300 Blackout Subsonic Load Data

[j706]

All right I have been attempting to work down a 220 SMK subsonic 300B load. There is all kinds of data online but I can't seem to find one that I can get below 1040 fps or so with what I have to work with. At the time I am kind of limited to Trail Boss, H110 and Lil-Gun with CCI mag primers. My barrel is a Wilson Combat 1/8 10.5" (w pistol gas) with a YHM QD Phantom suppressor. I have had success in getting it slowed down with stable bullet flight but still getting the sonic crack. I just now tried some loads of 9.9 grns of H110 (listed as a min load from my source) at 2.260 COAL. They cycled fine, were stable but no not to quite. What says you INGO 300 BO guys?

 

[avboiler11]

Online, I see 8-8.2gr LilGun works with PISTOL GAS and 200-220gr bullets.

I'm thinking of getting into 300 AAC or 450 Bushmaster for hunting, but Lil Gun seems like unobtainium right now...

 

[BroodXI]

Online, I see 8-8.2gr LilGun works with PISTOL GAS and 200-220gr bullets.

I'm thinking of getting into 300 AAC or 450 Bushmaster for hunting, but Lil Gun seems like unobtainium right now...

can you hunt with 300aac in long gun now? besides just hogs?

 

[avboiler11]

can you hunt with 300aac in long gun now?

Long gun? No.

AR pistol? YES!

 

[jblomenberg16]

Just to be clear, this isn't "Official" advice and you are responsible for results and all that good stuff...but try about 9.5 of the H110. Also, load as long as you can, which seems to be about what you have listed for your OAL. I've noticed in my sub loads that because you are using a very small quantity of powder vs. case capacity, that the results seem to vary a lot with OAL. For my particular gun it seemed like longer was better.

 

[j706]

Just to be clear, this isn't "Official" advice and you are responsible for results and all that good stuff...but try about 9.5 of the H110. Also, load as long as you can, which seems to be about what you have listed for your OAL. I've noticed in my sub loads that because you are using a very small quantity of powder vs. case capacity, that the results seem to vary a lot with OAL. For my particular gun it seemed like longer was better.

I am somewhat leery of using H110 in reduced loads. I do not have much experience with H110 but did read quite a bit about it getting weird in reduced loads. I have a few pounds of it but I think I will use it for regular loadings. I have a1680, Trail Boss, H110 and Little Gun to mess with on this caliber. All my other powders are more on the medium to slow on the burn side (5.56,308 ect) FWIW I have found a nice load of 10.0 Trail Boss with a 175 SMK for my .308 It is pellet gun quiet and fairly accurate although it is like shooting an mortar. I have to go up 8 moa from my Black Hills 175 zero for my sub load zero at 100 yrds!!

 

[poisonspyder]

10.9 grains of 1680 with a oal of 2.089 is a perfect load for my 9" 300 with yhm can. Chrono numbers were 1000fps give or take a few fps each shot from a ced Chrono.

I ran the h110 a few rounds and found it was not consistent. I would use it for a supersonic load. 125 grain balistic tips from nosler worked great with 18.8 grains of h110 at 2.15. 2050 fps FYI this is .8 over max load but slightly longer oal. To short of a oall and my gun wont cycle correctly. The 3rd round left in the mag caused failure to feed every time because it nose dives in the mag When oal was below 2.09.

 

[jblomenberg16]

I am somewhat leery of using H110 in reduced loads. I do not have much experience with H110 but did read quite a bit about it getting weird in reduced loads. I have a few pounds of it but I think I will use it for regular loadings. I have a1680, Trail Boss, H110 and Little Gun to mess with on this caliber. All my other powders are more on the medium to slow on the burn side (5.56,308 ect) FWIW I have found a nice load of 10.0 Trail Boss with a 175 SMK for my .308 It is pellet gun quiet and fairly accurate although it is like shooting an mortar. I have to go up 8 moa from my Black Hills 175 zero for my sub load zero at 100 yrds!!

No worries at all, and 1680 is a good powder as well, as noted by j706. I've even had some luck with 4198, although that on the verge of being "too slow" for my short barrel.

 

[j706]

I think my problem has been with my OAL.

 

[david890]

Have a look at this: