Marlin 336 short throat......trim down brass?

[45coltnut]

Hello everyone,

I hope this is best spot to post such a question. But, I recently received my NOE 311165 mold for my Marlin 336. I've loaded up some loads for testing, around 12 or so and then decided I had better see how they fed. Well, I was surprised when the lever wouldn't fully close. I figured at this point I might as well force it to close and then inspect the cartridge afterwards. Well, upon opening I discovered the boolit was still in the barrel. With a little light tamping from a cleaning rod it fell out. What I found is that the overall throat / chamber is, what appears to be, short! On another case I more gently closed the lever and discovered it actually seated the bullet a little deeper. I had a little room to go on the roll crimp groove and it took it all and maybe more.

So, I reseated the rest as low as I thought I could go without cutting into the boolit by the crimp. And, they do all fit now with only a very slight resistance. But, I'm wondering if I should look at trimming the case down a little?

Anyone have any thoughts or suggestions as this is all new to me in a lever gun?

[claude]

I shorten my cases to get a good crimp and a slight engraving. this boolit is famous for just what you are experiencing. It sure shoots fine after you get the fiddly stuff out of the way.

[45coltnut]

Thanks Claude.

I assume all is well with trimming the cases until you begin to have the boolit hang onto the case area. Correct?

[popper]

Try it with a sized case first, to check fit. Only trim if needed, I've never needed to trim 30/30. Then load a dummy and check for fit. You do NOT want it jamming the lands as it will wear the lever + is really hard to unload in the field. Crimp wherever is needed, usually NOT in the groove. Trim so it crimps in the groove if you must.
Edit: make sure whatever OAL you use will fit in the loading gate. RD just said trim short but I FCD in front of the groove toward the nose. The top of the GC is in the neck so it's OK. I don't know why the crimp groove, I never used it, no problems.

[KLR]

I've been down this road with this bullet and a Win 94.
My suggestion:
Do an impact cast of your chamber neck/throat.
Get Tom at Accurate molds to cut a custom mold for your specifications.

[45coltnut]

Thanks for all the replies guys.

I did just buy a custom mold, so I'm determined to get it to work. Although I do have molds from Tom as well and they are outstanding.

With my current seating/crimp depth its maxed out per the crimp groove. And, its currently just hitting the lands. I think I may take another .020-.030" off a case and test it out. This should be enough to get it to load and it will still be right at the rifling lands. I just wanted to check here first before doing so as most of my loading and casting has been for single shots and bolt guns.

Thanks again for the posts!!

[claude]

Thanks Claude.

I assume all is well with trimming the cases until you begin to have the boolit hang onto the case area. Correct?

That is a matter of personal choice that one can read volumes about for and against, it's a Ford vrs. Chevy choice replete with mountains of inconclusive evidence. Personally, I seat to the extreme depth allowed and still have the gas check remain in the neck simply because that is the depth for my Winchester that allows proper engraving. I tried the "B" version, the one you are displaying, and went back to the "A" version because in my rifle it worked better.

The "A" version, now called the 311-170gr RF, works better for me.

[Yodogsandman]

45coltnut, I would seat the boolit to where it needs to be for proper function and accuracy and then trim the case to whatever length is needed for proper crimping. Those shortened cases would then be kept separate from others and only used for that boolit.

That's a great boolit and you won't be sorry! Trim a few cases and go for it!

[leadman]

you never posted if your cases were already trimmed to proper length or not or what size the nose on the boolit is or the throat. I have used the Lyman 311041 in a Winchester 94 with no problems.
From appearances you will have to trim the brass back to whatever length will allow the boolit to not engrave the rifling. I would check the size of the boolit and bore/throat to make sure all are compatable.

[45coltnut]

Yeah, sorry for the lack of info given. The slugged bore is .3095" and the boolit is sizes at .311". Also, the cases were all trimmed for uniform size which I can't remember the actual length, but it's only like 0.25" under the max.

As long as no one sees any issues, I should be good to simply trim them a little more in order to keep the crimp groove at the crimp location and the boolit just off the lands.

[cainttype]

The LEE Factory Crimp Die might allow you to crimp where you want without trimming your cases shorter than normal. I use them for exactly that reason occasionally.

[Dan Cash]

As with Leadman, ensure that the case is trimmed to a proper length; I prefer slightly shorter than load book reccomendations as ,30-30s stretch with full house loads. seat and chamber a bullet in an uncrimped but resized case and chamber it. Use the results to determine the desired final seating depth. Once adjusted to that point apply only a slight crimp if you must. Your picture shows a bullet and brass destroying crimp, nuch more than needed.

[45coltnut]

Thanks for the reply.

The crimp looks so rough as the boolit was seated farther into the case causing the case to actually cut into the boolit. The crimp wasn't originally too tight. Just a good positive crimp. I believe in a lever gun with front to back rounds against each other a good crimp should be used. In a bolt gun, I never crimp.

[WV Mountaineer]

I'm just a Newbee but, from the pic, it looks like if you'd trim to spec, you have plenty of room to seat the bullet deeper and, still be in the neck of the case. I'd personally seat one by the bolt, back it out .005 or .010, crimp it, make sure it fed properly, than measure to ensure the check stayed in the neck of the cartridge, and go shoot. Unless something about it screamed no.

Like I said, I'm not very experienced shooting/loading lead but, other than the case being fouled up by jamming the round into the chamber, I see nothing wrong there to believe different. God Bless

[45coltnut]

Well, this morning I made a dummy round with even a shorter case length to an even 2.00". Then I seated a boolit to the crimp groove. BUT, the dies would not crimp it as the shell holder bottomed out on the die.

I guess this mold design just isn't going to work in the Marlin. I'll have to find a shorter noses boolit mold.

[KLR]

Sand/grind a little off the bottom of the crimp die. I modified a 7.62x54r this way to work on a 30-30.

Edit: Note- I'm talking about modifying a Lee Factory Crimp Die.

[EDG]

You can size the bullet nose only to clear the rifling or using a throating remaer to move the origin of the rifling forward.

[popper]

Get an FCD. Any 170 will get seated deep. If your neck tension is correct, just remove the belling at the mouth. Shot many RD from my 336, full tube - no setback. FCD on the nose, not in the groove.