View Full Version : My 300 blkout looks like it has lice inside after I shoot with suppressor...
33539
Noticed this the last couple times I went to the range when I was running my 300 blackout suppressed. The only thing I can think of is spent powder because the gun was clean before.
firefighter37
06-02-15, 17:48
33539
Noticed this the last couple times I went to the range when I was running my 300 blackout suppressed. The only thing I can think of is spent powder because the gun was clean before.
Mine is the same way. Unburnt powder
33539
Noticed this the last couple times I went to the range when I was running my 300 blackout suppressed. The only thing I can think of is spent powder because the gun was clean before.
This happens on many suppressed guns, normally it can be trended to certain powders. It may seem unusual in an AR as it's 5.56 counterpart normally uses powder that leaves more of a soot type of deposit than the flakes.
Rayrevolver
06-02-15, 20:12
What ammo?
I believe I saw a thread (maybe at a 300BLK forum?) about Gemtech subsonic doing this. I have some of their 187gr but have not shot it yet. I bought a bunch of 220gr SMK FOG Ammo and so far nothing like the above residue suppressed.
That looks like Gemtech ammo and the filler or whatever was being put in there.
firefighter37
06-02-15, 21:07
That looks like Gemtech ammo and the filler or whatever was being put in there.
Mine was with Gemtech subsonic ammo
SurplusShooter
06-03-15, 09:00
I've seen this same problem with my hand-loads. It's a problem with unburnt powder left behind in the action. Some powders are much worse than others.
The rifle powders they seem to like high pressures to make a full burn, trying to load rifle powder to subsonic velocities makes it misbehave.
That looks like Gemtech ammo and the filler or whatever was being put in there.
why does that not surprise me that Gemtech would put filler in their subsonic ammo.
Ive probably shot somewhere between 10 and 15 thousands rounds of suppressed, subsonic 300BLK and never thought to myself "hmm, I think I should add some filler to the cases".
A1680 powder is notorious for being nasty dirty when shot with subs. Doesnt look like that though, looks like unburnt grains of powder stuck everywhere.
why does that not surprise me that Gemtech would put filler in their subsonic ammo.
Ive probably shot somewhere between 10 and 15 thousands rounds of suppressed, subsonic 300BLK and never thought to myself "hmm, I think I should add some filler to the cases".
A1680 powder is notorious for being nasty dirty when shot with subs. Doesnt look like that though, looks like unburnt grains of powder stuck everywhere.
Adding filler to handloads is fairly common among older reloaders who would make up subsonic loads (especially for cast bullets) for large cases. I had a coworker who made up cast subsonic loads for 30-06 and used filler in the cases. The 187gr bullet in the Gemtech ammo may be too short to maintain a consistent velocity from the powder charge (i.e. the powder is allowed to move around too much) and they used the filler to keep the powder column packed back by the primer for consistent ignition.
I would agree about it looking more like unburnt powder, though.
It's hard to tell from the picture what the little pieces are. It almost looks like brass shavings. I had a AAC upper with a faulty chamber that would shave copper off the bullet and send it down into the lower as well as gum up in the chamber. Could it be something like that?
Also, the Gemtech 187grn Subsonic 300 Blackout ammo doesn't have any filler in it. I just pulled one apart out of curiosity. It had 11.5grns of powder, not sure what kind.
On an another note, the bullets they use in that ammo don't seem that great. It's a flat base bullet that appears to be plated. I pulled the bullet with a collet style puller and the very slight pressure I used put a big crimp in the jacket. I have pulled and reloaded lots of jacketed bullets this way without doing damage. The Gemtech bullets are just fragile. For what they are charging I would expect a better bullet. I probably wont buy any more than the couple boxes I got to try it out.
Back on topic, I also have experienced unburnt powder from subsonic 300 Blackout getting into my lower and supressor. I was shooting handloads that used A1680. I don't remember the charge though.
Adding filler to handloads is fairly common among older reloaders who would make up subsonic loads (especially for cast bullets) for large cases. I had a coworker who made up cast subsonic loads for 30-06 and used filler in the cases. The 187gr bullet in the Gemtech ammo may be too short to maintain a consistent velocity from the powder charge (i.e. the powder is allowed to move around too much) and they used the filler to keep the powder column packed back by the primer for consistent ignition.
I understand why filler was/is used, but in 300BLK its not needed in my experience. Ive loaded some 90g Hornady XTP's using like 3g of titegroup and I didnt use filler and had zero ignition issues through 100 rounds. IF that aint a HUGE amount of empty case space, I dont know what is!
I understand why filler was/is used, but in 300BLK its not needed in my experience. Ive loaded some 90g Hornady XTP's using like 3g of titegroup and I didnt use filler and had zero ignition issues through 100 rounds. IF that aint a HUGE amount of empty case space, I dont know what is!
Not function issues, velocity inconsistency. I've experimented with the minimum charge in an AE223 round using pulled down powder. I was at about a half full case and saw huge velocity variations as recoil moved the powder around. I would also agree filler's not needed in 300 BLK, just not discounting the possibility of its use.
I believe that Gemtech recently changed. So it would depend on how old his ammo is.
It's hard to tell from the picture what the little pieces are. It almost looks like brass shavings. I had a AAC upper with a faulty chamber that would shave copper off the bullet and send it down into the lower as well as gum up in the chamber. Could it be something like that?
Also, the Gemtech 187grn Subsonic 300 Blackout ammo doesn't have any filler in it. I just pulled one apart out of curiosity. It had 11.5grns of powder, not sure what kind.
On an another note, the bullets they use in that ammo don't seem that great. It's a flat base bullet that appears to be plated. I pulled the bullet with a collet style puller and the very slight pressure I used put a big crimp in the jacket. I have pulled and reloaded lots of jacketed bullets this way without doing damage. The Gemtech bullets are just fragile. For what they are charging I would expect a better bullet. I probably wont buy any more than the couple boxes I got to try it out.
Back on topic, I also have experienced unburnt powder from subsonic 300 Blackout getting into my lower and supressor. I was shooting handloads that used A1680. I don't remember the charge though.
Not function issues, velocity inconsistency. I've experimented with the minimum charge in an AE223 round using pulled down powder. I was at about a half full case and saw huge velocity variations as recoil moved the powder around. I would also agree filler's not needed in 300 BLK, just not discounting the possibility of its use.
Half a case of powder in 300blk doesnt mean much when you are putting a 1.5" bullet into the case.
this round is weird in that I have seen some of the best groups shot that were the least consistent and some that were very consistent shooting like shit. I dont really chrono anything until AFTER I have load developed it. I do OCW work ups(or work downs with subs), find what shoots best in my gun, and move along. As long as subs stay sub, I dont care what they are doing speed wise(unless I am very close to breaking mach, then I may slow them down even more until I find another node down lower) and supers are what they are, but I like to know how fast they are going for a ballistics calculator. Trying to chase low ES and SD's in this round, from what I have seen, doesnt gain you anything. You CAN get great accuracy from this round(I have talked to one of the top end barrel makers and he says .5's are EASY with his barrels with factory ammo), but like all other things AR15 people put a $99 barrel on a gun and wonder why it dont shoot, while my $450 AAC barrel shoots under 1" all day long. Sorry, off on a tangent there.
I did bolt gun load development the other day. subsonic, 208g AMAX, H110. Everybody says "you cant shoot H110 subsonic, not enough case fill, low velocity, not consistent, etc...". Only thing I agree on is subsonic H110 may or may not cycle an AR15, but a bolt gun who cares. This stuff is stupid quiet compared to A1680 load I used as sighters to rezero my scope. Now to be honest my A1680 load is probably getting closer to super than these were and I probably have a little transsonic noise in that round, but it cycles my SBR with and without a can.
I got into a node from 9-9.2 grains of H110. Group on left side of picture was my sighters for zeroing(had zero stops in the scope I raided so couldnt get any lower, but wasnt concerned). The group I am pointing to was the 9.1g group. The 9.2g group is not visible in this picture, but it looked like the group on the right which was 9g. None of the other groups were all that great. No chrono used so I have no clue what they were doing, I know they werent going super and beyond that I didnt care much.
http://img.photobucket.com/albums/v324/rjacobs1/300%20Blackout/0602151344a.jpg (http://smg.photobucket.com/user/rjacobs1/media/300%20Blackout/0602151344a.jpg.html)
...On an another note, the bullets they use in that ammo don't seem that great. It's a flat base bullet that appears to be plated. I pulled the bullet with a collet style puller and the very slight pressure I used put a big crimp in the jacket. I have pulled and reloaded lots of jacketed bullets this way without doing damage. The Gemtech bullets are just fragile. For what they are charging I would expect a better bullet. I probably wont buy any more than the couple boxes I got to try it out...
The bullet is designed for subsonic velocities. Of course the jacket will be softer.
If anyone thinks the residue is actually unburned powder, scrape it out and try lighting it
I believe that Gemtech recently changed. So it would depend on how old his ammo is.
The round I pulled apart was purchased sometime around January 2015, so that is very possible. I don't have any more recently manufactured Gemtech ammo.
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