Some mangled cases last range trip...

cwlongshot · May 24 2017 05:49:16 AM MDT

I dont have pics... YET.

Last weekend I took all the Glock's to the range. I had the slide milled on the G20 for a RMR red dot. First shots since. I used it on the G21 Frame this time as its where the G20 slide will be used now. I use the G20 frame on the MECH TECH.

The case mouths where dented from nearly 1/2 closed to 15% ish. The brass on a few cases was almost torn and not use able. Now these where mixed loads, some med and a few heavy loads, but not top loads and all proven safe accurate loads. All jacketed or plated bullets. IIMN the gun has a 20# spring and this is where I am looking first for the problem.

I was really surprised to see the case smashed 1/2 closed!!

Am I on the right course here? I do not remember seeing this on the G20 frame but doubt its a frame issue.

Pics later.

CW

Ridgerunner665 · May 24 2017 05:58:11 AM MDT

Swap ejectors between the 21 and 20 frames and see what happens.

Pablo · May 24 2017 06:37:48 AM MDT

So this only happened on the Glock?

Was it working perfectly before?

Was just the slide disassembled?

So this isn't a long slide?

Does sound like maybe could be over sprung but if it worked before? ??

Not enough information given.

cwlongshot · May 24 2017 07:10:21 AM MDT

It was completely disassembled for milling.

Also did same with LW & KKM barrels

The extractors are different, the G20 is very early 1991 frame, the G21 is a late Gen3 SF "rail" frame.

cw

Pablo · May 24 2017 07:21:44 AM MDT

If it did not do this behavior before then something obviously changed. Possibly something impeding slide movement or extractor or ejector issue .

The_Shadow · May 24 2017 07:31:35 AM MDT

Here is what I would suggest as a course of action. Seeing you added mass to the slide in the form of the RMR, sights and the charging handle and adding in the comp barrel. The comped barrel can change timing of the slide velocity, usually slowing its rearward travel. That and the increase in the slide mass may add up to change the dynamics.

Recoil springs might could be lighter, start with factory spring setup & weight. If you still see issues try lighter or heavier weights.
Extractor, likely you have that clean, being you had the slide milled and freshly reassembled. Did you swap extractors by accident from other slides by chance?
Ejectors, compare them to insure they are correct and didn't get swapped or damaged.

Is there a chance the RMR mounting screws are placing pressure on something or grabbing. The plunger/extractor in particular.

cwlongshot · May 24 2017 07:40:18 AM MDT

It did this with the 6" KKM as well as the 5.5 LW barrels. barrels are existing and have been used with these loads many times.

The G21 slide was not touched, the G20 was disassembled by me and sent out. When returned re assembled by me. All parts got a ultra sonic bath while slide was away. The slide handle is also old and has been used with these loads in the past. I do need to double check that the extractor rod and spring are in correct orientation.

I agree on mass added to slide, I looked close and cannot see any problems. These loads have been fired many times with no problems. Minor dents to case mouths are a non issue. Wish I had pics. Some of these are far from minor. ${$default_smiley_smiley}$

Variables are the G21 frame and this milled RMR added slide. I HAVE shot this slide on this frame 2-4 times BEFORE milling, and did not have issues I remember. This last weekend I fired about 75-100 rounds.

Thanks guys!!

CW

sqlbullet · May 24 2017 07:46:24 AM MDT

My guess....

The extra slide velocity from the mass reduction is causing the extractor to loose grip on the case. This results in a weak ejector strike, leaving the brass in the action, at least partially. Case mouths get chomped as the action closes. I would bet the torn ones will match up to some part of the ejection port/barrel hood.

But, that is just a guess.

cwlongshot · May 24 2017 10:35:42 AM MDT

That makes alot of sence. Its odd how much force is needed to mangle the case this way.

I had a idea...

These new phones now have a "slo-Motion" setting.
I used it the other night on a fire. The effects where apealing. I also have a go-Pro that very high resolution so should work very well for slowing down.
Ill bring both next range trip and try that out. Ill keep them short so i can post results.

CW

cwlongshot · May 25 2017 05:22:43 AM MDT

CW

The_Shadow · May 25 2017 06:51:35 AM MDT

It looks as if the rounds are not being kicked out by the ejector and the slide is picking up the next round, as the slide is moving forward the next round is wedging and pushing the trapped casing out.
Slide timing issue possibly, not sure what changed to cause this...
G-21 ejector is out of position and not kicking the smaller 10mm casing out.
Recoil spring may be binding and limiting travel.
Extractor holding tightly.

cwlongshot · May 26 2017 04:36:55 AM MDT

Interesting...

I can simulate this on the bench maybe...

Ill look when I get home tomorrow!

CW

Solitaire · May 26 2017 09:55:18 AM MDT

In the close ups it looks like a small chunk out of the rim on both cases possible extractor hang up?

Sent from my iPad using Tapatalk

Ten Ten · May 26 2017 06:50:15 PM MDT

Goodness!!...that brass is getting hammered....

cwlongshot · June 05 2017 09:52:04 AM MDT

OK,
Took both frames side by side and compared things... The G20 frame has a short 1/4" long ejector, while the G21 has a bent much longer ejector over 1/2" long.

With the slide locked back, the G20's ejector stands 1/8"exposed while the G21 stands with nearly its full 1/2" length showing.
IMHO the G21 frame is causing the longer 10MM case to slam HARD on the side of the chamber then slide as it ejects. the added length is needed for the shorter 45 ACP case.

CW