To tie into a different post I just made, I think there is a point of diminishing returns, when it comes to barrel length and center-fire rifle silencers. I am currently of the opinion that if the barrel is under ten inches, you may as well leave the can at home, and go for ultimate compactness, because it's friggen loud either way. If I am gonna have to wear hearing protection regardless, I'll go ahead and take the smallest configuration possible.

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Originally posted by KSGM:
If I am gonna have to wear hearing protection regardless, I'll go ahead and take the smallest configuration possible.

A perceptive observation that bears being kept in mind. Thank you.

quote:

Originally posted by KSGM:
To tie into a different post I just made, I think there is a point of diminishing returns, when it comes to barrel length and center-fire rifle silencers. I am currently of the opinion that if the barrel is under ten inches, you may as well leave the can at home, and go for ultimate compactness, because it's friggen loud either way. If I am gonna have to wear hearing protection regardless, I'll go ahead and take the smallest configuration possible.

I believe it depends on the SBR. I have an 8" 300BO AR-15 and suppressed with subsonic rounds I can shoot it comfortably without hearing protection. With supersonic rounds it can get a little uncomfortable but without a suppressor it's hell. Considering that it is one of my home defense weapons that is always suppressed I shoot it as such. The only benefit IMO to not use the suppressor is if I was in a vehicle (which is highly unlikely as it's illegal to drive around with a loaded rifle) but if it's the end of the world and I gotta bug out in a vehicle I'm taking the maneuverability over suppression. I'll wear the electronic muffs to make up for it.

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I believe it depends on the SBR. I have an 8" 300BO AR-15 and suppressed with subsonic rounds I can shoot it comfortably without hearing protection.

Of course you are right. I had a short .300BO in the past, and it was absolutely fine, with subs. My comment was in regards to 5.56mm carbines.

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Originally posted by KSGM:
A The same goes for your 553; all (that I have messed with) Swiss barrels are timed to be swappable. So, you could get a threaded 552/3 barrel to allow silencer use on your 553, while preserving your factory barrel. With the right valve, the 553 is a badass weapon with a can.

Doesn't one need specific tooling to change barrels on the 55X series? It's certainly not as easy as an AR15 barrel install AFAIK but I have no experience with it. when you mention 553, are you talking about 5.56 chamberings? Was told by JDI they sucked suppressed in that cartridge compared to 300bo or 7.62x39.

Is it worth trying to port a 550 valve for silencer use or is the "normal" gas position good enough.

You do need a fixture to hold the receiver; a pretty significant amount of torque is required, to break the barrel loose. If you are interested in removing and installing barrels, you're welcome to email me.

I am talking about 5.56 guns. I disagree with JDI, and that isn't logical of him to say; they suck no more than any other sub-10" 5.56 long stroke piston gun. Of course the two he mentioned will be better performers; you can shoot subs through both of them, and they both have ~13" barrels. Guess what else is better than a 553: a 553LB, because there's more barrel to burn propellant before the can has to deal with it. I have shot my 5.56 553 almost exclusively with a silencer, and it actually performs quite well, other than it being quite loud because of the barrel length. I did damage one of my silencers because of it's use on that short barrel though, so that's something to take into account.

If your valve question is about the 550, I'd say the factory valve is likely ok; that gun has a long enough barrel and gas system that any negative characteristics will probably be negligible. That is an educated guess; I haven't shot a 550 with a can. Shorter barrels and gas systems will always benefit from a modified valve. SIG makes one for the 553 system. If you need one for the larger piston systems found in the 551 and 550, I have one for sale in the classifieds. Of course I can't guarantee the porting I chose will be perfect for your application.

Yesterday afternoon, I told my wife I had plans to shoot a little bit, when I got home from work. I got home, fiddled with the gun I wanted to shoot, and went into the woods behind the house to the normal spot; this spot is about 150m from the house. I did the shooting I intended to do, returned to the basement, put things away, and went upstairs. She asked if I had done the shooting I said I wanted to do.

Being able to shoot a 5.56mm carbine 150m from a structure, without it's occupants having any idea, is pretty dang cool. The recent thread about whether or not to suppress 22 magnum perfectly illustrates a common misunderstanding: a silencer's usefulness is not limited to calibers that can be made to shoot reliably at subsonic velocities. Everything depends on the user's goals; maybe anecdotes like this one will help redefine someone's goals, when considering silencers for 5.56mm and other similar calibers.

I shoot my SIG 553 suppressed all the time with a Sig SRD556 can. It gets so hot, it glows cherry red and has a sweet rainbow coloring to it now. https://youtube.com/shorts/Y7o5qE_uIuE?feature=share

My 553 sits just beyond the acceptable threshold. I use a Gemtech HALO or Griffin M4SDK on it; your SRD may be quieter. With the silencers I use on mine, it is uncomfortable enough without earpro to be a distraction. Far better than without, of course, but not as good as a 10" DI AR.

We only shoot outdoors and still wear ear-pro.

I also typically use ear protection when using silencers, but lately I have been more critical of my weapons' performance with cans; this has included determining which ones I think are acceptable setups, when it comes to use in a situation that has me utilizing them without earpro on a more regular basis.

The 553 SB is loud enough (outdoors) that I don't want to shoot it without ear protection. Is it quiet enough that you could use it in a pinch, in a HD scenario, and avoid serious hearing damage? Of course; but that is not the standard to which I am holding my guns, in my current way of thinking and assessment.

Anything with a barrel that short is going to struggle. As previously stated, a 10" DI AR is noticeably better, not doubt thanks to the operating system, and the G36 with it's very comparable "C" barrel is also quieter, even with an OSS can. I guess something about the long-stroke piston operation is largely to blame.

For me, just the additional blow back with the Suppressor on vs. not using it.

There are a lot of options for mitigating blowback on ARs, and piston guns can quite often be tinkered with to good effect as well. ARs can utilize adjustable blocks and/or carriers, properly ported barrels, custom ported gas tubes, special charging handles, different springs and buffers, etc. I am one of the people that is especially sensitive to gas blowback, and I agree that it can be a huge deterrent to silencer use; the benefits of a silencer make it worth the extra effort and money required to mitigate the blowback effects, IMO.

Also, there are a growing number of reduced back pressure designs available. I have an OSS, and can vouch for it's effectiveness.

This message has been edited. Last edited by: KSGM,

If I run more than a couple mags through my scoped AR with the can. The mirage created from the heat of the can is super annoying. Where I don't even put the suppressor on if I plan to shoot more than 20-30 rnds through it.

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Originally posted by myrottiety:
If I run more than a couple mags through my scoped AR with the can. The mirage created from the heat of the can is super annoying. Where I don't even put the suppressor on if I plan to shoot more than 20-30 rnds through it.

Ran into that problem with the SCAR 17. Then I put one of these on. Works great.

I have yet to shoot enough rounds at a rapid enough rate, through my scoped AR10, to notice the negative effects of mirage. However, I have read enough about it to know that a cover is advisable; I have considered a mirage band as well.

I have always had a cover on the one suppressor I own. I have never even thought about heat wave effects on vision, but because of the limited number of shots I fire in any one string, not because of the effectiveness of the cover. What is very apparent to me, though, is that as few as five 308 Winchester rounds fired quickly is enough to heat the suppressor to the point that it can’t be held comfortably. What is a suppressor that’s used on an AR (and is often smaller than my TBAC) like after a magazine or two—and especially with a shorter barrel?

You can probably guess that they get pretty damn hot, and contact ought to be avoided; you get used to it.

Agreed. My next purchase is a cover for my suppressor.

Records state that I have 8,800 rounds on my Surefire SOCOM mini suppressors. Mainly 223, but some 300blk. Used on AR15s with barrels from 14" to 24", with optics center line mounted 2.5" to 2.75" above bore. Shot in temps from below freezing in winter to 90+ F in the summer. Casual plinking, full-on practice, training courses, run-and-gun competition, precision rifle competition. Never felt that the lack of a suppressor cover caused heat mirage that interfered with aiming and shooting. Maybe the relatively high scope-over-bore height makes a difference.

Probably the hottest the can got was at a Competition Dynamics team match in central Wyoming. I was the carbine guy on a 5-minute maximum so-called assault stage. I used an 18" barrel Wilson with a 3.5-15x Nightforce. In that stage I dumped two 30-round mags of 55 grain FMJ into paper IPSC targets, then transitioned to part of a 20-round mag of 75 grain HPBT match ammo. The final shot was a precision shot -- resting the rifle on a boulder, with a 2 MOA-ish steel plate at around 250 yards. I hit the plate with the first round.

In 2-rifle matches in New Mexico, the rifles/cans see 20-30 rounds in portions of match stages that last 2 minutes or less. The initial rounds tend to be fired quickly at close targets, with the final rounds fired at a more measured pace at targets 300-400 yards away. Never had a mirage issue.

Now I do have heat covers for my precision suppressors -- Thunderbeast cans on long-barrel ARs and bolt actions. The bolt actions have optics mounted centerline 1.8" to 2" above bore, and I have experienced mirage from an uncovered can on them.

Suppressors get hot. Sometimes really hot. Ixnay touching bare skin or synthetic fabrics. But I don't experience mirage issues with my AR15s and nekkid cans.