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Anyone Tune their Saint Victor adjustable gas system?

MurphyPeoples

MurphyPeoples

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I have a YHM suppressor that I wanted to mount to the St. Victor. I found the rifle out of the box to be over gassed. So I used the color coded jets to "tune" the rifle to where it cycled reliably without the suppressor. My thinking is, once I mounted the suppressor I wouldn't be WAY over gassed. I don't run the Sup constantly. My worry is that the brass constantly hits the brass deflector bump. Whether I have the suppressor on or not. Anyone else mess with the adjustable gas system? What were your experiences? Thanks in advance. - Murphy
 
MurphyPeoples said:
I have a YHM suppressor that I wanted to mount to the St. Victor. I found the rifle out of the box to be over gassed. So I used the color coded jets to "tune" the rifle to where it cycled reliably without the suppressor. My thinking is, once I mounted the suppressor I wouldn't be WAY over gassed. I don't run the Sup constantly. My worry is that the brass constantly hits the brass deflector bump. Whether I have the suppressor on or not. Anyone else mess with the adjustable gas system? What were your experiences? Thanks in advance. - Murphy
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@xdman have any thoughts. Will be following as this will apply to me also (once my gov permission slip clears)
 
I have attempted to use the different “jets” to help fine tune my Saint Victor Pistol chambered in 300 black out and although it helped it didn’t completely fix the issue I have shooting subsonic.
I don’t use or have a suppresser.
As far as the brass contacting the ejection bump I never saw that as an issue as all my AR platform rifles will show strike marks but obviously I can tell it’s not from every round fired.
 
Keystone19250 said:
I have attempted to use the different “jets” to help fine tune my Saint Victor Pistol chambered in 300 black out and although it helped it didn’t completely fix the issue I have shooting subsonic.
I don’t use or have a suppresser.
As far as the brass contacting the ejection bump I never saw that as an issue as all my AR platform rifles will show strike marks but obviously I can tell it’s not from every round fired.
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Thanks Keystone. I watched this video on adjusting a gas system:


So I took the St. Victor to the range, and tried to use their method of noon to six 0'clock. Regardless of what jet I used, the brass would fly between 1 and 3 o'clock.

So I had my daughter slow-motion film the ejection with her phone. We watched it and found the brass would hit the brass deflector every time, and get throw forward from there into the 1 to 3 position. Thus making using their method kinda useless.

So what I did was tune by seeing "how low" I could reduce pressure into the chamber (Without the Can) and still have the last shot lock open the slide. This turned out to be the green jet (smallest) at 0.062. Which seems strange.

Edit - I was using Federal Premium 175 grain with BTHP.

For those interested. The St. Victor in .308 would NEVER lock the slide with ANY jet when using premium subsonic ammunition. I tired 3 different brands of subsonic, with each jet and can mounted. I did not however fool with the "adjustable" jet. I was trying to find a balance where I hoped I could get:

1. Slide to lock with Can and subsonic ammo. (Can't)

and....

2. Use Federal Premium 175 grain with BTHP with Can and not be over gassed.

I could only achieve #2.
 
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Not sure I find that strange at all. You’ve back off the gas pressure to the BCG during the action of ejection, reloading or bolt locking back on the empty magazine. In my opinion you’ve succeeded in finding the optimum middle ground. I still don’t understand your concern about the ejected brass hitting the ejection bump?
 
Keystone19250 said:
Not sure I find that strange at all. You’ve back off the gas pressure to the BCG during the action of ejection, reloading or bolt locking back on the empty magazine. In my opinion you’ve succeeded in finding the optimum middle ground. I still don’t understand your concern about the ejected brass hitting the ejection bump?
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I have nearly always had my AR's throw brass between 3 and 4 o'clock out of the box. The last time I had a weapon which brass constantly hit the deflector, H+K asked me to send it back. Which I did and they fixed it. That was a long time ago. Personally I do not think every empty cartridge should hit the deflector. Something seems "off" about that. However, I will honestly say that this is my first AR-10 in .308. So I wondered if other St. Victor .308 owners are experiencing this. Thanks again Keystone for chiming in. I appreciate all input. : )
Murph
 
Keystone19250 said:
Great video RandomHero, I did see an increase in the distance of the ejected cartridge however as mentioned in the video this upgrade was performed after thousands of rounds and I still noticed that a couple of the ejected cases impacted the bump which I believe is inherent and normal.
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I agree with you 100%. A brass deflector is exactly that. It deflects brass. In my opinion, if your brass deflector is showing marks on it things are working as designed. However, if it's bouncing brass in all directions there is an issue that needs diagnosed.
 
3-4:00 is ideal. The “objective” is to tune your gas block to operate where your BCG will cycle and lock back while throwing the casings 3-4:00. Over-gassed will throw them forward 1:00ish. Adjust your gas block so that your BCG will hold your bolt back and then start by 1/4 inch turns and maybe 1/2 turns till you get it throwing the brass in the 3:00-4:00 range.
 
The brass will always hit the hump, thats what it’s there for. My opinion you are spending too much time worring about where your brass is flying. Gas is just one part of the system, you also have the back und with recoil spring and buffer. Normally when you adjust a gas system you would close the port and slowly open it back up until you are getting reliable cycling again. You are turning the gas down to give the rifle just a little more than it needs to cycle reliable. Any more gas above that is excess and goes towards beating the rifle up, that gas is getting vented towards the bolt. The bolt only needs so much gas to work. Again the extra gas is getting to the bolt throwing it with more force than needed, and dumping the gas/carbon into the upper making it dirtier faster.

There is another thread that had a 300blk popping primers. Popping primers is a classic sign of over pressure. Any reloader knows this and uses it as a sign when working up loads. You will get warnings before popping primers, when reloading even unseating primers is an initial indication. Gassing has nothing to do with this, that factory ammo should not be popping primers. That ammo has to be safe enough to run in a bolt action, those have no “gassing” like an AR. That case should stay intact and handle the pressures required to get the bullet out of the barrel and within the performance envelope of that calibre. So on an AR you should be able to shut the gas completely off and not blow a primer. then when you open the gas you are lowering the pressures faster since the gas is diverted before the bullet exits the barrel. That goes to manipulate the bolt. Now even over gassing should not pop the primers. Over gassing will make the bolt work faster and speed up wear, but not pop primers. By the time the bolt is unlocked the bullet should have left the barrel or pretty damn near it. Again going back to a bolt action there is no gassing and you should not be popping primers. And even in bolt actions unseating primers is caused from over pressure rounds. Over pressure rounds has its on variables. Too much powder. Not the right powder. not the right depth. Crimp to tight. Chamber to small giving you bullet setback.
 
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