What makes a suppressed .22LR semi-auto run reliably with subsonic ammo?

[benenglish]

In another thread, it was observed that reliably quiet subsonic rimfire ammo "Won't cycle in anything without heavy mods".

If someone wanted to build a semi-auto rifle (say, starting from a 10-22) with a suppressor that's almost never removed and using only subsonic ammo, what sort of mods are required to get it to function reliably?

Same question, again, but for a pistol (say, starting from a Ruger MK)?

And the same question, again, but for a Ruger Charger takedown? (This is probably the same as the first question, but I'd like formally note each of the three use cases I'm considering.)

I may start the process of getting a suppressor this year and this line of inquiry would be helpful. TIA for any thoughts.

 

[dermunkee]

For a Ruger 22/45 the secret sauce is CCI SV on a broken in gun run fairly wet. It took ~750 rounds of HV ammo to get the recoil spring flexible enough to run SV ammo reliably along with the LCI delete on my Mk III. A good scrub down every 500 rounds to get any grit from inside the upper and around the bolt and rubbing oil all over the bolt (not dripping, but wet) will keep it running well. Essentially, the secret is to keep things as frictionless as possible, since SV will not reach it's rated speed in the short barrel.

I don't have a 10/22, but I do have a Savage FV-SR, and have had a couple of CCI SV rounds go super on really cold days (around freezing), so I'd be willing to bet your 10/22 would have the same behavior with regards to sub vs. super.

I think the only way you could potentially run CCI quiets in a 10/22 would be to have a reduced power recoil spring and get rid of as much reciprocating mass in the bolt as possible. I know they made a 10/22 Lite, but I'm not sure if the only weight savings came from the aluminum frame or if they actually reduced weight in that bolt.

This bolt: https://volquartsen.com/inventory_configurations/1083 states it's actually meant to run CCI Quiet on a 10/22. I'm a big fan of VQ and use a few of their parts in my 22/45.

 

[dermunkee]

I may start the process of getting a suppressor this year and this line of inquiry would be helpful

Also just noticed this part of your message. I would HIGHLY recommend getting one with stainless steel baffles, especially for a rifle. You can get lighter aluminum ones, but rimfire cans are a huge pain to clean. I bought a rock tumbler and stainless steel pins because I got so tired of scrubbing. I'm currently trying out different coatings to see if any of them have an impact on cleaning.

If you want to try my Element 2 on your 10/22 some time, let me know and I'll see if we can arrange a time/place to meet up.

 

[benenglish]

Useful info, dermunkee. TYVM.

 

[Brains]

An option that seems to work well for me is a heavier slug. I can run the Gemtech 42gr. 22LR in my 22/45 and my Mist-22 10/22 TD quite reliably.

 

[smittyb]

My 22/45 and Charger both run subsonic ammo just fine, suppressed or not.
My buddy has got a 10/22 that he got to run CCI Quiets by polishing the bolt and using a lighter recoil spring. I’m not sure I would want to run high velocity ammo in it, though.
I would not necessarily agree with the advice to get a SS can. Sure, they do open up more cleaning methods, but at the expense of being a lot heavier.
I would strongly suggest a mono core baffle though. K baffles just aren’t meant for rimfires, unless you have to have a modular can. Same buddy with a Tac Sol K baffle can will tell you the same thing, he is envious of my monocore can.
My monocore aluminum baffle is a breeze to disassemble and clean. I usually just unscrew the end cap, give the tube a few twists and blow it out. When it does require cleaning, simple soap and water with a toothbrush does the trick.
Ben, you are also welcome to shoot my guns and suppressor anytime.

 

[mroper]

Thanks for asking this question I have been thinking about the Same. I will try this in my S&w victory and 10/22 with ryder suppressor and report back.

 

[grumper]

I didn't have to do anything to get Fiocchi subsonic to work in my Ruger Mk III

 

[dermunkee]

Useful info, dermunkee. TYVM.

You're welcome

I would not necessarily agree with the advice to get a SS can. Sure, they do open up more cleaning methods, but at the expense of being a lot heavier.

On a rifle, a few ounces won't make much of a difference, but it becomes pretty noticeable on a pistol. If you're on top of your cleaning after every range session, I'm sure it's easier. I'm not that good about cleaning, so SS baffles were a priority for me. If I had a soda blasting cabinet, I'd probably look into an aluminum monocore just for pistols.

 

[Joshua - Capitol Armory]

Subsonic should work fine in pretty much any semi auto. If subsonic ammo isn't working in your gun, something is wrong.

CB and boutique ammo like CCI Quiet is a different story. That's not really "subsonic ammo" - it's a whole different beast.

 

[Joshua - Capitol Armory]

I would strongly suggest a mono core baffle though. K baffles just aren’t meant for rimfires, unless you have to have a modular can. Same buddy with a Tac Sol K baffle can will tell you the same thing, he is envious of my monocore can.
My monocore aluminum baffle is a breeze to disassemble and clean. I usually just unscrew the end cap, give the tube a few twists and blow it out. When it does require cleaning, simple soap and water with a toothbrush does the trick.

Yeah, but aluminum cans are a nightmare to clean and much easier to damage. None of the top-tier cans out there are monocore, they just aren't as quiet. They also exhibit bad first round pop across the board, so they aren't really the best on pistols.

Nothing wrong with them, but both aluminum cans and monocore cans are more "special use" items, not really what I would recommend to a first time rimfire can owner. The same goes for 5.56 suppressors though, nothing wrong just not generally a "beginner" suppressor.

 

[smittyb]

Yeah, but aluminum cans are a nightmare to clean and much easier to damage. None of the top-tier cans out there are monocore, they just aren't as quiet. They also exhibit bad first round pop across the board, so they aren't really the best on pistols.

Nothing wrong with them, but both aluminum cans and monocore cans are more "special use" items, not really what I would recommend to a first time rimfire can owner. The same goes for 5.56 suppressors though, nothing wrong just not generally a "beginner" suppressor.

Tell me again how soap and water in the kitchen sink is a nightmare?
Nightmare is having th lip of your K baffle break off and having to send it back to be repaired.

 

[benenglish]

CCI Quiet is a different story. That's not really "subsonic ammo" - it's a whole different beast.

Could you expand on that?

 

[popper]

My MKIII wouldn't cycle with CCI subs, no suppressor.

 

[rl96ss]

Run CCI standard out of my 10/22 with minimal upgrades (barrel, trigger) suppressed with no issues. Never tried CCI Quiet as it's not really made for semi autos, but I have ran it in my CZ 455 and it's sounds literally like a puff of air.

 

[orbitup]

I don't have any problems cycling any ammo except the primer only variety. My 10/22 has an aftermarket barrel but other that that the action is stock. My 22/45 runs fine too. In the pistol I can run high velocity ammo and keep it subsonic because the barrel is so short.

 

[smittyb]

Could you expand on that?

It is 100% subsonic. Low velocity ~700 FPS, meant to be quiet without a suppressor.
Not meant to cycle semi autos, like Aguila Super Colibri.
But you already knew that.

 

[CyberWolf]

CB and boutique ammo like CCI Quiet is a different story. That's not really "subsonic ammo" - it's a whole different beast.

This pretty much goes to my comments earlier that I perhaps didn't do the best job articulating clearly...

As stated in the posts above, most subs should work most of the time unless there's a problem, or once you get too dirty (which can happen mighty quick running suppressed with some crap brands of ammo who shall go unnamed).

Once you start chasing decibels however, things get a bit interesting. Most of the generic subsonics will ride fairly close to the transonic barrier, and even without actually hitting/traversing it (and getting the associated sonic boom), generally the closer you get the louder it is.

Also, if shooting in low temps, it may go supersonic anyway. Remember that many of the same atmospheric considerations that apply to long-range ballistics apply here as well, but with regard to acoustic signature.

I refer to the CCI Quiets as the smallest "full" 22lr round simply as I believe that any of the smaller varieties are primer-ony (no powder).

The main point here is that the CCI Quiets come in around 300fps slower than the "standard" subsonics. This means way less noise and no chance of SB just because of how much slower it's going. But, it also means way less pressure (pf) to cycle the action of a SA, without implementing some the aforementioned solutions (replacing/polishing parts for lower mass/friction/spring-power).

Here's a pic which helps illustrate this:

 

[benenglish]

But you already knew that.

Actually, I didn't have a good handle on the specs. CCI's website says they travel 710 fps. A bit more Googling shows other subsonics run faster. I was a little curious why you classified them differently but now I know.

I'm learning. Thanks.

 

[smittyb]

I wasn’t trying to be smug, I just figured with all your rimfire competition knowledge, you already knew.

Actually, I didn't have a good handle on the specs. CCI's website says they travel 710 fps. A bit more Googling shows other subsonics run faster. I was a little curious why you classified them differently but now I know.

I'm learning. Thanks.