Barrel shim orientation

[JCSC]

If required to shim for barrel nut orientation or hand guard, is the preference to slit the round shim and insert between the upper receiver face and barrel extension or.... slide it on the barrel prior to nut installation.

The only time I did this, I used the latter method. I put some grease on the shim and tightened up to spec.

[Kswhitetails]

If it were me, I'd bed the barrel, and place the shims on the outside of the shoulder of the extension. If at all possible, I would stray from this type of union. I've never liked shims in this circumstance, though thousands of fellow builders have used them to great effect. Good luck.

[JCSC]

Thanks. I felt they should not be between the upper and barrel, although I saw it done on YouTube.

[FRB6.5]

Placing shims between the receiver and extension has the potential to change headspace. The proper location is between the extension and barrel nut.

[ARErector]

I have always put them between the barrel and nut. I would think that messing with spacing between the barrel and upper is a bad idea. Until now I'd never even considered it would be done that way.

I do like the handguards that don't use them. They are much simpler to put together.

[JCSC]

Placing shims between the receiver and extension has the potential to change headspace. The proper location is between the extension and barrel nut.

I thought this may change headspace, but I didn?t want to bother asking the question. I saw some folks build it up this way on line.

Proves you can?t always trust what you see.

[FRB6.5]

I thought this may change headspace, but I didn?t want to bother asking the question. I saw some folks build it up this way on line.

Proves you can?t always trust what you see.

If you noticed one of the more easy to find youtube videos showing that method has comments disabled.

[Mad Charlie]

I don't cut shims, for AR barrel nuts or M1a gas cylinders.

[A5BLASTER]

I think I would find a diffrent handguard to use that didn't need shims to time the barrel nut and gas tube.

[Lastrites]

Sometimes just using a different barrel nut resolves the issue.

[LRRPF52]

If required to shim for barrel nut orientation or hand guard, is the preference to slit the round shim and insert between the upper receiver face and barrel extension or.... slide it on the barrel prior to nut installation.

The only time I did this, I used the latter method. I put some grease on the shim and tightened up to spec.

If you're talking about flat shims that come with some of the handguards out there, you install the barrel into the upper, then slide the shim over the barrel up against the face of the barrel extension flange. Then the barrel nut goes on and torques against the shim.

[Mad Charlie]

Thanks. I felt they should not be between the upper and barrel, although I saw it done on YouTube.

There is a shi% ton of misinformation on you tube, I always try to cross reference anything I look up on you tube.