Flat shooting G34

[Chapo]

I was reading here a bit on flat shooting on a post from 2012.  The concept of "more gas means less red dot movement (flat shooting)" was the base of the argument in that post.  I have a G34 with a carver 4 port comp, 11lbs RSA, and other reduced springs.  Today in the range, I was able to make it 8.3grs of HS6, but the red dot was still moving very visibly.  For those of you G34 owners with open guns, how high have you gone with HS 6? Or What other measures or steps have you taken to make the comp work to its max potential or what have you done to achieve straight back recoil?  If possible.

[Sarge]

Did you chrono those loads? How do the primers look?

 You probably won’t like the answers you get. Many will be along the lines of that gun will never settle down like a 2011.

[Chapo]

Thanks Sarge.  The primers looked fine with the typical glock stamp.  I know it will never be like a 2011, but trying to be in the ballpark.  Read another old posting from a "george" who stated (he) "settled at 8.6 HS6 for 1368 fps at 1.130" OA".  Not sure if its true but def scary.

[ickus]

The 11 port SJC runs flat as I can get it, around 170-72 PF.  I like HS6  or  WAC with 124'S...... Always be a little bounce and   you'll  probably  need another slide on hand,  stock one will crack 

[Chapo]

Great pics ickus.  How much HS6 do you use?  And where did your slide fail?  what is your OAL? mine is 1.145

Edited January 29, 2020 by Chapo

[ickus]

 HS6 gets me around 170-72 PF  OAL 1.145 - 1.150 .do your own load development  for safety sake .... have you crono'ed  your 8.3 gr loads ?  My ejection port cracked on both stock slides.. I use a Lone Wolf 416 hardened stainless steel slide, Beveled rails and lowered ejection port. 

Edited January 30, 2020 by ickus

[Wvaughn7]

That plastic mount and heavy sight may have a lot to do with your dot behaving crazy as well, although the others are right about never getting a Glock open gun to run flat. I built my first open gun off of a G17 setup almost identical to yours (short of the colors) and I settled on 8.2 grains of HS-6 with a coated 115 at 1.145 OAL. The gun ran ok but was violent and moved all over the place. I never realized it was even that bad until I bought a steel gripped CK 2011 to replace it. 
 

Anyway, back to the scope mount. I had the same one as you and switching to an SJC 90 degree mount took what I can best describe as “vibration” out of the dot. It still had vertical movement but wasn’t as wild. 

[parvusimperator]

Have you tried adding weight, maybe the brass SJC magwell to help stabilize things?

[Chapo]

Have not crono'ed my loads.  Need to get one.  Will def look into the SJC 90 degree mount, Vaughn.  Just trying to get the ideal amount of powder to get more rearwards recoil and not so much vertical.

[Chapo]

 parvusimperator, not sure the rear magwell would affect the front movement anymore at this point.

[parvusimperator]

Oh, fair point.

 

This gets expensive to try, but maybe add barrel porting? That puts gas toward fighting rise instead of recoil.

[parvusimperator]

Also, can you add weight to that mount under the barrel?

[Chapo]

yeah.  Been thinking of an sjc frame weight.

[iflyskyhigh]

Sorry, I know this post is silly long, but I have experienced many of the same issues as you in my development and tuning of this gun, so I though the info might be helpful.

 

I actually built my open Glock out of a 17 vs a 34. I run PD, RMR, or Everlgades 115 JHP's under 7.8 grs of Silhouette at 1.135". I reemed my barrel throat out so I can run the rounds at 1.160", but I discovered if you are going to run the 170mm Taylor extensions you are limited to 1.125-1.135". Bummer. 

 

This load chrono'd out of the Lonewolf G17 extended threaded barrel at 1488FPS when 1.160" and 1492FPS at 1.130". So shorting the rounds made almost no difference in velocity. With the 1492 the SD was 11.9 and the ES was 43 (over the course of 30 or so rounds, so it's consistent). I may have given up a tiny tiny amount of accuracy going to the shorter COAL, but so is the sacrifice for more rounds. it's still very accurate out to 25 yards.

 

You are fur sure giving up something by going with the Glock platform vs the 2011. This is why I ended up going with the 115gr vs the 124gr. You can squeeze more powder in with a 115, and hence the comp works better. I have shot thousands of the 124's and the 115's and I just like the performance you get with the 115's. You might give it a shot and if it helps. Also, I tired HS-6, and it for sure works, but I like Silhouette much better. Cleaner and cheaper. I notice not many other guys seem to run it in open guns, so maybe it's just one of those powders that happens to work well with Glocks?

 

I also experimented quite a bit with recoil springs. I tried both captured and uncaptured from 10lbs to 17lbs. I ended up going with a Wolff uncaptured 15lb spring. You might try going up in spring weight. The results may surprise you. I found that my SD's and accuracy were best with the 15lb spring. Regardless of 115's or 124's (JHP's). I'm not sure but it might have something to do with keeping the gun locked up a little longer.

 

Don't get me wrong this gun isn't, nor will it ever be a 2011 open gun, but it shoots damm flat in the current configuration. The 2011 guys who have shot it still like their 2011's better (obviously) but are surprised how well it handles and how flat it shoots. But, we are also taking about a gun that I have probably less than $2000 into, vs $5000 and up. You get what you pay for. But this a good way to get in the game and see if it's for you. You are most likely going to have to put a little time and money into that gun to flatten it out, so you have to ask yourself if it's worth it to you, or if you want to invest that money towards a traditional open gun. For me it was worth it. I'm not super serious about any of the pistol divisions I shoot. I like to dabble a little in everything, so investing 2011 time and money isn't worth it to me personally. I have no doubt it's worth it though.

 

I used a bare Glock 17/34 frame and built it up with the Zev complete Ultimate Trigger kit. I think the extended mag release is Carver, but it may be SJC I can't remember. It's just the stock mag release drilled and tapped to accept the extended screw on mag release. The stipple and frame job was done by a local guy, SW Precision Arms. The magwell is also a Carver heavy with the additional weighted insert. The frame reduction, mag well, and stipple job really help's with the handling of the gun which in turn allows me to get a better grip on the gun, and thus shoot quicker and flatter. Just for reference I'm 6-4 / 230, and have gorilla hands, which I'm sure also help my cause.

 

The CMore mount is the SJC frame mount which duracoated to match the slide.

 

It's a Lonewolf G17 bare slide also built up with the rest of the Zev Ultimate components. The ejection port on the Lonewolf slides is lower than the stock Glock slides, but I lowered it a touch more. I painted the slide myself with duracoat. I have been running this slide for severals years and have yet to have an issue. Not that I won't, but haven't yet.

 

The comp is the newer 10 port Bull nose Carver (3 each side, 4 on top). I had the older Carver comp and this one does work better.

[Chapo]

Nice perspective ifly. 

[iflyskyhigh]

Nice perspective ifly. 

Thank you


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[regor]

@Chapo, you haven't mentioned what bullet weight you are using, but I am guessing based on your comment about "George" having a load with 8.6gr going 1368fps that you are loading 124grs.

 

I would strongly suggest you chrono your current load before going any higher. Loads will vary from gun to gun and folks with popple holes will need to cram more powder in to make the same velocity. You really need to do your own load development, not just blindly assume someone else's load will chrono the same out of your gun. Out of my Czechmate (5.2" barrel vs the G34's 5.3") I hit 1370fps with 7.9grs HS6 under a 124gr JHP; I suspect a load of 8.6grs would be pushing past 1450fps (180PF) and showing major pressure signs, and you are loading shorter than I did as well. Pushing the pressure way up on an open Glock in pursuit of flatness is asking for unnecessary parts breakage. 

 

I will also second others; the plastic mount is almost certainly flexing under recoil and should be replaced with something more rigid (and that gives you a lower bore offset). 

[Midwest3Gunner]

You might want to contact the guys at DC Precision. They seem to have a pretty good understanding of what it takes to make an open Glock run well.

[Chapo]

Thank you all

[Absocold]

Glocks are great once you replace every single piece of the gun with something better.

 

Jokes aside, grip angle and lack of weight are two of the biggest enemies to a flat Glock. Help solve both with an aftermarket frame. Companies that make actual steel or alloy frames for Glocks come and go, none are currently in business that I know of. However Polymer80 now makes complete serialized frames with the 1911 grip angle (or should I say the "correct" grip angle?) and ZEV just came out with a 2011-ish modular frame with a near 1911 angle and a little more weight. After that, a giant comp with lots of baffles and weight, then barrel porting if necessary. Cramming on weight, especially at the front or at the magwell, is a big help.

 

I think trying to work the comp harder than you already are will just result in a more violent recoil impulse (it might look flatter from the side but to the shooter it's a jumbled mess). And you'll break stuff.

 

But I said all that to say this: Unless you just like to tinker, have a mad desire to be different or are a masochist, get a 2011. By the time you buy a Glock and Gucci that sucker to the moon and back then spend a ton of time, effort and money on load development and parts swapping, you could probably buy a decent used 2011 or dang near it. And an Open Glock will be difficult to sell for a reasonable price whereas a decent used 2011 commands good prices.

[Fo0]

On 1/28/2020 at 7:35 PM, parvusimperator said:

Oh, fair point.

 

This gets expensive to try, but maybe add barrel porting? That puts gas toward fighting rise instead of recoil.

 

any place to recommend for barrel porting? for threaded non OEM barrel

Edited February 8, 2020 by Fo0

[parvusimperator]

A buddy of mine got porting work done by Mod K armory https://www.modkarmory.com/

It shoots pretty nicely. Big disclaimer, he's NOT running a comp on it or major ammo. So I'd talk to them a bit if you/the OP want to send your barrel in. Maybe send it with the comp.

 

I think ideally you'd find a gunsmith near you who could port your barrel, then add ports until you got something that worked right for you.

[Whoops!]

It’s funny, the other guy thought his post was long.  I think it’s about right-sized.  
 

 

I have a slightly different perspective than the other posters.  I have shot everything from an M&P and Glock open gun to CZ and Tanfoglio open guns to the highest end 2011s.

 

In my book, there are two main differences between the Glock and the 2011 - the 2011 has a better trigger and the 2011 can use lighter recoil springs (the striker spring acting against the recoil spring in a Glock means the lightest recoil spring most Glocks will ever be able to use is an 11 pounder - I’m shocked you are able to make an 11 work in your gun with how heavy that slide and barrel combo is)

 

When it comes to muzzle flip, an Open 2011 with an 11 pound recoil spring and an open Glock with an 11 pound recoil spring are shockingly similar if the same load is used and both comps are effective.

 

A couple others have stated one of the main issues with your open gun - it’s too long.  The comp is not using as much gas with the same load in a shorter barreled gun.

 

The second, less significant issue - the cheap mount.

 

I’ve used that mount.  It’s not terrible.  But, the metal Carver Custom mount is a lot better.
 

I see you have the major Carver Custom comp.  That comp is fine.  I had one of the fastest runs on a classifier type stage at Area 3 with that exact same comp and an open Glock I had literally owned for 3 weeks before the match.  I was also using a nylon belt and duck tape to keep my holster in place.

 

If you want to keep the same length open gun, the best way to compensate for the length would be to add popples so that the gas can be used earlier when it’s higher pressure.

 

Otherwise, one of the best Glock open guns I’ve ever used without popples was based on a Gen 5 Glock 45 (it’s an updated G19).

 

Don’t let anyone fool you into thinking you’ll ever have a gun that recoils flat.  The people who think their dot doesn’t move simply can’t see their dot move because of how quickly it moves.  I have run grand master classifier runs with a dot that flips every time.  The key is the return to center.

 

The least amount of flip you’ll ever see is in a Ruger 10/22 - and even that flips.

 

 

Even with the competitive disadvantages mentioned - with the right load and grip - you could make Master with your gun as it currently sits.

 

GM though?  That’s tough.  I don’t even know if KC Eusebio could do it with a comped g34 and a plastic scope mount.

 

 

 

Edited February 8, 2020 by Whoops!

[Chapo]

Thanks whoops!!  I agree totally with your post. I will be getting and sjc mount with red dot soon. Also, I just received my crono and will be testing loads next week. More to follow. 

[iflyskyhigh]

Chapo, I sent you a PM.


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