View Full Version : Char? On 9mm rounds.
August 12, 2012, 07:51 PM
Remington UMC JHP 115gr.
firing from used Kel-Tec Sub-2000.
ejected rounds all seem to be 75% charred down the round.
weapon performed flawlessly in every shot.
Would this be normal due to increased pressure of a 9mm carbine or is it indicative or perhaps wear and too much gas coming around the round when firing?
I.E. should it be cause for alarm?
August 12, 2012, 08:04 PM
Might have something to do with the fact that the gun uses a blow-back operating system. My guess would be a bit of a loose chamber area to aid in floating the case out as the gun cycles... perhaps?
August 12, 2012, 08:11 PM
It did not seem to affect the performance at all, and amazingly quiet for the fact as well. Could comfortably shoot without plugs.
I have just never seen this, and since it is used, thought it prudent to ask.
August 12, 2012, 08:17 PM
It was just a educated guess on my part. I've seen rings and stuff in chambers of some weird European blow-back pistols, and H&K uses a fluted chamber in the "gas delayed blow-back" system on their P7 models to aid in extraction.
Shoot Kel-Tek an e-mail tomorrow. They don't mention blow-back in their description of the gun... so who knows? :rolleyes:
Shoot without plugs? :eek: Does it have a can on it?
August 12, 2012, 08:26 PM
I had considered it because I figured if I were to ever use it anywhere but a range, it would be bad (would still bet it is uncomfortable in an average room).
But really outside, it is comparable to a large fircracker. Just guessing because I do not have a meter, but shooting the same rounds a factor of 1/3 of the noise generated in my handgun.
Had I shot it after the .223 I would have sworn it was hearing loss.
chris in va
August 12, 2012, 08:30 PM
Blowback. My HiPoint did the same thing.
August 12, 2012, 08:43 PM
So no cause for alarm, just a different MO for the mechanics?
I will ask Kel-Tec, see what they say, will post if they respond.
August 13, 2012, 06:25 AM
It is because the case is not swelling up enough to seal off the chamber. It is perfectly harmless. Since the 9mm case has a very slight taper you really don't want it to expand too much, it would wedge the case tightly in the chamber and the extractor would have a hell of a time pulling it out. It has nothing to do with the gun using blowback operation.
chris in va
August 13, 2012, 10:28 AM
Well, if that is the case then why don't my 9mm get dirty from use in my CZ with locked breech. Sorry but that statement makes no sense.
August 13, 2012, 12:54 PM
Maybe the statement sounds wrong but it's right. On very many low powered cartridge rounds, this includes nearly all handgun rounds, the case just doesn't expand enough to completely seal the chamber. It really does NOT hurt anything. The reason a round will seal better in one gun than another is caused by a lot of things including the weight of the bolt/slide and the tightness of the chamber.
August 13, 2012, 02:14 PM
Since the 9mm case has a very slight taper you really don't want it to expand too much, it would wedge the case tightly in the chamber and the extractor would have a hell of a time pulling it out.
It's tapered, but the taper is such that the mouth is narrower than the base (9.65mm vs. 9.93mm). So I don't think it would get stuck at any rate.
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