Converting small shank receiver to large
I tried doing a search but came up empty. My basic question is this... has anyone recut a small shank receiver and rethreaded it to accept large shank barrels?
Background:
I have a LRP on order in 6.5 Creedmoor and I also have a Shilen barrel coming for it. The only thing I'll be using for my build is the action/trigger from the LRP. I'll be putting the Shilen barrel on it and mounting it in a composite stock designed for Metallic Silhouette competition. So that means that I will have a perfectly nice LRP barrel and stock left over.
My buddy happens to have a nearly new Stevens model 200 sitting around doing nothing (.243). I'd like to use his action and build another rifle with it on the cheap. I guess I'd also have to deal with screw spacing though, I haven't looked at that yet.
Anyway, anyone ever recut a small shank receiver and rethreaded it to accept large shank barrels? I have a master machinist at my disposal so cost would be very minimal.
Thanks!
Trent
Re: Converting small shank receiver to large
Being exceptionall paranoid about high pressure cartridges I would be very leery about reducing metal in an action around such. I would certainly check w/ a gunsmith who is familiar w/ this type cartridge. Conversely I would think that rethreading the bbl. would be a piece of cake. Good luck.
Re: Converting small shank receiver to large
I don't think Savage increased the size of their receivers when they went to larger shanks. Besides, the overall dimensions are no different... barrel thickness + receiver thickness on either one is the same. On the small shank the barrel is thinner and the receiver is thicker. On the large shank the barrel is thicker and the receiver is thinner. But the overall for each of them is equal.
Re: Converting small shank receiver to large
Have the barrel turned down but don't even go with enlarging the receiver. Savage made WSM's on small shanks at for a while and I had a Savage 112U 7MM STW on a small shank. Having a large shank turned down and re-threaded is not a big deal for a good machinist. Have had several done.
Re: Converting small shank receiver to large
Quote:
Originally Posted by wbm
Have the barrel turned down but don't even go with enlarging the receiver. Savage made WSM's on small shanks at for a while and I had a Savage 112U 7MM STW on a small shank. Having a large shank turned down and re-threaded is not a big deal for a good machinist. Have had several done.
It is easier to cut external threads than internal threads, easier = cheaper too.
Re: Converting small shank receiver to large
I'd rather not mess with the barrel in case I ever want to put it back on the target action for any reason.
Either way metal is being removed. The end result is no different though. The thickness of the barrel and receiver are the same either way. The receiver on a large shank barrel is thinner than the receiver on a small shank barrel. There is no way to get around that.
Re: Converting small shank receiver to large
rethreading a barrel $40-70, rethreading an action $180, the choice is yours, I recommend the barrel
Re: Converting small shank receiver to large
Sounds like you already made up your mind.
I'm also of the opinion that it is a bad idea to remove material from a heat treated action.
Re: Converting small shank receiver to large
Money is of no issue. I have a personal friend that is a master machinist/gunsmith.
I've definitely not made up my mind. I'll either have him cut/rethread the receiver or I won't. I'll definitely not be cutting the barrel though.
I'll talk it over with my machinist and see what he feels. 0.031" of material being removed during rethreading. Besides, it is already heat treated. Machining will be harder on the tools, but I won't be annealing the steel in the process. It will still be heat treated. As far as I know receivers aren't surface hardened. They are treated all the way through.
I may post this up over in the gunsmith forum on the Hide and see what some of the gunsmiths think there.
If it turns out to be a no go on the receiver then I'll just scrap the whole idea and locate a different receiver.
Re: Converting small shank receiver to large
My point is, that you are removing heat treated material and replacing it with lesser strength thickness of barrel tennon.
Unless your machinist has an extensive metallurgical background or similar background in an engineering field he won't be giving you a qualified opinion.
Re: Converting small shank receiver to large
If money is no issue, acquire another large shank action.
Re: Converting small shank receiver to large
Quote:
Originally Posted by sharpshooter
If money is no issue, acquire another large shank action.
This isn't meant to be offensive, just safety advice.
Or another barrel, be safe. Just because that's what ya want to do, don't mean it's the best idea, trust me I have come up with what I thought were sound ideas, only to learn I was way off. I promise you the receiver modified is much tougher to get rid of than a changed barrel. Besides, a lot of guys with the small shank receivers would probably be glad to buy the barrel.
My suggestion, would be to ask Savage themselves, about having a smith do the work. Let them tell you why the receivers are different.
Re: Converting small shank receiver to large
I wouldn't worry about opening one up, but I'm not an engineer that can back my thoughts up either. I have a hard time believing it would be dangerous. Your friend might be an excellent machinist, but make sure he understands how to set up an action for threading. You don't just chuck it up and go. It needs to be indicated to be running straight in the lathe and not just at the one end. Look up an action truing fixture to see what I'm talking about. If you already knew that sorry, but didn't want you to think that just any machinist could rethread an action. If not indicated straight you could end up with a barrel not pointing straight with the action.
Re: Converting small shank receiver to large
Quote:
If money is no issue, acquire another large shank action.
+1
Re: Converting small shank receiver to large
Just for my own edification...are the threads the same pitch on both diameter barrels?. I agree that the tempering process, if Savage uses one, does not make the action too dificult to turn. I also agree that setting the action up would require a well thought out fixture for a lathe. Just me talking here but I like the journey more than the destination most of the time, but I have learned to chose the journeys that are within the realms of reason.
The purchase of a large bore action or turning the barrel are the most logical choices here. Good luck with which ever route you choose and keep us updated.
Remember Sir Edmund Hillary when asked why....
Re: Converting small shank receiver to large
If you want the action opened up, contact Jim See at Centershot Rifles (www.centershotrifles.com). He came highly recommended to me from 358Hammer on here and he has converted two for me. I am of a little different school of thought I guess than most others on here. By that I mean that yes it makes no difference on the amount of metal around the cartridge at the receiver ring but makes a good bit of difference for that part of the barrel that is outside the receiver ring. On a standard size cartridge it really doesn't matter but for belted magnums and up, it makes me feel better to have thicker chamber walls for that part that is outside the receiver ring. I am no metalurgist so I have no facts but I want to preface that with what I am about to say because they are only my beliefs. First, I get what others are saying about the heat treatment thing but I say hogwash. I doubt the heat treatment is only paper thin deep into the steel and doubt that removing the metal to rethread gets into steel that is too soft to handle the pressures. Second, barrel steel itself is not very hard and probably not as hard as the steel on the receiver and they seem to handle the pressure just fine even for the part that is extended past the receiver ring. Yes it is true that Savage made RUM's and WSM's on small shanks initially and they haven't recalled them and I haven't heard of any blowing up. A RUM chamber in a small shank leaves relatively thin chamber walls and they handle the pressure so I wouldn't worry about the receiver ring being too thin. It is your decision to make as to which way you want to go but don't worry about the receiver being weak if you decide to have it rethreaded. I have two of them that I have converted. One is a 300 win mag and the other is a 338 win mag and they are doing just fine. It just makes me feel better having thicker chamber walls out past the receiver ring for the larger cartridges and I feel that the receiver after converted would still be strong enough to have a safety margin of twice the pressure of any SAAMI max pressure load. All modern bolt actions are built to handle about twice the pressure of the max load of a cartridge.
Re: Converting small shank receiver to large
Quote:
Originally Posted by sharpshooter
If money is no issue, acquire another large shank action.
You guys aren't reading the post thoroughly. I didn't say that money is of no issue... I said that it is of no concern. Meaning that my gunsmith/machinist is a friend and doesn't charge me. I made that clear in my previous posts. I'm not saying I'm rich... I am stating that the work wouldn't cost me anything.
Re: Converting small shank receiver to large
My buddy with the Stevens 200 decided to keep it and rebarrel it to 7mm-08 so the whole opening up the receiver issue no longer matters.
Re: Converting small shank receiver to large
Quote:
Originally Posted by efm77
If you want the action opened up, contact Jim See at Centershot Rifles (
www.centershotrifles.com). He came highly recommended to me from 358Hammer on here and he has converted two for me. I am of a little different school of thought I guess than most others on here. By that I mean that yes it makes no difference on the amount of metal around the cartridge at the receiver ring but makes a good bit of difference for that part of the barrel that is outside the receiver ring. On a standard size cartridge it really doesn't matter but for belted magnums and up, it makes me feel better to have thicker chamber walls for that part that is outside the receiver ring. I am no metalurgist so I have no facts but I want to preface that with what I am about to say because they are only my beliefs. First, I get what others are saying about the heat treatment thing but I say hogwash. I doubt the heat treatment is only paper thin deep into the steel and doubt that removing the metal to rethread gets into steel that is too soft to handle the pressures. Second, barrel steel itself is not very hard and probably not as hard as the steel on the receiver and they seem to handle the pressure just fine even for the part that is extended past the receiver ring. Yes it is true that Savage made RUM's and WSM's on small shanks initially and they haven't recalled them and I haven't heard of any blowing up. A RUM chamber in a small shank leaves relatively thin chamber walls and they handle the pressure so I wouldn't worry about the receiver ring being too thin. It is your decision to make as to which way you want to go but don't worry about the receiver being weak if you decide to have it rethreaded. I have two of them that I have converted. One is a 300 win mag and the other is a 338 win mag and they are doing just fine. It just makes me feel better having thicker chamber walls out past the receiver ring for the larger cartridges and I feel that the receiver after converted would still be strong enough to have a safety margin of twice the pressure of any SAAMI max pressure load. All modern bolt actions are built to handle about twice the pressure of the max load of a cartridge.
Thank you for your first hand information efm77. I really appreciate it! My train of thought is right along with yours. I'm going to keep an eye out for another donor action. If I can find a large shank action and not have to cut new threads then I'll go that route, but if I find a good deal on a small shank then I feel confident in opening it up. Cheers.
Re: Converting small shank receiver to large
Quote:
Originally Posted by mscott71
I wouldn't worry about opening one up, but I'm not an engineer that can back my thoughts up either. I have a hard time believing it would be dangerous. Your friend might be an excellent machinist, but make sure he understands how to set up an action for threading. You don't just chuck it up and go. It needs to be indicated to be running straight in the lathe and not just at the one end. Look up an action truing fixture to see what I'm talking about. If you already knew that sorry, but didn't want you to think that just any machinist could rethread an action. If not indicated straight you could end up with a barrel not pointing straight with the action.
Nah, this isn't my machinists first rodeo. He has been around the block a time or two. He is a loooong time competitive shooter and has built many rifles.
Re: Converting small shank receiver to large
No prob. I'm with you finding one already a large shank. I tried that myself but lost out on a bid on one online so just decided to have mine done. It was basically a package deal in that he not only converted the shank size but blueprinted the whole action too so for the price paid it was a pretty good deal. Back to the heat treatment thing, when a smith blueprints an action, they re-cut the threads then too which enlarges them some and I've never heard anyone complain about that ruining the heat treatment. Although it's not completely going to the large shank size, they are larger after that and it's probably not that much of a difference vs. cutting to the large shank. Good luck with your build whenever you find another action.
