The Roland Special

MojoNixon

Established
Yes. Just like air has mass, and wind can exert force on a ship's sail, but of course much more so at the high pressure & velocity of gas exiting a gun muzzle.
Does a gas that increases in volume as it gets hotter also increase in mass? I think the velocity of the expanding volume is what causes a comp to function. I could be way wrong as I only know 2 things about this. The first thing I know is jack and the second thing I know is shit. ;)
 

Yondering

Regular Member
Wouldnt there be more pressure with a heavier load?

Let me clarify "heavier load" we're all on the same page:

- Heavier bullets in a load, no, peak pressure is still the same as a comparable load with light bullets (within what we're discussing here, there are exceptions). For example, 115gr +P and 147gr +P are both loaded to 38,500 psi, assuming both are loaded to potential. The 147gr load will use a smaller powder charge to reach that pressure; that smaller powder mass has less effect on the compensator.

- What we normally call a "heavier load" does mean higher pressure. This has nothing to do with bullet weight, but refers to the difference between standard pressure and +P or +P+ loads for example. In this case, we'd say a 115gr +P is a heavier load than standard 115gr ball. A heavier load in this context does work a comp more efficiently.
 

Yondering

Regular Member
Does a gas that increases in volume as it gets hotter also increase in mass? I think the velocity of the expanding volume is what causes a comp to function. I could be way wrong as I only know 2 things about this. The first thing I know is jack and the second thing I know is shit. ;)

:D

No, volume and pressure increase as a result of combustion, but it does not increase mass. Some of it is wasted as heat, but the expanding gas (solid powder converted to gas by burning) creates the high pressure that propels the bullet. This gas, being under pressure, exits the barrel just like air from an air compressor, and without a comp it just disperses into the air with a very loud pop.

You have the right idea with the velocity of the expanding gas. When a comp is on the barrel, that gas slamming into the baffle faces in the comp are what does the work to push the barrel & gun forward, resisting the rearward force from bullet momentum. The forward force on the comp is less than the rearward force of momentum, so we still experience some recoil to the rear, but not as much.

As a side note - I'm ignoring rocket effect at either the muzzle or comp ports for simplicity of discussion.
 

MojoNixon

Established
:D

No, volume and pressure increase as a result of combustion, but it does not increase mass. Some of it is wasted as heat, but the expanding gas (solid powder converted to gas by burning) creates the high pressure that propels the bullet. This gas, being under pressure, exits the barrel just like air from an air compressor, and without a comp it just disperses into the air with a very loud pop.

You have the right idea with the velocity of the expanding gas. When a comp is on the barrel, that gas slamming into the baffle faces in the comp are what does the work to push the barrel & gun forward, resisting the rearward force from bullet momentum. The forward force on the comp is less than the rearward force of momentum, so we still experience some recoil to the rear, but not as much.

As a side note - I'm ignoring rocket effect at either the muzzle or comp ports for simplicity of discussion.
Thanks for the explanation. Like I said I only know 2 things the rest being something akin to deductive reasoning
 

KyleDuPrey

Newbie
I'm trying to track down this information as well.

If anyone has ATEi in house work please let us know.

I went with the carry grip texture and although I don't have anything else from ATEi to compare it to, it's more than adequate to aid in gripping the gun and I'm very happy with it so far.

I carry it AIWB but can't comment on the rubbing against the skin because I always wear an undershirt. Hope this helps
 

Sunshine_Shooter

Established
Gas definitely has mass. If it didn't, it wouldn't be able to exert force (like photons of light don't exert force and are massless).

Apparently, NASA disagrees:

https://www.nasa.gov/mission_pages/tdm/solarsail/index.html

Okay, photons of light were a bad example. They act like both particles and waves and contradict themselves. How about we just use the kinetic energy equation? Or even the momentum equation?

I feel like we'really getting off on a tangent and lost in the weeds here.
 

ggammell

Does not pass up an opportunity to criticize P&S.
Is agency the only company that makes a lower profile magwell that can accommodate the agency 4 back straps? Seems like it's the only one I've found.
 

MisterHelix

Newbie
As a follow up to ammo selection and compensator function/gas volume thing...

The 115+P+ (9BPLE) yielded ~slower~ split times (for me) than 147 grain loads (147HST) and performed with ~less~ consistency at distance (100y) under windy conditions compared to the 147 grain load.

The "light projectile/high gas volume" seemed to make sense, but the numbers don't add up for me.

YMMV
 

Rick4673

Amateur
Well, I finally completed my home-made, Walmart RS (done on a G19 MOS with a Vortex Viper). I got my barrel and comp from KKM last Thursday. Ran a couple of hundred rounds of duty 147gr G2 through it. Runs fine so far. About half of those rounds was fired in 10 round groups off the bags at fifty yards to zero the Viper. The groups were a very consistent, nice, round 3" to 3.25". The G2 has not been the most accurate ammo in its class for me in the past. I am eager to see what 147 HST will do.
 

MojoNixon

Established
Well, I finally completed my home-made, Walmart RS (done on a G19 MOS with a Vortex Viper). I got my barrel and comp from KKM last Thursday. Ran a couple of hundred rounds of duty 147gr G2 through it. Runs fine so far. About half of those rounds was fired in 10 round groups off the bags at fifty yards to zero the Viper. The groups were a very consistent, nice, round 3" to 3.25". The G2 has not been the most accurate ammo in its class for me in the past. I am eager to see what 147 HST will do.
What's the dot size of the Viper?
 

ggammell

Does not pass up an opportunity to criticize P&S.
For those keeping score on the KKM barrel, mine shipped today (ordered on 3/22/2017). I sent them an email today to check the status and got an email back a few hours later saying it would ship today or tomorrow. Tracking generated this afternoon as promised.
 

Yondering

Regular Member
As a follow up to ammo selection and compensator function/gas volume thing...

The 115+P+ (9BPLE) yielded ~slower~ split times (for me) than 147 grain loads (147HST) and performed with ~less~ consistency at distance (100y) under windy conditions compared to the 147 grain load.

The "light projectile/high gas volume" seemed to make sense, but the numbers don't add up for me.

YMMV

Because you're comparing a +P+ load to a standard pressure load. Obviously hot loads still feel hotter and generally have slower split times.
 

MisterHelix

Newbie
Right, that is exactly what I was comparing, with the goals of determining which loads yielded the best overall performance with regards to both speed and accuracy at distance.

It wasn't obvious (to me) that a hotter load (with a lighter bullet) would still feel hotter, given the mitigating forces generated by the compensator.

I thought that was the whole premise of the "lightweight projectile/high gas volume vs heavy projectile/low gas volume in a comp'ed gun" discussion.

But yeah, apparently it's true.
 

Abusek

Newbie
For those keeping score on the KKM barrel, mine shipped today (ordered on 3/22/2017). I sent them an email today to check the status and got an email back a few hours later saying it would ship today or tomorrow. Tracking generated this afternoon as promised.

Well that's interesting, as I ordered mine on 2/27/17, got confirmation of payment on 3/8/17, and called last week and it was to be in the next batch received from anodizing. Now I wish I had ordered from a dealer, but I am still eager to receive it and run my gun.
 

ggammell

Does not pass up an opportunity to criticize P&S.
Well that's interesting, as I ordered mine on 2/27/17, got confirmation of payment on 3/8/17, and called last week and it was to be in the next batch received from anodizing. Now I wish I had ordered from a dealer, but I am still eager to receive it and run my gun.

LE deal direct. It was worth it to go through them. That can apparently only be done by phone order. And I did not have any extra finish done to the barrel if that makes a difference.
 

Abusek

Newbie
LE deal direct. It was worth it to go through them. That can apparently only be done by phone order. And I did not have any extra finish done to the barrel if that makes a difference.


Ok but on 3/21/17 you said you were also on week three, did you order two different barrels or am I losing it lol?

Edit: as for finish did not elect to receive the matte black either, just the standard silver.
 
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