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drkphibr
10-29-2014, 7:02 AM
Anyone have a recipe they'd share for 300 AAC/Blackout with the following:

150gr FMJBT Hornady bullet
H110 powder

We've followed Hornady's load recommendation of 15-16.2gr on the H110 with a COAL of 2.235".

Regardless of the powder charge, we have the same results, FTF on second round, regardless of magazine. First round will eject, second round won't feed.

AR piston driven pistol (9.75" barrel) platform from PWS. All factory parts. The piston is actually attached to the BCG, so it's heavier than a normal BCG.

We've read too much H110 is bad and so is too little. I don't think this is a powder charge issue now as much as I do a pressure issue with COAL. Thinking about seating the bullet deeper (from 2.235 to 2.180, 2.140, 2.100 and finally 2.088 or so) to increase pressure to fully cycle the BCG in order to feed the second round in the magazine.

Anyone have any recipe or strategy input/recommendations?

Victor Cachat
10-29-2014, 9:23 AM
I had the same issue with my 300 AAC/Blackout rifle using factory rounds.
I have an 18" barrel and carbine gas system.

My thread research found multiple possible solutions, but the cheapest, fastest, and easiest was to make sure the BCG was wet with lube.

It works like a champ now.

rg1
10-29-2014, 9:46 AM
Most info I've read for 300 BLK. using 150gr. Hornady FMJ's says to seat to 2.065" oal. Your loads from 15-16 grains should cycle. Most info says to measure the bullet ogive and mark where the diameter is .250". Then seat the bullet to where the .250 mark lines up with the center of the inside hump of the AR magazine. This is supposed to insure good feeding from mags because it is about the same dimension of the .223 case neck that also is located straight by the magazine hump.

MrWindow
10-29-2014, 9:49 AM
What size is your gas port?
Carbine gas for this caliber can be problematic. As said a wet BCG is a good start.
The charge weight seems ok so my conclusion would be you gas port is too small.
Go here.

http://micromoa.com/?page_id=496

Thought is carbine gas system my bad.

chiliman21
10-29-2014, 9:51 AM
Check out 300blkout.com. Lots of helpful info.

Doesn't the pws have an adjustable gas block?

MrWindow
10-29-2014, 9:52 AM
http://www.300blktalk.com/forum/index.php
Fixed it for you.

drkphibr
10-29-2014, 10:07 AM
What size is your gas port?
Carbine gas for this caliber can be problematic. As said a wet BCG is a good start.
The charge weight seems ok so my conclusion would be you gas port is too small.
Go here.

http://micromoa.com/?page_id=496

The PWS 300 Blackout piston pistol does not have an adjustable gas block (their other models do however).


Check out 300blkout.com. Lots of helpful info.

Doesn't the pws have an adjustable gas block?

I have sifted through all 147 pages of the handloading posts. My recipe question and COAL approach is a result of all the information gathered there.

MrWindow
10-29-2014, 10:17 AM
Does your barrel have hole in it that gas from the bullet firing goes through to make the piston move? That hole is too small.

RookieShooter
10-29-2014, 10:23 AM
I'm using 15gr of H110 & 150 gr bullet, COAL of 2.1" with no FTF on my 16" Wilson Combat barrel.
Try to reduce your COAL and see if that will resolve your problem.

MrWindow
10-29-2014, 10:28 AM
That load should cycle any pistol setup if the gas port is the correct size. If it is too small it won't. Been there done that. I would suggest a lighter bufferif you are using anything but a carbine if your BCG is heavy.The point of the caliber is for it to eat anything at that barrel length and would give you less options. You would be limiting yourself on the top end of things if you do that.

MrWindow
10-29-2014, 10:36 AM
You shouldnt have to adjust your load at supersonic levels to get a 300aac pistol to function properly. If you are in recomended ranges for the powder and bullet weight. Only for accuracy. The failure is in the gas system with the load you are trying not the componants or recipe. There is enough there to cycle an ar set up properly.

Eljay
10-29-2014, 3:45 PM
The gas port issues seems right to me as well. I load cheap plated 150gr flat tips way down at 14.6gr to keep them at an acceptable velocity for the plated bullets without any problems at all.

fast54vw
10-29-2014, 4:06 PM
my 300 blk load is 17.3gr of H110 with a 147grain M80 bullet seated to 2.115".
i also use the same load with the M2 150gr flat base bullet.

G38xOC
05-13-2016, 8:46 PM
Fast54vw

have you chrono those two loads ? what barrel length were you shooting out of

Hornady book shows 15.9gr MAX @ 2.220"