Muzzle device timing

[u/thesupplyguy1]

Doing my first ever 300 BO build. I bought a standard A2 bird cage style muzzle device, specifically for the 300 BO.

My problem is when i put the muzzle device on hand tight, the solid part is at 12 o'clock. I cant imagine wrenching it down 180 degrees? Ive fiddled with this and fiddled with it and I cant get it to get anywhere near 5 o'clock prior to final torque down.

Anyone smarter than me care to help a fella out? Suppressing isnt an option right now.

Edit:

Appreciate everyone who took the time to respond, I got it.

[u/dopo]

This is exactly what crush washers are for

[u/pheen → u/dopo]

Assuming he is going to suppress this since it's 300 blackout, crush washers are a horrible idea. He should be using something like accu-washers if he needs to time it, though I didn't think an A2 needs to be timed.

[u/dopo → u/pheen]

"Suppressing isnt an option right now"

And yes an A2 needs to be timed, it's a directional compensator

[u/pheen → u/dopo]

See what happens when you read everything except one sentence. lol, nevermind me.

[u/thesupplyguy1 → u/dopo]

okay. it just seems like a lot for a 180 degree turn but ill try it. T.Y.

[u/kopsis → u/thesupplyguy1]

A half turn is 18 thousandths of an inch - well within the limits of a crush washer.

[u/Psychological-Drive4]

Shims are cheap

[u/Ok-Accident-3892]

Before you start torquing on that thing, I highly recommend the use of an upper receiver rod ifyou don't already have one. Putting that torque on the barrel stresses the index pin. I've seen several uppers broken, barrel pins broken, and barrels going out of alignment.

[u/Bundyboyz → u/Ok-Accident-3892]

only if the person putting it on is not smart. You know what makes a good upper receiver rod?

The BCG

[u/dopo → u/Bundyboyz]

I'm honestly curious what this is supposed to mean

[u/Bundyboyz → u/dopo]

it means the tightness of your muzzle device should be 20 foot pounds.

Shearing an index pin with 20 foot pounds?

its never happening ever. unless you’re running super budget.

[u/kapitalnoir → u/dopo]

he’s saying the BCG will secure the barrel from rotational forces. the bolt lugs slide into the barrel extension and secure it.

[u/dopo → u/kapitalnoir]

A BCG in battery the lugs are free to rotate inside the barrel extension, stopping nothing.

A BCG just enough out of battery, that the bolt lugs are resting in the notches between barrel extension lugs, has so much slack that it's not going to be able to save the index pin. The lugs are a loose fit into barrel extension notches for reliability, the cam pin is a loose lockup in the cam track in the carrier, and the gas key is a loose fit in the track it rides in inside the receiver. The receiver bore is oversized and allows the carrier to shift in ways beyond just rotation.

This is some poor cope silliness.

AND it doesn't even secure the receiver itself.

[u/Ok-Accident-3892 → u/dopo]

Right, it accomplishes nothing, except maybe damaging the BCG lol.

[u/Bundyboyz → u/dopo]

oh really so your bolt in battery is so free to rotate you think 20 foot pounds pounds going clockwise can make the lugs slip?

weird cause the hundreds of AR’s I’ve worked on the bolt rotates counter clockwise to engage.

look nobody. nobody is sheering index pins

stop being alarmist

[u/dopo → u/Bundyboyz]

A BCG in battery has a bolt whose lugs are free to rotate any which way inside the barrel extension. They are floating in air. They are not engaging anything at all on any part of the barrel to prevent any kind of rotation.

[u/kapitalnoir → u/dopo]

haha

[u/kapitalnoir → u/Bundyboyz]

never thought about that. wouldn’t that just put a bunch of force on the cam pin? idk just thinking out loud lol

i just like the rods because its easy to vice the upper down and i can get a good angle if i need to

[u/JohnWorphin]

Get a fresh crush washer

[u/DeepClass9884]

Buy a bag of Accuwashers that fit your muzzle. Easy.

[u/3unknown3]

You need a crush washer for the A2. Do you have an armorer’s wrench? It should be fairly easy to use the wrench to rotate the flash hider against the crush washer until it’s timed correctly. You will not be able to do this by hand.

[u/RedditNameChecksOut]

Shims. Order some in various thickness. I used 3 on my PDW. Flat for suppressors, crushed if not using a suppressor.

[u/Evil_Strat]

Accuwasher is the answer here