Subsonic 556 load data1/7/2024 ![]() You'll be needing that Nemo spring and a chronograph. If you would to Beta test the load - email me. I have a carbine 16" 1:9 barrel, SBR with 10.3" 1:7 barrel, Service Match with 20" 1:9 barrel, Ruger Hawkeye stainless carbine 1:9 bolt gun and several cans. With a range just 4-5 minutes down the road I have no troubles testing. I live in Alaska and have a nice place to shoot the next street over - so - my normal routine the past years has been to fire a string or two after dinner and then load a new set of test rounds before bedtime for the next day. If anyone has any better ideas - I would love to hear it. If your shooting buddy wants the data - just send him to me so I can get him on the list. That would allow me to develop an email list of 'users' so if someone does discover a firearm or condition where there is a problem I can flash the info out to everyone at once. I would like to share the load data with some of the people here - people that can keep it a secret. I am quite satisfied the load is safe - I've been working with it up and down the scale for years - and using it in several carbines and SBR's. ![]() Great for the bolt gun guys but not for us gasser's. Everyone is spinning their wheels with Traiboss, Clays, and Titegroup that have published non-cycling loads. I searched online - nobody is working with the powder that does the trick. If you decide to try this - avoid the matte color, these have abrasives added to make them matte. They look great - but - seem to move 50-70 fps faster than Allox lubed. I was experimenting with powder coated cast bullets. that would be just over the top awesome to get folks with a can and 1:9 barrels into this. then moving to 68/69 grain HPBT by mid July. I will probably be working on 78gr cast rounds next. I can also get 75gr Hornady A-Max that are too big for a mag to cycle - but - I do get the 75gr Hornady HPBT to be subsonic and cycle just fine - and those fit in a mag. Guess what happened when I put that in my 5.56mm? I got 77gr Sierra HPBT that fit in the mag to cycle just fine subsonic. That buffer spring made a nice difference in the 300Blackout subsonic loads and ease of cycling. and learned of the Nemo custom buffer spring. Past 7 months I have been working with 300Blackout subsonics. Less than 80gr I could not get anything subsonic to cycle. Then 80gr Berger HPBT that were too big for a mag but cycled - then I hit a road block. I was able to replicate their load - buy several hundred of their projectiles and duplicate it - then walk that 100gr load down to 90gr Sierra HPBT that were too big for a mag, but cycled. I was inspired by the 100gr subsonic rounds made by Extreme Shock that cycled. In the case of the 7.62 Thumper XCR SBR, 12 grains of 4227 or 11 grains of SR-4759 over 220gr-240gr bullets will shoot right about 1000fps and, with a suppressor, provide enough pressure to reliably cycle the action.ĮmptorMaven » Blog Archive » 7.I started working on suppressed AR-15 223/5.56mm loads 7 years ago. After significant research and testing I have found that the two best powders for subsonic SBRs are IMR 4227 and IMR SR-4759. ![]() The new standby for subsonic loads, TrailBoss, is too bulky to work in any rifle cartridge capable of firing and cycling both high-velocity and subsonic ammo. ![]() Hopefully they will produce enough gas to cycle the action consistently. The fastest powder I've loaded (not fired yet) is IMR SR-4759 although I traded for some VV-110 and VV-105 that I will be trying soon. Those fast powders wont cycle the action, check out the XCR thumper article. Red dot and the others mentioned are TOO fast and that article does not mention that they are fired through a bolt action. Yes I have some brass drilled out to 9/64th I think it was. ![]()
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |