Relationship Between Suppressors and Barrel Length - 10.3"/11.5"

[SeriousStudent]

Pappabear has a 10.3 colt with a sig titanium q.d. can that shoots like a dream and is quiet as any suppressed sbr I've shot.

I have been seriously thinking about that as my next SBR can. A buddy has one and raves about it as well. And the price is really reasonable.

[triggerguard]

There's a bigger difference between a full sized can and a short can than there is between different barrel lengths on the same can. Short can's are not quiet. Maybe once you get to 16" or over (for 5.56) with a short can you might be getting sound levels similar to a full-sized can on a 10.3.

I have not noticed a big sound difference between 10.3 and 11.5 barrel lengths given the same silencer. You can have some impact on the sound levels at the shooters ear (not measured, but from my own perception of it, whatever that's worth) by tuning your gun with gas port size, heavy buffers, adj. gas blocks, or specialized bcgs.

Both those builds sound awesome... so I say do both, just pick one to do first.

1) Suppression - I think ther 10.3 build will be quieter by a fair margin. This is based on my experience with a 12 inch KAC QDC (full size) combo and a 10.3 surefire build as well as experience with a Saker K 556 and AAC mini-4 on an 11.5. Not the exact builds you're looking at but the mini cans on the 11.5 are louder than the socom on the 10.3. The KAC full size can has similar sound levels (maybe slightly better) as the surefire in my experience so the mini kac is probably a fair bit louder, more in line with the AAC. I don't consider any of those configurations hearing safe and wear ear plugs or muffs when shooting any of them indoors or out. Hearing safe for me means bolt gun with a full sized can.

2) length - you don't seem too concerned about the difference.

3) I doubt that you'll have huge velocity differences. Maybe 50-75fps? 100 max... based on charts I've seen. Many people will say both are insufficient. I'm not an expert in this area.

My other comments:
I like the KAC QDC mounting better and think that the mini-mams is a great muzzle device. The surefire devices are all a little larger. My guess is that they add more length than the mams if you shoot without the muffler.
The G is hot right now though... I am working on a similar 10.3 build as you mentioned.

good luck with whichever you choose.

[BufordTJustice]

This, not to mention the RC/RC2 is 1" shorter than the pogo stick sized specwar & 2.5 oz lighter.


Maybe it's me, but I don't get guys who go out shooting cans side by side chasing a Db or two. At the end of the day there is no such thing as truly hearing safe 556 or 762, they will most definitely prevent a lot of hearing damage without ears, with ears it makes shooting rifle calibers comfortable. I've never shot a rifle with a can and focused on how it sounded.

I'm getting significantly lower SPL at the ear than my buddy's rig. This being due to the can, the LMT e-carrier, the SLR AGB, the Vltor A5H4 buffer, and the tubbs AR10 action spring.... all working together.

However, when not surrounded by berms, mine is extremely quiet and comfortable to shoot without any ear pro, in stark contrast to my buddy's rig. High overbore cans trade dB at the muzzle for reduced SPL at the ejection port. But, I can control the gas and thus, the dB, at the ejection port. So, overbore cans, whether they are for caliber or larger than caliber, don't benefit me at all.

I don't buy the "I don't chase dBs" line because I'm currently having my cake AND eating it, too.

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[BufordTJustice]

Of course the Specwar is an older legacy suppressor. The Saker ASR units are the current offerings. Shorter and lighter....

In regards to POI shift, my Sakers have a .75" MOA shift at 100 meters when used on both 14.5" and 18" rifles.

My Saker 762 is right around there, and the Specwar is right at 1".

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[triggerguard]

My Saker 762 is right around there, and the Specwar is right at 1".

Sent from my SPH-L720T using Tapatalk

Since the topic has shifted to POI (pun intended) and nobody's complained... My surefire Socom shifts the POI about 6 MOA (left and up from what I recall) when mounted to a 14.5" Colt M4A1 Sopmod block 1 clone. The shift was very repeatable. I haven't taken the time to check it on anything else yet but probably should as the surefire now stays mostly on a 10.3 mk18-ish thing.
In discussions with others it sounds like the shift can be host / can pairing specific so while you may experience a minimal shift on one rifle it doesn't guarantee the same shift on another. I haven't tested their theories. Best thing is to take it out and shoot it. Know your gear, don't talk to strange rifles.
Oh, and my Saker 762 is also around a 1MOA shift from what I recall, with no shift in windage which is way easier for my little brain to work with.

[BufordTJustice]

Since the topic has shifted to POI (pun intended) and nobody's complained... My surefire Socom shifts the POI about 6 MOA (left and up from what I recall) when mounted to a 14.5" Colt M4A1 Sopmod block 1 clone. The shift was very repeatable. I haven't taken the time to check it on anything else yet but probably should as the surefire now stays mostly on a 10.3 mk18-ish thing.
In discussions with others it sounds like the shift can be host / can pairing specific so while you may experience a minimal shift on one rifle it doesn't guarantee the same shift on another. I haven't tested their theories. Best thing is to take it out and shoot it. Know your gear, don't talk to strange rifles.
Oh, and my Saker 762 is also around a 1MOA shift from what I recall, with no shift in windage which is way easier for my little brain to work with.

My Saker, too, has a vertical ~.75" shift (up, after mounting) on both of the current rifles with which it mates. I'm sure it's not identical, but both wear red dots and both are on-target on an IPSC swinger at 500 with or without the can. I don't care to invest more time to find out how the shift differs. I should note that I'm using the ASR adapter (before it was cool) on the Saker.

My Specwar has a lateral shift (to the 8-oclock) after mounting on both my guns of about 1" @ 100. Might be slightly less. Out to ~350/400, I'm on that IPSC swinger regardless of can-on or can-off. At 500, it matters. But my Specwar 556 lives exclusively on my 11.5" Sionics RGP barrel. I coated the mating surfaces/threads with nickel based 2400 degree F anti-seize on each can and mount, so I don't have to bother with breaking the carbon on the mount as I'll always be able to get them off. If the anti seize is good enough to keep outwardly rusty header bolts easy to remove after a decade (and it is), it's good enough for going a few thousand rounds on my cans without me worrying.

[scooter22]

Everyone has their opinions so, fair enough. What cans do you personally like better or would choose over a RC for a hard use 11.5 SBR? Just curious.

Disclaimer: I have a SOCOM 556 RC on my BCM 11.5".

Surprisingly, I really like the Griffin Recce 5. If Dead Air makes a dedicated 5.56 K can, I'm all over it.

[tommyrott]

just assembled a 11.5 using BCM ELW turned down the port size to.063 using a BRT microtune gas block, I have a Griffin Armament Spartan 3 pinnable can to make it into a one stamper so I can travel back and forth for pig hunting in the surrounding states. I can testify that the can is gassy as when I was shooting it left handed I could feel a definite puff in my face upon ejection. I have an A5H2 buffer that I was going to add another tungsten weight to see if it will alleviate the gas issue as well as slow the bolt down, I was getting a 3'oclock ejection and the brass was landing 7-8 ft away with enough speed to travel another 7-8 ft on concrete.

[scooter22]

just assembled a 11.5 using BCM ELW turned down the port size to.063 using a BRT microtune gas block, I have a Griffin Armament Spartan 3 pinnable can to make it into a one stamper so I can travel back and forth for pig hunting in the surrounding states. I can testify that the can is gassy as when I was shooting it left handed I could feel a definite puff in my face upon ejection. I have an A5H2 buffer that I was going to add another tungsten weight to see if it will alleviate the gas issue as well as slow the bolt down, I was getting a 3'oclock ejection and the brass was landing 7-8 ft away with enough speed to travel another 7-8 ft on concrete.

You will need a smaller port to alleviate the gas issue

[Bob Sacamano]

Based on reading/online research, If I were going to build a dedicated suppressed gun, I would start with a port size 0.046-0.050". The 0.063" port is said to be a good size for a mixed use gun, maybe even on the larger side for an 11.5"