

I have a Marlin 1889 in 38-40 and the Lee 40s&w boolit is too long when crimped in the groove. It will not feed from the magazine. So I too am looking around for a fat boolit with a shorter portion ahead of the crimp groove.

[Rick B]

After numerous unsuccessful trips to the range with a worn 1892 in 38 WCF, I ordered an Accurate Mold 40-190C .403 diameter. This is the only bullet I have had any success with. Even then loads had to be held back to get any respectable groups at 50 yards. Load I settled on was 5.0 grains of Bullseye. It’s slow! Both jacketed and cast pushed harder would not hit inside a washtub at 50 yards
Rick

[KirkD]

The fact that your most accurate load was with a faster powder, suggests that the pressure spike is bumping up your bullet to better seal the bore. I have an original Marlin 1889, shipped in 1889, chambered in 38-40 that slugs at a whopping .410" groove diameter. I can only chamber cast bullets up to about .406" but if I cast them out of pure lead, that does the trick. They are soft enough to bump up and seal the bore with even medium speed powder like SR 4759. I have a custom mould from accurate moulds.

[Rick B]

Will try casting some softer bullets. Wow a 38-40 barrel at .410. My 1892 is .402 groove diameter