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

[methical20]

Hi All,



First off, I have done quite a bit of searching for results on this topic, however, I am not finding what I'm looking for. If anyone has helpful links, please post them here and I will be happy to read them! Thanks to a series of fortunate events and blessings I am able to purchase/build my first SBR and suppressor and would like to get some advice from those that already have experience.

I am going to be suppressing either a 10.3" with a FULL size can or a 11.5" with a MINI can. From what I understand, the shorter the barrel, the louder it is going to be for the shooter. Obviously, the shorter the suppressor, the less it will reduce dBs. I am wondering how the relationship of shorter barrel/longer suppressor and longer barrel/shorter suppressor compare.



The proposed rifles are:

- 10.3" Colt, all Geissele'd out with SOCOM RC2, full-size.
- 11.5" SR15 Mod 2, KAC QDC CQB



Here are my main criteria for making a decision, in the order of importance (for me).

1. Sounds Suppression (indoors and outdoors) - Will there actually be an appreciable difference shooting the two indoors and outdoors? Some say that a 10.3" with SOCOM RC2 is hearing safe outdoors, while others say that it is not. I would think that with the mini can, I would absolutely need hearing protection with a mini can. Some may suggest to get a .300BLK if sound suppression is what I'm chasing. While that is a great suggestion, for the time being, I am not looking to add a new caliber.

2. Overall length (not barrel length, total length with suppressor attached). With the proposed setups, the length is a wash. I just don't want the 11.5" with full size KAC suppressor.

3. Velocity - For my needs/wants, a 10.3" would have enough velocity for me, putting this at the end of the list. That being said, with suppressors attached, how dramatic is the velocity difference between the 10.3"/11.5"?




Thanks in advance for your assistance!

[VIP3R 237]

Hearing safe (sub 130db) with a 5.56 short barrel is an unachievable goal. My 11.5 with a full size Recce 5 which is one of the quieter cans on the market (130db with 16") is still pretty damn loud, and Mini cans are more concussion reducers that suppressors at that barrel length.

[BooneGA]

Hearing safe (sub 130db) with a 5.56 short barrel is an unachievable goal. My 11.5 with a full size Recce 5 which is one of the quieter cans on the market (130db with 16") is still pretty damn loud, and Mini cans are more concussion reducers that suppressors at that barrel length.

140 is typically the number I see for hearing safe. I have no issue shooting my SOCOM 5.56 can outdoors on a MK18 (10.3) or my 12" personal gun. The intent of the mini can isnt to make anything hearing safe. If that is your goal you should be looking at full size cans only.

Rick

[VIP3R 237]

140 is typically the number I see for hearing safe. I have no issue shooting my SOCOM 5.56 can outdoors on a MK18 (10.3) or my 12" personal gun. The intent of the mini can isnt to make anything hearing safe. If that is your goal you should be looking at full size cans only.

Rick

Technically hearing damage can start as low as 85 db's. The reason the 140 db's mark is used by silencer companies is that is OSHA's cutoff for impulse noise exposure in the employment setting, however 140 db's is definitely not safe for your ears.

[MegademiC]

Technically hearing damage can start as low as 85 db's. The reason the 140 db's mark is used by silencer companies is that is OSHA's cutoff for impulse noise exposure in the employment setting, however 140 db's is definitely not safe for your ears.

There is no cutoff. They just stick a number on it. 140 isnt going to make you deaf while 139 lets you listen to it all day without damage. You should wear hearing pro for extended shooting sessions regardless.

Throwing a can on an hd or hunting rifle is healthy.

On top of all that, most measurements I've seen are at the muzzle, not the shooters ears (both as each is exposed to different levels).

Op if possible, try to try out each and see what sounds better to you. Maybe someone with both could do a side x side.

[Jwknutson17]

There is no cutoff. They just stick a number on it. 140 is going to make you deaf while 139 lets you listen to it all day without damage. You should wear hearing pro for extended shooting sessions regardless.

Throwing a can on an hd or hunting rifle is healthy.

On top of all that, most measurements I've seen are at the muzzle, not the shooters ears (both as each is exposed to different levels).

Op is possible, try to try out each and see what sounds better to you. Maybe someone with both could do a side x side.

Give me til the weekend and I'll do one. They are still loud and I don't shoot anything 5.56 without ears, even with suppressors. I started hunting with cans a few years back.. best thing Ive done.

[themonk]

What is the goal of the rifle's config?

Neither of them will be hearing safe. 556 is a loud round and you should wear earpro even when shooting suppressed.

[methical20]

Give me til the weekend and I'll do one. They are still loud and I don't shoot anything 5.56 without ears, even with suppressors. I started hunting with cans a few years back.. best thing Ive done.

That would be great. Thanks!

Thanks for all of the replies. Sounds like regardless of what config I go with, I'll have ears on almost always.

[BooneGA]

What is the goal of the rifle's config?

Neither of them will be hearing safe. 556 is a loud round and you should wear earpro even when shooting suppressed.

Ive shot thousands of rounds of 5.56 suppressed without ear pro and my hearing hasn't been effected at all (per annual army testing).

Rick

[Pappabear]

IMHO, I would run a 14.5 with a mini, and do. Anything shorter needs a full sized can. And that pretty much sums up much of what your asking. Different folks have different views so YMMV.