Reduced load for suppressor

[1911man]

It's been quite a while since I've posted on this site. Mostly because my setup has been running well . I've got a 16" AA barrel shooting 28.0 grains of AR comp with the 123 ELD and it consistently shoots 3/4 MOA to 1 MOA. I just picked up a Witt Machine Mod 1 specifically for the light weight and reduced back pressure. Problem is the gun is still over gassed with the suppressor on although it's shooting very accurate.

So here is the question: Is my logic correct that I could reduce the charge on my load to then decrease chamber pressure? I'm sure there is another accuracy node at a lower charge but can I really get the benefits I'm looking for instead of adjusting the gas setting?

Here are 2 videos of me shooting my setups at home:

3 shot group:

https://youtu.be/I7lMYuqAL4U?si=UqlmpbGeBYWabVo6

At the muzzle:

https://youtu.be/uR1z2gKP63k?si=iBQkm66TTEnhn2kf

[Harpoon1]

Get an adjustable gas block, reducing the charge weight is not going to make that much of a difference in being over gassed.

I like these but, there are others that work well too.

https://www.midwayusa.com/product/1094240120979

[Happy2Shoot]

Your rifle is not over gassed at all, don't change a thing.

Your ejected brass is at the 3 or better yet 4 o'clock position.

No noticeable gas cloud from the ejection port.

If you care, your name is visible on youtube.

[Happy2Shoot]

Gas from the ejection port clearly visible from a 9mm at 1:25 mark. Looks like smoke is pouring out of the magwell with the magazine still in it!

[video=youtube_share;RSUPsFW1-OA]https://youtu.be/RSUPsFW1-OA?t=83[/video]

[1911man]

Your rifle is not over gassed at all, don't change a thing.

Your ejected brass is at the 3 or better yet 4 o'clock position.

No noticeable gas cloud from the ejection port.

If you care, your name is visible on youtube.

I would agree but I'm getting deep ejector marks on my brass and recoil us noticeably more harsh. Not worried about the name. My YouTube channel is used for marketing my business. My firearm videos are private for political reasons.

[1911man]

Get an adjustable gas block, reducing the charge weight is not going to make that much of a difference in being over gassed.

I like these but, there are others that work well too.

https://www.midwayusa.com/product/1094240120979

That's not an option. It's the obvious norm to adjust gas for the suppressor but this setup cannot be changed now.

[grayfox]

The problem you have may be related to direct gas blowback that a suppressor does to ARs. Its increased backpressure and dwell cause gas to blow back directly over the case into the bcg area. The only way I've read to handle that differently is to get a bleed-off gas block that blows some of the gas forward, thus out of your face; they are mentioned on here but I've not used one. As to gas flow down the gas tube, either an adjustable gas block or an adjustable carrier like the Bootleg model. More closed for suppressed, more opened for normal non-supp.

[Klem]

1911,

In answer to your question about lesser loads reducing gas pressure at the receiver, I doubt it.

The reason I say this is that you couldn't low load the Grendel enough to make a noticeable difference. Take the 9mm calibre for example. It's only about 4-6gns of powder/35K peak pressure, and yet when suppressed can spit a lot of gas in your face. The H&K K 9mm,when suppressed spits gas and crap back in your face through the ejection port. If you are a left-handed it's even worse. Eye protection is compulsory or it's like getting sand thrown in your eyes. The H&K SD however with its dedicated suppressor is totally different, no sense of excess gas or sting at all. These examples are also relevant because all the gas coming back into the receiver is from the chamber, not the gas system. No gas system in the H&K MP5 9mm, it's all roller locking delayed blowback.

In your case you won't change the amount of soot coming back into the receiver and onto you by loading less powder. You won't notice the difference. I do however recommend you choke off the gas somehow when using a suppressor, or that gun will be getting hammered every time you pull the trigger.

[1911man]

1911,

In answer to your question about lesser loads reducing gas pressure at the receiver, I doubt it.

The reason I say this is that you couldn't low load the Grendel enough to make a noticeable difference. Take the 9mm calibre for example. It's only about 4-6gns of powder and yet when suppressed can spit a lot of gas in your face. The H&K K 9mm,when suppressed spits gas and crap back in your face through the ejection port. If you are a left-handed it's even worse. Eye protection is compulsory or it's like getting sand thrown in your eyes. The H&K SD however with its dedicated suppressor is totally different, no sense of excess gas or sting at all. These examples are also relevant because all the gas coming back into the receiver is from the chamber, not the gas system. No gas system in the H&K MP5 9mm, it's all roller locking delayed blowback.

In your case you won't change the amount of soot coming back into the receiver and onto you by loading less powder. You won't notice the difference. I do however recommend you choke off the gas somehow when using a suppressor, or that gun will be getting hammered every time you pull the trigger.

I fear you are correct sir

[Harpoon1]

I would agree but I'm getting deep ejector marks on my brass and recoil us noticeably more harsh. Not worried about the name. My YouTube channel is used for marketing my business. My firearm videos are private for political reasons.

If recoil is an issue, try a heavier spring and/or buffer! Sprinco make quality springs.

[1911man]

If recoil is an issue, try a heavier spring and/or buffer! Sprinco make quality springs.

It's not the recoil itself. It's the signs of over pressure

[LRRPF52]

If your mags and chamber will allow 2.290” COL, try that.

28.0gr of AR Comp is a max load with Hornady 123gr with longer than normal 2.260” COL.

[1911man]

If your mags and chamber will allow 2.290” COL, try that.

28.0gr of AR Comp is a max load with Hornady 123gr with longer than normal 2.260” COL.

My chamber is actually pretty short on this rifle. I got one of the AA barrels that was in a large batch of short chambers and AA had to ream them out. 28.0 is definitely ar the top but unsuppressed I don't have any chamber issues. I am loaded to 2.260 COL. I'm going to do a small work up starting at 26.0 up to 27.0 just to see if I notice any real difference.

[LRRPF52]

My chamber is actually pretty short on this rifle. I got one of the AA barrels that was in a large batch of short chambers and AA had to ream them out. 28.0 is definitely ar the top but unsuppressed I don't have any chamber issues. I am loaded to 2.260 COL. I'm going to do a small work up starting at 26.0 up to 27.0 just to see if I notice any real difference.

I think you’re doing the right thing.

Does factory 120gr Nosler Ballistic Tip chamber and extract ok without jamming the lands?

[1911man]

I think you’re doing the right thing.

Does factory 120gr Nosler Ballistic Tip chamber and extract ok without jamming the lands?

I've never had any of that particular ammo.