Barrel installation problems ??

[Jwp2578]

This is my first time changing barrels. I've got a 10p 308 that I'm putting a 26 Shilen on. My factory barrel spun right off and I put it back on with my go nogo guages just to make sure I was doing things correct then when I tried to put the shilen on it wouldn't go more than two turns and I didn't want to mess up the threads by forcing it on. I got the calipers out and the factory was 1.05 the shilen threads at 1.053 I don't know if that makes a difference.

[drybean]

Sounds like the shilen has proud threads, lightly run a flat file over the threads

[Jwp2578]

Another thing my barrel nut went on fine with a little oil I don't know if that makes a difference

[JW]

Sounds like the shilen has proud threads, lightly run a flat file over the threads
+1
sandpaper on the top of barrel threads should do the job too
clean the threads after the filing or sanding
Jack

[Jwp2578]

I'll give it a shot thank you guys!

[Jwp2578]

I tried the sand paper to no avail but I probably went to light on it and need to do it again but my question now is whats the difference between the threads in the action and the barrel nut that the nut will go on but not the action?

[limige]

Nuts tend to be a looser fit. It can be tbe same thread with a tighter fit. Check the reciever with a flashlight for any grit or blast media. Ss action are often sandblasted and the bead can lock up a barrel in a heartbeat. I would hose it with brake cleaner and oil it and try again.

If it still wont go take your old barrel and point the muzzle opposite from the new one and try to mesh the threads so they interlock. If tbey wont interlock than the barrel is threaded wrong. Not likely but some to check.

Flattening the tops of the threads wont hurt anything. Dont be scared. You can lightly file them and take scotchbrite to clean the up. Hose with brake cleaner and oil to try again

[Szumi]

The correct way to measure is to check over wires (https://www.google.com/search?q=three+wire+method&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&channel=sb) to get the pitch diameter.

[Jwp2578]

I'll give that a try and if that doesn't work ill call shilen thank you.

[short round]

If the front scope base is on action, the screw may be protruding into threads.