300 Blackout/Lil Gun/195 LRNFP load recommendations

[Linko]

I have a 16" AR upper in 300 BLK. I would like to load 195 grain Lead RNFP bullets with Lil Gun powder. (both on hand). This will not be a suppressed rifle.

There is limited published data for this combination.

I could use first of all a seating depth (COAL) dimension if anyone has worked with this before and had success with these rounds cycling well.

I have found COAL recommendations between 1.91 thru 2.10

I am using Starline brass and CCI 400 primers.

As for powder load I am still researching a safe range to start with.

(although lead and jacked bullet loads are not equal, for reference a 195 gr jacked boat tail sierra load range is 8.9 to 12.6)

I watched a you tube video (hate to admit that here, but with such limited published data I had to look elsewhere)

someone loaded 2 coated weight lead bullets. The 202 grain noe coated bullet load data that worked for him was:

202 lead coated bullet
7.8 grains Lil Gun
2.100 COAL

This seams reasonable, but I could use a recommendation for a SAFE starting load. (I dont have the quick load program software that some of you do.)

 

[rockrat]

I just looked at Hodgdonreloading.com and a 190 gr had a max of 8.3 and a 208 gr had a max of 8.2 Lil gun. Jacketed bullets

 

[Park ranger]

I’d bet these max loads are to keep it subsonic. I bet you could safely push a 208 at 1250 fps, but why?

 

[Oso]

A few things for you to consider:

1) Lil'Gun is temp sensitive, but in the wrong direction. It is known for its Temperature Inversion... the loads become hotter as the temperature decreases. Just keep this in mind as you are developing a load in Summer... as weather cools off it will become faster and pressures will increase.

2) If you are using standard 5.56 PMags then your load length will be considerably shorter than mag length because of the Ogee contacting the internal alignment ribs inside the magazine. With it being a Round Nose Lead bullet the COAL will be different than COAL used for heavy BTHP bullets.

3) 300BO performs much better (accuracy and power) as a Supersonic cartridge shooting 100gr - 130gr bullets. This translates into faster, cleaner kills in hunting and also greater accuracy for reliable shot placement at greater distances. Most subsonic loads shoot in the 1"-2" group sizes at 50 yards, whereas Supersonic loads can deliver 1" groups at 100 yards. This is a big difference, and it only gets worse when you shoot the subsonic at 100yards.... dropping like a brick.

Your load is going to be very close to a subsonic trajectory... Good Luck

 

[dellet]

A safe starting load will be dependent on seated depth and jump. Without knowing the exact bullet, it’s impossible to help you with that. If you bought the bullets, the manufacturer should be able to help. Maybe others who have used that same bullet.

Short for weight, flatnose bullets are the most difficult to find a length that will feed properly.

Once you have the length that will feed, then you can compare seated depth with known loads. A wild guess, I would start with a length of 2.100” or .030” off the lands, which ever is shorter. Flat nose bullets tend to feed better short, but that depends on the width of the metplat, and the feed ramps of your barrel. With a true 30 caliber feed ramp, it’s pretty easy. The problem is many barrels still use a 223 barrel extension.

Something you did not mention is you gas tube length. If it’s carbine gas, unsuppressed, you may have problems with low end loads cycling. It’s a poor powder choice for that bullet at low velocities and carbine gas.

If I wasn’t worried about keeping it subsonic, I’d probably start around 10 grains to maximize the potential of full function, feeding, locking back on empty.

If this is your first stab at loading 300 BLK in an AR, you’ve set yourself up for some possible frustration. But it’s entirely doable, and with a decent bullet, even cast, 1.5-2 MOA out to 200 yards subsonic is possible.

 

[Linko]

this rifle is a carbine length and I am using 300 Blk Pmags. Upper looks to have M4 extension

 

[Linko]

I believe I am going to abandon this project. The flat nose does not run on the feed ramps well and fails to feed every so many rounds.

 

[unodemo]

Late to the party by about 2 yrs. One word...don't. Lil' Gun is too fast,, too damm hot, and hard on the barrel. I just found out Pb has it's own problems on top of that. Further, no chance of staying <1100fps with a 16" barrel.

Slow down the propellant to ~11.5gr A1680 for that weight bullet. Now lets move on to the other problem I found out the hard way. Mike the barrel at the muzzle. If it's anything over 0.309", then you're screwed for firing lead as they'll tumble starting at 10yds. Ask me how I know.

If plated/jacketed bullets run fine on target, then you know you have an over-sized barrel bore.

Running the 300 BLK has been an 'interesting' exercise for sure.