I'm scratching my head over hear. I went to shoot some 22LR today. I took a custom barreled 16" rifle and my CZ 455 with a 22" barrel. I shot them both suppressed using Wolf Target Match that is advertised at 1050 FPS. I was experiencing super sonic cracks out of the 16" custom barreled rifle. All shots through the 20" CZ 455 were subsonic as expected. Both are bolt guns using a Dead Air Mask.
I did not have a chronograph with me as I was sighting them in to shoot suppressed. The plan was to thin out some squirrels on our hunting lease next weekend. It looks like I'll be taking the CZ.

Same thing happens with my Mask and 80% of the "subsonic" ammo.

I don't know how cold it is where you are shooting but the speed of sound goes lower with the colder temperatures. Ammunition has a summer and winter season when it comes to suppression. You may need to use slower ammo in the winter months if you are shooting outside.

Is this a Mask 'thing' or does this happen with other 22 suppressors?

Cant add much, but wanted to say that The only subsonic ammo ive tried is this Gemtech stuff. Its riddiculously quiet! Only cycles my wifes Beretta 87 with the suppressor on, as expected. Good shit though.

The longer barrel is slowing down the subsonic ammo. The top velocities for 22lr are out of shorter barrels than 20".

quote:

Originally posted by thezoltar:
I don't know how cold it is where you are shooting but the speed of sound goes lower with the colder temperatures. Ammunition has a summer and winter season when it comes to suppression. You may need to use slower ammo in the winter months if you are shooting outside.

Bingo, that is the answer.

At 100f the SoS is 1160fps
At 80f, the SoS is 1139fps
At 60f, the S0S is 1117fps
At 40f, the SoS is 1096fps
At 20f, the SoS is 1073fp
At 0f, the SoS is 1051fps

A good rule of thumb is about 1FPS difference per degree Fahrenheit.

Atmospheric pressure has no bearing on SoS; only temperature and to a very slight extent, humidity.

I was unaware the speed of sound drops in colder temperatures. It was 17 degrees out yesterday when we were shooting. That would make sense.

quote:

Originally posted by swage:
I was unaware the speed of sound drops in colder temperatures. It was 17 degrees out yesterday when we were shooting. That would make sense.

Don't feel bad, most people are unaware of that fact. They all think it's affected by altitude because of the drop in air density. The only thing about the altitude that affects the SoS is the temperature. It's cold where airliners travel.

In long range shooting we have to be aware of that fact insomuch as it may affect calculations. We know that bullets fly slower in dry cold air but the SoS drops also. In my load development, I make sure that my bullet will arrive at the 1000 yard target at above Mach 1.25 in the coldest, driest conditions that I will ever encounter. The load actually goes in at above Mach 1.4 during a South Texas summer, 100pct humidity and 100degrees F. In hot humid air, bullets fly faster.

quote:

Originally posted by PorterN:
Cant add much, but wanted to say that The only subsonic ammo ive tried is this Gemtech stuff. Its riddiculously quiet! Only cycles my wifes Beretta 87 with the suppressor on, as expected. Good shit though.

This surprises me as I’ve run this same ammo in many guns, both suppressed and unsuppressed and had no issues with cycling. Same with CCI SV.

There are a number of factors in play here. First, the Mach speed chart that Nikonuser posted. I've experienced supersonic cracks in cold weather that I don't get on hot days.

Second, barrel length versus muzzle velocity. The site ballistics by the inch has good information --22lr ballistics. For many 22lr loads, barrel lengths beyond 10" add limited additional velocity. Eventually, the friction of the bullet in the barrel begins to overcome the force of the propellant gases, and thus the bullet begins to slow. But that will depend on the load and the barrel.

Third, quirks of each barrel. I have a Kimber bolt action K22 Classic which has a fast barrel, at 22" in length. The ballistics by the inch website's test K22 also shows a fast barrel. For example, Eley Match EPS lists the MV on each box. Using ammo listed at 1058 fps, I get 1131 in my Kimber. With the same ammo, I get 1077 fps in a JP AR-15 upper with an 18" barrel. The JP barrel tends to be 10-20 fps faster than MVs listed on boxes, but the Kimber is consistently 60-70 fps faster than manufacturer's expectations. This means that even in the middle of summer, most of my subsonic match ammo in the Kimber is bumping up against Mach 1. In winter, almost everything is supersonic.

Further examples, measured by a Magnetospeed chrono, in similar summer temps:
Wolf Match Extra -- 1131 in the Kimber, 1034 in the JP
Lapua Center X -- 1097 Kimber, 1020 JP
RWS R100 -- 1177 Kimber, 1105 JP
I could go on with another handful of loads, but the data is similar.

22lr seems to be a different animal than center fire ammo, say like 223.

Fritz,

I was unaware that there could be that big of a variance between rifles with 22LR ammunition. Interesting that there is a 100fps difference between rifles with the Wolf ammunition, as I was shooting Wolf as well. My curiosity is piqued and I'm going to take both of my rifles to the range and run them through the chrono.

I picked up 1000 rounds of SK Rifle match to play with as well. Had I known barrel length could have a negative effect on speed I would've had it cut down to 16" when I sent it off to be threaded.
We could see the bullet nose dive into the snow 150 yards away when shot from the CZ. I don't typically shoot in extremely cold weather like we've experienced here lately. But I'd like to know that I could and have a general idea of what to expect.

quote:

Originally posted by swage:
Had I known barrel length could have a negative effect on speed I would've had it cut down to 16" when I sent it off to be threaded.

It's true that the ballistics by the inch website shows how additional barrel length beyond 14" or 16" doesn't seem to add much (if any) velocity to a 22lr round. But they only go to 18", and they don't use true match ammo, so it's debatable what happens with really long barrels.

Note that my 18" JP semi-auto produces slightly more MV than Eley lists on their ammo boxes. And that my 22" Kimber bolt action produces significantly more MV than the JP. Of course for whatever reason, Kimber sporter barrels seem to be inherently fast.

True competition 22lr rifles tend to have really long barrels -- often around 26" in the Anschutz line. Now much of the reason for that long barrel is to gain accuracy from the front iron sight being so far forward from the rear sight. I can only guess that if Anschutz's 26" barrels were really slowing the bullets, competitors would be griping about pokey ammo, and thus cutting down the barrels. Still, just a guess on my part.

http://www.cci-ammunition.com/...spx?use=3&loadNo=960

^^^^^^^^^^^^
I’ve got some of that and it won’t cycle any of my rifles and none of my pistols unless I have suppressors on the pistols, and only a few pistols.

quote:

Originally posted by Excam_Man:
Is this a Mask 'thing' or does this happen with other 22 suppressors?

No. A suppressor does not increase the speed a bullet travels. The dead air mask is the quietest 22lr suppressor on the market. That is my opinion having shot it next to about every other 22lr suppressor.

quote:

Originally posted by kimberkid:
^^^^^^^^^^^^
I’ve got some of that and it won’t cycle any of my rifles and none of my pistols unless I have suppressors on the pistols, and only a few pistols.

I've had the same experience. Won't cycle the Browning Buckmark or the Ruger Mark III. I assume the problem persists with long guns as well.

The CCI stuff has been relegated to revolver and bolt gun duty.

Gemtech and Eley are the go-to makers of reliable subsonic, semi-auto, ammo for me.

H&K-Guy

quote:

Originally posted by H&K-Guy:

quote:

Originally posted by kimberkid:
^^^^^^^^^^^^
I’ve got some of that and it won’t cycle any of my rifles and none of my pistols unless I have suppressors on the pistols, and only a few pistols.

I've had the same experience. Won't cycle the Browning Buckmark or the Ruger Mark III. I assume the problem persists with long guns as well.

The CCI stuff has been relegated to revolver and bolt gun duty.

Gemtech and Eley are the go-to makers of reliable subsonic, semi-auto, ammo for me.

H&K-Guy

Have either of you tried CCI Standard Velocity? I've never had any cycling issues whether suppressed or not. Typically a lot easier to find that the Gemtech and Eley stuff, usually cheaper to boot.

I've taken to keeping a lot of different standard velocity (sub-sonic) .22lr ammo around for testing. There is a lot out there, and some of it is better than CCI SV, but it's also more expensive and harder to find. I guess where I am going with this is if you're just looking for plinking ammo, you'd be hard pressed to beat CCI SV for price, availability, and performance. Gemtech and American Eagle Suppressor are both great plinkers as well, just a little less common.

quote:

Originally posted by SigM4:

quote:

Originally posted by H&K-Guy:

quote:

Originally posted by kimberkid:
^^^^^^^^^^^^
I’ve got some of that and it won’t cycle any of my rifles and none of my pistols unless I have suppressors on the pistols, and only a few pistols.

I've had the same experience. Won't cycle the Browning Buckmark or the Ruger Mark III. I assume the problem persists with long guns as well.

The CCI stuff has been relegated to revolver and bolt gun duty.

Gemtech and Eley are the go-to makers of reliable subsonic, semi-auto, ammo for me.

H&K-Guy

Have either of you tried CCI Standard Velocity? I've never had any cycling issues whether suppressed or not. Typically a lot easier to find that the Gemtech and Eley stuff, usually cheaper to boot.

I've taken to keeping a lot of different standard velocity (sub-sonic) .22lr ammo around for testing. There is a lot out there, and some of it is better than CCI SV, but it's also more expensive and harder to find. I guess where I am going with this is if you're just looking for plinking ammo, you'd be hard pressed to beat CCI SV for price, availability, and performance. Gemtech and American Eagle Suppressor are both great plinkers as well, just a little less common.

I can't get the CCI standard velocity, and slightly below standard velocity, rounds to suppress. Sonic cracks abound.

I use CCI standard velocity when not suppressed, and it works and cycles fine.

H&K-Guy

quote:

Originally posted by wcb6092:


http://www.cci-ammunition.com/...spx?use=3&loadNo=960

I use those rat shooting and you don't need no steeenkin can.