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Adjustable gas block and velocity/POI changes.

nortac

"Can't Raise an Eyebrow"
Has anyone compared changes in muzzle velocity and/or bullet drop/ POI with changes in AGB settings? I would think that this would only be noticeable when trying to shoot tiny groups at 100 yds or greater. If just banging steel, I'm sure that there would be no noticeable difference. I would suspect that just using a suppressor without gas block adjustment would make some difference, even more so with. I'm talking about POI changes that would make a difference in all shots falling in the X ring vs. all shots in the 10 ring. Anyone have any experience with this? Just curious.
 
Properly tuned, your (adjustable) gas system should not cause loss of velocity or change in POI. Ideally, you're blowing enough gas to positively cycle the action, without excess force in recoil.

Said simply, but there are quite a few variables:

  1. Ammunition?
  2. Is your current action in-spec?
  3. If so, on the high or low side (gas volume)?
  4. Dedicated suppressed or variable usage?
  5. Outside of suppression, what is your personal goal in adjustment?
Short version, if tuned for a consistent ammunition, you should see an increase in velocity and accuracy.

If tuning to optimize for using a wide range of ammo, at the higher quality end, it will lose some performance as you have to allow for lower quality fodder.

I got a good deal on a KNS adjustable piston, and it is a dramatic change in action, along with a really nice linear comp set up. Less like dropping a hammer on the side of a tin box full rocks, and more like shooting a rifle now.😜 No noted change in POI, but hey, Wolf...
 

nortac

"Can't Raise an Eyebrow"
I would be using either top notch factory or precision reloads. This would be primarily 6.5 Grendel or 6.5 Creedmoor, perhaps .308 or .223 as well. But no low end ammo. I'm not currently having any issues, it's more of an intellectual exercise of "what if"?
 
😁Go for it! Seriously, it does allow an extra bit of tweaking. If you ran a lighter buffer, you could use less gas with less recoil...
 

nortac

"Can't Raise an Eyebrow"
If you ran a lighter buffer, you could use less gas with less recoil...
Most of my builds utilized the JP Silent Captured Spring System which seems to be working pretty well for me. I have not tried extensive tweaking of the gas settings yet and haven't gone beyond reliable ejection patterns. You can switch springs and weights with the SCSS, but I have not ventured to do so. I certainly am not experiencing excessive recoil, but it might be nice to be able to stay on target better shot to shot with some of my precision calibers to observe impact and be able to achieve rapid follow up shots at distance, but I haven't gotten there yet with my shooting needs. Most of my precision shooting is not very "dynamic", mostly unhurried shots from the bench where I have all the time in the world. If I were competing in timed events like PRS, that would be a different animal entirely. But at my age that is not likely to happen.
 
I get it. My first build up was a 20" HBar Bushmaster that I added one of the early Smith brake/FH and a DPMS pneumatic buffer to, along with some trigger stoning.

.223 is by no means snappy, but with the comp & buffer, the rifle was neutral-position in firing. It's pretty cool to have a real carbine caliber that shoots like a laser with no rise and minimal rearward impulse.

In the 6.5 & .308, if I could achieve that, I'd have an idiot-grin for weeks!😁

Anxious to see what you decide!...😎
 

nortac

"Can't Raise an Eyebrow"
Well I probably won't be doing much fiddling/testing in the near future. I have too many (shooting) irons in the fire right now! I have been shooting mostly factory ammo with my 6.5's and I need to develop an accuracy reload for both the Creedmoor and the Grendel before I do any serious tweaking of gas settings and I would like to avoid changing any springs or weights in the JP SCSS, or at least put it off for as long as possible. I'm in the midst of shooting several of my rifles for accuracy and I get easily distracted from completing one project before beginning another!
 
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