Too much gas?

[d3ydx3]

Tried 3n38 yesterday at the range for my 9 Major load. I have been using 9.6gr of AA7 behind a 124gr Everglades JHP V2 bullet, which runs the gun fairly flat and not a lot of push. The 8.8gr 3n38 load that I tested yesterday didn’t feel as good and seemed to push the gun a lot more than I wanted. Got back home and reviewed some of the practice video, where it looks like a lot of gas coming out of the front of the gun and even the ejection port. 8.8 out of this gun is around 175-177 PF, so I’m thinking of dropping it down to 8.4 for 172 PF. Videos below. 
 

 

 

 

[Kevrend]

Do you have any footage of your previous load for comparison?

[d3ydx3]

Just now, Kevrend said:

Do you have any footage of your previous load for comparison?

Sure do, but not from that same angle. 1st video is me shooting some plates with the same 9.6 AA7 load and the 2nd is a comparison of different AA7 loads and N350. The 9.6 AA7 happens to be the 1st one in the 2nd video.

 

 

 

 

[zzt]

Having and using both powders for Open, I can tell you that the AA&/SWMP powder is the best, IMO.  The extra push you felt with the lighter charge of 3N38 was because it didn't make as much gas as the AA7 load and the comp baffles were not pushed on as hard.  If you want even flatter, use 115 JHPs.

 

I cannot fit enough 3N38 in a 9mm case to make major with a 115 and still seat the bullet to 1.161", so I'm using that for minor.  10.2 gr SWMP/AA7 under a 115 JHP for 169 PF works in both Open guns.  10.4 is a tad flatter and a little harsher.  10.4 is compressed slightly while 10.2 is not.  I use 6.8 gr 3N38 under a 124 JHP or 7.2 under a 115 JHP for my (minor) SCSA loads in my 1911 Open gun.

 

Your AA7 load shoots considerably flatter than the 3N38 load.  I question your PF estimates.  8.4 3N38 under a 124 does not make major in my guns.

 

To see if you are making too much gas, hold the muzzle an inch away from a white no shoot and fire.  If you get minimal splatter about the size of a quarter, you do not have too much gas.

[d3ydx3]

25 minutes ago, zzt said:

Having and using both powders for Open, I can tell you that the AA&/SWMP powder is the best, IMO.  The extra push you felt with the lighter charge of 3N38 was because it didn't make as much gas as the AA7 load and the comp baffles were not pushed on as hard.  If you want even flatter, use 115 JHPs.

 

I cannot fit enough 3N38 in a 9mm case to make major with a 115 and still seat the bullet to 1.161", so I'm using that for minor.  10.2 gr SWMP/AA7 under a 115 JHP for 169 PF works in both Open guns.  10.4 is a tad flatter and a little harsher.  10.4 is compressed slightly while 10.2 is not.  I use 6.8 gr 3N38 under a 124 JHP or 7.2 under a 115 JHP for my (minor) SCSA loads in my 1911 Open gun.

 

Your AA7 load shoots considerably flatter than the 3N38 load.  I question your PF estimates.  8.4 3N38 under a 124 does not make major in my guns.

 

To see if you are making too much gas, hold the muzzle an inch away from a white no shoot and fire.  If you get minimal splatter about the size of a quarter, you do not have too much gas.

 

The paper test is definitely on my list of things to try. I just haven't gotten around to it yet. Here's my load data for 3N38. Seems I just have a fast barrel and also no popple holes.

 

 

 

 

 

[CHA-LEE]

I would suggest videoing it in slow motion to see what is really happening and exactly when.

 

As far as the "Too much gas?" question, the movement of the dot should tell you that. When my Open gun has a "Too much gas" ammo config the dot dives straight down as soon as the shot fires. With the proper volume of gas vs the port/popple hole config the dot should smoothly rise as the slide starts to come backwards.

 

To be totally honest, your weak grip and bent elbow arm position is creating a crap ton of excessive gun movement that isn't needed. You will likely need to fix that stuff before worrying about how much gas is too much or not enough.

[d3ydx3]

1 hour ago, CHA-LEE said:

I would suggest videoing it in slow motion to see what is really happening and exactly when.

 

As far as the "Too much gas?" question, the movement of the dot should tell you that. When my Open gun has a "Too much gas" ammo config the dot dives straight down as soon as the shot fires. With the proper volume of gas vs the port/popple hole config the dot should smoothly rise as the slide starts to come backwards.

 

To be totally honest, your weak grip and bent elbow arm position is creating a crap ton of excessive gun movement that isn't needed. You will likely need to fix that stuff before worrying about how much gas is too much or not enough.

That bad, huh? I did buy your book so I’ll make sure to read the section on stance.
 

Grip strength is one area that I’ve put some effort into recently. Curious what you’re seeing? Wrist separation or just overall weak grip? I’ve been looking to see if the trigger guard lifts off my hand in video, and I thought that was something that I had fixed. 

Edited May 30, 2021 by pealandco

[CHA-LEE]

11 minutes ago, pealandco said:

That bad, huh? I did buy your book so I’ll make sure to read the section on stance.
 

Grip strength is one area that I’ve put some effort into recently. Curious what you’re seeing? Wrist separation or just overall weak grip? I’ve been looking to see if the trigger guard lifts off my hand in video, and I thought that was something that I had fixed. 

Once you push your arms out so that your elbows don't bend during recoil then the grip issued will be exposed. Once again, slow motion video is good for seeing what is really happening.

[Stevenchrist]

You don't need to worry about too much gas or not enough .

[d3ydx3]

6 hours ago, zzt said:

Having and using both powders for Open, I can tell you that the AA&/SWMP powder is the best, IMO.  The extra push you felt with the lighter charge of 3N38 was because it didn't make as much gas as the AA7 load and the comp baffles were not pushed on as hard.  If you want even flatter, use 115 JHPs.

 

I cannot fit enough 3N38 in a 9mm case to make major with a 115 and still seat the bullet to 1.161", so I'm using that for minor.  10.2 gr SWMP/AA7 under a 115 JHP for 169 PF works in both Open guns.  10.4 is a tad flatter and a little harsher.  10.4 is compressed slightly while 10.2 is not.  I use 6.8 gr 3N38 under a 124 JHP or 7.2 under a 115 JHP for my (minor) SCSA loads in my 1911 Open gun.

 

Your AA7 load shoots considerably flatter than the 3N38 load.  I question your PF estimates.  8.4 3N38 under a 124 does not make major in my guns.

 

To see if you are making too much gas, hold the muzzle an inch away from a white no shoot and fire.  If you get minimal splatter about the size of a quarter, you do not have too much gas.

 

Tried the paper test this afternoon and for what it is worth, 8.4gr (new load) had quarter sized splatter and the 8.8gr load (load in the videos from the original post) had splatter 2-3x the size. 

[d3ydx3]

1 hour ago, CHA-LEE said:

Once you push your arms out so that your elbows don't bend during recoil then the grip issued will be exposed. Once again, slow motion video is good for seeing what is really happening.

 

Makes sense. I did notice in one of my videos my elbows were more straight out and the gun looked like it was shooting very flat. The particular day I tested the load that I complained about my elbows are definitely bent and more inwards. Something that I will need to consciously work on during practice.

[zzt]

15 hours ago, pealandco said:

 

Tried the paper test this afternoon and for what it is worth, 8.4gr (new load) had quarter sized splatter and the 8.8gr load (load in the videos from the original post) had splatter 2-3x the size. 

 

The 8.4 is your load if you stick with 3N38.  All shots are over 170 PF, so you are good at the chrono station.

 

I'll second what Cha-lee says about elbows.  Sometimes near the end of a match my elbows hurt so much I bend them.  Gun control goes out the window.  It is possible to fully extend your arms, but only semi-lock your elbows.  It is hard to maintain, but does take some strain off if you do it right.  I'll also note that now that the gyms are open, my wrist and arm strength are improving.  That helps a lot, because there is less impact on your joints.

 

Added later:  I still prefer the slower powder, especially if I'm using 124s.

 

Do the same experiment with AA7.  If you are still not as flat as you want, your only alternative is poppels.  Two 3/16" or three 5?32" holes will rob gas from the comp to the tune of between 4 and 6 PF.  You can add more powder to make up for that and the gun will shoot flatter and probably close to the same softness.

Edited May 31, 2021 by zzt

[Ludde]

This is a CZ Shadow 2 I have built.

 

I have no extreme grip strength.

 

9mm Major roughly 7.95 grain 3n38 166pf 124grain bullet.

No popple holes.

 

Mine is not perfect, but I contribute alot of the gun movement to technique or lack of. For me going up in pf above 168pf has only negative effects. 

 

Looking at this same footage frame by frame clearly shows the gun staying flat, even dipping a tiny bit as the comp works and the hammer is cocked. The muzzle flip comes from the slide bottoming out on the frame.

 

With the previous comp I used I even went up to 24lbs hammer spring, ended up selecting 20lbs because at least earlier it felt like a good compromise when looking at farther distance target hits/splits/dot movement and feeling (rotation) in hand. I will revisit the hammer spring weight soon with this new comp.

 

 

Frame by frame:
 

 

Edited June 1, 2021 by Ludde

[AverageJoeShooting]

ive used both in open and AA7 is way flatter. i do 9.3 grains AA7, 124 grain coated bullet

gun is super flat

[yelpspoon]

On 5/30/2021 at 11:34 AM, zzt said:

Having and using both powders for Open, I can tell you that the AA&/SWMP powder is the best, IMO.  The extra push you felt with the lighter charge of 3N38 was because it didn't make as much gas as the AA7 load and the comp baffles were not pushed on as hard.  If you want even flatter, use 115 JHPs.

 

I cannot fit enough 3N38 in a 9mm case to make major with a 115 and still seat the bullet to 1.161", so I'm using that for minor.  10.2 gr SWMP/AA7 under a 115 JHP for 169 PF works in both Open guns.  10.4 is a tad flatter and a little harsher.  10.4 is compressed slightly while 10.2 is not.  I use 6.8 gr 3N38 under a 124 JHP or 7.2 under a 115 JHP for my (minor) SCSA loads in my 1911 Open gun.

 

Your AA7 load shoots considerably flatter than the 3N38 load.  I question your PF estimates.  8.4 3N38 under a 124 does not make major in my guns.

 

To see if you are making too much gas, hold the muzzle an inch away from a white no shoot and fire.  If you get minimal splatter about the size of a quarter, you do not have too much gas.

 

@zzt what PF are you generally aiming for with SCSA with your 3N38 loads?

[zzt]

21 minutes ago, yelpspoon said:

 

@zzt what PF are you generally aiming for with SCSA with your 3N38 loads?

 

I was as low as 140 PF with the 6.8 load.  The brass just dribbled out.   I went to 7.0 and now 7.2.  That gave me more reliable function and more gas.   It should be about 150 PF.  I think 150~155 PF is the sweet spot for minor Open.  I could go higher, because I built the gun for major.  The limiting factor for me is when more than a tiny bit of 3N38 starts jumping out of the case and onto the shell plate when it rotates.  At 7.2 it is starting to do that.

 

Most of the Open SCSA shooters I shoot with use WAC and 115s for 155 PF.  I would love to do the same, but I have 8+ lbs. of 3N38 to use up, and nothing else to use it for.

[yelpspoon]

9 minutes ago, zzt said:

 

I was as low as 140 PF with the 6.8 load.  The brass just dribbled out.   I went to 7.0 and now 7.2.  That gave me more reliable function and more gas.   It should be about 150 PF.  I think 150~155 PF is the sweet spot for minor Open.  I could go higher, because I built the gun for major.  The limiting factor for me is when more than a tiny bit of 3N38 starts jumping out of the case and onto the shell plate when it rotates.  At 7.2 it is starting to do that.

 

Most of the Open SCSA shooters I shoot with use WAC and 115s for 155 PF.  I would love to do the same, but I have 8+ lbs. of 3N38 to use up, and nothing else to use it for.

Thanks for that.

In my limited experience it seems that 155PF is a nice PF to be at for minor...I wonder why that is...
I have done 155PF loads (CFE pistol) taking a recommendation from Adam (Atlas) in terms of saving a bit of wear-and-tear on the open pistol for practices, etc.

[Snoopy47]

1 hour ago, yelpspoon said:

........In my limited experience it seems that 155PF is a nice PF to be at for minor...I wonder why that is...........

I agree as well. I'm using a GLOCK with N350, and my ideal load is around 145-150PF. So it's probably the compensator port and gas combination driving most of that. 

[zzt]

14 hours ago, yelpspoon said:

Thanks for that.

In my limited experience it seems that 155PF is a nice PF to be at for minor...I wonder why that is...
I have done 155PF loads (CFE pistol) taking a recommendation from Adam (Atlas) in terms of saving a bit of wear-and-tear on the open pistol for practices, etc.

 

That is exactly why.  You make enough gas to help flatten the pistol.  It feels like a softer version of major.  It's great for SCSA.  I still would not practice USPSA with minor.  Your splits are faster and it feels different enough to make a difference.  I practice with the load I'm going to shoot in a competition.

 

As far as being easier on the gun, maybe.  If you too light a recoil spring for major, you are 'saving' the slide with minor.  I don't buy it.  I tried setting up a gun to shoot both major and minor.  Obviously that involves compromises.  The consequences were enough to persuade me that was not a good idea. 

 

My major load is a 115 JHP @ 1470 fps.  My main major gun wears an 11 lb. recoil spring, and 19 lb. mainspring and a standard Cheely radius on the FPS.  That setup tames the gun.  My backup wears 11, 17 and the same FPS.  Both have very tight slide to frame fits.  If I fire my minor load in one of them, the slide doesn't go back far enough to eject the case.

 

My minor Open gun is set up for 150 PF loads.  7 lb. recoil spring, 19 lb. mainspring (I will change to 17 next time I deep clean) and a FPS radiused all the way up to the firing pin hole.  I originally built the gun for major, so it has the same barrel, poppels and comp my major gun has.  That's why it won't run anything lower than 144 pf.  If I were starting from scratch I would either use a much shorter comp with no poppels, or a poppel or two with no comp. 

[Chapo]

Your videos were unavailable so I can't comment on that.  However I have several videos shooting my open Glock with HS6 just over 7gr and the recoil is minimum.

 

https://www.youtube.com/channel/UCLEAh7Bstw0lf4LLNWm9P6A