Need some help with my 300BO build

[Allsmiles]

If you have access to a suppressor, it can confirm low gas pressure in present condition . The extra gas dwell time will cycle the BCG with the suppressor and will do exactly as you are describing without it. One of my builds had a bad (miss drilled) gas block and this is how we found it.

 

[Bushwhacker]

We'll i adjusted the gas block a credit card thickness off the hump and put it all back together. It cycled great with supersonic. Slapped a H2 buffer in and still ran fine.

Now subsonic, not so much. (Standard carbine buffer in place), it fires and ejects but doesn't put the next round in battery. Not as far but still kicks brass around the 4 o'clock position. I'm assuming still under gassed. What say you?


All of this without my can attached.

 

[billieco]

Yes buffer spring is to heavy.

I agree. Mine did the same thing and I had to get a 300 blk specific spring. Not sure who made it but will look. Runs perfect now.

 

[billieco]

https://www.brownells.com/rifle-par...blackout-carbine-buffer-spring-prod56149.aspx

 

[Duce4trey]

We'll i adjusted the gas block a credit card thickness off the hump and put it all back together. It cycled great with supersonic. Slapped a H2 buffer in and still ran fine.

Now subsonic, not so much. (Standard carbine buffer in place), it fires and ejects but doesn't put the next round in battery. Not as far but still kicks brass around the 4 o'clock position. I'm assuming still under gassed. What say you?


All of this without my can attached.

How did it cycle with your can on? or did you not try?

 

[Plinker66]

Adding your can might increase the gas enough.

 

[jeep78]

I agree. Mine did the same thing and I had to get a 300 blk specific spring. Not sure who made it but will look. Runs perfect now.

https://www.brownells.com/rifle-par...blackout-carbine-buffer-spring-prod56149.aspx

 

[Bushwhacker]

How did it cycle with your can on? or did you not try?

Adding your can might increase the gas enough.

Haven't run the can on it yet. I figured the added pressure will cycle the subs just fine. Trying to make sure I can get it cycling reliably with all ammo first.

 

[Bushwhacker]

I agree. Mine did the same thing and I had to get a 300 blk specific spring. Not sure who made it but will look. Runs perfect now.

That will.be the next thing I try!!! Thanks

 

[Plinker66]

I used a skinny credit card, or maybe a drivers license, btw, one that fit just right, after I lined up the holes in bright light w the gas block upside down. A thick credit card was a little too much gap, if I recall.