Anyone used these bullets for a sub in their 300 BLK yet? I am about to load up a batch as subs and just wanted to see what the consensus might be. I have LOTS of brass available and a pound of H4198 not even opened yet. The Hodgdon data shows 11.5 grains of H4198 or IMR 4198 under a 220-gr HPBT will chunk the projo at 1068 and 1036 fps respectively. This sounds like a good start. Any opinions? I am sure that the charge will have to be a bit smaller with the 210-gr Berger HPBT. Anyone have any opinions about it cycling the action in my AR? (16" AR-Stoner barrel, 1:8 twist, YHM Phantom)

That does sound like a good start. Remember when loading subs start high and work your way down. I am not familiar with that bullet but the weight is fine as many use Hornady 208 grain bullet very well for subsonic shooting so I can't see any problem with  your 210 grain bullet. Good luck and let us know how it goes.

Thanks for the reply!
Gonna load up several tomorrow in 0.10 grain increments from 11.5 down to 10.5. I am taking a nephew who is a USMC Reservist down to a shooting range to chrono them and see how they do. I'll report results for sure. I hope these work like I think they will. The last rounds I shot out of this rifle were the Barnes 110-gr Tac TX loaded over 19.0 gr of H110 and they were about as loud as a 22LR...we could hear the bullets whizzing downrange. If these are any more quiet than that, I will be more than happy and won't have to do the whole process for a suppressor. I just hope these rounds will reliably cycle the action on this new rifle. If they do...gents we will have a winner!

I would expect it to cycle no problem- having a shorter barrel should make that no problem with most powders. Most of the cycling problems seem to happen on carbine length guns.

Did you end up  testing the 210gr with the 220 starting measure? I'm curious - had good experiences taking a 220gr load as low as 178gr and remained subsonic w/o performance issues. That was using aa1680 for powder though. 4198 is so close it shouldn't matter

They are 50% more expensive than the Hornadys. I have tried them in 308 but consider my subsonic rounds plinking rounds and cost per round is more important that squeezing out a hair of accuracy.

Sorry I didn't get back into this thread before now.
Yes, I used the starting measure for the 220-gr rounds for the 210-gr Berger HPBTs. I ended up working down to a 10.9-gr load of the H4198. This past weekend I finished up the load using 10.9, 11.0, and 11.1 grain loads. THe 10.9-gr load of H4198 ended up working the best for some reason at an average of 990 fps. I had cycling issues with 11.0 and 11.1 gr loads. I even stuck a bullet with the 11.0-gr load. The bullet stuck right in the chamber on the lands, so I was able to tap it out with a cleaning rod. Thank God I followed the "check the bore" rule when working up the subsonic rounds. It sure is cool to see your round hit the backstop berm BEFORE you hear the muzzle report.

That sounds more like a squib than a light load.

Maybe so, but it follows published load data as a starting point. Hodgdon's data gives a 11.5-gr starting load with a 220-gr bullet and H-4198. I just worked down from there with a 210-gr bullet and that's what I found to work the best.