Question barrel lugs

[rmatt]

I started building a rifle using a Colerain C weight barrel in 58 cal, 42 in length. My concern is cutting dovetails for the barrel lugs.  Measurements are 1.125 breech,.812 waist and .875 muzzle. Bore is .575, groove is .012 to .016. Not leaving much wall thickness. Any idea what would be safe. I do not have the resources to silver solder.
Thanks

[bob in the woods]

On occasion, I will solder the lug on the barrel at the "waist" in order to not have to cut a dovetail.  Usually on A weight .40 cal barrels.  Also solder the lugs on oct to round barrels.  I've never, ever used silver solder. Regular lead/tin solder is easy to use, and plenty strong enough.   That said, if you lay out your lugs on the barrel, you can avoid the narrowest portion , but shallow dovetails work well enough.

[Dennis Glazener]

I don't think I would cut ANY dovetails, soft solder all lugs in place.
Dennis

[smart dog]

Hi Bob,
I think you have those last two measurements reversed unless yours is a tapered barrel rather than swamped.  I built quite a few 58 cal guns with C weight swamped barrels and you should not have any problems cutting dovetails. Dovetails do not need to be deep. A sixteenth of an inch works fine and you have plenty of extra metal. If you are nervous just avoid putting a lug at the waist.  Also avoid locating your sights where there is a dovetail.  No need to solder anything.

dave

[SingleMalt]

I agree with Smart Dog.  A "C" weight has plenty of "meat" for dovetails.

[Dennis Glazener]

I do too after recalculating. When I did it earlier I had a little less than .100 wall thickness before cutting the dovetail. Not sure where I made the error but here is what I just calculated for the mid-lug. I normally cut my dove tails .035 to .040" deep and that would allow plenty of wall thickness under the mid-lug on your barrel. Less at the muzzle but most of the pressure is gone by then.

.975 - .575 = .400 divided by 2 = .200 wall thickness before rifled
.200 - .016 = .184 thickness over groove

.184 - .062 (I use .040 max depth) = .122 wall thickness under lug that is directly over a .016 deep groove
Dennis

[yip]

  0.50 is good

[rmatt]

Hi Bob,
I think you have those last two measurements reversed unless yours is a tapered barrel rather than swamped.  I built quite a few 58 cal guns with C weight swamped barrels and you should not have any problems cutting dovetails. Dovetails do not need to be deep. A sixteenth of an inch works fine and you have plenty of extra metal. If you are nervous just avoid putting a lug at the waist.  Also avoid locating your sights where there is a dovetail.  No need to solder anything.

dave

Waist should have been .812

[smart dog]

Hi Bob,
Doesn't change my answer.  Been there and done this several times.  Just don't get carried away with the hack saw. You mentioned you don't have resources for silver soldering?  You don't need high temp silver solder. Plumber's solder will work fine and better a low-temp silver bearing solder like Hi-Force 44.  You just need a propane torch to melt those.

dave

[davec2]

I used to dovetail the lugs in about 0.050" to 0.060" deep.  Then I did a test and made a dovetail in a scrap piece of barrel 0.025" deep.  I did this on a mill so I knew exactly how deep the dovetail was.  And then I tried to pull the lug out of the dovetail with a piece of maple with a channel cut in it and cross pinned with a 1/16 inch diameter pin (just like the stock would be held to the barrel).  On three tries, the pin bent or the wood gave way.  The lug never came loose.  So, since the purpose of the lug is to hold the very thin wood of the forearm to the barrel (not the other way around), I only dovetail to a maximum of 0.030 inches.  Sometimes I soft solder them as well.....no reason to.....they just clean up a little nicer and I don't have to worry about getting a tight, driving fit.

[David Rase]

I usually shoot for a dove tail depth of .030".  Never had a problem.
David

[rmatt]

Thanks guys. Just wanted to be sure before t I cut too deep.