I’ve been through two sets of dies, first the Lee dies, and the latest being the RCBS small base dies. I plan on using the Barnes 110GR Tac-TX, the Sierra 110 GR Varminter HP, the new Sierra 125 GR OTM FB Matchking, and the Sierra 220 GR Matchking for subsonic. I’ve also had major problems with failure to chamber, regardless of the bullet used or OAL.Ĭases were trimmed to 1.358, the middle of the tolerance, and that specified for the Barnes 110 GR Tac-TX, and at least one commercial re-formed case producer I’ve talked to. Pingback: Internet reloading recipes- a cautionary tale | kR-15: info and resources for firearms enthusiasts kR-15.Com neither assumes nor authorizes any person to assume for it any liability in connection with the use of any data. NOTE: Users assume all risk, responsibility and liability whatsoever for any and all injuries (including death), losses or damages to persons or property (including consequential damages), arising from the use of any data, whether or not occasioned by publisher’s negligence or based on strict liability or principles of indemnity or contribution. I run this load recipe on my Lee Precision 4-hole Turret Press and load both factory BLK brass and 5.56 brass trimmed to 300BLK specs. KB ALERT: Winchester or a similar, harder primer are the only safe ones to use in a Lee Progressive loader-be sure you use the correct type of primers with a Lee Progressive system. rI use CCI primers because they are a bit faster burning than Winchester and that’s handy for subsonic loads to help ensure you maximize ignition to help cycle the action. The bolt locks open after the last round clears.Īccurate 1680 is tough to find sometimes but the powder density matches the case capacity very nicely in the BLK. I’m using 220gr Sierra Match HPBT for the projectiles and AA1680 for powder. About 50 rounds of this recipe fired through my 16″ rifle at distances up to 200 yards to punch paper and plink. This is the recipe I use for supersonic loads for my Model 1 300 Blackout Carbine. The BLK was designed to run suppressed too- so if real quiet os your bag and you I enjoy some closer range shooting ( effective hunting range is about 100m). 5.56 ‘heavy’ projectiles weigh in at 75-80gr. That’s a mere 3.4 times heavier than common 62gr 5.56 ammo. The subsonic loads are intriguing: who wouldn’t want to send a 220gr Sierra HPBT for a big, heavy projectile to create high performance at subsonic fps. So if the load works for you I’d stick with it, one of the things about hand loading is you can try different things and find they will work for your gun.The BLK was designed to accommodate both supersonic and subsonic ammo without any tuning or performance headaches. However you also find the faster burning powders don’t typically produce enough gas to reliably cycle an AR. The reason you were quieter with the H110/Win 296 is because it is a faster burning powder, and it likely had much less energy left at the muzzle, then the much slower burning 1680. If it’s a bolt gun, then he might use a powder that gets the velocity, without needing to worry about fueling a gas system.Ī commercial ammo maker has to make a subsonic round that will absolutely cycle the rifle so they will load as hot as they can, but still keep the bullet velocity below 1100fps. So a handload with 1680 might be quieter and subsonic if the guy loading the road has a 16in barrel and he’s loading it so it just barely cycles his firearm. It depends on how much energy is left in the powder at the muzzle. The problem is “Quiet” is more then just a function of powder.

300 blackout subsonic loads