Big leap in my understanding of Compensators

[Snoopy47]

I've starting playing with my Phone Camera Slow-Motion function. It gets me some good data, and today I tested batch of test loads that differed by 0.1gn. 

 

Anyway.......... through a Glock G34 KKM barrel in 9mm with a Carver 3 top port (7 total) using 800x (yep, building loads to get rid of all my less desirable powders) I stumbled upon exactly what is meant by "enough gas needs to be there to work the comp". 

 

124gn plated 

1.16 OAL

15lb recoil spring

 

at 5.3gn the gun did not cycle, slow motion did not show any noticeable fireball out the comp.

at 5.4gn again same result.

at 5.5gn the gun started functioning and feeding and ejecting. I had one stove pipe. There was a slight glow in the slow motion.

at 5.6gn the gun stopped working. While 5.5gn it would mostly work at 5.6gn is just would fire, and then jam up every single round. 

 

I thought that was strange. Why would it work at 5.5 and stop working at 5.6? But look at the slow motion there was a pretty cool fireball out of the compensator, but the gun stopped working (relative to the spring rate for that load). 

 

There we go, at 5.6gn with 800x through this barrel and comp combination it has enough gas there to let the wind out of the sales. I don't know what the best load is yet, but with this compensator it needs to be north of 5.6gn. I could go DOWN spring rates, but that defeats the comp. At 5.5gn for example the barrel length of the G34 is enough to build up the pressure to cycle and feed the next round, but that is the point just before the compensator starts to kick in. 

 

Anyway........... I thought that was cool to learn as see a visual hint as to what goes on with compensators. 

 

**********

BTW:

The Hodgdon max load for 800x is 5.7gn at OAL of 1.15. 

 

Maybe 800x is a good powder, but it sucks to load and measure.

 

[nhyrum]

How does going down in spring weight defeat the comp? The way I see it, it allows the comp to do most the work in slowing down the slide, and all the spring does is pick up the next round and close the slide. 

 

It is fun to watch the gun stop functioning as you turn up the load.

[konkapot]

Very very very cool post/topic. Any chance you can post the various videos?

[AverageJoeShooting]

why would anyone use 800x?

why would springs defeat the comp?

why would anyone use a glock in open?

 

so many questions unanswered

[Fo0]

This is minor PF?

[Glock17open]

2 hours ago, AverageJoeShooting said:

why would anyone use 800x?

why would springs defeat the comp?

why would anyone use a glock in open?

 

so many questions unanswered

Some people like Glocks, but I shoot a 2011 open gun now.

[Snoopy47]

This is the slow motion video

 

 

[Snoopy47]

Geography limits my firearm options (California). Ownership of a threaded barrel is illegal. This example is welded on so the slide and barrel comp are all one unit. 

 

As well there are no approved 2011 frames on the roster. So the whole process of a straight up race gun is a complicated process that can only be accomplished by

1) Buying one brought in from a resident who moved to CA with said race gun and decided to sell private party (less magazines)

2) managed to get a 2011 frame by same private party purchase process and build it up

 

What this Glock is really designed for is the GSSF Glock matches where all guns are Glocks. Yes, very narrow objective and goal. I started with one thing, then another, and then I just went ALL IN. 

 

I also use it for Steel Challenge which requires no Major PF. 

 

I'm using 800x because I'm on my last 1/2 pound of 3M38 and am not interested in paying $70 a pound to get it to my door. So I looked at the burn charts of what powders I have on hand and I'll be just using the stuff up as I practice and get better. 

 

At best, when I step into the 1911 realm of Open Guns I'll be limited to a 1911 frame, and then have to convert it to 9mm myself (only two 9mm 1911's are on the roster). So it will still only be a 10+1 9mm, but at least all steel. My compensator options will still have to be welded on, but at least I can remove the barrel from the slide, but the bushing will be trapped. 

 

Is a 9mm 1911 threaded bull barrel a thing?

 

Here in California, I suppose CZ would be the go to donor platform. 

[Snoopy47]

I had a "theory" that if I could "tune" the recoil spring and load to cycle just enough to eject/feed without actually bottoming out the spring and slam the slide against the frame that it would help shoot flatter. Slow motion showed that the barrel didn't come up until the slide was fully back. 

 

My theory didn't pan out.  

 

I have slow motion of FTE's and of course the slide doesn't even cycle back far enough eject let alone bottom out the spring but the barrel rises about as much as any other load in that realm. 

 

I'm guessing "flatness" is a function of recoil cycle pulse pitted against compensator effectiveness in junction with the user's grip strength. 

 

That all said............. I'm rather content with the above posted video in as much as the gun comes up, and I think I have pretty good control getting it back down. So I'll finish using this 800x and hope I get more 3N38 without getting raked over the coals.

 

I've seen "flat" guns on youtube, but I've not seem them in slow motion. So I'm not convinced they are actually "flat". So I'm going to stop chasing that ghost, and just start having fun shooting. 

[CHA-LEE]

Good luck getting an Open Glock to function reliably........ Even "Team Glock" couldn't make it happen with unlimited resources.

[Fo0]

6 minutes ago, CHA-LEE said:

Good luck getting an Open Glock to function reliably........ Even "Team Glock" couldn't make it happen with unlimited resources.

 

what year was that?

and wasn't KC winning matches back then

[CHA-LEE]

Just now, Fo0 said:

 

what year was that?

and wasn't KC winning matches back then

 

It was the KC era of Team Glock and sure he won some matches with that abomination of an Open gun but he also lost many as well due to its unreliability. I personally seen him lose several major matches because that thing wouldn't run.

 

I will put it this way....... NOBODY at the top of this game is going to risk their match performance trying to make an Open Glock work.

 

There is an endless cycle of shade tree mechanics that think they can make an Open Glock work until they waste enough money and ruin enough matches because they don't work. I just think its funny that people keep trying to make them work.

[Fo0]

2 hours ago, Snoopy47 said:

Geography limits my firearm options (California). Ownership of a threaded barrel is illegal. This example is welded on so the slide and barrel comp are all one unit. 

 

As well there are no approved 2011 frames on the roster. So the whole process of a straight up race gun is a complicated process that can only be accomplished by

1) Buying one brought in from a resident who moved to CA with said race gun and decided to sell private party (less magazines)

2) managed to get a 2011 frame by same private party purchase process and build it up

 

What this Glock is really designed for is the GSSF Glock matches where all guns are Glocks. Yes, very narrow objective and goal. I started with one thing, then another, and then I just went ALL IN. 

 

I also use it for Steel Challenge which requires no Major PF. 

 

I'm using 800x because I'm on my last 1/2 pound of 3M38 and am not interested in paying $70 a pound to get it to my door. So I looked at the burn charts of what powders I have on hand and I'll be just using the stuff up as I practice and get better. 

 

At best, when I step into the 1911 realm of Open Guns I'll be limited to a 1911 frame, and then have to convert it to 9mm myself (only two 9mm 1911's are on the roster). So it will still only be a 10+1 9mm, but at least all steel. My compensator options will still have to be welded on, but at least I can remove the barrel from the slide, but the bushing will be trapped. 

 

Is a 9mm 1911 threaded bull barrel a thing?

 

Here in California, I suppose CZ would be the go to donor platform. 

 

not sure a bull barrel with no threads will shape in the right spot where the slide is. You might be able to make a cone compensator work.

[CalTeacher]

I’m sorry, but getting a 2011 open gun in CA is not very difficult at all.  

[Fo0]

4 minutes ago, CalTeacher said:

I’m sorry, but getting a 2011 open gun in CA is not very difficult at all.  

 

Do you have to use STI Trubor barrels?

[CalTeacher]

3 minutes ago, Fo0 said:

 

Do you have to use STI Trubor barrels?

Legally, yeah.  

[AverageJoeShooting]

6 hours ago, CHA-LEE said:

 

It was the KC era of Team Glock and sure he won some matches with that abomination of an Open gun but he also lost many as well due to its unreliability. I personally seen him lose several major matches because that thing wouldn't run.

 

I will put it this way....... NOBODY at the top of this game is going to risk their match performance trying to make an Open Glock work.

 

There is an endless cycle of shade tree mechanics that think they can make an Open Glock work until they waste enough money and ruin enough matches because they don't work. I just think its funny that people keep trying to make them work.

at the end of the day its 100% about reliability. if you cant get your gun to run the recoil wont matter...and neither will anything else

[Furrly]

 Atlas Gunworks can get you a an open gun into CA.. 

[38super]

Snoopy, not sure where in Kommifornia you are but check with Jimmy or Jojo Vidanes at JV Dynamics.

edit: use a better powder.

Edited September 15, 2021 by 38super

[zzt]

9 hours ago, Fo0 said:

 

Do you have to use STI Trubor barrels?

 

Brazos Custom makes two one-piece barrels with integral comps.

[Furrly]

We had a local GM that was sponsored by the Glock Store. They built him an open glock gun he could not get it to work if his life depended on it.. 

 

 

[Balakay]

3 hours ago, Furrly said:

 Atlas Gunworks can get you a an open gun into CA.. 

I thought Atlas got out of the Open game.  The Chaos 2.0 has been  "coming soon" for a long time.

[Furrly]

5 minutes ago, Balakay said:

I thought Atlas got out of the Open game.  The Chaos 2.0 has been  "coming soon" for a long time.

There going to release the 2.0 after nationals 

[Balakay]

5 minutes ago, Furrly said:

There going to release the 2.0 after nationals 

Thanks for the update!

 

[Furrly]

32 minutes ago, Balakay said:

Thanks for the update!