CCI 22LR Subsonic Issues
My nephews wanted to shoot. So, I set up a backstop in the yard and broke out the suppressed Ruger 10/22. We’d shot for a while and, with that set up, all you’d hear was the bullet hitting the backstop. Then, suddenly, quite a few rounds started going supersonic and that was annoying. I was using CCI 22 (this kind). Is CCI ammo that inconsistent or is it indicative of some other problem?
February 5th, 2010 at 10:28 am
Does your Ruger have a ported barrel or are you using a can? Jack.
February 5th, 2010 at 10:31 am
can. gemtech outback 2
February 5th, 2010 at 10:55 am
I’ve personally had a lot of consistency issues w/ CCI brand in my Marlins. I use the Remington Subsonic and haven’t had any issues w/ it.
February 5th, 2010 at 11:00 am
Lots of things can lead to rounds going supersonic or transsonic. That ammo (at least according to the manufacturer) is at the top edge of subsonic – and if you’re in a cold environment or at a higher altitude the speed of sound is lower.
Plus .22 ammo can be pretty inconsistent, so it could be no more than an ammo issue.
About the only problem I can think of that would be can-related is if you’ve managed to fill it with lead. Unless you’ve put over 10k rounds through it that’s unlikely.
February 5th, 2010 at 11:07 am
Granted I shoot high velocity stuff since it helps my semi .22s cycle (P22 and Armscor AK-22, which is very picky). I’ve found that for me Federal stuff is the most consistent priming and the most consistent performer.
Remington Thunderbolt/Golden Bullet is awful. Winchester is ok. CCI is good. Federal is the best. The priming backs this up and I think really helps .22 consistency. If you pull some bullets and then look at the priming compound and then pop them it will back this up.
Remington is a dull dirty green and not spread very well. It makes a quiet pop when you shoot the primed case only.
Winchester is a step up from Remington in primer color, spread, and loudness.
CCI makes is a bright green and is well spread and makes about the pop of a cap gun.
Federal looks like the CCI but maybe thicker priming and go “BANG” to the point where I wished I would have had on hearing protection.
February 5th, 2010 at 11:30 am
Rounds move faster the warmer they are. Once the chamber and bbl were heated up, you probably just went over the threshold of being super-sonic.
February 5th, 2010 at 11:43 am
This looks like a good excuse to buy a Ballistic Chronograph 😉
February 5th, 2010 at 1:03 pm
I did similar experiments with a number of ammo brands and settled on CCI Green Tag for suppressor use.
February 5th, 2010 at 2:07 pm
barrel length?
February 5th, 2010 at 2:09 pm
16.25inches
February 5th, 2010 at 2:20 pm
Could a lead/lube buildup in the bore cause enough of a restriction that it alters the pressure curve of the rounds?
February 5th, 2010 at 4:17 pm
The VP of our shooting club is pretty OCD, and actually sat down and ran a lot of different brands of .22LR through a chronograph to find the most consistent stuff to use for silhouette shooting. I don’t recall the exact numbers. But I do recall that all the more cost effective brands (CCI, Winchester, Federal, etc.) had fairly significant standard deviations, especially the bulk boxes.
However, since yours weren’t drifting back and forth, but went supersonic and stayed that way, I would suspect it’s more likely a temperature related issue as mentioned by Diomed.
February 5th, 2010 at 6:07 pm
I saw that Remington standard velocity never jammed my .22 so I stuck with it for thirty years. Quien sabe?
February 5th, 2010 at 8:15 pm
Are you sure the bullets went that fast, or were you going by the sound only? Shooting with a can here on a .22 pistol, we observed the report getting significantly louder as it warmed up, or was filled with exhaust gas, or both. Several things are changing; the gas medium inside the can, the temp inside the can, and the temp of the chamber/cartridge/barrel. The bullets may be getting faster, but the whole system is changing too.
February 5th, 2010 at 8:21 pm
sound signature definitely increased down range, with a pop. Definitely super sonic.