300 AAC bullets or 308?

[DIYguy]

I have Berry's Bullets in 220g and 150g spire point currently. Have the 220g worked up for subsonic at 1,090 FPS with 16" barrel and suppressor. Built the 16" gun so I didn't have to deal with the NFA. Decided to "bit the bullet" and did the paperwork for the SBR, that's submitted, approved, now waiting for stamp. I've already received my 8.5" barreled upper, new optics ordered and will now have two blackout guns, one 16" one 8.5", both suppressed. I want to keep the SBR running at 1,090 FPS but going supersonic with the long barrel.

With all that said, Berry's are rated not to exceed 1,650 FPS for the 150g. I really want to run more in the 1,900 FPS range or slightly more depending on what the barrel likes for groups. Haven't been having much luck finding 150g reload bullets for blackout. My question is, do 308 bullets work in 300 AAC? I believe they SHOULD work but that doesn't mean they actually do. Can get Hornady 308 150g FMJ-BT in bulk locally but don't want to make the road trip and spend the money if not going to work as anticipated.

[Sigarmsp226]

Yes - You can use any 308 Winchester bullet for 300 Blackout.

[Joe4d]

Bought a case of 300 reloads that was loaded with surplus pulled 308 147 grainers.. Ran fine. 
ALso Winchester loads their deerseason 300 150 grn poly tipped hunting ammo with the same bullet they use in the 308..
Runs and is accurate, but a bone head move by WInchester IMO,,, as they dont expand at all at 300 AAC velocity.  Especially considering they have 140 years of 30/30 bullet experience. I would think one of those would have made much better deer ammo

 

[DIYguy]

While the diameter is the same I was slightly concerned about bullet length. The bullets that are listed as blackout are spirepoint which is slightly more rounded, bit shorter point. Magazine length is a hard measurement and makes a difference. I found with my bolt guns they like a short jump to lands and bullets like Sierra worked great but Hornady ELDs where breaking the tips of. Wasn't sure if the profile of the average 308 was different and longer since totally difference magazines.

 

I did make the long road trip to my local supplier and pick up (500) of the Hornady 150g 308 FMJ-BT and going to try Starline brass this time. Been using Carolina Brass so far which is re-manufactured 223 and 5.56 but a LOT of prep time chamfering and beveling the necks and chamfering/sizing the primer pockets. Primers still crunch a bit in the Dillon.

[DIYguy]

Had to send the 8.5" BLK upper back to manufacturer for repair, "please allow up to 30 days to complete repair".

Been working up new pistol loads so yesterday was finally able to make it to the 100yd to run some test on the BLK. Plan is to set up the 8.5 for subsonic loads and the 16" for super. Mounted the new LPVO 1-8 optic on the 16" upper.

Loaded a small batch of the 150 FMJ-BT at 15.8 of Lil-Gun as a test point and had pretty consistent velocity of 1,983fps average with (20) rounds, four strings. Took my data for the loads and velocity and set it all up in QuickLoad and was surprised that my velocity hit the Optimum Barrel Time Node right on but according to QL that load is five lines into the "DANGEROUS LOAD-DO NOT USE" ?? Hornady manual says 15.7 is at 1,800fps but not sure barrel length. 15.8 looks like perfectly good load??

 

While at the range ran into JP (JP Precision Rifle), had a good catch-up chat and talked loads. He recommended skipping the 150s and load 125 for supersonic. From what I've been seeing/reading H110 which is what I can get locally is the recommended powder for that weight and supersonic. Down side, having trouble finding 125g bullets at a decent price.

 

Opinions on Lil-Gun / H110?

Experience with loads at 125 & 150?

Preferred velocities with 16"