.300 Blackout: Hornady 125gr HP and H110. Searching for Accuracy, Part 1 

Sorry for the late comment but I just saw your video. I've been where you are. H-110 is happiest when there is no air in the case, there is considerable resistance to the bullet moving and there is a hot primer. After not liking the results I took the TNT bullet from 2.100" to 2.000" and put on a hefty Factory Crimp. Case necks are very clean to minimize anything helping the bullet to slide in the neck (always an issue with the 300 BLK). The powder charge was dropped to 18.1gr of H-110 and I ran CCI 41 primers (roughly a magnum primer). H-110 needs all the help you can give it for good ignition. Then, like in magnum pistol cartridges, it performs like nothing else.

Hi, I stopped the deflector dings in my cases, especially the 223/5.56 cases that I want to convert to 300 Blk. Or just reload back to 233/5.56.. By cutting out black heavy duty peel and stick fuzzy side velcro, I cut it out and shaped it like the deflector, clean or wipe down deflector area with rubbing alcohol and stick in place... You may have to do a little trimming so it doesn't interfere with your dust door, you can give it a little haircut to thin it if ya want. I put one every AR upper also put on family/friends too!.. As time and wear happens just pull off clean upper and replace, I make em in batches.. Give to people too!. It also stops the brass dings/nicks and marks on the deflector too! Try it..From Dave, a disabled vet and long time reloader..... If I could make a buck making and selling em I would, but too simple...

Try that powder with the 168 hpbt Sierra Matchking and see how it does

17.2 H110 125 gr TnT in my 8” AR produces 1800 FPS Mild- accurate-cheap Compared to most ammo

If you use blackout specific bullets you will get great groups like lehigh or tac tx etc..... I reload them all myself and the sierra 125 pinched tip blackout bullet like palma kind rock.....

There’s a propane tank in the bed of the truck.

I’ve not had luck with the H110. Seems to not produce enough gas to cycle the rifle.. and that’s on a pistol length.. functions perfectly with 1680 and lil gun. You running an adjustable gas block?