Switch barrel gun building

[mtbugle]

I have a winchester 70 that was originally a 7stw. now has a 30-338 barrel on it. I am thinking of making it a switch barrel gun. I notice that lots of bench rest shooters do this with there rifles with the barrels are only hand tightened on so can switch to other barrel with minimum of torque required to take barrel off. If I have the barrels squared sufficiently to action that they are solid when hand tight what would prevent from having this system on my winchester? thinking using a spaner wrench in front sight holes therefore have enough wrench to losen. The righthand twist in rifling will tend to keep barrel tight when shooting. Hoping you more experienced gun tinkering types have some insight to let me know if this is a half baked idea, doable, or possible dangers involved.
Thanks Don.

[gunnut69]

That would work just fine but you can't relie on the barrel/receiver friction to keep the barrel snug.  A simple spring loaded tenon should do the job just fine and be easy to make. It worked for the M99 Savages at least in the last varient. Splitting the stok and putting a front half on easch barrel would make a change easier.

[Nobade]

When I make a switch barrel bolt gun for a customer I usually supply with it a Wheeler (Midway) barrel vise with oak inserts bored to fit the barrel just in front of the forearm, and a side or rear entry action wrench. If it is a sporter you need to remove the stock since the barrel won't clear the inletting. If a bench style stock with a straight barrel channel you can leave the stock on. Clamp the vise to a table with C clamps and have at it. Cheap and works well.

[alan in ga]

When I make a switch barrel bolt gun for a customer I usually supply with it a Wheeler (Midway) barrel vise with oak inserts bored to fit the barrel just in front of the forearm, and a side or rear entry action wrench. If it is a sporter you need to remove the stock since the barrel won't clear the inletting. If a bench style stock with a straight barrel channel you can leave the stock on. Clamp the vise to a table with C clamps and have at it. Cheap and works well.

Great vise and same brand of action wrench is a good one, too. I never have any problems with barrels loosening when hand tightened but I always 'check' them! Probably the best way is to put 20 to 30 lbs of torque [not much] on a barrel when installing. I inletted a sporter stock to an open forend barrel channel so stock removal was not necessary. Some may not like the look of a large gap there though!

[gunnut69]

Nobade method is good but he asked about hand tight and wrenches are not hand tight.. While is doesn't take a tremendous amount of torque to hold a barrel still it does require a wrench. Thus a mechanism to avoid loosening is needed.. The M99 Savage allowed the use of the forearm to loosen the barrel from it's initial position.. The first varient used an interupted thread and they quickly shot loose, especially in higher prssure rounds.. What to do with the fore stock is the real buggabo.. Carbon fiber (ala carbon cannon) tube form sporter??

[mtbugle]

It is the heavy stock from factory, Channel is quite large. So sounds like may need to tighten more than what use a small spanner wrench for. But sounds like rest of idea recieves favorable marks. I believe I will work soon on getting the stw barrel back on and evaluate from there if I want to try a 338 RUM or 338 edge.  Thanks for the input guys and please if there is any more advise/ideas lets hear them.
Thanks Don.

[gunnut69]

I would suggest a witness mark on the barrels and the receiver. A simple line cut with a small chisel and hammer. This will give the same torque each time a barrel is installed..at least it'll be close.

[alan in ga]

Hand tight has been as accurate as I could ever expect. I put the butt stock between my legs, grap the barrel with both hands and don't even strain when 'tightening' a barrel to a Ruger 77 Mark II action. Thread shank on a Shilen barrel in .250 Savage Ackley Improved was cut precisely to a fit that just does screw without interferance. Shoots in the .3's which is as good as I can shoot with my 'limited' bench rest techniques. The barrel is right hand rifling and shooting it 20 or more rounds seems to make it just a 'tad' tighter but never more loose. I can tell that it takes more effort to loosen than it did to tighten. I've hand tightened it, then after a minute loosened it [a basis for effort needed for removal without shooting]. Then I shoot it and loosen the barrel, definatly a micro effort more to loosen after shooting. I guess if you had a left hand riflled barrel it would shoot 'loose'.
The safest way is to use a wrench to put a few more ft/lbs of torque when installing, and then same wrench/vise is used for removal.
After years of switch barrel fun, I decided I like keeping a barrel on an action for a good while and  not need to resight it so often. It's not a good feeling to have rifles sitting around that "need a sight check group' before being able to use them. Keep them sighted in and 'ready to go' [hunting].

[mtbugle]

alan. it sounds like you have the experience in what I am thinking. When you remount a barrel do they maintain 0. I mean if I have set scope settings would the same barrel generaly reset to the same scope settings, or at least hunting close? Simular idea to the scopes that have 3 different collored 0 readings for different barrels. Think I saw something like that for the blaser switch barrel rifles.
Thanks Don.

[alan in ga]

I removed my barrel [hand tightened] and replaced it. Groups were within 1" of 'before' groups. If you are hunting short range [under 100 yards] I would trust it.
I tend to want to always want a 'test group' though for big game. Just me. Not worth risking a wouned animal or missed shot altogether. I did not repeat the barrel removal/reinstall enough times to report a 'for sure' result. It probabl y depends on the time spent  with set up and total fitting process on the lathe, measurements taken throughout the fitting, etc. I tend to be anal about it. Want and achieve close to perfection!

[mtbugle]

Thats cool. If presets get me withing inch or two that make resight in quick and easy.
Thanks Don.

[roper]

I have a winchester 70 that was originally a 7stw. now has a 30-338 barrel on it. I am thinking of making it a switch barrel gun. I notice that lots of bench rest shooters do this with there rifles with the barrels are only hand tightened on so can switch to other barrel with minimum of torque required to take barrel off. If I have the barrels squared sufficiently to action that they are solid when hand tight what would prevent from having this system on my winchester? thinking using a spaner wrench in front sight holes therefore have enough wrench to losen. The righthand twist in rifling will tend to keep barrel tight when shooting. Hoping you more experienced gun tinkering types have some insight to let me know if this is a half baked idea, doable, or possible dangers involved.
Thanks Don.

I can only tell you how I changed barrels when I shot BR.  Most action were glued in and barrels were free floated.

For my Kelby Panda,Kodiak actions I had a wrench tha would slip in the rear of the action and I had a barrel vise and be clamped to a table you clamp the barrel in and just give a little tap to loosen the barrel then screw if off by hand and install a another  barrel that way.

All the action I used bolts were coned same with barrel and for Kelby actions they kept a blue print on each action   and you could order a barrel without them having the rifle based on the serial number of that rifle.  that little tap you give it with the action wrench  lock you into the correct headspace.  You kind of develope a feel for changing barrels and I'm sure others may of done it different.  Most barrels I seen changed at a match used a barrel vise here a picture of barrel vise and wrenches
http://www.sinclairintl.com/.aspx/pid=36311/Product/Davidson_Action_Wrenches___Barrel_Vise

[mtbugle]

Apreciate the inpute Roper, and I will have to think about getting those type wrenches. Did you happen to keep track of how close to zero your barrels were when changed back on?
Thanks Don.

[roper]

Apreciate the inpute Roper, and I will have to think about getting those type wrenches. Did you happen to keep track of how close to zero your barrels were when changed back on?
Thanks Don.

Don, these were 6ppc bench rifles that with 5 shot groups shot at 5 targets in 5 relay  at 100/200yds would agg in the .2's depending on condition you could be alot higher and you get sighters at each target.    I really never kept tack but if I was to guess be maybe .0XXX".

I've never had a hunting or varmit done up as a switch barrel.   I read Nobade post and I think you need to get someone like him to set you up for a switch barrel rifle your existing barrel may be on too tight vs trying to do it on your own.    Well good luck

[Tom H.]

Getting in a bit late on this one.
Lots of great info. 
As Alan said, having threads cut to match the action matter a great deal.  The sooner the barrel has limited wobble when you are screwing it in the better. Hit the threads with anti gall compound too.
 At the very least, true out the part of the barrel that butts against the action. Face off the action in a lathe, and you will have a perfect fit between the two. In many cases you can do this by only removing a few thou.
 I know that it requires a little lathe work but it is worth it. As you can guess, too much to true it out and the chamber needs to be lengthened.
Definately go for the witness mark as well.
If you have the metal to work with, cut a flat under the chamber and use an adjustible wrench or a spanner to give it a couple extra ft lbs.

I had three trued barrels in different calibers (.225, .250imp, 308) and they all fired within 8" of each other at 100.  Go figure.

I took one M48 in .450 marlin and ran a thumb screw with a rounded profile through the left reciever.  Not horribly obtrusive and it works well keeping the barrel in place without a wrench.

Hope that helped.

Cheers
Tom