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sutherpride59
09-03-2017, 02:15 PM
So I just bought an AR in 300 blackout with a 1:8 twist, pistol length gas system, and adjustable gas block. I want to load the Lee 312-155 water dropped wheel weight, gas checked with Felix lube. I want to load super sonic loads for this.

From the immense amount of reading I have done on here I think I have settled on H110 for my powder. However I'm on the fence between it and lil'gun. Thoughts?

My main question is with annealing and seating depth. For annealing the brass which is apparently a big part of good accuracy with this round would it be dumb to anneal the brass just using my electric coil stove top? I tried it once and it seems to work. I really don't want to blow a lot of money on map gas and propane tourches. I have a source of free 223 brass so I'm cutting and forming my own.

For seating depth does any one have a good medium between function and accuracy for that depth? There isn't a whole lot of cast data that I can find for this round so I don't want to seat too far in and cause excess pressure issues.

tsubaki
09-04-2017, 06:19 AM
Just out of curiosity, where are you getting the data for cast with Lil'Gun and H110?
Lyman does list some cast data using powders like 2230, IMR-3031, H335, Rx7 and H4198 with 160gr and 180gr projectiles.
As to annealing, the brass is so thin, with proper flame tip placement a regular propane torch should do the job.
Look around at various reloading sites, new brass for the 300AAC is becoming economical. Even sites that sell converted .223 to 300.
Remember when converting brass, there are certain manufacturers you want to stay away from due to the wall thickness of the case.

osteodoc08
09-04-2017, 08:34 AM
If you get free 223 brass, don't stress the annealing. Form and load and toss after 2 loadings. If you want to anneal on the cheap, read about annealing using your lead pot. Start with starting loads for jacketed data for the same weight. I prefer as do my firearms in BLK, 296/H110. Get a good case gauge.

sutherpride59
09-04-2017, 01:36 PM
I will probably just end up getting a torch for the annealing, I haven't found any cast data for 300 aac but from all the post on this forum most people seem to get good results with the 312-155 over 15grains of H110, also lil'gun and aa1680. No official data just 2 hours worth of reading from the search results.

popper
09-04-2017, 03:06 PM
I use 110/296 for the 145gr cast, 1680 for the heavier 170 & 185. Problem is getting enough powder (4227,Rl7,etc) into the case for supers. I've heard reports of l'lgun burning too hot but it does work. It's an AR, function over anything else first. Make dummy rnds and check function, increase OAL til it stops then back off a bit. I have a 1:8 pistol port 10", fun. You will end up almost shutting the gas off. Loaded neck dia. over 0.330 won't fit.

waco
09-05-2017, 01:11 PM
I use 15gr of IMR4227 with the Lee 312-155 but this is in a bolt gun.

sutherpride59
09-06-2017, 04:58 PM
Well I loaded up some cases with a stepladder load of H4198, best group was .62" at 50 yards with a Lyman 200 grain 311644c seated to 2" oal and 13grains of powder with Winchester small primers. Oddly enough I was having a hard time getting the rounds to chamber and played with the die when I got home. I believe the shoulder is t being pushed back far enough with my lee die, could be the die could be the rifle. I took the shell holder to a piece of sand paper on the table and after about 10 minutes of sandi g with 220 grit they seat a hell of a lot easier. Cheap easy solution to a problem, with this hurricane it's going to be a while before I can load and test out a bunch of rounds to really dial it in but for a 200 grain load H4198 seems to work pretty well in summer time north Florida weather.

popper
09-06-2017, 05:10 PM
Head space varies a lot. I just grind down the sizer die, less work. Replace the Lee lock rings with Hornady and lock them down tight. Be safe and set the HS short so you don't get slam fires. Firing pin is floating and safety doesn't block it. SIL told me he got one in a 243 Weatherby - shot his laser printer. I don't understand but the safety is different on that rifle.

sutherpride59
09-06-2017, 07:08 PM
***** excellent advice, if I load a live round into the chamber on any gun I always go out back and point into the dirt lol. I like my printer too much.