300BlkTalk

I've used Lil'gun and IMR 4227 for subs in my SBR Blk. Both work and cycle the action but 4227 runs much cooler than Lil'gun, MUCH cooler. The Lil'gun never went past load development. I found that cast bullets shoot ok but the accuracy wasn't what I wanted. I went with SMK 220 gr as my target loads...

What headstamp brass did you end up using? I know you said it was sorted using the good/bad list but there are some that are more gooder than others.
WCC, and Lake City are my go to cases now, but I've used RP, PMC, FC, and Winchester in the past with no problems.

What velocity are you getting with that 9.7 grains? Thats the other thing to worry about. You want an accurate load that stays subsonic at all temperatures.

Are you shooting Supers or Subs and not having it function? Adjustable or fixed gas block? Whats your gas port size right now? My 8" barrel wouldn't cycle with subs until I opened the gas port in the barrel to .108" When I add the suppressor I can dial the adjustable gas block to exacly wh...

I use WCC for supers (because I could get a ton of them for cheap/nothing), and LC for subs(because I wanted good brass but not WCC for subs)

Here you go, straight off my recipe list:
200 Maker HP – LC case, 8.4 gr IMR 4227, CCI 400 primer, 2.120 COAL, 1.740 CBTO @ 1.026 BBTO, case trimmed to 1.358”

Gets me 970-980 fps which my 8" supressed barrel likes and it will touch holes at 50 yards. YMMV

What ranges are you looking at? Deer hunting with subs is like bow hunting with a rifle. Practically the same effective range. Attempting a shot over 50 yards you better have figured out your bullet drops/yardage. My 220 SMK loads sighted in at 50 yards are 6" low at 100, and my 200 gr Maker ex...

I built my 5" barrel pistol just as I would any other 300 BLK. Standard BCG, Carbine buffer, KAK pistol receiver extension, standard spring. The only thing I did specifically for the build was add an adjustable gas block. My primary use for it is supers (already have an 8" barrel sub gun) ...

You can't go wrong with 220 gr Sierra Match Kings over IMR 4227, and a CCI srp. 970-980 ft/sec with my loads and touching holes at 50 yards if I do my part.

I worked on using Lil'gun for 220 gr subs. It worked alright, but IMR 4227 was more accurate and ran cooler.