How well does the Raptor-SD Ambi Charging Handle mitigate gas blow back when a suppressor
is used on the following AR-15 type rifles, SBRs, or Pistols:
1) 5.56 NATO
2) 300 BLK
3) 9mm

I've only used one on my 16" Mk12, but it wasn't amazing. Tuning with an adjustable block and carrier worked a lot better.

Having used both a Raptor-SD and PRI Gas Buster in a 10.3" with a Surefire RC, I'd say the Gas Buster works better overall. My experience was that the Raptor-SD did a good job as long as the gun was extremely dirty, but was of little to no benefit in a clean gun. I love the function of a Raptor purely as a charging handle, but in the end, I kept my Gas Busters and sold the Raptor-SD. That said, based on how it performed in a dirty gun, I'd think the SD would work quite well in combination with an RTV seal.

I have it on a 9" 300 blackout.   Does pretty well IMO.

I run all my stuff suppressed, to include 10.5. When it comes to 5.56 and you shoot a little bit of volume, few mags in a few minutes, no charging handle is going to do anything. I run Bootleg Adjustable BCGs. They are pricey, but the best option for redirecting gas away from your face.

In my experience, a quality gas diverting charging handle like a Gas Buster can make a noticeable difference. I don't even use an adjustable gas block or BCG, just a low back pressure can, a reasonable gas port size, H3 buffer and a Gas Buster - I can dump multiple mags over a short period without gas becoming any sort of major issue. You can smell gas, but the GB keeps the gas out of your eyes; to me, it's doing what I want it to do.

A gas diverting charging handle is just one small part of an overall system; one tool in the toolbox for dealing with excess gas. It's not a fix-all solution in and of itself. Of course, other factors, such as suppressor design/back pressure, gas port size and extraction timing are going to have far more impact on the amount of excess gas. However, when used properly and with realistic expectations, a gas diverting charging handle is a beneficial addition to a suppressed weapon.

ding

Great feedback - thank you.

I have a gas buster. When I didn’t have the adjustable carrier, I was at a 2 gun shoot and put a couple mags down range in about 90 seconds. Halfway through, lots of gas in my face. If you are shooting from a bench sure, but if you are shooting volume, charging handle does almost nothing. I am well away of all the things you have stated, I have been shooting suppressed for last 15 years and got paid to shoot suppressed weapons.

Well, I don't get paid to shoot suppressed weapons (more's the pity), but I do shoot in volume and the only time I shoot from a bench is to zero; I don't have problems with gas in the face with the setup described.