Best Powders for 12" 300-221

[A62Rambler]

I've been gathering all the loading info I can for my SBR project. What are powders that would work best? Barrel will be 12" with pistol gas port. I want to do both 125gr supersonic and 190 to 220gr subsonic and will be using a 762 YHM Phantom. I didn't want to hijack another thread I read.

[cav_scout_tj]

I too have an SBR barrel on the way. While I don't have any true experience yet, my research says the faster burning powers in 300 whisper should work best. That would be slower to faster: 296, Lil Gun and 2400. I stocked up on some Lil Gun and 296. I have some 2400 left over from 44 mag loads.

I'll let you know when my barrel shows up. I have a 9.5" coming.

[JFettig]

I have a 10.5 coming soon for a pistol, I have some hogdon 110 that I plan on using initially. I will primarily be shooting supersonics, 147-165 and some smaller.


Jon

[A62Rambler]

Well, a call to the ATF and I've got time to wait. They guessed it would be 6 weeks before it even gets to someone to start the approval process. The guy told me it would be May before I got it back with a stamp. :eek: It's going to be a long wait. On the bright side, I should have had plenty of time to gather everything I need. :wink: I guess I'll try AA9 and maybe N110 from Vhitavouri. By the time I get it you guys will have loads worked out and can tell me how well H110, 2400, 296 and Lil Gun work.

[jarhead1086]

I just got an SBR permit back about 2 weeks ago. It took 5 weeks from mailbox back to my mailbox. Sure beats the old Chicago days waiting 8 months or longer on Forms. I fired my 12" AR tonight for the first time without my chronograph since I was mainly testing function. It seemed to go super on loads that were sub in my 16" using AA#9. I tried 8.9 & 9.0 grain charges and both cracked. I will shoot some more loads across the chrony this weekend and share. BTW my 16" was a Shilen and the 12" is a Noveske and both 1:8's. It was also colder outside by 30 degrees compared to when I worked the other load up. Which could account for a slower speed of sound. Remember speed of sound = 49.06 times the square root of (T + 459). Temp is in good old Fahrenheit. Every powder lot and barrel is a little different. I used a titanium QSM suppressor too which is tighter than the Thundertrap so I suspect some more freebore boost too. I'm gonna hopefully find out this weekend.

[A62Rambler]

Hey Jarhead,
What bullet weight were you using?

[jarhead1086]

Rambler, using my 12" Noveske barrel and a QSM can with 220 MK's and WCC820 powder I got 1020 fps with 8.4 grains, 1040 fps with 8.7 grains, and 1120 fps with 9.3 grains. This is the strange part. My 16" Noveske barrel using the same powder, bullet, and suppressor shot slower with the same charge. I got 930 fps with 8.4 grains, 995 fps with 8.7 grains, and 1080 fps with 9.3 grains. Since it was my first try with this powder I only shot 1 or 2 shots of each. I will shoot 5 each next time for a better average. With regards to the PM I sent about the buffalo, subsonic Whisper will indeed kill a buffalo. We shot 2 cows that weighed about 1000 lbs (not full grown) that my friend raised. We used 220 Nosler Partitions. Both had to be shot twice because we both shot simultaneously at an agreed location between the eyes, which on a buffalo is sinuses. A follow up shot higher on the head dropped them like a rock. Live and learn, but a sub will absolutely drop a buffalo in one shot if a rookie isn't running the gun. We still have the heads, but I haven't recovered the bullets.

[A62Rambler]

I ended up getting my approved forms back on 3/15. That was about 5 weeks mailbox to mailbox. I've been so busy with another project that I haven't posted since then. My 5.56 barrel should be on it's way from being cut down early next week. I'll have to order my 300 barrel as soon as I can pay for it. Trying to start a business and funds are going to be tight for a while.

[AlcoholicusMaximus]

I just received my Model 1 sales 10.5" .300 fireball AR barrel yesterday.Haven't shot it yet,but after reading the above posts,it seems to me that the reason that you guys are getting higher velocities with shorter tubes is because there is no extra barrel to slow the bullet down. I remember reading here somewhere that the .300 whisper only requires 7 or 8 inches of barrel to achieve subsonic velocities.

[dflicker]

With a 12" LWRC AR-15, Jet Ti suppressor, 220g SMK, CCI400, gas block turned off, I'm getting a consistent 1035-1040fps with 9.2g of Accurate #9. Couldn't be happier. Now looking for a maximum load for 150 grain bullets as I have a ton of them. Any suggestions?

[jarhead1086]

dflicker, you have to post some pics of your rifle, especially your block. My brother has a Jet Ti can and I have the QSM, but I haven't compared them side by side yet. I'll never buy another steel can again. If your LWRC is the piston deal you may be coming up with your own data and powder choice. Your #9 load is a full grain more than mine with a 220MK in the same barrel length. My max loads I've been using WCC820 because I have several kegs of it, its cheap, and it loads like #9. I also use H110 to get the 130 TNT's ripping downrange. I just bought some 2400 and Lil'Gun because the senior crowd here gave them good reports. Thanks for being our Guinea Pig with the LWRC, now share some info!!

[dflicker]

Jarhead, sorry for the slow reply but I've been away from my computer for the past week. Did some outdoor shooting with the LWRC last week, it is not yet set up to cycle the action but I'm going to send the upper back to them along with the supperessor in the next few days to have them drill out the gas port. Regarding the Jet suppressor, I'm a bit disappointed in it's performance. There is very little difference in noise level with it installed or not. I think it just has too little volume (5.5" x 1.75") and I'll probably get a fulll-size .308 suppressor soon to use in its place. So far I've only shot subsonic 220 gr. SMK's. I'll use the Jet with my 8" PSD (6.8SPC) to reduce muzzle blast. LWRC has offered to buy it from me to test with the PSD but at this point I think I'd rather keep it.

I'll post some pics when I can get my daughter to upload them for me :o

[jarhead1086]

That is a size I didn't know they made, I've only seen the larger ones like my brother has. My QSM is less than half the weight of my Thundertrap and smaller, but sounds as good super and only marginally louder shooting sub due to the volume like you say. It is still very quiet, but I am convinced that Hollywood quiet sub cans need volume to lower the volume : ) Since your small Jet is made as more of a moderator they may have gave the baffles extra clearance too and you could be getting some blow by. Blow by gas is supersonic and noisy. Try adding a squirt of Break Free CLP. You have a hard to get set up and it will be nice when its all together.

[dflicker]

Mike Brown is actually a big supporter of the 300/221 and builds a lot of them on the 700 action. I'd like to get one of these for my daughter but the price is slowing me down, considering what I've spent on other things in the past few months. At one point he was talking about manufacturing ammo but I don't know what has happened with this. He chambered my Mike Rock AR barrels (12" & 7.5") with a short turnaround time. At one time I considered investing in his company but he didn't get a proposal to me in a timely manner so I increased my investment in LWRCi instead.

At one time LWRCi was going to make the 300/221 a standard offering but since the 6.8SPC has taken off it has been dropped. I doubt if any more will be built, other than my 7.5" upper.