I have a full auto with a 11.5 inch barrel and went from an AAC M4-2000 (which is an excellent suppressor) to a SilencerCo Saker ASR 556k. I did this for a reduction in length and weight over the M4-2000. I really like the ergonomics of the Saker and how it feels on the end of the rifle. My only problem is the Sakers backpressure makes the cyclic rate jump drastically compared with the M4-2000. It has to be an increase of at least 200 RPM.

I was hoping to find an option to lower the backpressure without resorting to an adjustable gas port as I want to keep this rifle stupid simple and as it stands right now it is a machine that has never malfunctioned in its current setup and I don't want to introduce any more complexity into it.

Are there any vented end caps or other methods to reduce the backpressure? Maximum sound reduction isn't the highest priority. I just wanted to get rid of the flash, report and tone the sound down but in its current configuration it is almost hard to keep it on target because it cycles so fast.

I have purchased the surefire OBC hoping that helps but I have a feeling that it won't be enough.

I would hate to have to put the M4-2000 back on or get something like the Surefire 556mini2 if I can find it and wait a year when I have already found a nice suppressor in the Saker with just one flaw.

Maybe an adjustable bolt carrier?

More & than an adjustable block but stupid easy and simple.

Heavier buffer, bolt with a longer lockup time and then if that doesn't work maybe look into a gas block with reduced or limited ports. YHM makes a dedicated suppressor gas block and then Black River Tactical makes a gas block with a limiter that's also a non-adjustable solution. They also make reduced port gas tubes but not sure how robust of a solution that is. You could also swap the barrel as a last resort.

I guess theoretically you could swap out to a 7.62 front cap to allow more gas out the front. I know the 556k is compatible with Charlie front caps. I also don’t know what buffer you’re using, but unless you’re already using an H3, you could always try slowing things down that way.

Edit: Looks like Silencerco makes a Charlie front cap all the way up to a 9mm diameter. That should let a decent amount of gas out.

The OBC will definitely slow the rate down, but I’ve never measured it.  The elongated cam path delays unlocking and the stroke is longer if you use the shortened buffer.  The recoil impulse will feel weirder as the carrier has a moving weight that reduces bolt bounce. Hydraulic buffers are another option but the OBC should do the trick.

The adjustable carriers are a relatively inexpensive drop-in solution.   The lack of fine-tuning is made up by the portability, durability, and lack of hassle compared to messing with the gas block.

I don't use them on FA platforms but I've lost count as to how many I have, like 5+ or something.

Thanks, those are both great options that I didn't even know existed. I may try the gas tube because the gas block is pinned. At $59 though for a gas tube I may wait to see what the new bolt and a larger front port cap can do for it.

Thanks for the suggestion.

I will add that to the suppressor as I have a couple Titanium ones lying around for my Omega that are ported for a .308.

Thanks for the suggestion.

I can see myself using this if the OBC and a larger ported end cap don't slow it down enough.

Have you tried multiple brands? If so which on seems the most reliable for full auto?

I like the idea of the bootleg one that only has 4 adjustments vs a screw type. Have any of the adjustments ever changed while shooting?

A BRT gas tube to reduce gas flow, without using an adjustable gas block.

Check out their site, different tubes with different size ports, and if you call or email them and discuss the issue they can make a recommendation as to which one to use.

https://blackrivertactical.com/WP/