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Gemtech question

BillOrrBillOrr Member Posts: 99 ✭✭
edited March 2014 in Ask the Experts
I have gemtech 2 that is relatively new, only a few hundred rounds through it.

I have 2 platforms I use it on: Ruger 10/22 and walther P22

Now.

When I screw that thing on the P22 it'll shush just about anything I put through it. Super-sonic, Sub-sonic, sonic-the-hedgehog, etc all quieted significantly. There are no special upgrades or changes to the P22, it's factory.

When I screw it onto the after-market 16 inch fluted tactical solutions barrel of my 10/22 it only quiets the sub-sonic rounds. The super-sonic stuff sounds just as loud with or without the suppressor. I am by no means the world's foremost authority on firearms but I'm thinking that the longer barrel should make it even more quiet right?


Any ideas as to why this is would be much appreciated.

Thanks,
Bill

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    dcs shootersdcs shooters Member Posts: 10,969
    edited November -1
    The short barrel P-22 is not long enough to get LR sonic as the 1022 barrel will do [;)]
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    rufe-snowrufe-snow Member Posts: 18,650 ✭✭✭
    edited November -1
    1100 FPS is the rule of thumb. Although a lot of variables will affect this. Short barrel pistol under 4", most all ammo is under this velocity.

    Rifle with a 16" barrel, completely different kettle of fish. Your going to have to buy ammo that is classed as subsonic. That is under 1100 FPS from a rifle.
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    BillOrrBillOrr Member Posts: 99 ✭✭
    edited November -1
    Excellent. Thanks for the quick responses. The short barrel thing I should have known... Duh.

    The reason I figured it would be quieter is because I can shoot "super-sonic" ammo through my Remington 597 (which I believe is also a 16 inch barrel?) and I don't need ear pro. Doesn't make sense to me why it would be super quiet without a can on one barrel (597) and super loud with the can on another (10/22)...
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    tsr1965tsr1965 Member Posts: 8,682 ✭✭
    edited November -1
    Rufe has this one covered pretty well. If you are over 1080 FPS, under standard conditions for laboratory testing, you will be traveling above the speed of sound. In other words, you are breaking the sound barrier. It does not matter how big of a muffler you put on it, if that bullet is traveling above 1100 FPS for sure, it will break the sound barrier. They have air rifles out there now, that sound like a 22LR, or 22 WMR, because they are breaking the sound barrier.

    If you get some standard velocity ammunition, which most target rounds are, they are usually rated around 1000-1-40 FPS...you will get your accuracy, and silence...and we all know, that silence, is golden.

    Best
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    BillOrrBillOrr Member Posts: 99 ✭✭
    edited November -1
    Thanks a bunch guys, much appreciated
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    62fuelie62fuelie Member Posts: 1,069 ✭✭✭
    edited November -1
    An option you may consider is one of the after-market quick-twist barrels that will stabilize the Aquila SSR 60 grain .22 round. These are loaded to sub-sonic velocities, but the weight gives more kinetic energy. If your Gemtech is a "wet" can or an either/or type a tablespoon of water sloshed around inside it before screwing it on the barrel will quiet it even more (good for 2-4 shots).
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    beantownshootahbeantownshootah Member Posts: 12,776 ✭✭✭
    edited November -1
    quote:Originally posted by BillOrr

    When I screw that thing on the P22 it'll shush just about anything I put through it. Super-sonic, Sub-sonic, sonic-the-hedgehog, etc all quieted significantly. There are no special upgrades or changes to the P22, it's factory.

    When I screw it onto the after-market 16 inch fluted tactical solutions barrel of my 10/22 it only quiets the sub-sonic rounds. The super-sonic stuff sounds just as loud with or without the suppressor. I am by no means the world's foremost authority on firearms but I'm thinking that the longer barrel should make it even more quiet right?

    Answer already given.

    So called "supersonic" ammo is still subsonic from a short barreled pistol, explaining why its quiet in that platform.

    When you fire supersonic ammo from a long barrel, the bullet makes a crack **AFTER** it leaves the barrel so long as the bullet is travelling faster than the speed of sound. A suppressor CANNOT reduce or remove this crack, explaining why most shooters who want truly silent shooting try to keep their rounds subsonic.

    If you want your shots from a rifle to be quiet the EASIEST way to do that is to use ammo that will remain subsonic from a rifle. As mentioned most match ammo will do that, as well so called "subsonic" ammo (including the 60 grain Aguila "subsonic sniper", which runs better from faster than normal twist barrels).

    For what its worth, I bet if you measured the sound pressure on a dedicated machine you'd find that even the SUPERSONIC ammo was quieter with the suppressor in place, just not all that much quieter. Military snipers and such typically still do use suppressors even with supersonic rounds, because of this. . .even thought the shot won't be quiet, by muffling the muzzle crack (which is what the suppressor does) it helps make it harder for observers/listeners to pinpoint the origin of the shot.

    quote:The reason I figured it would be quieter is because I can shoot "super-sonic" ammo through my Remington 597 (which I believe is also a 16 inch barrel?) and I don't need ear pro. Doesn't make sense to me why it would be super quiet without a can on one barrel (597) and super loud with the can on another (10/22)...
    The explanation there is pretty simple. I bet the ammo in question is BARELY supersonic from the Ruger, but not supersonic from the Remington. Only a few feet per second difference can make a round super or sub-sonic, and different barrels (ie different guns) can easily shoot the same ammo +/- enough velocity difference for this to happen.

    EDIT:
    Note that under certain conditions, particularly with cheap promotional "bulk pack" ammo, ordinary variation in round velocity between rounds **FROM THE SAME BOX THROUGH THE SAME GUN** can make some shots supersonic and some subsonic. It can be a little "vexing" on the range when you can hear this difference between shots!
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