A little help loading 300BO subs

[2aBaC̶a̶]

1st time loading subs. using
A1680
18" WC, carbine gas (non adjustable)
200+gr whatevers
lightest buffer & spring I have.

Anything from about 1100-1200fps it will cycle but not stay back on last round. oser to 1100 and I start getting double feeds. any less it wont cycle. next round at all.

225gr bullets are very similar to above.

What can I do to get better cycling at the preffered speed for subs?

 

[culater]

Buy a David Tubbs recoil flatwire spring they have one for 300 blk

 

[spife7980]

Got an adjustable gas block?

 

[GregP42]

Carbine gas is hard work for subs unless suppressed, but you might try CFEBlk if you have any, it seems to make more gas, but is a little more port pop.

 

[2aBaC̶a̶]

Got an adjustable gas block?

I have several. just not on this rifle.

 

[2aBaC̶a̶]

Carbine gas is hard work for subs unless suppressed, but you might try CFEBlk if you have any, it seems to make more gas, but is a little more port pop.

I was afraid of that. wonder if opening the gas port would help.

 

[M4orturnate]

Is it suppressed? If not theirs no reason to shoot subs. The can usually give you the extra backpressure to cycle. Also i have one that wont work with 208g bullets but 220 and above are fine

 

[2aBaC̶a̶]

Is it suppressed? If not theirs no reason to shoot subs. The can usually give you the extra backpressure to cycle. Also i have one that wont work with 208g bullets but 220 and above are fine

yes, that is the point. it's a fairly accurate rifle and now I would like to make it fairly quiet one.

I have parts to build a pistol upper and Its looking like I should be finish and pursuing a sub load for that instead.

 

[roostercogburn98]

Find a 16 inch barrel with pistol length gas and won’t need adj gas block

 

[spife7980]

I have several. just not on this rifle.

Time to get the drill out and open up that block port then (probably a bad idea),

Presumably you have a can on? That should help increase pressures and since subs without one is retarded I just want o make sure.
Youre going to need more pressure to push that bolt back, the carbine length is ultimately your biggest issue but already on the lightest springs buffer combo and no adjustable block to tune hurts still. Just doesnt seem top be set up for subs.

 

[redbullitt]

Cfeblk with a can could possibly run, but as was mentioned, that gas port is not ideal... 1680 is usually pretty reliable.

Can you go lighter on spring bcg and buffer? May have to buy something oddball?

Opening the port and using an adjustable block may br viable, but not 100 pct sure.

I think that barrel may simply be best as a supersonic gun, with your pistol build eating the subs well!

 

[vinniedelpino]

Carbine gas is hard work for subs unless suppressed, but you might try CFEBlk if you have any, it seems to make more gas, but is a little more port pop.

This worked for me. Filthy though.

 

[2aBaC̶a̶]

I'll explore opening the gas port and finding the lightest spring buffer combo. while keeping an eye out for some CFEblk.