New AR build will not cycle open

Helka

Helka

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Location
Guelph,ON
Hey gang

I just finished my build and took it to the range. It cycles enough to eject the casing but not enough to stay open.

I have a BCM complete lower with BCM upper receiver and MRA match barrel and accessories.

I’m using the superlative adjustable gas block and Brownells lightweight BCG.

I have the gas block wide open so my best guess is that the H1 buffer that came with the lower is too heavy. So I’m thinking of using one of these 3 options. Would love feedback/opinions.

1) TNA standard buffer 3oz for $25
2) upgrade to MRA 3oz for $50
3) Odin Works 2.1oz to 4.2oz for $70

Any other suggestions are welcome.

Am I missing anything else? Should I have gone with a standard BCG vs lightweight?

Thanks
 
No fail to feed in a sense that I was only loading 1 at a time to see if it would cycle open. I was in a rush at the range and didn't get a chance to closely look at the brass. chance to look at the brass
 
Helka said:
No fail to feed in a sense that I was only loading 1 at a time to see if it would cycle open. I was in a rush at the range and didn't get a chance to closely look at the brass. chance to look at the brass
Click to expand...

It's either you don't have the gas block on right or your BCG is outrunning your magazine follower.
 
Make sure that your gas block isn't partially covering the gas port in the barrel. A lot of barrels require a small space between the gas block and the shoulder of the barrel. This is a pretty common problem causer.
 
Just to clarify, you said you have your superlative arms gas block "wide open".

'Wide open' would imply that you are fully venting the gas out the front hole.

All the way screwed in, the screw cuts off ~100% of the gas. As you screw/click it out, it functions like a normal adjustable gas block, increasing how much gas can pass by. But once you get a certain number of clicks out, it starts bleeding gas out the front of the block.
 
*MALICE* said:
Just to clarify, you said you have your superlative arms gas block "wide open".

'Wide open' would imply that you are fully venting the gas out the front hole.

All the way screwed in, the screw cuts off ~100% of the gas. As you screw/click it out, it functions like a normal adjustable gas block, increasing how much gas can pass by. But once you get a certain number of clicks out, it starts bleeding gas out the front of the block.
Click to expand...

I guess I need another range day to figure this out.
 
Helka said:
The barrel I bought from MRA has the gas port drilled slightly off centre so i’m thinking I didn’t have it on properly.
Click to expand...

It's possible, but usually the hole in a gas block is a decent amount larger than the gas port, so you can still be a little off and not obstruct the hole
 
Helka said:
The barrel I bought from MRA has the gas port drilled slightly off centre so i’m thinking I didn’t have it on properly.
Click to expand...

Best is to measure. Because no point of throwing parts at it. When it may be as simple as blocked off gas block. I just put a dot where the gas block is. Measure from where it stops to the gas port Then compare that with where it is on the gas block. That way I can line up the gas block and ensure that its over it proper.
 
OkayShooter said:
Best is to measure. Because no point of throwing parts at it. When it may be as simple as blocked off gas block. I just put a dot where the gas block is. Measure from where it stops to the gas port Then compare that with where it is on the gas block. That way I can line up the gas block and ensure that its over it proper.
Click to expand...

I will look at that!
 
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