Do I need to have a washer between the barrel and the barrel extension? Yep its dumb question yo some people but not to knuckle head like me.
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Do I need to have a washer between the barrel and the barrel extension? Yep its dumb question yo some people but not to knuckle head like me.
Interesting question! I have never removed the extension.
Normally you would use the "washer" or shims to clock the handguard and help it line up while tightening it to the correct torque value. In answer to your question, maybe not. I have built a few uppers that they (shims) were not needed.
My understanding is there is no washer. The extension is torqued to the barrel and then the gas port and alignment pin are drilled to top dead center.
It would be difficult to replace a barrel extension and have the gas port and alignment pin in proper orientation.
Most barrel extensions come already on the barrel, for ARs anyway.
What is the torque value for a barrel extension. If you had the tools and talent to install a barrel extension drilling a gas port would like be pretty simple. But why?
No, a washer or shim will change your headspace and indexing and should normally never be used or needed. Could out of spec assemblies be fixed using a shim? Yes, but that is for out of spec assemblies.Quote:
Originally Posted by 10mm Witness
They do make shims that go between the barrel extension and the upper receiver.
https://news.aroutfitting.com/2018/0...G%20Pro%20rail.Quote:
Originally Posted by gumbo333
A barrel nut is very different from an extension. The AR15 extension is torqued to 150 foot pounds.
You are correct. I am multitasking today (not very well) with a septic pump issues and snow removal issues. I posted specs for the barrel nut not the extension. Thanks for posting the correct specs.Quote:
Originally Posted by imashooter2
Shims are used to clock the gas tube to the nut hole. Most new barrel nuts don't have the notches/holes so shims not needed.
I am speaking about the extension not the barrel nut. They are 2 different parts doing different jobs.
Shouldn't be any shims for extension unless somebody screwed up. No reason for any!! The alignment pin is for the feed ramp alignment - the barrel itself has NO alignment. If installing a barrel into an extension that has the hole pre-drilled, the pin has NO reason to go into the barrel.