300BlkTalk

I'm working with two loads. Both with converted brass. I'm not necessarily in need of great accuracy, I shoot mostly 3-gun under 50yds, mostly CQ. I'm looking to develop loads that cycle and lock back the bolt on the last shot. 16" Wilson Combat 1:8 Carbine Gas.

So far I have loaded:

147 M80 Pulls (FMJ)
15.8gr Lil Gun
(Locked back the magazine 2/3 times)
Felt like a fast cycle

and

230gr Lee Mold Cast Allox Lubed
11.4gr 1680
Didn't lock back at all. Slow cycling.

Both cycled well, extracted cases very well. I have to work on the OAL of the 230gr's, they came out of the magazine a little hard and it did cause a missfeed. I think this will be solved once I load them up right.

My Q's: I don't care about sub/super sonic. I want to have a 230gr load that will lock back the bolt back every time. How much 1680 can I use safely? Does anyone have any data from when they started to see pressure signs? My powder measure (lee auto disk) doesn't allow for very fine tuning and I don't want to push it too much. I will be trying 15.5grs and 16.5 of lil gun if I can make a disk drop it constantly, I hope for this to lock the bolt back. I'm almost thinking lil gun is too fast and the magazine couldn't push up the catch fast enough.

I use 15gr lil gun @ 2.045, 147gr pulls. They are just under 2000k fps and 100% function in my 16".

Mech,

Are you running carbine gas? I'm loading up some test rounds so when this blizzard rolls on out I can get out and try them. I've done a few 12.0gr 1680's for the 230gr and a few 15.4gr for lil gun.

I load 11.5 grains of 16980 and a 190 grain Nosler Comp for a velocity of 1045 fps

so I think you could use a little more powder

I run 17.5 lil gun with 125 Ballistic tips at 2.125 OAL, that runs 2144 fps average with 100 percent function

I run 16.5 lilgun with 150 nosler bt's at 2.220 OAL THAT AVERAGE 1987 FPS WITH 100 PERCENT FUNCTION

This is in a Daniels Defense with 16" match barrel, 150's are over published max, but show no indications of pressure in my gun, work up to it and good luck. One other thing, I have noticed that over all length makes a LARGE DIFFFERNCE in VELOCITY WHICH equals a large difference in pressure. Which brings up the thought, that your current load may be good and 100% reliable with a slightly different OAL.

Yes, carbine gas.

I tried a 8.7-9.0 gr lil gun at 2.120-2.240 with reg and mag primers behind 220gr sierras yestetday. Was trying to make subsonic w/ lilgun but would not cycle nor lock bolt back. Lil gun is definately a no go for subs in a carbine gas system...

Snowblowed the range, then took out the AR.

15.5-16.0gr of lil gun @ 2.200" OAL with 147gr FMJ worked without issue. Locked back 10/10 shots.

11.8-12.2gr of A1680 @2.250" OAL with 230gr Cast Cycled 100% but did not lock bolt back at all.


May need a adjustable gas block, I don't want to push the cast's too fast. I'm going to try and borrow a chrono to see what type of velocity I am getting.

Adjustable gas block shouldn't be necessary for 300blk...

Ideally supers w/can and w/o can, and subs w/can and w/o should function and lock back without gas adjustments...

That being said, I can't get factory Remington 220gr subs to lock back the bolt w/o a can, but function 100% suppressed. I am ok with that, no use for subs without a can for me.

But anyway, are you running suppressed?

Thought I had put that. Unfortunately I'm not. After the wedding I'm saving for, I hope to get myself a trust and then pay uncle sam.

I'm not so much looking for sub sonic, as I am looking to get a load that shoots the lee 230gr cast boolits without needing a gas check and that will lock the bolt back. I'll just keep working the load up. Hopefully I get lockback before I run into leading issues.

I did pick up another 500 FMJ M80 pulls, so that gives me something I can shoot for my 3-Gun matches.

Lee 230gr Mold - 228gr drops, WW - 12.5gr A 1680, Loaded to Magazine length

This load locks the bolt back, but is more than likely super-sonic.

The bad: out of 6, I had one keyhole I'm thinking it was one that was a bad molded bullet, with a crimp I'm not normally using to boot.

I loaded 10 up, flared to seat bullet, just enough crimp to remove the flair will test them tomorrow. at 25yds. If they don't keyhole, I'll move out to 50yds to start testing accuracy.