762-SD versus 762-SDN-6 ... which is quieter?

[pneumagger]

So I had a 762-SDN-6 approved a short while ago. I had planned on using it on a 14.5" .308 AR and 20" bolt rifles but with the $200 promotion I decided to just get a different suppressor for my bolt rifles. So in the mean time, I just gut done ordering the larger 762-SD for use on my already 51T mount equipped bolt rifle(s). I know the SDN6 is fully welded, lighter, and tougher. But I've heard from different sources that the SD is louder, quieter, and/or the same than the SDN6. So what's the deal? If (when) I stick the SD on the same .308 rifle shooting the same ammo back-to-back with the SDN6... which will be louder? By about how much?

Like I said, I plan on using the larger SD only on the bolt guns and the smaller/lighter SDN6 only on the ARs, so I don't really care either way. I'm just curious as to what the truth is since I've read 3 different things.

[MCKNBRD]

What it meters at and what you can tell at the ear are two completely different things.

As I understand it, the SDN6 has an advantage with regards to less backpressure, size, and weight; the sound differences are maybe 2-3 db.

You won't notice the backpressure changes on your bolt gun; size and weight may be a different story, though. As far as which will be quieter or 'better sounding', that will be up to your ear and your perceptions.

The 'truth' will be based on your personal observations; I'd be REALLY surprised if you see much of a difference (on a bolt gun), to be honest.

Byrdman

[ikickhippies]

The 2014 762-SD is a longer SDN-6. Longer and heavier and (yes) quieter. More volume wins.

[pneumagger]

it's my understanding there are differences in the baffle stack to make the SD cheaper to produce than the SDN6. For one, I seem to remember Jason say that the SD core is not fully welded. I wouldn't be surprised if the bigger can is quieter, but if it has different baffles as well... well then it's a toss up.

[JasonM]

it's my understanding there are differences in the baffle stack to make the SD cheaper to produce than the SDN6. For one, I seem to remember Jason say that the SD core is not fully welded. I wouldn't be surprised if the bigger can is quieter, but if it has different baffles as well... well then it's a toss up.

All AAC rifle cans have fully welded cores (well, the baffled cans since 2008).

The new 762-SD has some cost-saving features (easier/quicker to machine) but I don't know all the details.

The old 762-SD was awesome except for the stainless baffles (for high volume use). The new one should be even better.