internal wrenches

I haven't switched a barrel yet, but I'm getting ready to start buying the tools. My research has discovered the internal wrenches, but not much mention of them on this site. Is there a problem with this type of design? My thoughts are that you won't need to remove scope mounting bases and you won't run the risk of scratching up your action.
I'd like to hear what you guys think of them and if you have had any success in building your own. My neighbor has the welders and metal cutting tools and I have enough woodworking equipment to do the wood pads for the barrel vise--I figure a dollar saved is more bullet and powder for me!! Steve

Internal action wrench's, are not mentioned much because, using them can cause the action to twist and warp, especially on a factory installed barrel. They would be OK to use after the barrel has been broken loose. Yes you need to remove the scope mounting bases, because many times the front scope mount is bottomed out against the barrel threads and makes turning the barrel a chore.

Make / get one that fills the entire length of the bolt head raceways in the action to help prevent twisting.

Make sure none of the scope mount screws up front or the stock screw touch the barrel threads.

Don't tighten the barrel nut too tightly..........and you should be fine with an internal action wrench for changes without removing the scope / rings / base, but as noted use it only after you have broken the factory barrel free with an external action wrench.

Yeah, I can't recommend a rear entry wrench for factory installs., but after that it isn't a problem. With an opened ended spanner ( nut wrench) you can leave the scope in place.
http://i42.tinypic.com/2hz7sli.jpg

http://i40.tinypic.com/20iwen6.jpg

As far as the mount screw getting into the barrel threads (or lug recess) ....you supposed to check the lengths BEFORE installing them.

Bill

I'd spend my efforts on a good barrel vise. If you have a good vise and a barrel nut wrench, there is no need for an action wrench.

I made an internal action wrench and used it exactly once, it now hangs in the shop as a dust collector. It worked fine, I just prefer a clamp on wrench and and barrel nut wrench since I don't use a barrel vise. I use the Wheeler action wrench and a Mcree Precision barrel nut wrench.

Bob

Question, How would you twist the action if you used a internal action wrench like the one in BillPa's picture? I can see how a Wheeler action wrench or one that clamps on the action rails could cause a twisted action.

I prefer a barrel vise and wood blocks with a barrel nut wrench and a big hammer. Has anybody bent a barrel using this method? I fabricate my own barrel blocks and fit them as close to the action as possible.

Bill