Tightening a barrel
 

I just got a Navy barrel for a project I'm working on, so I read postino's excellent tutorial to prepare myself for the installation. One thing that worries me a bit is that the barrel can't be hand tightened to the 1/8 turn described as "just right" in the tutorial. There's a little less than a 1/4 turn left, so do I need to trim the flange or just lean on the wrench and use my extensive vocabulary?

I don't think it would be too difficult to trim it, but from what I gather, the flange surface on these barrels should be slightly tapered to give it some "crunch". Does anybody know how many degrees of taper it needs?

People actually read that??? :eek:

You could lap it in...I've used Rubbing Compound, or Polishing Compound (one is coarser than the other) to lap a barrel in that was 'almost' right...Clean dry threads, put the compound on, tighten & loosen a couple times, take it apart, clean it, put a dab of grease on the threads, and see how close it comes then...repeat as needed... :thumbup:

But that's just my way...there's lots of ways...even some right ways... :D

Well, I did look at the pictures. :D

That sounds way easier than turning it! I think I'll try and tighten it a bit with the wrench first, the surface still has some machine marks so they'll probably give me a few degrees as well. Thanks for the tip, I have that nagging feeling that I'll take off too much if I turn it... :eek:

Exactly so! :thumbup:

The Rubbing Compound is coarser than the Polishing Compound...And if you really want to remove metal, Valve Grinding Compound takes off a lot of metal in a hurry (use with caution...I wouldn't use it here)... :)

I have some different grit compounds I use for lapping scope rings, and if the going gets tough there's some valve lapping compound back in a drawer... That, a few beers and a large pipe wrench should do it! :D

If not try a larger wrench and more beers!

I think we can all agree that the proper tools are essential for any aspiring gunsmith... :thumbup:

Just keep in mind the old adage;

"A gunsmith's best friend is a home gunsmith"

That's probably the reason why I was able to buy this project gun for $300. It looked like the home gunsmith actually did use the BFH to take it apart... :rolleyes:

:cheers:I like the 2nd one from the right!!!! That is George Fortier's favorite gunsmithing tool!!!!:roflmao:

Hugh..I have to disagree..George wouldn't use a BRASS hammer! Or one that small...

:thumbsup::cheers::thumbup::roflmao:

Did you tried frozen state installation? It may give you just enough what is needed to time it right.
After barrel expands again it will be solidly married especially if you use proper bounding agent.
Try only barrel not slide. Liquid Nitrogen is your best friend.

terminology....sp.???
 

Hi Guys, we need to get on the same page on one item of barrel installation... 1/8 of a turn... by degrees, is considerably different the 1/8" inch of rotation on the circumference.... if the edge of the extractor relief of the barrel is close to the extractor relief on the receiver... just prior to lining up, (just visible)... it's going to get tight fast!!! If it is 1/8 of a turn of a rotation, or more, it is going to be too tight!!!!!... or at least close to the end of what ever crush rate is figured in the flange undercut... tough to hold everything when it gets to that point... best to all, til...lat'r....GT:cheers:

Ok, now I'm getting confused.... So if I can hand tighten it until I'm 1/8 turn from 12 o'clock I'll be alright, and I can do the rest with the wrench? Or how does the 1/8" come into play? It's Saturday evening and I have had a few glasses of wine, so please explain in simple terms. :p

last 1/4" ....
 

Hi to all, Rich has certainly been there and done that...:thumbup: with excellent success I might add... He knows that last 1/4" inch can seem like a mile when you can't hold things tight enough!! ...:eek:... I'm still learning, and it's great to have other forum members to bounce ideas and thoughts off of!.....:cheers:... best to all, til...lat'r...GT

I have been trying to figure out how this would affect the installation. Seems like freezing the barrel would actually defeat the purpose, as it will reduce the distance from the shoulder to the thread, and it may also affect the pitch of the screw. I know that freezing works great on press fitted parts, but I'm still not sure how it would work on threaded parts. Have you tried this method?

Olle, dont forget to check the headspace when your done. If you dont have a gauge, you can always turn out a gauge on your lathe.
John

John,

I was planning to buy the gauges, quite honestly I didn't even think about making my own. I'll look into that. :thumbup:

anti seize...
 

Hi Rick, great tutorial! I've not used the anti-seize, but will start... I'm thinking about making a hardened receiver thread fixture, and a hardened barrel thread, with the class fit you mentioned... just for a benchmark when checking out parts for compatibility... :thumbup:,... again, great thread! best to you Rick, til...lat'r....GT:cheers: