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Discussion Starter #1 (Edited)
My project 336 is going along nicely. I am now planning to re-stock using wood from Treebone carving. George at Treebone noted that a cap-type fore end would probably make the rifle group better as it heats up but is unsure about the safety of cutting the barrel dovetail into a barrel that has been thinned out by re-boring from .30-30 to .38-55.

Has anyone tried this? How deep must the dovetail be? Unfortunately, the tenon is on back order now so I can't get one to measure. What about re-shaping the tenon and brazing it to the barrel?

Thanks in advance for the input.

Sig
 

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Dovetail slots are cut into barrels all the time. for sights, hangers. you should be fine.
brazing would create a whole other set of issues with heat distortion and tempering. I would stay away from that. soldering may be OK.
you then have bluing or barrel finish to consider.
Good Luck and have Fun!
 

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Someone here will come along with a solid answer I 'm sure , I have to admit it would make me nervous on a thinned barrel. Mic the OD of the barrel at cut location, subtract the bore ID, divide the result by 2, subtract the depth of a dovetail cut, that will give you remaining barrel thickness under the cut area. Maybe some custom work using the top half of a rear band welded and blended to the forend cap?
 

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Discussion Starter #4
Thanks!

Dovetail slots are cut into barrels all the time. for sights, hangers. you should be fine.
brazing would create a whole other set of issues with heat distortion and tempering. I would stay away from that. soldering may be OK.
you then have bluing or barrel finish to consider.
Good Luck and have Fun!
Sounds fine, but I can't find the tenon to measure how deep the matching dovetail would need to be cut. Anybody out there know?

I know there are some exotic brazing processes out there that should be cool enough to make this work but I agree that the finish may suffer, which I don't want.
 

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Discussion Starter #5
Thanks for the input.

Unfortunately, although the wall thickness is fairly easy to calculate, the depth of cut required isn't known because I don't have the tenon to measure and Midway is sold out and Brownell's doesn't even list it. I went to the new Marlin site but can't see any way to contact their parts department...I guess I'll have to call.

The search continues.

Someone here will come along with a solid answer I 'm sure , I have to admit it would make me nervous on a thinned barrel. Mic the OD of the barrel at cut location, subtract the bore ID, divide the result by 2, subtract the depth of a dovetail cut, that will give you remaining barrel thickness under the cut area. Maybe some custom work using the top half of a rear band welded and blended to the forend cap?
 

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Do you have access to another Marlin, they all use the same tenon. A I understand it, to contain the pressure, at least 1/10th inch of metal should be between the bottom center of the cut and the interior of the barrel.
 

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Discussion Starter #8
Sounds reasonable.

I don't have access to another Marlin except other 2-band guns...no cap-type fore ends in my neighborhood.

The good news is that I found the tenon on line and, making an eyeball judgement, it appears to be workable. I'll know when I get the tenon in my hands.

Regarding pressure resistance, I believe that it would depend on how close to the chamber the cut occurred. Obviously, the pressure diminishes the further the bullet travels up the barrel. One tenth of a inch is probably a good benchmark. Nearer the chamber, I'm sure that you'll agree that most barrels a much thicker.

Do you have access to another Marlin, they all use the same tenon. A I understand it, to contain the pressure, at least 1/10th inch of metal should be between the bottom center of the cut and the interior of the barrel.
 

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My 375 Winchester Marlin has the short mag tube hung the way your talking about. There are no issues with them. Pretty sure the barrels are the same diameter as the 35 and 30 cal. barrels. DP
 
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Discussion Starter #10
Thanks for the tip. It sounds like it should work but I won't know for sure until I have all the parts at hand. I'll post my findings once that happens.

Sig



My 375 Winchester Marlin has the short mag tube hung the way your talking about. There are no issues with them. Pretty sure the barrels are the same diameter as the 35 and 30 cal. barrels. DP
 

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When I had JES punch our my 30-30 to 356 he said that he didn't recommend the band type rifles in favor of the cap type rifles for heavy recoiling rifles, as stated all of the heavy recoiling rifles have caps, they cant be that weak?
 

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What you need is to have several people who own 375's or 38 - 55 ' s to measure their outside barrel diameter at the dovetail. If you have the same outside diameter, you should be fine. I just don't know if all the barrels are the same O.D.
 

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Discussion Starter #13
Got the hardware!

I just received the end cap, tenon and screws from Brownell's. The tenon was much smaller than I had envisioned and I have no doubt that a dovetail cut to fit it will not compromise the strength of the barrel. Now I just need to wait for Tree Bone to carve and ship the stocks so I can pin point just where the dovetail needs to be cut.

Thanks to all those who have contributed their thoughts and ideas to this thread.

Sig
 

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Discussion Starter #14
Making progress, still need some help

Guys-

Again, thanks to all who have contributed. Here's what I've learned so far. The tenon dovetail measures .362 and has a 60-degree angle. Both Brownell's and Midway list cutters in the .359 to .360 range. One site suggess roughing in the cut with a quarter-inch end mill, finishing with the cutter mentioned above and then final filing with a "safe" triangular file to clean up the last .002" to .003" or so. Since a three-eights works out to .375", I would consider using that cutter and setting the too-small dovetail with epoxy or Loctite but that would be a last resort.

At this point, I took the parts to my local hobby machinists and both are reluctant to start carving on a valuable rifle barrel. I offered to buy them the dovetail cutter but that wasn't enough incentive to make them take the chance, even when I relayed George's (from Treebone) note that if the cut were a little too far toward the receiver, the fore end could easily be trimmed co compensate. Too close to the muzzle is another animal altogether.

SO...do any members here know of a reliable machinist who can do this work, preferably in the Mid-Atlantic region?

Thanks again, Guys,

Sig
 

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My 375 barrel diameter on either side if the dovetail cut is .683 and .681 so lets call it .682 at the center of the dovetail. Checking from dovetail bottom it checks .591. Making the
dovetail cut .091 deep leaving .062 wall to the bore. Of course the 35 would be .0085 thousands thicker at .0705. My hanger that goes into the slot is not tight like a sight, but slips through pretty easily.

The issue I am having right now is the boyd's laminated stock set I got the forearm is about 3/16 " to short, Must call boyds's.
 

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Discussion Starter #16
Thank you

Thanks, ksutley-

I'm afraid I couldn't quite follow your geometry. My rifle is a .38-55 now, having been rebored from a .30-30. I'm no longer all that concerned about the depth of the cut. Mainly, I'm trying to find somebody in my part of the country (Central Maryland/PA/VA/DE) that can do the machine work. Did you do your own?
If so, do you want to do another one?

Re: Boyd's stocks; I'm surprised. The few that I've used over the years have fit pretty well.

Thanks again,

Sig

My 375 barrel diameter on either side if the dovetail cut is .683 and .681 so lets call it .682 at the center of the dovetail. Checking from dovetail bottom it checks .591. Making the
dovetail cut .091 deep leaving .062 wall to the bore. Of course the 35 would be .0085 thousands thicker at .0705. My hanger that goes into the slot is not tight like a sight, but slips through pretty easily.

The issue I am having right now is the boyd's laminated stock set I got the forearm is about 3/16 " to short, Must call boyds's.
 

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Just for an added observation the tenon on my newly purchased 1983 444S with the end cap is also free to move in the dovetail with vey little pressure. I noticed it and thought that maybe it is meant to be slightly free floating rather than solid.
 
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Discussion Starter #18
Thank you

Thanks, Billy Jack-

I agree that there's no visible benefit from having the hanger tenon super tight in the dovetail cut. Once the cap is screwed to the hanger, there's nowhere for it to go.

I've had miserable results over the years trying to drift dovetailed sights with any degree of precision. Once I find someone to cut the dovetail, I plan on making it a slip fit with the hanger tenon and just putting a drop of blue Loctite (no cleaner/primer) in the joint before final assembly.

Sig
 

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I would suggest you not use the loctite. Apparently slip fit is good. I just took my G 30 apart and the tenion was not anywhere near as tightly inserted as a sight.
 
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Discussion Starter #20
Thanks!

I would suggest you not use the loctite. Apparently slip fit is good. I just took my G 30 apart and the tenion was not anywhere near as tightly inserted as a sight.
Thanks, Papabear-

I suppose that's true.
After all, all (most) of the force is front-to-back, not side-to-side. Very little of the firing energy is trying to slide the tenon sideways.

Now if I can just find someone to cut the dovetail!

Sig
 
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