How can I fix my AR...?

[Hokkmike]

M-9 bayonet won't fit properly on my AR. Barrel is too long and the knife blade only extends partially past the muzzle. While the bayonet snaps into place OK the ring on it is several inches down the barrel and rattles around.

Seller of the gun says that to shorten the barrel would be to make the gun illegal. I WON'T do that.

What DO I DO?

 

[CapnMac]

You can use one of these: https://www.apgdefense.com/product-page/bayonet-lug-extender

Although many use something like this, instead: https://cogburnarsenal.com/product/two-part-clamp-on-bayonet-lug/


There are other options, but these are the two common ones.

 

[jmr40]

Sounds like you have a carbine upper. Bayonette won't work with that. You need a mid-length upper. I suppose you could clamp something to the barrel, but I'd rather do without the bayonette than that.

 

[gotboostvr]

Sounds like a 16" barrel with carbine length gas system.

You could rebarrel to a 16" mid length gas system barrel, or have the current barrel cut to 14.5" and have a extra long flash hider pinned and welded on.

Or one of those clamp on devices.

 

[N555]

You fix it with a midlength upper.
There's no reason, at all to have a carbine gas system on a 16 inch barrel.

 

[gotboostvr]

To expand on the subject:

The carbine length gas system was really optimized for the 14.5" barreled M4's and similar rifles.

It works OK on 16" barrels and was the defacto gas length for 16" barrels for years. The mid-length gas system was optimized for the popular 16" barrels a fair bit later. Unfortunately, some manufacturers still produce carbine gas, 16" barreled guns. Dunno why, there's no measurable advantage to that set up.

 

[NIGHTLORD40K]

It wont fix the length problem, but they sell sleeves that go over the muzzle and tighten against the flash hider- this will fix the loose/rattle issue. Looks like this when done-

 

[Hokkmike]

I DO appreciate all of your replies. Learned much here.....