trunion inside diameter romy UF

[ae13291]

hello i got a Romy UF 1969 trunion, i got my Barrel today and the barrel chamber end would just slide right into the trunion, the barrel outside diameter measuer 23.10 MM and the inside trunion measured 23.08 is my trunion oversized or is my barrel not made correctly? thank you

[bigthaiboy]

What barrel are you using?

I have pressed a mismatched 23mm barrel into a trunnion by hand before, but it was tight enough that once fitted, there was no sloppiness or wobbling. The barrel pin then held it firmly in place.

[ae13291]

its a virgin US made chrome lined barrel build to original mil spec,

[ae13291]

can anybody measure there chamber outer diameter for me? is this correct? i sent back my trunion hopefully to get one with the correct sizing if the trunion is the problem

[Z ME FLY]

So you are saying that the barrel just slides into the trunnion without any force?

[ae13291]

^^^^

thats correct man, i called Andrew at Arms of america and he told me 23mm is standard on romy barrel and that the trunion must be oversized, so i called CFS and they gave me a RMA number and i sent my trunion back and i am going to wait for another one. i just want to varify with somebody and make sure that the trunion is the problem

[motorhead]

check your trunnion THOROUGHLY for cracks!
ideally, you want a .001-.002" interference fit.

[ae13291]

^^ thanks for the tip, i will do that for sure

[SJgunguy24]

^^ thanks for the tip, i will do that for sure

Yep check for cracks, also thats not the end of the world. You could turn the barrel down a bit and use a sleeve to make up the difference. Trunnions are cheap when compared to shop time though.

[ae13291]

sleeve?? i wanted to install everything safe and not have the barrel blow up, have people used a sleeve before?

[69Mach1]

Matt Yeamans has "knurled" barrels to fit into loose trunnions before. I've seen barrels that can just slide into the trunnion but still be tight the very last few centimeters. Once the barrel pin is in it's not going anywhere.

[SJgunguy24]

sleeve?? i wanted to install everything safe and not have the barrel blow up, have people used a sleeve before?

It won't blow up and yes it's been used plenty of times. You remove a little material from the chamber area and turn a sleeve to make up the difference. You can dial that press fit in just how you like it, and it will be just as strong. When that gets pinned it's GTG.

[ae13291]

nice, did not know that. hopefully they CFS sends me back a arrow trunion like the one i had. Tom, the entire thing slides in and out all the way there is no part in it that gets rough, i think its still a bit loose for just the pin to hold it into place. hopefully the new trunion is better im really hoping so (ok good night guys, im off to bed)

[69Mach1]

You really should have let me check that trunnion on my Romy barrels. Where did you get these US virgin barrels from?

[SJgunguy24]

nice, did not know that. hopefully they CFS sends me back a arrow trunion like the one i had. Tom, the entire thing slides in and out all the way there is no part in it that gets rough, i think its still a bit loose for just the pin to hold it into place. hopefully the new trunion is better im really hoping so (ok good night guys, im off to bed)

The only real limit to what can be done is the tools avalible and the experiance of the smith. It's always good to have the best on call in case there's a problem.