Supersonic 300 blackout powders

[CoyHunter38]

I'm in an area that can have major temperature changes throughout the year, and I'm looking to reload 300 blackout. What are some temperature stable powders for supersonic loads?
I've seen some people claim magnum small rifle primers can help ignite powders that are temp sensitive more consistently, but I couldn't find any data that could confirm this. Has anyone done any testing to see if this is true?

Thanks for any input on this.

 

[ARlife4me]

I don't know about temp stable, but I do reload 300bo supersonic projectiles. I've been using 450s with 296, h110 and 1680. Bullet weights from 110 to 170 from an 8.5" barrel.

 

[Bob the nailer]

I use IMR 4227 with supers and subs. 135grn HP for hunting with no zero shift during summer or winter conditions also CCI 400 primers will ignite with out issue. Stop by 300blktalk.com for good info on anything 300BO

 

[JasonAL]

I also reload 300 BLK. I have only used H110 and CCI450's. I believe the temp stability isn't an issue because of the small case capacity. I've only reloaded 101,110, and 125gr bullets.
H110 is also the preferred powder for .357 Mag and .44 Mag, I haven't read of temp issues with those cases either.

 

[eastbank]

i have been useing lit,gun for both 125 gr and 150 gr bullets.

 

[Mike D Texas]

Not sure about temp sensitivity since the 300 blackout typically uses pistol powder.

I use Alliant 300MP in mine and get phenomenal accuracy and velocity from an 8" SBR.

I run the 110 Barnes TAC-TX at 2315fps from my 8"'barrel. The below plate was shot at 300 yards. Disregard the high flyer, I mis dialed the yardage the first time.

 

[cohunt]

H110

 

[mongo4567]

I've used 300MP for supersonic, have only been able to get close to factory ammo accuracy (1.5 moa) with 110grn SST while chasing velocity. Will be trying some others.

 

[300sendero]

H110 for light bullets and 1680 for heavies.

 

[Chrsm]

I like lil gun Because it was cheep at the time Can hit anything I want, out to where I need to. I Like the 300 KO! A pound of powder goes a long way. 4 goes longer and 8 your great grandchildren will be burning!

 

[338RUM&7MMREMMAG]

H-110 with 110 Hornady V-Max and Barnes 110 Tac-TX. Same charge under both bullets have the same impact. I have shot them sub zero temps for Coyotes to summer plinking at Groundhogs.

 

[QuietTexan]

I've seen some people claim magnum small rifle primers can help ignite powders that are temp sensitive more consistently, but I couldn't find any data that could confirm this. Has anyone done any testing to see if this is true?

I've used Rem 7 1/2, CCI 450s, and Fed 205M-ARs, and CCI 41s, never had a problem with any of them.

As long as your load density is decent (the case is more than half-75% filled), the risk in using a mag primer is increased case pressure pushing the bullet out on it's own. This isn't normally a problem in the 300 BO (it's more of a pistol problem) because the bullets tend to be heavy when you're shooting light charge weights for subs, but if you're using a light 110-gn bullet and a low density load you could get a double-pressure spike and lower velocity than you want.

 

[rewiltshire]

Ditto on the Lil' Gun. I use it with 124gr Sierra HP's and Remington 7 1/2 primers out of a 16" barrel. My 'Hog gun'.

 

[Chrsm]

Ditto on the Lil' Gun. I use it with 124gr Sierra HP's and Remington 7 1/2 primers out of a 16" barrel. My 'Hog gun'.

Yup I've thrown 125 nos BT, speer 130 HP, Sierra 135 HPBT and the slower Hornady168 A max! The A max is the most accurate being longer than the latter. Shot a nice 9 point with the sierra ran 20yrds dropped! Wish they came out with a 1in12 twist for supers in 300 BO! I'd jump all over it! I know I know the hammers out there….. blablabla. Used H110=W296 and LiL Gun like them all!