Something Hits my cheek every once in a while

[MegademiC]

Videotape yourself on an iPhone @ 240fps slowmo and shoot till you feel it and watch the vid. You should see what's hitting you.

[usmcvet]

I was going to say unburned powder when I thought you were a lefty. Try a CH from a different gun. I like the video tape idea. You'll have to share your results!


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[5.56 Bonded SP]

I don't really agree with the shoot it till you figure it out mentality, no offense.

Only time I had a gun blow shit into my face was an AK with fuqed up headspace.. It was piercing primers and such..
I was lucky it didn't literally blow my face off.

I vote take it to a gunsmith, or better yet send it back to BCM on their dime. Something is wrong, and if it was my gun I wouldn't shoot it anymore till the problem is properly resolved.

[militarymoron]

I wrote about the BCM Mod 0 and particles here: http://www.militarymorons.com/weapons/ar.access3.html

Maybe you're getting hit with some coming back off the truncated cone? I'd have someone hold a sheet of paper behind the comp when you're shooting next time to see if some particles are making their way back.

From my writeup:

"The one thing I do find with open comp designs is that I get more particles hitting me in the gas stream than with closed designs when standing to the side. The particles can include unburnt powder, primer residue, copper jacket flux etc. Due to its conical baffle, the BCM Mod 1 does direct particles to the side and forward - more so than the BCE and Flash Comp. The reason that BCM went with an open design was more for consistent flash reduction. The small ports or holes on the closed comps trap the particles better, but then they start building up then combust, causing a larger than normal flash. The open comps tend to have a more consistent flash, whether it's large or small, because they expel the unburnt particles more completely.

Particles exiting any comp can be a concern in a tactical environment, so it's important to note that the BCM comp is really designed to be used on barrel lengths 14.5" or longer. With the right ammunition and barrel configuration, the only particles that will be coming from the BCM comp will be unburnt powder. If the user uses crappy ammo, and/or the wrong bullet weight and rifle twist, you may get copper flux particles, but very little. With the new powders that the military is testing and adopting, this will be a non-issue. The new powders are getting full burn within the first 8 inches of barrel length.

There are advantages and disadvantages to both type of comp designs (open vs. closed). The BCM offers more consistent flash, but possibly increased unburnt particles coming out the sides. With enclosed systems you can have carbon, copper flux and unburnt powder build-up within the comp. The downside to that is the sporadic flash and possible unsafe dislodging of copper flux and carbon, which may damage the comp or act as shrapnel to the person beside you."

[usmcvet]

I wrote about the BCM Mod 0 and particles here: http://www.militarymorons.com/weapons/ar.access3.html

Maybe you're getting hit with some coming back off the truncated cone? I'd have someone hold a sheet of paper behind the comp when you're shooting next time to see if some particles are making their way back.

From my writeup:

"The one thing I do find with open comp designs is that I get more particles hitting me in the gas stream than with closed designs when standing to the side. The particles can include unburnt powder, primer residue, copper jacket flux etc. Due to its conical baffle, the BCM Mod 1 does direct particles to the side and forward - more so than the BCE and Flash Comp. The reason that BCM went with an open design was more for consistent flash reduction. The small ports or holes on the closed comps trap the particles better, but then they start building up then combust, causing a larger than normal flash. The open comps tend to have a more consistent flash, whether it's large or small, because they expel the unburnt particles more completely.

Particles exiting any comp can be a concern in a tactical environment, so it's important to note that the BCM comp is really designed to be used on barrel lengths 14.5" or longer. With the right ammunition and barrel configuration, the only particles that will be coming from the BCM comp will be unburnt powder. If the user uses crappy ammo, and/or the wrong bullet weight and rifle twist, you may get copper flux particles, but very little. With the new powders that the military is testing and adopting, this will be a non-issue. The new powders are getting full burn within the first 8 inches of barrel length.

There are advantages and disadvantages to both type of comp designs (open vs. closed). The BCM offers more consistent flash, but possibly increased unburnt particles coming out the sides. With enclosed systems you can have carbon, copper flux and unburnt powder build-up within the comp. The downside to that is the sporadic flash and possible unsafe dislodging of copper flux and carbon, which may damage the comp or act as shrapnel to the person beside you."

You said it so much better than me. Using a sheet of paper is a great suggestion.


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[tb-av]

I would use a white micro fiber cloth to try and catch what ever it is.

[Doc Safari]

Maybe you're getting hit with some coming back off the truncated cone? I'd have someone hold a sheet of paper behind the comp when you're shooting next time to see if some particles are making their way back.

From my writeup:

"The one thing I do find with open comp designs is that I get more particles hitting me in the gas stream than with closed designs when standing to the side. The particles can include unburnt powder, primer residue, copper jacket flux etc. Due to its conical baffle, the BCM Mod 1 does direct particles to the side and forward - more so than the BCE and Flash Comp. The reason that BCM went with an open design was more for consistent flash reduction. The small ports or holes on the closed comps trap the particles better, but then they start building up then combust, causing a larger than normal flash. The open comps tend to have a more consistent flash, whether it's large or small, because they expel the unburnt particles more completely.

Particles exiting any comp can be a concern in a tactical environment, so it's important to note that the BCM comp is really designed to be used on barrel lengths 14.5" or longer. With the right ammunition and barrel configuration, the only particles that will be coming from the BCM comp will be unburnt powder. If the user uses crappy ammo, and/or the wrong bullet weight and rifle twist, you may get copper flux particles, but very little. With the new powders that the military is testing and adopting, this will be a non-issue. The new powders are getting full burn within the first 8 inches of barrel length.

There are advantages and disadvantages to both type of comp designs (open vs. closed). The BCM offers more consistent flash, but possibly increased unburnt particles coming out the sides. With enclosed systems you can have carbon, copper flux and unburnt powder build-up within the comp. The downside to that is the sporadic flash and possible unsafe dislodging of copper flux and carbon, which may damage the comp or act as shrapnel to the person beside you."

Interesting. Especially the part I bolded. IIRC I've shot nothing but Armscor and PMC since I bought this upper from my girlfriend.

And your estimation of the truncated cone having something to do with it sort of goes with my "gut" on this. I've already ordered a standard A2 flash hider from Bravo Company, and if the problem persists I may just swap them out. Switching to different ammo is not really much of an option since I've got so much of the other stuff.

Literally, this has occurred about ONE time per range session, so I'm debating if I should just put up with it and make sure I've got my full-eyeball-enclosing goggles on when I shoot.

Frankly, I remember when I ordered this upper for my girlfriend, BCM did not even offer the option for a standard A2 hider, or I would have ordered that to begin with.

[1168]

Excuse me if I've missed something, but is it a pin/weld upper? If not try removing the comp and seeing if the problem resolves.

[Doc Safari]

Excuse me if I've missed something, but is it a pin/weld upper? If not try removing the comp and seeing if the problem resolves.

No, it's threaded on, but I didn't want to remove the comp without some pretty good assurance that's the problem. I don't want to get into this round-robin of try-removing-this-part-try-removing-that-part.

[jackblack73]

Literally, this has occurred about ONE time per range session, so I'm debating if I should just put up with it and make sure I've got my full-eyeball-enclosing goggles on when I shoot.

There's no way I would put up with it if it's launching stuff at my face. Maybe someone shoots your rifle without eye pro. Maybe your eye pro gets knocked off. Maybe it gets worse. Stuff happens.