336 conversion

[pahermit]

Going to send my 336 to JES for the 38-55 conversion.The twist is 1/15.Am only going to shoot lead from the 336 so which groove is better,the 3 or 5 groove?Forgot to mention my marlin has a 18" bbl.

[fordwannabe]

I just asked him what type rifling to use when he did my Winchester from 30-30 to 38-55. I think it is a 3 groove but whatever it is he got it right. Boy howdy is that thing a shooter.

[TXGunNut]

I'd tell Jesse what you plan on doing with the rifle and what you expect from it and ask him what he thinks. My 35 Whelen rebore is a 3-groove.

[ReloaderFred]

I had Jesse rebore a 336W for me in .375 Winchester and he did the 3 groove rifling. It loves cast bullets, and the side benefit is if I want to shoot .38-55 through it, I can, but if I want to shoot full .375 Winchester loads for elk hunting, I can do that, too.

Hope this helps.

Fred

[TXGunNut]

Wish my 375 Win and 38-55 would shoot the same boolit. I think JES bores the 38-55 to .375.

[davidheart]

I can convert my 336 to something else? Who's JES? Where could I find out more?

Thank you!

Edit: Found it -> http://www.35caliber.com/8.html

[rbertalotto]

I've had him do four rifles for me now. All three groove. I like the big lands a three groove leaves. More metal to displace the heat and erosion. All shoot excellent!

And yes, all are .375 which makes bullet selection easy. My original 38-55 rifles are from .378 to .381

[W.R.Buchanan]

I guess I'm different,,, he is doing my #4 mk1* Enfield to .35-303 with 4 grooves. Cost an extra $25 for the 4 or 5 groove job.

Randy

[TXGunNut]

I guess I'm different,,, he is doing my #4 mk1* Enfield to .35-303 with 4 grooves. Cost an extra $25 for the 4 or 5 groove job.

Randy

What made you decide on 4 grooves, Randy?

[Bphunter]

Does the 38-55 conversion require work on anything besides the barrel? I'm thinking this might be a cool way to upgrade my 30-30 to a short range elk rifle. How much does something like this cost (ballpark)?

[ReloaderFred]

Converting the .30-30 to .38-55 is easy. All it requires is having Jesse Ocumpah (JES Reboring) rebore your barrel. He charged me $220.00 to convert my Marlin 336W to .375 Winchester about 3 years ago, and that included return shipping. He received my rifle on Saturday, and I had it back the following Friday, and the work was excellent.

Here is the link: http://www.35caliber.com/index.html For 3 groove rifling, the current charge is $225.00, including return shipping.

Hope this helps.

Fred

[Bphunter]

Thanks Fred. That helps a lot. If the 336 can handle 375 pressures, then the 38-55 should be a piece of cake! I'm assuming more grooves might be better for cast, but I'll ask Jesse which way to go for best results with cast bullets. He probably has some good advice for chamber dimensions as well.

[ReloaderFred]

I opted for the 3 groove, and it shoots cast bullets really well.

Hope this helps.

Fred

[W.R.Buchanan]

What made you decide on 4 grooves, Randy?

3 grooves has always seemed weird to me. 2 grooves seems weird too. 4,5,6 seems OK to me?

I know they shoot well but I just can't warm up to the idea of it.

I can more easily measure a boolit or slug also.

No other reason than that.

I might have him do a Springfield to .375 Whelen and I may do a 3 groove on that one.

Randy

[Bphunter]

That's a good point about measuring slugs. Even numbers are easier to get the calipers and/or micrometers on. How many grooves are really necessary to shoot cast well probably depends a lot on the depth of the rifling. Fewer grooves may leave more polished bore surface which could make cleaning easier. Fred has good results with 3 grooves, and I would be doing the same caliber, so that would probably be a safe bet for me as well. If anything, my 38-55 loads will be much tamer than the 375 WIN loads he's shooting, which in turn should require even less traction with the rifling. I would still go with a minimum of 3, but maybe 4 for the reason you just pointed out!

[dragon813gt]

My 358 is a three groove. I'm going to have him convert a 336 to 3 groove 356 Winchester one of these days. Bills won't stop coming for some reason :(

[yeahbub]

Some years back I spoke to the lead engineer at Marlin and he told me they wouldn't convert any 336's to .375 Win because the Marlin Model 375's had a different heat treat regimen to deal with the higher pressures of that round. They weren't willing to re-heat treat a 336 to bring it up to speed because of added expense. SAAMI's pressure ratings for the .30-30 is 42000 cup while the .375 is 52000 cup (http://www.leverguns.com/articles/saami_pressures.htm ). I don't know how hard one has to drive the .375 to abuse a 336, but this might be food for thought when developing loads for a 336 in .375 Win. My sense tells me to enjoy it, but without pushing the envelope too zealously. JES must have looked into this pretty closely since he's willing to do it. I wonder what his take on it is. . .

[TXGunNut]

3 grooves has always seemed weird to me. 2 grooves seems weird too. 4,5,6 seems OK to me?

I know they shoot well but I just can't warm up to the idea of it.

I can more easily measure a boolit or slug also.

No other reason than that.-W.R.Buchanan


Three sounded odd to me but feedback around here on 3-grooves was good, that's what Jesse suggested as well. Four or five sounded better to me but I'll take advice from someone who cuts rifling for a living. My thinking was that fine threads on bolts are stronger than coarse but I wasn't sure how that relates to rifling.

[Bphunter]

My hottest 38-55 loads are under 30K PSI, so I'm not too worried about pressure. I believe the stress on a barrel increases with the square of the diameter, so it isn't even fair to think a 42000 CUP 30-30 barrel would be able to handle a .375 bore at 42000 CUP. I with you on leaving that call to Jess.

[TXGunNut]

My 375Win cast boolit loads (fired in a 94 Big Bore) are probably within the capabilities of a standard 336 receiver but I do have some factory and some reloaded ammo that lives up to the 375's billing. I've always thought the 336 was a stronger action but I'd be just as happy with a 38-55....matter of fact, I have two Winchesters chambered for 38-55. ;-) Most days 38-55 brass is easier to find, too.

[W.R.Buchanan]

The 1894 action is supposed to be good to just short of 50K psi. The 336 action is a little stronger.

The problem with doing a conversion is that you might not want to shoot any .375 Win Factory ammo,,, But some other fool might,,, and not know the difference.

I was appalled that someone would convert that Springfield I bought to some bastard caliber,,, .30 Ackley #1?,,, and not mark the damn barrel?

People do dumb stuff with guns,, some live to tell about it.

Randy

[TXGunNut]

....The problem with doing a conversion is that you might not want to shoot any .375 Win Factory ammo,,, But some other fool might,,, and not know the difference....W.R.Buchanan


I feel the same way; some of my guns have probably outlasted 2 or more owners. My guns will be around a long time after I'm gone, I don't want them to hurt anyone. Most folks will buy ammo off the shelf for whatever's marked on the barrel and simply won't give it a second thought. That's why I feel a 38-55 is a better option, especially if it's a .375 bore.