problems 38-55

[dancast]

hi folks,
i have a marlin 336 cb, in 38-55, just started loading a dummy round, to see if every thing works well. brass is a ww, at 2.080, 230 cast bullet at .379, slight crimp. brass case at .010x2, dummy round at crimp is .397/.396,
using lee steel dies. oal at 2.50. problem, dummy round does not feed into chamber with out force. rubs on neck, and middle of case. maybe resize better? your thoughts. thanks....dan cast

[country gent]

Your crimp may have started to buckle swell the neck. run one round into die about .400"- 1/2" short of shell holder and try

[country gent]

On my BPCR Rounds Single shot rifles no lever actions yet. I perfer to use the sizing die with the decapping stem removed to set tension instead of crimping with the sizing die. I measured the gap from press head to bottom of the lock ring and had a washer made to that thickness + .015 so I could fit it down if I wanted. My rounds slide into place easily with just my thumb and shoot very well. Im loading bothe the lyman 335 postel and a 365 grn bullet.

[fryboy]

Rubs on the neck ? Thought it was all neck ...
The rubbing on the middle does sound like it isn't sized down - if it's rubbing all the way around that is
Factory spec's at the neck mouth list .3922" so I'd be more concerned there,maybe more than a light crimp ? Will it chamber a unflared sized empty case ?

[Nrut]

dancast,
I have a Marlin CB also..
I found that I had to use Starline brass which is thinner than Winchester brass..
You can buy Starline brass in two lengths both which are longer than Win. brass..
I use the longest length they sell in the Marlin CB..
With their long brass I can load and chamber up to a .382" bullet for my rifle which has a .381" groove dia.
BTW not all Marlin CB's have the same grove dia. so you will have to measure yours to determine what size bullet that you need for your rifle..

Fought with the short, thick Winchester brass for several years before I found Starline brass..

Go to this forum for some great info on loading your Marlin CB:
http://www.marlinowners.com/forum/32...dard-calibers/

And this "Sticky" thread within that forum dealing with brass:
http://www.marlinowners.com/forum/32...ase-study.html

Powders you should look at are..
1. Unique
2. H4198
3. Rl-7
4. 3031
Haven't tried 2400 but it should work also..

38-55 can be a bit of a pain to load for until you get the right brass and bullet size to feed them..
But the work is worth it in the end..

You are going to have fun!

[rockrat]

Nrut has it right. The WW brass is too thick. some have reamed the chamber on their 38-55 marlins and use the thicker brass, but getting Starline brass is the ticket.

[Hickok]

I also had to go to Starline brass in a Model 94 Winchester AE.

[dancast]

hi folks,
thanks for all the replys, ordered some starline brass today, and believe that should fix my problem. thanks....dancast

[dancast]

up date, rec'd my short 38-55 starline brass, 239 gn redman cast bullet, and with a very light crimp, these feed into the marlin cowboy with no problem. will have a range report in a few days........dancast

[R. Dupraz]

Typical Marlin 38-55 Cowboy problem. The chamber necks are too small in relation to the throat and bore dimensions and when trying to load and shoot over sized cast bullets they cause the problem that you posted. So if a smaller cast is loaded that will chamber, It won't shoot worth a hoot and will more than likely lead because the bullet is too small for the throat and bore. The chamber and bore dimensions are askew. Don't know why Marlin did this but the explanation that I read several years ago is that SAAMI has no standard specs for the 38-55. Don't know if this is true or not. But all the Cowboy 38-55 owners that I know have had the same problem.

Powders that work for me

Imr 4227
Imr 3031
Hodgdon BL-C(2)

I have been shooting A Marlin Cowboy for ten years or so and is used monthly for our lever action silhouette matches. It has had probably in excess of 2000 rounds of cast through it by now. And it shoots like gang busters with either the lee PB lee or the RCBS 375 GC. Both about 260 grns. and sized to .380".

The real solution is to have the chamber neck reamed with an over sized neck chambering reamer that is specifically ground for the Marlins. After this. these guns will shoot cast like crazy. When using a set of RCBS loading dies, I size the necks just enough to hold the cast bullet and then crimp. I started with about 400+ Starline cases that were dedicated to the Marlin and after having been loaded several times, none have been lost because of failure yet.

[dancast]

hi rd,
thanks for that important info, be another day or two before the range. thanks........dan

[jrmartin1964]

The chamber and bore dimensions are askew. Don't know why Marlin did this but the explanation that I read several years ago is that SAAMI has no standard specs for the 38-55. Don't know if this is true or not. But all the Cowboy 38-55 owners that I know have had the same problem.

SAAMI, since at least as early as 1992, has indeed maintained standard specifications for the .38-55 Winchester. Both for the cartridge and for the chamber.

The attached is from ANSI/SAAMI Z299.4-1992 "Voluntary Industry Performance Standards for Pressure and Velocity of Centerfire Sporting Rifle Ammunition for the Use of Commercial Manufacturers". The current specs, published in ANSI/SAAMI Z299.4-2015, are identical.

[Nrut]

SAAMI, since at least as early as 1992, has indeed maintained standard specifications for the .38-55 Winchester. Both for the cartridge and for the chamber.

The attached is from ANSI/SAAMI Z299.4-1992 "Voluntary Industry Performance Standards for Pressure and Velocity of Centerfire Sporting Rifle Ammunition for the Use of Commercial Manufacturers". The current specs, published in ANSI/SAAMI Z299.4-2015, are identical.

Would have been nice if Marlin had adhered to those SAAMI spec's, but they did not..
The groove dia. on mine is .381"+ not the .379" listed in the drawing..
I have read that they vari, from .379" to .382"..

[jimofaz]

My marlin .38-55 CB also has a .381" groove dia. Could not chamber a loaded round having a bullet bigger than .379". Had to rent a special (.400" OD at neck, IIRC) chambering reamer from CH/4D to allow chambering a loaded round with the .382" cast boolits I wanted to use.

[Prodigal Son]

I have a Marlin 30AS rebored & chambered by JES Reboring and likes any 2.080 brass! 256 PB boolit and NRA lube, 28.9 grs. of IMR 3031! Shoots real good, but mine is a true .375 bore, it's so easy to load for! Now the Ledgendary Woodsmen is not as nice, but it does use long brass!

[Geezer in NH]

The attached is from ANSI/SAAMI Z299.4-1992 "Voluntary Industry Performance Standards for Pressure and Velocity of Centerfire Sporting Rifle Ammunition for the Use of Commercial Manufacturers".

Note: Voluntary