Glock Open Gun Porting

[Blcksmk]

I was looking at some video's on Glockworx's website and it showed a guy shooting a hybrid ported G17 in 3-Gun. I know most people use comps in Open but, what about completely shooting a hybrid ported gun? Basically 5-6 holes in the top of the slide and barrel shooting a major 9 load. How do you think it would shoot VS a comp gun? I'm sure it would be much louder than a regular comp gun but I'm more concerned on how flat it would shoot.

Blcksmk

[Parallax3D]

1. A Glock 17 barrel is shorter than a standard 2011 9x19 Major open gun to begin with, (more like a shorty 2011), so you're already going to have a harder time making major.

2. A ported barrel is just going to bleed off gas and make it harder to make major. (Ask the guys with shorty 2011s and poppel-holes) You want a comp. The idea of a comp is that there are flat surfaces between the ports for the gases to push against to create backforce/downforce. Not so much with just a port in a barrel.

Basically, I'd say get a good aftermarket barrel with a fully supported chamber, with no ports and a threaded end, then add a comp to the end with the most ports you can get. (SJC makes an 11 port 9MM Major comp that fits 9/16" - 32tpi barrels.)

Edited January 16, 2012 by Parallax3D

[Blcksmk]

1. A Glock 17 barrel is shorter than a standard 2011 9x19 Major open gun to begin with, (more like a shorty 2011), so you're already going to have a harder time making major.

2. A ported barrel is just going to bleed off gas and make it harder to make major. (Ask the guys with shorty 2011s and poppel-holes) You want a comp. The idea of a comp is that there are flat surfaces between the ports for the gases to push against to create backforce/downforce. Not so much with just a port in a barrel.

Basically, I'd say get a good aftermarket barrel with a fully supported chamber, with no ports and a threaded end, then add a comp to the end with the most ports you can get. (SJC makes an 11 port 9MM Major comp that fits 9/16" - 32tpi barrels.)

I see what your saying. But I have seen several hybrid guns run well but never had the chance to ask questions or shoot them. By doing some research it seems as if you need more powder than a regular comp in order to make it work and function and make the PF. I think if you could angle a few of the ports forward and the rest straight up you would have a solid hybrid open gun but I would like to get some more opinions.

[Guest]

The first generation 17L guns came stock with ports. Folks were making major pf out of them by loading with WW540 (now HS6). The ports were like a half moon cut in the top of the barrel, not like the Scheumann ports, and the barrels would crack at the corner of a port...and occasionally break off while shooting which was always entertaining. This is probably why the second generations were sans ports. The ports certainly were effective as a compensator, not sure how good compared to what is available nowadays.

Just a little history and FYI - I'm not not really a glockster so those who are may want to really answer your question.

[sb3]

Will let you know in about a month. I'm going to give one of their full hybrids a try. I will probably try and load some major for it but that really isn't my plan. My uses are primarily outlaw 3 gun and steel so I'm sure it will be nice with minor. Ill keep you posted.

[Whitefish]

I too had the idea to make a cheap open gun with a Glock 34 9 mm with ports/popple holes drilled to vent out the stock slot in the slide. I started with a KKM barrel with 8 popple holes (.125" dia.) drilled in a V pattern. That was fairly harsh, so I had 3 more holes drilled down the middle in between the V for a total of 11 holes. I'm sitting here looking at that barrel as I write this. I still made major using Silhouette and 3N37 with a 125 gr Zero JHP and it was fairly flat shooting, but the gun was so abominably harsh that it occasionally caused feeding issues with rounds actually popping up out of the mag during cycling. And yes, the mag springs and followers were new!

I abandoned that experiment and built a G17 with a KKM gunsmith fit barrel and a Jager comp which is flat shooting and much, much softer. Both guns used slide mounted Docter sights. Your experience may vary, but I found the all ported G34 to be much too harsh at major regardless of what powder I used.

[Blcksmk]

I too had the idea to make a cheap open gun with a Glock 34 9 mm with ports/popple holes drilled to vent out the stock slot in the slide. I started with a KKM barrel with 8 popple holes (.125" dia.) drilled in a V pattern. That was fairly harsh, so I had 3 more holes drilled down the middle in between the V for a total of 11 holes. I'm sitting here looking at that barrel as I write this. I still made major using Silhouette and 3N37 with a 125 gr Zero JHP and it was fairly flat shooting, but the gun was so abominably harsh that it occasionally caused feeding issues with rounds actually popping up out of the mag during cycling. And yes, the mag springs and followers were new!

I abandoned that experiment and built a G17 with a KKM gunsmith fit barrel and a Jager comp which is flat shooting and much, much softer. Both guns used slide mounted Docter sights. Your experience may vary, but I found the all ported G34 to be much too harsh at major regardless of what powder I used.

When you say "flat" shooting, how is it compared to using a comp? If I were to use a 17, I was thinking total of 5-7 Holes if possible. But I may just end up going with a comp in the end but I would like to try this first.

[Whitefish]

My ported Glock 34 was brutal to shoot and RO's complained mightily about the loudness and concussion. I went with the smaller ports for that very reason, but it seemed every bit as harsh as the guns with fewer and larger ports. It was probably as flat shooting as my G17 with a 4 port Jager comp, but the comped G17 is so much more comfortable to shoot and so much more reliable that I haven't looked back. I also have a G17 with an 11 port SJC comp and KKM barrel. It is slightly flatter shooting and softer than the gun with the Jager comp, but not demonstrably different. More holes and more comp is not always the answer. You have to match your load to the comp and/or ports and you have fewer powder options in 9 major in a G17 because of the overall length you can load to in a Glock.

A gun with a combination of ports and a comp is the best for flatness, but that is a lot of work for not a whole lot of gain in a G17. I have an acquaintance who cut a G34 like slot in his G17 slide, drilled 3 large ports in the barrel, and added a 4 or 5 port comp that he machined. He also added a piece of brass attached to the rail to put additional weight out front. The gun is as flat shooting as any G17 open gun I've seen, but he did all the work himself. Paying a gunsmith for that work can add up in a hurry. Even just having (only) barrel ports drilled correctly is not cheap.

[Blcksmk]

My ported Glock 34 was brutal to shoot and RO's complained mightily about the loudness and concussion. I went with the smaller ports for that very reason, but it seemed every bit as harsh as the guns with fewer and larger ports. It was probably as flat shooting as my G17 with a 4 port Jager comp, but the comped G17 is so much more comfortable to shoot and so much more reliable that I haven't looked back. I also have a G17 with an 11 port SJC comp and KKM barrel. It is slightly flatter shooting and softer than the gun with the Jager comp, but not demonstrably different. More holes and more comp is not always the answer. You have to match your load to the comp and/or ports and you have fewer powder options in 9 major in a G17 because of the overall length you can load to in a Glock.

A gun with a combination of ports and a comp is the best for flatness, but that is a lot of work for not a whole lot of gain in a G17. I have an acquaintance who cut a G34 like slot in his G17 slide, drilled 3 large ports in the barrel, and added a 4 or 5 port comp that he machined. He also added a piece of brass attached to the rail to put additional weight out front. The gun is as flat shooting as any G17 open gun I've seen, but he did all the work himself. Paying a gunsmith for that work can add up in a hurry. Even just having (only) barrel ports drilled correctly is not cheap.

It seems as if the comp is the thing to go with really. This is something I would like to try just because I have an extra slide and barrel which have been laying around for quite some time now. You don't happen to have pictures and video of this G34 in action do you? I would love to see this thing shoot or at least the barrel and the way it was ported.

I think either way I will build both a comp gun for USPSA and a ported gun just to mess around with during winter or steel matches.

Also, as far as the hole size for the ports... What would you recommend for the biggest and smallest and how many holes based on the size? What about powders? VV3N37, HS6, VV3N38? OAL?

Edited January 19, 2012 by Blcksmk

[Whitefish]

I do not have any video of the gun and barrel. The barrel was a drop-in KKM G34. The original holes were .125 drilled equidistant to vent out the opening in the 34 slide and were 4 in a line on each side slightly off-center angled to the outside to vent. I then had three more .125 holes drilled down the centerline of the barrel equidistant between the existing holes that vented straight up. As I said, this was a project that did not work out exactly as I had planned. You can buy a ported barrel from Storm Lake - either 4 bigger holes to vent out the slide opening or an extended barrel with 6 ports - 4 venting out the slide and two in the extended portion in front of the slide. Bigger ports tend to be harsher shooting though. The small ports I used were too harsh for me at Major power. I never shot it at minor, so I cannot tell you how that feels. With a G17, you will have to cut openings in the slide for the ports and with the shorter slide and all ports, I'm not sure you can get enough velocity for major as someone else mentioned earlier. You are on your own there.

I use 125 gr Zero JHP's at 1.145" OAL. As far as powders go, you will find that Silhouette, 3N37, HS-6, N340, WSF, AutoComp, and 3N38 will work for 9 major. All save for 3N38 are about the same burn rate. 3n#8 is the slowest of these powders. I'm currently using N340 as I have 6 lbs of it to use up. It is difficult to get enough 3N38 in the case and still have enough space to seat the bullets. Some make it work, but I do not. There is plenty of load data on Enos for 9 major. Just do a search on the forums. With all ports, you will want to use the slowest powder that you can fit enough of in the case to make sufficient velocity - more gas for the ports.

[Blcksmk]

Well by sitting down and looking at the barrel this afternoon I have come to the conclusion it will be close to impossible making major with how short the barrel is. There isn't enough room between the barrel ports and the chamber. So, I guess I'm gonna scrap the idea and continue to shoot limited unless I can pick up a comp and barrel for either .40 or 9mm.

Appreciate all the help Whitefish! Learned quite a few things in this conversation.

[Bansheex]

You can always get a Glock 34 complete slide. That would give you a little longer barrel, and the slide is already coffin cut.

Just a thought.

Edited January 24, 2012 by Bansheex