Crush Washer Thickness?

[woojos]

I decided to try a brake on my AR but the crush washer that came with it doesn't look like it is going to work. It's a 3 port brake and when I tighten it down until where the brake contacts the washer, it's about a 1/4 turn past where it needs to be. I played with it and it doesn't look like any safe amount of force will rotate it all the way back around to time correctly.

I'm thinking I need to order a thicker or thinner washer? Is there a smart way to go about figuring out what dimension to order and any suggestions on where to pick it up from?

 

[AvsFan]

I decided to try a brake on my AR but the crush washer that came with it doesn't look like it is going to work. It's a 3 port brake and when I tighten it down until where the brake contacts the washer, it's about a 1/4 turn past where it needs to be. I played with it and it doesn't look like any safe amount of force will rotate it all the way back around to time correctly.

I'm thinking I need to order a thicker or thinner washer? Is there a smart way to go about figuring out what dimension to order and any suggestions on where to pick it up from?

I've ran into this problem - there's an easy solution. If you have a set of knife sharpening stones, simply stone w/cutting oil the side of the crush washer that faces the barrel (not the side touching your muzzle device). A few strokes and check frequently...a little stoning go's a long way. Get it to where you need between 1/2 - 1/4 from TDC for timing your muzzle device.

You will be able to correctly crush the washer from there. Right now you need 3/4 of a turn to crush all the way to TDC...which is feasible (sometimes). However, that's a lot of unnecessary torque on your barrel. I personally go somewhere between 1/2 - 1/4 turn which is around 3/8 from TDC.

Cheers!

AvsFan

 

[Ballista One]

I decided to try a brake on my AR but the crush washer that came with it doesn't look like it is going to work. It's a 3 port brake and when I tighten it down until where the brake contacts the washer, it's about a 1/4 turn past where it needs to be. I played with it and it doesn't look like any safe amount of force will rotate it all the way back around to time correctly.

I'm thinking I need to order a thicker or thinner washer? Is there a smart way to go about figuring out what dimension to order and any suggestions on where to pick it up from?

A crush washer will accommodate one full turn after the muzzle device makes contact with it. Properly fixturing the barrel is important to its successful installation. That being said, there is only one size and trying to modify one is questionable.

 

[woojos]

I'm not happy about having to torque on the barrel like that, so I'll pick up a stone and take it down a bit. Thanks guys.

 

[Tacsnipe73]

I had the same issue with a spikes dyna-comp, what AvsFan said is true, you just sand/file/stone the washer until it's a 1/2 - 1/4 turn from desired timing position.

Good Luck.

 

[Ballista One]

I'm not happy about having to torque on the barrel like that, so I'll pick up a stone and take it down a bit. Thanks guys.

Wouldn't a peel-away shim or shim set be a better option than purchasing the wrong tool to remove material from a crush washer? It's going to take some elbow grease to remove 0.015 to 0.020 from your crush washer with a stone. Let us see how it works out for you...

 

[cb_tikka]

Wouldn't a peel-away shim or shim set be a better option than purchasing the wrong tool to remove material from a crush washer? It's going to take some elbow grease to remove 0.015 to 0.020 from your crush washer with a stone. Let us see how it works out for you...

+1. Peel washer is much easier.

 

[Metal Gear]

I had to get a little bit sanded off a crush washer when installing a compensator on an AR about a year ago. That approach works just fine as I have had no issues with it coming loose or anything, and have since fired well over 1k rounds through that AR. Like mentioned already though, a peel washer would work if you don't want to mess with the crush washer.

 

[GH41]

Less than 1/4 turn on a crush washer is asking for it to fall off. A full turn is no big deal with a new washer. Sounds like the OP was no barrel vise. I would only use a crush washer on a flash hider. They have no place behind a comp with a tight bore. Sanding will make it more ifffy. I like the accu-washer system.

 

[woojos]

No barrel vise, but I do have some scrap wood in the garage that I could probably adapt easily. Looked up that accu-washer system, $25 is pretty steep.

It's actually, like 1/16-1/8 past TDC, so even if I take some off, it will probably still have some room to crush at least a 1/4 turn.

 

[Tough Guy]

No barrel vise, but I do have some scrap wood in the garage that I could probably adapt easily. Looked up that accu-washer system, $25 is pretty steep.

It's actually, like 1/16-1/8 past TDC, so even if I take some off, it will probably still have some room to crush at least a 1/4 turn.

https://palmettostatearmory.com/index.php/catalogsearch/result/?q=32710

 

[woojos]

https://palmettostatearmory.com/index.php/catalogsearch/result/?q=32710

I have one of those and someone correct me if I'm wrong, but torqueing on a barrel in an upper receiver block is a bad idea as the aluminum is a lot softer than the steel barrel and you can easily ruin an upper. Good price though.

 

[GH41]

"Looked up that accu-washer system, $25 is pretty steep"

It is if you are doing only one gun. But less than the cost of two mag dumps!

 

[Ballista One]

I have one of those and someone correct me if I'm wrong, but torqueing on a barrel in an upper receiver block is a bad idea as the aluminum is a lot softer than the steel barrel and you can easily ruin an upper. Good price though.

Not likely. 7075-T6 aluminum is harder than a bulls balls. The index pin on the barrel will shear before you damage a receiver. I don't even use the block, a good machinists vise works fine.

 

[GH41]

Not likely. 7075-T6 aluminum is harder than a bulls balls. The index pin on the barrel will shear before you damage a receiver. I don't even use the block, a good machinists vise works fine.

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