A Thank you and a few questions

[Jules1985]

All of you have a nice good evening
First of all, I would like to thank everyone present, your tips for my first open weapon have helped me in many ways and brought my shooting skills to a whole new level.

For the first time in my life i ended up in the top ten at a big match.
I still have a few questions about a few topics where in many of them iam  simply interested in the answer.

 

1.

I often hear that shooters have stabilizer holes drilled in their comps.

what exactly is it and what is it good for?

 

2.

 when porting guns, I often hear the terms v6 v8 or v12 porting.
does this refer to the number of holes? and how important is it whether the ports point directly upwards or are aligned to the side, such as in the eric gold open weapon?

I still notice some trembling of  my dot movement to the sides and wonder how this could be eliminated.

3. how do you know if a compensator is overgased? I am very satisfied with my load, but the higher I go from the powerfactor, the wilder the movement of the dot  becomes. could that be an indication of excess gas?

 

Thank you all 

 

[MikeBurgess]

1  This may be side ports on the comp? if so they just make it louder for those around you, there are those that believe gas going sideways will hold the gun still side to side unfortunately physics says otherwise ( I will concede that side ports can increase the amount of gas that is diverted to horizontal so it can increase the overall brake affect due to there being more port area)

 

2 Yes that is in reference to how many ports and their orientation, ports that point other than up waste some of their gas on forces that don't push the muzzle down. 

 

3 I'll go out on a limb and say its not actually a thing to be "over gassed" if it was then NOBODY would shoot a super with its larger case and powder charge, the more gas you have the better. That said as you change your load you change how fast the slide is moving, a hotter load may be flatter but also may have the slide moving faster and hitting the frame harder causing the dot movement you are seeing, between main spring weight firing pin stop geometry and recoil spring weight there are lots of places to make adjustments to get the gun to behave the way you want. 

 

Here is my $.02 on comps and ports, people think it makes way more difference than it actually does. Look at the comps and ports on several "top" builders guns and you will see there is a huge variety of designs (2 port, 3 port, huge side ports small side ports no side ports, lots of barrel holes a few barrel holes small holes big holes) if there was a setup that was enough better to make an actual difference then they would all look the same, but they don't. The differences are all so small as to be immaterial and most of it is fashion, currently guns are being made super heavy in 10 years lighter will be the hot ticket again. 

Think about this, how much actual scientific testing do you think open gun builders are doing? not we made something new and went to the range and shot it and though it was better but actual show me the numbers better or worse testing? I bet the answer likely rounds to zero 

[MikeyScuba]

One benefit to 38sc I'm only just discovering is keeping the RO's at bay.   Got 2 ports, 4 popple holes.

 

And boy is it fun, just don't get lazy and use whatever is handy (aka motor oil) to lube things up a bit the night before without actually cleaning the gun properly.  Arg..... Would have come 2nd in open as I had 2 stages where I got malfunctions, threw me off big time.  But still for my first official  match in open I can't complain.  Like you Mike I transitioned from revo.   Pretty sure nobody expected me to come out of the gate like I did, I've already set a new goal for this year.  fun times.

[Guy Neill]

You may consider the 9x25 was over gassed since it would drive the gun down, as I understand.

 

[Braxton1]

6 minutes ago, Guy Neill said:

You may consider the 9x25 was over gassed since it would drive the gun down, as I understand.

 

 

Those who fail to learn from history are doomed to repeat it....

 

When it first came out, I built a .357 SIG on a Glock 22 chassis.  Shooting 95 grainers at Major would actually push the gun down.  Ended up running 115s to get the gun to track straight.

 

I knew about the "down push" issues that TGO had with his 9X25, but figured that there was no way that the .357 SIG would have enough case volume to replicate the problem.  WRONG!!

 

In the end, having capacity (9Major or Super) was much more of an advantage than having a dot that didn't move.

 

[MikeBurgess]

2 hours ago, Braxton1 said:

 

Those who fail to learn from history are doomed to repeat it....

 

When it first came out, I built a .357 SIG on a Glock 22 chassis.  Shooting 95 grainers at Major would actually push the gun down.  Ended up running 115s to get the gun to track straight.

 

I knew about the "down push" issues that TGO had with his 9X25, but figured that there was no way that the .357 SIG would have enough case volume to replicate the problem.  WRONG!!

 

In the end, having capacity (9Major or Super) was much more of an advantage than having a dot that didn't move.

 

Just to be clear a 95 grainer is never " at major" regardless of velocity Appendix D1 lin3 3 Minimum bullet weight 112 grains for major power factor.

 

 

[AverageJoeShooting]

On 7/16/2021 at 6:52 PM, Jules1985 said:

 

1. sideways holes drilled in the comp to eliminate the shake of the dot. 

2. v6 v8 and v12 refers to a certain type of porting. v6 is 3 holes either side of the barrel, v8 is 4 holes either side. v12 is 4 holes on each side and 4 in front. 

3. place a while target two inches in front of the muzzle. when you shoot it, it you see the target get blown upwards its too much gas coming out of the front of the barrel, meaning not enough gas is getting dispelled out of the popples and comp which means too much gas. the more gas the harder everything is going to be (ie slide hitting your hand etc) and the more your dot will bounce.  That not necessarily a bad thing, because you should be looking for the perfect return to zero. if the dot bounces an inch but returns to the same spot as the first shot id almost say thats not bad because it means your follow up shot is going to be in close proximity to the first shot, which is what you want on paper. ideally, most people will work up their load, i usually load to 170 and then back it off a little to get around 168ish.  Then you want to tune your recoil and mainspring so its relatively flat shooting but also returning to zero. if you use a slow motion camera from the side you can see exactly when the slide dips. 

[Whitefish]

4 hours ago, Guy Neill said:

You may consider the 9x25 was over gassed since it would drive the gun down, as I understand.

 

The one good thing about 9x25 open guns was that you almost never had to ask a squad to stand back. If they didn't beforehand, they sure did after the first shot.  The concussion was breathtaking and most RO's I knew tried mightly to avoid running an open shooter with one. Those guns fell out of favor rather quickly after guys started to get fractured teeth and or stress fractures in the elbow area - in addtion to the excess gas driving the gun down.

[caspian guy]

3 hours ago, MikeBurgess said:

Just to be clear a 95 grainer is never " at major" regardless of velocity Appendix D1 lin3 3 Minimum bullet weight 112 grains for major power factor.

 

 

Yep... And if you wonder why, I gather that 9x25s with light bulletson steel is why.

Edited July 20, 2021 by caspian guy

[Braxton1]

13 hours ago, MikeBurgess said:

Just to be clear a 95 grainer is never " at major" regardless of velocity Appendix D1 lin3 3 Minimum bullet weight 112 grains for major power factor.

 

 

According to the current Rulebook, Yes, but not in the old days.  That is a relatively new rule change.  Been doing this for a minute....

[zzt]

On 7/16/2021 at 6:52 PM, Jules1985 said:

3. how do you know if a compensator is overgased? I am very satisfied with my load, but the higher I go from the powerfactor, the wilder the movement of the dot  becomes. could that be an indication of excess gas?

 

Not necessarily.  If you change nothing else and simply increase the PF, you increase slide speed and secondary recoil.  As you go up in PF you have to change recoil springs and possibly rethink your FPS radius and Mainspring weight.

 

When I switched to 9 Major I had to approach the problem differently.  Now I'm case capacity limited so I literally cannot fit enough powder in the case to make the gun shoot soft AND flat at the same time.  There is also no way I can overdrive the comp, even if I fill the case to capacity and compress the charge.  So I developed the load first, then tuned the guns to it.

 

I shoot a 115 JHP over 10.2gr SWMP (AA7) powder for 169 PF with an SD of 5.9.  Both guns are tightly fitted.  The main gun wears a three up port comp and two 3/16" poppels in a V2.  The backup gun has a  Brazos Thundercomp 2 and three 5/32" poppers vertical.  The main gun has the least muzzle rise using an 11 lb. recoil spring, 19 lb. mainspring and a 'normal' Open radius FPS from Cheely.  The backup gun has a 10 lb. recoil spring, 17 lb. mainspring and Cheely FPS.

 

The idea when tuning your gun to your load is to have the dot return to 'zero' as quickly as possible while having enough dwell time to allow proper feeding.

 

BTW, the TC2 comp has six side holes for 'stabilization'.  The dot on both guns track straight up and down, so all they do is increase the noise level.  Whenever I shoot the backup gun EVERYONE comments on how loud it is.

Edited July 21, 2021 by zzt

[Jules1985]

@zzt

 

I have now let my gunsmith do the ports. We also installed a new firing pin block with a smaller radius and worked on the hammer spring. The diffrence is absolutely fantastic, would Never again Go without Ports.

I test the gun in the shot with a slow motion camera and millimeter paper and the ports have resulted in a significant reduction in the dot movement.

I lost 4 Powerfactor but im still at 168, and 160 is needed.

I noticed That the gun is shooting the best with 165-167 PF…

 

Thank you all for your great help!

 

I will now shoot the gun for 4 big matches and after another 5000 shots recap whether it is perfect.

 

https://ibb.co/hFqxMcF

 

 

 

 

 

 

 

Edited July 23, 2021 by Jules1985

[AverageJoeShooting]

3 hours ago, Jules1985 said:

160 is needed.

major is 165pf

but 168 is a safe spot

[Jules1985]

In Germany its 160 at the moment.

[zzt]

If you find the gun too muzzle heavy, try a shorter comp.  With four large poppels there is no way on earth you can generate enough gas to work a 5-chamber, 7-port comp.  You would have to go to 38sc or 40sw for that.

[Ludde]

10 hours ago, Jules1985 said:

@zzt

 

I have now let my gunsmith do the ports. We also installed a new firing pin block with a smaller radius and worked on the hammer spring. The diffrence is absolutely fantastic, would Never again Go without Ports.

I test the gun in the shot with a slow motion camera and millimeter paper and the ports have resulted in a significant reduction in the dot movement.

I lost 4 Powerfactor but im still at 168, and 160 is needed.

I noticed That the gun is shooting the best with 165-167 PF…

 

Thank you all for your great help!

 

I will now shoot the gun for 4 big matches and after another 5000 shots recap whether it is perfect.

 

https://ibb.co/hFqxMcF

 

 

 

 

 

 

 

It would have been interesting to see how much effect you would have seen from all the tuning without the popple holes.

[zzt]

1 hour ago, Ludde said:

It would have been interesting to see how much effect you would have seen from all the tuning without the popple holes.

 

In 9 major is is very unlikely you can fully work any efficient comp.  So poppels are what you resort to if you want flatter, and you are willing to accept the harder hit to the hand.

 

To answer your question, the result would have been softer and flatter than prior to the tuning, but not as flat as when you add poppels.

 

 

Edited July 23, 2021 by zzt

[Jules1985]

@zzt

managed to do a photography  in ultraslowmow of my gun firing.

Looks like there is plenty of work on the Comp?

 

[zzt]

3 hours ago, Jules1985 said:

@zzt

managed to do a photography  in ultraslowmow of my gun firing.

Looks like there is plenty of work on the Comp?

 

 

Nice shot.  Look like gas coming out the poppels and particles coming out the comp ports.  I'll have to try that.

[Ludde]

On 7/23/2021 at 8:49 PM, zzt said:

 

In 9 major is is very unlikely you can fully work any efficient comp.  So poppels are what you resort to if you want flatter, and you are willing to accept the harder hit to the hand.

 

To answer your question, the result would have been softer and flatter than prior to the tuning, but not as flat as when you add poppels.

 

 

 

Based on my own testing I would like to disagree.

 

No this is not a 2011 but a CZ. So the construction and some of the behaviour does differ.

 

This is one of many test, not the setup i run now. But you can clearly see the gun not lifting at all until the slide hits the frame and then the muzzle rises. When analyzing more footage there are cases when the muzzle even dips just a tad when the comp works.

 

Based on this and other tests I have done, by looking at slowmo footage frame by frame all my open gun tests have produced a flat recoiling gun, all the muzzle rise comes from the secondary recoil. I.e. when the slide bottoms out on the frame. If anything on my guns the popple holes would likely just increase the slide velocity resulting in even more secondary recoil and more muzzle rise. The popple holes don't do any work anymore once the slide has moved a bit.

 

Today I use a 24lbs main spring and my own made square firing pin retaining plate, all this to slow down the slide velocity.

 

But please remember that 2011s and CZs seems to react differently to similar changes.

 

E.g. I tested and simulated a heavy barrel/steel comp on my CZ and it did not decrease the unlocking speed by any noticable difference (slide speed) however I did notice another phenomena, I could clearly feel the barrel impacting the frame/slide stop before the slide bottomed out. It was not a good feeling setup and it did not improve my sight recovery or return.

 

 

 

[zzt]

8 hours ago, Ludde said:

Based on my own testing I would like to disagree.

 

Then I will opine your comp is not very efficient.  If it were you would not need a 24 lb. mainspring and a square bottom FPS to control slide movement.

 

I don't remember if I mentioned this earlier in the thread, so I say it again.  My main gun had two 3/16" poppels and a very efficient 3 chamber comp with only up ports.  Even if I completely fill the case with SWMP (AA7) and compress the charge while seating a 115 JHP, I get nothing more than a light splatter when I fire the gun 1" away from a white no shoot.  That tells me the poppels and the comp ports are exhausting almost all of the gas before the bullet exits.  This 2011 wears a 10.5 oz. slide, 11 lb. recoil spring, 19 lb. mainspring and a normal Open type FPS radius.

 

 

[Ludde]

1 hour ago, zzt said:

 

Then I will opine your comp is not very efficient.  If it were you would not need a 24 lb. mainspring and a square bottom FPS to control slide movement.

 

I don't remember if I mentioned this earlier in the thread, so I say it again.  My main gun had two 3/16" poppels and a very efficient 3 chamber comp with only up ports.  Even if I completely fill the case with SWMP (AA7) and compress the charge while seating a 115 JHP, I get nothing more than a light splatter when I fire the gun 1" away from a white no shoot.  That tells me the poppels and the comp ports are exhausting almost all of the gas before the bullet exits.  This 2011 wears a 10.5 oz. slide, 11 lb. recoil spring, 19 lb. mainspring and a normal Open type FPS radius.

 

 

 

Have you tested on a CZ style gun?

[zzt]

1 hour ago, Ludde said:

 

Have you tested on a CZ style gun?

 

Yes.  For one thing, I started shooting Open with a CZ.  I was not happy with it, so I went to 2011s.  Also, I helped a shooting buddy develop loads for his Czechmate.  Nothing we tried could get it to shoot as flat or as soft as any of my 2011s.

 

The initial impulse on your gun is flat because you have a square bottom FPS.  That delays the opening of the slide, so the muzzle rise is delayed.  Once the slide gets going you have a massive amount of secondary recoil.  The slide is moving fast and you are not mitigating the movement.  It is fast because your comp is not efficient and you have a lot of gas jetting out the front of the comp.  That drives the slide back hard.

 

With 2011s it is quite common to have a lightened slide, 7 lb. recoil spring, 17 lb. mainspring and a normal radius on the FPS.

[Ludde]

12 hours ago, zzt said:

 

Yes.  For one thing, I started shooting Open with a CZ.  I was not happy with it, so I went to 2011s.  Also, I helped a shooting buddy develop loads for his Czechmate.  Nothing we tried could get it to shoot as flat or as soft as any of my 2011s.

 

The initial impulse on your gun is flat because you have a square bottom FPS.  That delays the opening of the slide, so the muzzle rise is delayed.  Once the slide gets going you have a massive amount of secondary recoil.  The slide is moving fast and you are not mitigating the movement.  It is fast because your comp is not efficient and you have a lot of gas jetting out the front of the comp.  That drives the slide back hard.

 

With 2011s it is quite common to have a lightened slide, 7 lb. recoil spring, 17 lb. mainspring and a normal radius on the FPS.

 

That's what I am trying to point out. That CZs and 2011s do not behave the same and therefore you might not get the expected results if one base it on e.g. 2011 dos and donts when tuning a CZ and vise versa.

 

The initial muzzle rise if any would/could potentially increase because of the square FPS, more force required to cock the hammer resulting in more rotating force and more initial muzzle rise unless the comp keeps the muzzle down during that phase of the cycle.

 

All of the many setups I have run have been recorded in slow motion and later exported frame by frame to really see what happens. More detailed than the YouTube stuff.

 

I have also tried to find some food for thought and the few sources I could find clearly show that there is a significant difference in slide velocity/acceleration between CZ type construction and 1911/2011.

 

BUT I am still looking for some solution that could still improve on decreasing the secondary recoil.... The search continues.

 

Unless it is patent pending or an absolute business secret I would be interested in seeing what kind of comp design you have found works well for your setup. It is always interesting with more potential influence.

Edited July 30, 2021 by Ludde