Can a 45-70 Marlin barrel be set back 0.405"?

[briannmilewis]

Just wondering if anyone has done a rechamber of a 45-70 Marlin that required a barrel set back of 0.405" or more?

If this needs to move to gunsmithing, please do so.

[Terbltim]

Definitely a gunsmithing subject but the answer is...
"not without plenty of other work too."

BTW,
A replacement barrel might actually be cheaper.

[briannmilewis]

Terbltim - that's the kind of extra info that I was looking for if it applied. Not knowing the design of the Marlin lever-action, does a replacement barrel come fully chambered or partially so? A rechambered blank would be ideal I guess for the least amount of work.

[Terbltim]

You can buy a "factory new" replacement barrel for the 45/70 on the web site for Gun Parts corp. ( http://www.e-gunparts.com/model_new.asp?catID=11750 )  or Numrich (same company) for about $50.
It'll be a Micro-Groove (which I personally prefer.)

These are pretty much "drop-in" replacements. Dovetails are already cut in place so you can just unscrew the old one and screw in the new one.
The rim of the 45/70 was never really standardized so gun makers can make their barrels with a "ballpark" headspace and it'll still work fine, (true of many/most rimmed cartridges.)
I have not done one myself so I can't give first-hand info.
It might turn out that you have to "relieve" the barrel shoulder to get the barell all the way up to "top-dead-center" (TDC)
there is the possibility of a requirement for "finish reaming" but I don't think so. (Its been a long time since I looked into the notion of changing the barrel on my 1895.

If you want a Ballard replacement I think you'll have to deal with Marlin.
I have a letter from a Marlin Exec. that says they'd sell me a Ballard (cut-rifling) barrel for $150 (installed at the factory) and send my old barrel back with the rifle. No gunsmith can beat that deal...if its still good.

Setting the barrel back would change the relationships (positions) of all the dovetail locations with regard to the parts (forearm hardware & magazine tube, etc.,) they attach to. A lot of expensive work for a gunsmith.
If there is something seriously wrong with your chamber getting a new barrel would be my advice.
They're cheap, even if you need a gunsmith to mount it.
Just be sure that you really need that done before diving in.
Hope this helps.

[briannmilewis]

Thanks. It is for future reference in relation to a rechamber to a short 45-70. So it would appear that a new bored but unchambered barrel would be the way to go in order to make the fitting easy and just ream the new custom chamber. I appreciate the help and advice. Also, $50 for a new barrel, that is an amazing deal!

[gunnut69]

I restocked a Marlin 336 into an early style Marlin stock(with the half pistol grip) and Marlin did the rebarrel to 38-55 for the gentleman for under $200. Don't remember the exact price anymore but the work was beautifully done and the rifle performs great. He uses it in Cowboy shooting and does really well with the rifle. I was very interested in the rifles performance. The 38-55 is a round I'd like to work a bit with. I've one, a M94, but have never been in love with the M94. Plus my eyes are getting worse rather quickly so that some type optic sight is more than likely a mandatory accessory in the near future.

[Nobade]

I had Marlin do something similar for me. I sent them an older 336 and had them put the Cowboy front end on it, in 30-30 caliber. I really like how it hangs for offhand shooting, and someday I want to build some nice looking older style stocks for it, right now it's not really attractive but sure is a shooter. If I find another one for cheap enough I'll see if they'll build something similar in 38-55 to play with. It would be neat to have a matched pair. For what they charge, you can't even buy a barrel blank and do the work yourself.

[Winter Hawk]

I too had my older 336 rebarreled to .30-30 Cowboy by Marlin.  With the barrel, new magazine, forearm etc. it was $320, including shipping home.  The 24" octagonal barrel is definitely heavier than the 20" round tube, balance went from the receiver out to the rear sight. 

I asked for my old barrel back and Marlin did that, with all the old parts.  The gunsmith noticed that I had a sling stud on the barrel band, so he mounted a forearm cap with sling swivel stud, and enclosed another one without the stud in case I wanted to use it that way.  The new wood is gorgeous.  They did well, in my opinion!

-Kees-

[Terbltim]

Thanks. It is for future reference in relation to a rechamber to a short 45-70. So it would appear that a new bored but unchambered barrel would be the way to go in order to make the fitting easy and just ream the new custom chamber. I appreciate the help and advice. Also, $50 for a new barrel, that is an amazing deal!

I'm not sure why you might want a "short-chambered" 45/70. The gun will handle shorter cartridges without a blink or  hick-up.
I've made and shot 45/70 ammo with cases trimmed shorter than "standard length" many times... all the way down to 1.8" case-length and they worked fine in (the Marlin.)
In fact, they work very well.
That short reference, (1.8",) was what I cut them to so I could get the Speer 350gr Hot-Core bullet to crimp in the groove provided, (an experimental stage I went through about 15 or so years ago.) That is a long-ogive bullet and if seated to its intended crimp length it won't work through the action. (It's made for the 458 Win Mag.)

When the case mouths split I just trim them to whatever eliminates the split and go on loading and shooting them.
I don't think that would work as well with cast bullets [haven't tried them] but it presents no problems with jacketed ammo.
Just another of the many beautiful things about the care & feeding of a 45/70.
I think that cartridge was inspired by God.

[briannmilewis]

terbltim: That is great to know, thanks.

[gunnut69]

The Marlins are a bit sensitive to over long rounds though.. That is an interesting technique for dealing with long bullets in the tube magazine environment of a lever gun. As they must be crimped to avoid problems with setback.. How did the 350 grain bullet perform in your 45-70?

[Terbltim]

That Speer 350 Hot-Core bullet worked well in the Marlin.
I eventually just used full-length cases and stuffed the bullet down to wherever it would work thought the action and for a crimp I'd lay the case mouth down over the ogive, (similar to a lot of 22-Hornet factory ammo I've seen. In fact, thats where I got the idea.)
I never had any bullets setting back but that may be from the fact that I was filling the case with powder to mild compression for those experiments...which is the way I always load the 45/70 anyway.
I choose my velocity by changing the powder.
In answer: the bullet worked fine whether used in a shortened case of just stuffed into a normal case far enough to work through the action.
The only jacketed bullet I've used in recent years is the Rem. 405gr JSP which I routinely use at around 1600-fps.
I'm about ready to go back to the Rem. 300gr JHP loaded to give mid-1900s velocity because its a superior deer-slayer.
I've got a whole notebook on data I've developed over the years on this gun and the loads I've made for it.

[gunnut69]

I built a 45-70 Rigby style express rifle for a friend a few years ago when the Siamese actions were easily avaiable and I've lusted after one myself since. I don't know if I'll alter a regular 98 action to feed the rimmed rounds or maybe use a No4 Enfield.. Still I've way to many projects just now but perhaps if a deal prsents itself...