300 Blackout sub data

[MobileTaylor]

Not sure. I was given several hundred .308 bullets. Probably 20-25 years old. Look like maybe some military spitzer type bullets?

I'm also working up a load for my AR. 220 grain match king. That's why I asked about CFEBLK above. I loaded some with 12 grains of BLK. Everything cycled fine, but a few went super sonic. Going to reduce the load to around 11.5 and see how that goes.

 

[umrek]

I'm also working up a load for my AR. 220 grain match king. That's why I asked about CFEBLK above. I loaded some with 12 grains of BLK. Everything cycled fine, but a few went super sonic. Going to reduce the load to around 11.5 and see how that goes.

For my AR I settled on 10gr of BLK for a 220gr lead powder coated.... shooting suppressed.

 

[MobileTaylor]

For my AR I settled on 10gr of BLK for a 220gr lead powder coated.... shooting suppressed.

Thanks for the info!

 

[ch139]

Before screwing your can on, shoot some paper with your loads at close range and examine for clean holes indicating your setup is stabilizing the bullet adequately. I do this every time I shoot a new load I intend to shoot through a can to prevent baffle strikes. Just my 2 cents.

This is GREAT advice!

 

[ch139]

As for helping the OP's journey - I've not tried many jacketed bullets in my 300BLK AR (10.5-inch FN CHF barrel from PSA with old Surefire FA762K can), but have been working on sub loads with cast/polymer bullets.



50-yards

T&B 220gr cast/coated bullets

11.5gr CFE BLK on the left and 11.7gr CFE BLK on the right. Didn't have a chronograph for speed then, but recent trip with chronograph gave a 15-shot string with average of 1018fps, velocities were kinda "all over the place" low being 927fps, high being 1088fps, ES 161 SD 46. Not the best numbers, but subsonic and OK on accuracy.

 

[v0lcom13sn0w]

i use 10.8-11.3gr of 1680 for my subs with either 208gr hornady or 225gr hardcast

 

[JJE76]

i use 10.8-11.3gr of 1680 for my subs with either 208gr hornady or 225gr hardcast

I used 11.2 of 1680 quiet cycled gun great. Accuracy was terrible all over the place at 50 with a red dot. Honestly Berry 220's shot ,ore accurate then smk 208's. Could be my red dt is out of whack, but have great luck with the MRO. Overall length 2.21 CCI small rifle mag primers. Any thoughts?

 

[v0lcom13sn0w]

I used 11.2 of 1680 quiet cycled gun great. Accuracy was terrible all over the place at 50 with a red dot. Honestly Berry 220's shot ,ore accurate then smk 208's. Could be my red dt is out of whack, but have great luck with the MRO. Overall length 2.21 CCI small rifle mag primers. Any thoughts?

try the round in another 300blk upper if possible. mine arent super accurate compared to supersonics. theyre accurate enough to shoot a deer in the head though.

 

[umrek]

I used 11.2 of 1680 quiet cycled gun great. Accuracy was terrible all over the place at 50 with a red dot. Honestly Berry 220's shot ,ore accurate then smk 208's. Could be my red dt is out of whack, but have great luck with the MRO. Overall length 2.21 CCI small rifle mag primers. Any thoughts?

Twist rate? Maybe they are not stabilizing.

 

[Twodogs]

I'm shooting a 1-7" twist with the ruger ranch rifle and anything over 190 gr goes south past 50 yrds, hornady and Makers 190 gr will do 1 1/2" at 100 yrds if I was to go deeper into heavy subs I would get an X-caliber 1-5" twist barrel. Got my .44 mag setup to shoot subs so the 300 blk got side lined.
Here's a pic of my Left handed ruger ranch rifle in 300 blk.

 

[JJE76]

Tri Arc track 2 10"3 1:7 twist. Rounds aren't keyholing