Use of subsonic ammo

Discussion in 'Silencers' started by EyeBall, Oct 21, 2011.

  1. EyeBall New Member

    EyeBall
    While I wait on the Form 4 to clear on my 30P-1, I continue to make noise at the range. Recently, I witnessed a .308 suppressed rifle using CorBon 185 gr subsonic ammo - it was scary quiet. What is Thunder Beast's view on using subsonic ammo in your cans?
     
  2. Zak Smith Operations

    • Instructor
    Zak Smith
    [​IMG]

    There's no problem with it, if the bullets stay stabilized. I've shot a bunch of subsonic 210's up to 240's through my 30P-1 from my .300 Fireball upper and it works great.

    This question usually revolves around warranty. You can read our warranty in detail, but in this case it basically comes down to, if you get a baffle strike because of improper bullet/twist combination or anything we didn't screw up in the suppressor ourselves, it wouldn't be covered by warranty. The way we put the suppressors together it's impossible to get crooked threads, and we've never had a baffle strike in a production suppressor to my knowledge.

    Before shooting subsonic rounds through the suppressor, I recommend shooting about 50 of them at cardboard at 50 or 100 yards. If you can account for 100% of the rounds and all the holes are perfectly round, you're good to go*. If you get any keyholes or any rounds are not accounted for, you need to fix the load before you try to shoot it through the can.

    Usually if you decrease bullet length or choose a bullet that has more blunted/flat ends, like a round nose hunting bullet with no boat tail, it will be more stable than a BTHP of the same weight.

    hope this helps
    Zak

    * in the current ambient conditions and provided the ammo is consistent
     
  3. EyeBall New Member

    EyeBall
    Thank you for the speedy reply. Great advice on getting consistency on paper before trying the can.
     
  4. Old Bob New Member

    Old Bob
    GIDAY, new here. Hope I can learn and pass on what I know. Now owning a silencer in Australia is an offence but once they could be bought over the counter. If you load your own ammo use fast shot gun powder and try putting a BTHP projectile in back to front as it will tend to stablize better at the under the speed of sound speeds. As the case may only be a third full, a wad of foam as a filler works and burns up. A 45-70 with about 12 grain of shotgun powder with a 500 g cast hollow point will drop most things out to 150 meters. We used to mix half wheel weights and lead lubed with beewax and "Tetrol" (anti rust soup) mixed together with a little heat and NO LEAD FOULING even after a 100 shots. Had a bullet mold that was 650 but found the500 g shot better. The most noise is the thump of the bullet hitting flesh.
     
  5. scap99 New Member

    • Thunder Beast Shooter
    scap99
    Will my 30P-1 hold up well on a 16" .300BLK AR?
    I don't want to overheat it, but would like to be able to shoot it reasonably fast. Not looking to mag dump, just play at the range.
     
  6. Zak Smith Operations

    • Instructor
    Zak Smith
    It'll be fine.
     
  7. Old Bob New Member

    Old Bob
    As we all know echelon? checks all, but memory from the past my bisiness? Out here all the nice gear you guys can get is impossible here. So people have made there own. No need for threads make it so it slips on barrel and comes back to wood work(or plastic) Gives more area for expanding gas and held by a turn clip . Baffles are spaced on bullet length before ogive and a 30 mm space before baffle's. Behind barrel just space for gas so .30 cal. stuff works well with cast bullets. Also small 22 with 50mm barrel worked but with longer barrel failed because of breach opening before bullet exited. Chinese 7.62by 39 sks and skk work by changing bullet weight to 160 g from 130 plus silencer. Projectiles from sks ammo are .312" which are usable in .303. The Chinese ammo that has a cunard grove(hope that's spelt right)have a hard insert for flack jacket but are only suited for full auto as they did scatter. Easy checked with a magnet for steel insert.
     
  8. Cut2fix New Member

    Cut2fix
    Similar question to scap99:
    Just picked up an AAC9" upper in 300blk. Was hoping to use it for hog control on an upcoming hunt with my 30P-1. Paperwork just cleared on my 2 30P-1's last month. They are fantastic on my GAP .308 & 300WM, and I don't want to put them at risk. Any issues shooting factory Rem 125 supers or 210 subs?

    Was also wanting to try my new 223A on my LWRC PSD 8" 5.56 upper. There is no gas switch on the upper. Have you guys tested this combo? Any reason not to use it?
     
  9. Zak Smith Operations

    • Instructor
    Zak Smith
    As long as they are 100% stable, no issues.

    Haven't tested the 223A on the LWRC, but it works fine on our 7" Sabre.
     
  10. EyeBall New Member

    EyeBall
    I expect to get the pretty blue stamp for my 30P-1 in about a week. In the meantime, I performed subsonic ammo accuracy tests as recommended by Zak.

    Basically, the .308 rifle with 1:12 twist would not stablize the Corbon Subsonic bullets. Posting targets at 50 yards, the group was horrific. It looked more like a shotgun blast loaded with scrap metal, with rounds hitting all over an 8" area and many were keyholing.

    Using a different rifle, with a 1:12 twist, resulted in tight groups, hitting 6" below point of aim.

    I'll try to post photos.
     

    Attached Files:

  11. Zak Smith Operations

    • Instructor
    Zak Smith
    What weight are the Corbon bullets?

    If you're up for it, loading a more conventional weight bullet for a 1:12 .308 would be safer to prevent baffle strikes.
     
  12. EyeBall New Member

    EyeBall
    This is Corbon's factory load, Subsonic 185 grain FMJ-RBT. The reason I have experimented with this ammo is that I witnesssed how darn quiet it was from a Rem 700 w/1:10 twist and a can in October, 2011. This is a special purpose round, in my opinion, as the shooter told me he limits shots to 100 yards, because the round really drops off after that distance.

    I do not reload at this time, although I have been researching the activity for the future. I reviewed your notes about the round nosed and flat base bullets, so I may postpone using any subsonic ammo through the soon-to-be-in-my hands 30P-1. Between the purchase cost and the long wait to get the paperwork processed, I do not want to be hasty and damage the new can with the silly-quiet special purpose subsonic round, until I gain some more experience.

    My Rem 700 LTR rifle with 1:12 twist bull barrel performs well with Federal Gold Medal 168 grain SMK and Hornady 165 grain SST. I get similar performance from a Rem 700 ADL with 1:10 twist standard barrel.
     

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