Marlin Cowboy .38-55

[JudgeBAC]

Thanks to advice from Felix my search for a .38-55 has headed in the direction of the Marlin Cowboy .38-55 with a 1-18 twist barrel. I have read good things about this gun but ran into some discussion regarding inconsistent chamber dimesions. Does anyone know anything about this and what should I look for if this is a genuine problem? Looking forward to receiving some more sage advice. Felix kept me from making an expensive mistake.

[Denver]

As I understand it, Marlin barrels for the 38-55 had groove diameters as large as .379 in some rifles. When boolits of that diameter and larger were loaded, the chambers were of such dimensions that it was not possible to chamber the round.

[straightshooter1]

I have had two of the 38-55 Cowboys. The first had checkering which I detested, though the gun was very accurate. About three years ago, I found a new one without the checkering at my FFL's and traded the old one for the new one.

It, too, is very accurate. I use .380 LRNFPs with gas checks and have no trouble at all (and had none with the first one either).

The sole problem I had was loading 13 grains of Red Dot (the infamous or famous "load") and finding that it was an overload according to all the manuals. I found that it was inaccurate, and that it "unlocked" the gun when fired. I pulled a lot of bullets. I now don't take anything for granted w/o checking it out in the manual first.

RX7, IMR 4198 and the light but very accurate load everyone seems to know about, 10 grains of Unique, work great for me. 10 grains, I believe, is the max (some manuals say 9.5 IIRC), but it is a light, very pleasant load for the Cowboy 38-55.

I have an old 336 from the late 40s which shoots 30-30 cast boolits very well, but still am looking for a reasonably priced Cowboy in that caliber as well.

Bob

[Ed Barrett]

[QUOTE=The sole problem I had was loading 13 grains of Red Dot (the infamous or famous "load") and finding that it was an overload according to all the manuals. I found that it was inaccurate, and that it "unlocked" the gun when fired. I pulled a lot of bullets. I now don't take anything for granted w/o checking it out in the manual first.

Bob[/QUOTE]

The "Harris load" was intender for military type bottle necked cartridges with cast bullets. using it with a stright cased cartridge is taking it to a different ballgame.

[Pepe Ray]

Denver's post is correct. To enlarge, some of my shooting pals had the same problem. The simplest sollution is to use the same one used by the "old timers". By using a SOFT bullet of "standard" size ie. .376 or 7, the round would obturate into the rifling. This usually precludes the H.V. rounds so popular today.
The boys I know, sent the rifle back to Marlin who redid the chamber (I believe at NC). He did this because his common source for bullets were all HARD and .380ish in size. This also works and he's happy. Take your pick.
Pepe Ray

[floodgate]

Marlin has been bragging up their "new" Ballard rifling lately, apparently to offset the poor PR their 'Microgroove" rifling has gotten in some quarters. Granted, the term goes bacik to the 1870's-90's when they made the original Ballards, but I thought the current ads were modern hype. But in looking through the April, 1943 "Rifleman" in search of an article on Gordon Boser's ".401 Special", I spotted a Marlin ad (p. 46) with the statement: "All Marlin rifles - lever action, clip and tubular magazine and .22 [semi-]automatic, feature deep-cut, accurate 'Ballard' rifling."
\
floodgate

[straightshooter1]

Ed Barrett-I think you are correct, though I have heard it is good in larger calibers like the 45-70. I have never tried that one as I have a couple of great IMR 4198 loads when I shoot smokeless in my Marlin 1895 Ltd.

My problem was that there were several calibers I could not get cast to shoot well in. I tried "the Load" and most worked at least okay or better than okay. So, stupidly, I assumed (hate that word) that it would work on anything 30 caliber and above. Learned my lesson, nothing damaged but my pride (which I didn't have a lot of anyway).

Bob

[Sky C.]

Marlin claims the barrel groove dimension is 0.378" to 0.379". They use "spade gauges" (similar to a pin gauge but flat material that will slip between the rifling lands) to make their measurements.

Using a lead slug - the dimensions run a tad larger. In my rifle - groove dimensions per the slug method run 0.3809". Initially it would not chamber a 0.379" bullet. After returning to Marlin to have the chamber opened to max. SAAMI dimensions (as large as they would go) the chamber will now accept a loaded round with bullet dia. of 0.380" - barely. This IS a common observation among the folks who own these rifles. So far, I have not had a chance to rinng out how well it will shoot but initial loads with a Mountain Mould 265gr. GC'd air cooled WW bullet sized .380" shows accuracy promise and no leading. Though I was hoping to be able to load and shoot a bullet of 0.382" - it may prove to be no problem.

I've held off of doing serious load development hoping Starline will eventually release their .38-55 brass at orignial spec'd length (2.129" vs. current Winchester brass at 2.080").

Best regards-

Sky C.

[JudgeBAC]

Well I took the plunge and cut a deal on a Marlin Cowboy .38-55 with Redding Dies and brass. Based on what I've read so far, I think I am in for an interesting experience. A Saeco double cavity 265 gr flat point mold is on its way. I will keep this thread up to date with data upon receipt of the gun and dies etc. Lets hope for the best. Thanks for the information.

[DEVERS454]

I have a Meister slug kit for the 38-55 and would be willing to package it up and send it your way. $10 plus $5 S&H for USPS Priorty mail...

PM me if you are intersted. (I used only 4 of the slugs... one could easily slug the bore of 4 more guns)

[mdatlanta]

I have a Meister slug kit for the 38-55 and would be willing to package it up and send it your way. $10 plus $5 S&H for USPS Priorty mail...

PM me if you are intersted. (I used only 4 of the slugs... one could easily slug the bore of 4 more guns)

PM Sent.

[DEVERS454]

Sorry to say, the kit is spoken for.

Sold...

[NickSS]

I bought an old Marlin in 375 Winchester and found much to my dismay that the best it would perform was with jacketed bullets and produce groups in the 3 to 4 inch range. So I called Marlin and asked if they had any 375 barrels in stock. They didn't but when I asked about 38-55 they told me they could rebarrel it to that caliber. So off went the gun and when I got it back I had a pistol griped cowboy rifle. I found that the groove diameter was .3785" and that my 370 bullets would work. When I ran out of them I bought a Lyman 375248 mold and started using cast bullets sized to .379". My rifle shoots these very accurately with 18 gr of AA 5744.

[Last Spike]

Good thread! I'm taking delivery soon of a 1920 manufactured Winchester 1894 in 38-55 that slugs .379 groove diameter. Accuracy with Winchester factory ammo is 7/8ths of an inch at 50 yards and it shows similar accuracy with cast boolits sized .379. Will be picking up a 6 holer from the GB 375 mould Buckshot is honcho-ing. Also looking at the commercial moulds available also.

Life is good!