Learning about first round pop and noticed a few cans with very low FRP.
A well known one that has been around a few years.
Assuming the “K” indicates baffle design because it is longer than the earlier WCR-22 that does have FRP.
Collaboration with Ruger. I own one and the QD brake does seem to work well for capturing lead.
Getting a few years on, but useful video showing different cans’ FRP using measuring equipment.
First round pop is something that is occasionally possible to discern on a video depending on rate of fire. Trying to find one with CMMG rimfire cans on pistols, but this one using AB cans on centerfire rifles will demostrate it and the guy points out when it happens.
I have three rim fire cans. The Q el camino is the quietest and has the least/no frp.
I can tell you that if FRP is s cincern, the Banish .22 has significant FRP. After 1 it’s great. But #1 is loud. I have fired other 22 cans with more or less FRP than others but I cant honestly recall which was which.
Before I won the Banish .22 in a raffle I ran my Octane 45 on my .22s. Now, one would intuit that since O2 in the can causes FRP, more volume would mean more FRP right? Not my experience. The 45 can never exhibited FRP. Dead quiet from round one. Sample size of one. I can’t explain the physics.
The Silencerco Sparrow has quite a bit of FRP with a pistol, but not bad on a rifle as the Griffin video showed.
Same deal, i don’t know exactly why it does, i just know that it does. 
Smaller blast chamber usually reduces FRP with subsonic rimfire. Mask is very low. CGS’s is low, too. Lots of rimfire cans from established companies focus on FRP.
You can also just put a few drops of water or oil in there and/or purge it with airduster.
Edit: you guys reminded me that I have some varmints to smoke
Edit 2: tamed 2 critters
I have a two rimfire cans, a very old YHM sealed and an old Sparrow when they first came out. I pretty much only use CCI SV. On pistols the YHM has no discernible FRP due its larger volume. The Sparrow has a healthy FRP. Still, it’s not like ya need hearing protection. It’s simply noticeable. For range use (fortunately I belong to a club where I often have a range to myself) FRP is meaningless. At home… my wife can’t hear me while shooting off the back deck when she’s in the kitchen with only double pane windows between us. And no matter how quiet the muzzle blast, rabbits and squirrels are still gonna scatter upon bullet impact. Minimal FRP seems more about bragging rights than practical use, at least for me. How about you guys?
Tons of fun..
[quote=“ChattanoogaPhil, post:7, topic:486750”]
Minimal FRP seems more about bragging rights than practical use, at least for me. How about you guys?
[/quote
Well in my work as a super secret ninja assassin…. 
I can see possible reasons for wanting no/minimal FRP . Multiple varmints, etc. Though it doesn’t seem to work that way. Either the critters are skittish and jump at anything or they just don’t GAF.
ETA: I will say that the quietest .22 shooting I have ever experienced is the .45 Octane on my .22s. I don’t have experience with other pistol caliber cans on rimfires but I would expect it to be similar. The rimfire cans I have experience with, FRP aside, there is still a little residual sound. Very little but something. With the .45 on the bolt gun I hear the tick of the firing pin, the impact on the target, and that is it. The .22 AR sounds like manual operation of the action, nothing else. It doesn’t get any quieter than that.
Yeah, the longer barrel on rifles results in most all power being burned while still in the barrel and therefore less hot expanding gas before exiting the muzzle and into the suppressor. In the simplest of terms that’s what a suppressor does, slows and cools gasses before entering the surrounding atmosphere. The larger volume of your .45cal helps slow and cool gasses.
Barrel length example: I can heat up the suppressor on my Ruger pistol in a couple magazines. I can do mag dumps wth my AR rimfire yet the same suppressor barely gets warm.
As long as ya got a place to shoot without obnoxious unmuffled guns around… suppressed rimfire is a ton of fun. My old CMMG dedicated. I use the larger diameter YHM suppressor just cuz it looks more proportional to standard AR.
