Pressed in barrel

[Flashpoint]

What is involved with replacing a rifle barrel that is "pressed in"? Example SU-16, AR-180, etc. Are these basically throw away guns when the barrel is shot out, or is this something a gunsmith could do? I guess even if they could, where would you get a barrel with the correct machining on the receiver end besides the original manufacturer?

 

[Scsmith42]

My MP5 has a pressed in barrel. Replacement involved cooling the new barrel down to sub zero temps with liquid nitrogen (which shrinks the metal so that it can be pushed into place instead of pressed) and the dropping it into place before it heated and expanded.

The biggest challenge is to get it in place before it expands, and to hit the headspace target while you’re doing so.

 

[Flashpoint]

My MP5 has a pressed in barrel. Replacement involved cooling the new barrel down to sub zero temps with liquid nitrogen (which shrinks the metal so that it can be pushed into place instead of pressed) and the dropping it into place before it heated and expanded.

The biggest challenge is to get it in place before it expands, and to hit the headspace target while you’re doing so.

I guess removing the old one involved heating the receiver?

Were MP5 aftermarket barrels available or was the manufacturer pursuaded to sell you one?

 

[dalek]

Have you checked apex gunparts? They might have them

 

[Scsmith42]

I guess removing the old one involved heating the receiver?

Were MP5 aftermarket barrels available or was the manufacturer pursuaded to sell you one?

The original barrel was pressed out w/o heat. My replacement barrel was a factory HK SD barrel. Curtis Higgins, owner of S&H Arms in Oklahoma, had obtained it and was the gunsmith that installed it. He did excellent work.

 

[Short Fuse]

They are all replaceable like Scsmith42 said. Depending on which firearm it is there will be different procedures but most pressed in barrels are either friction fit or friction fit with a pin retaining them for good measure. Pin removal if it has one is always the first step, then some they are put in a fixture in a press and pulled apart some with heat some without depends on the gun. If they are heated it is not by very much only enough to get the reciever to expand slightly but not enough to effect the tempering of the metal. Installation is usually again depending on the firearm in question either a cooling of the barrel or a combination or cooling the barrel and heating the reciever some will just drop in while others will have to be tapped or pressed in during this and then if it is supposed to be pinned or not have the pin replaced. Some are headspaced during this procedure and some after. Hope this helps, if you have any further more specific questions them pm me and I will try and answer them for you.