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View Full Version : Glock 22 Gen4 - counterbore vs. pre-counterbore versions



DHart
01-08-11, 19:50
Hoping this thread may be useful to other potential buyers of Glock 22 Gen4s.

I'm thinking about getting a G22 Gen4 to shoot as a .40 and as a 9 (with a 9mm conversion barrel, G17 mags and possibly different recoil spring assembly).

Here's what I've learned so far from some research done here and elsewhere on the Gen4:

Early Gen4 versions (aka Variant 1) had no counterbore in the slide at the front position of the recoil spring assembly (RSA) and the open spring end sometimes got stuck in the front of the slide.

I believe that Glock issued a new spring design to work in these pre-counterbore models so that the spring would no longer get caught.... Is that correct? Pre-counterbore versions are identified by pre-PUN s/n prefix.

Moreover, to address the issue in the most recent production models (aka Variant 2), Glock began to cut a counterbore in the inside front of the slide where the RSA sits and changed the front of the RSA to fit it. These RSAs now sit securely in the counterbore and don't get stuck. Counterbore models are identified by PUN- and later s/n prefix.

Each of these production versions take different springs, designed for how the front of the spring interfaces the front of the slide.

It looks like the counterbore version is likely to be the version that Glock will be using going forward.

SO.... cutting to the chase... would there be any particular benefit to go with the counterbore version, particularly for the person who would want to use a G22 Gen4 for both .40 and 9mm, or is either version likely to be equally desireable?

Given that Glock is still making changes to the RSA's on the Gen4 guns (particularly for the G17), it would seem that choosing a counterbore version might ensure better forward compatibility with various RSAs and aftermarket (e.g. Glockmeister) RSAs... but I wanted to put this out to the forum members to hear your thoughts on the question...

======================================

The following information was released, by Glock, I believe. I have copied it from another thread and reformatted it for easier reference.)

GLOCK RECOIL SPRING ASSEMBLY (RSA) PART NUMBERS FOR GEN4 PISTOLS
11-20-10 - Glock now offers 6 different Gen4 RSAs for our Gen4 pistols

1st Model Gen4 G17 serial # prefixes prior to but not including “PUN”
NOT-COUNTERBORED
(still current & in production now, on into 2011)

· SP 08692 – RSA for “Variant 1” Gen4 17 with flat-back slide-nose-ring.
· Use in Gen4 G17 pistols serial # prefixes “PFB, PMN, PMP, PMR, PMS, PPM, PPP, PPR, PPS”, etc.
· For all Gen4 G17 serial # prefixes prior to but not including “PUN”.
· SP 08692 is marked on the rear flange: “0 2 1”


2nd Model Gen4 G17 serial # prefix “PUN” & later, & all Gen4 G34 pistols
COUNTERBORED

· SP 08284 – RSA for “Variant 2” Gen4 G17 & G34 that have a “chamfer” or “counterbore” around the
nose-ring-hole inside the slide (like a G26 or G27).
· Use in Gen4 G17 pistols with serial # prefix “PUN” & later, & all Gen4 G34 pistols.
· NOTE: One small batch of serial # prefix “PUN” Gen4 G17 pistols was run for the commercial market (not
LE), to test the new SP 08284 RSA for Gen4 G17 & Gen4 G34 pistols.
· “Variant 2” Gen4 G17 pistols are not currently in production as of 1120-18-10.

· Do NOT use the SP 08284 in Gen4 G17 pistols with serial #s prior to “PUN”.
· SP 08284 is marked on the rear flange: “0 2”


1st model Gen4 G22 & Gen4 G37 serial # prefixes prior to but not including “PUN”
NOT-COUNTERBORED

· SP 08694 – RSA for “Variant 1” Gen4 22 & Gen4 G37 with flat-back slide-nose-ring.
· Use in Gen4 G22 & Gen4 G37 with serial # prefix “PCG” & other serial # prefixes prior to “PUN”.
· SP 08694 is marked on the rear flange: “0 1 1”


2nd model Gen4 G22 & Gen4 G37, & all Gen4 G31 & Gen4 G35 models # prefix “PUN” & later, & all Gen4 G31 & G35 pistols
COUNTERBORED


· SP 07577 – RSA for “Variant 2” Gen4 G22 & Gen4 G37 pistols that have a “chamfer” or “counterbore”
around the nose-ring-hole inside the slide (like a G26 or G27), & all Gen4 G31
& Gen4 G35.

· Use in Gen4 G22 & Gen4 G37 with serial # prefix PUN & later, & all Gen4 G31 & Gen4 G35 models.

· Do NOT use the SP 07577 in Gen4 G22 & Gen4 G37 pistols with serial #s prior to “PUN”.
· SP 07577 is marked on the rear flange: - “0 1”


ALL Gen4 G19

· SP 08703 – RSA for all Gen4 G19 pistols.
· Standard on all G19s beginning with serial # prefix “RCY” on 11-03-10.
· Available as Spare Parts about 11-20-10.
· SP 08703 is marked on the rear flange: “0 4”

jonconsiglio
01-08-11, 20:52
I don't believe there would be any difference between a Gen 4 non-counterbored with the "021" and a Gen 4 counterbored with the "02" spring.

Mine has been great over 4,000 + rounds. I personally have never experienced the spring hanging up, which is the reason for the "021" spring and the new counterbore.

DHart
01-08-11, 22:24
Jon... I was checking out a G22 Gen4 at a gunshop yesterday and comparing it to a Gen3 RTF version. Trigger pull was noticibly heavier with the Gen4. Slide operation didn't seem quite as smooth as with the Gen3.

I asked the clerk about checking to see if it had the counterbored slide. He acted as though he had never heard of such a thing. He removed the slide, but the RSA would not come free from the front of the slide... we presumed it must have been a pre-counterbor. I didn't know the s/n prefix to check at the time.

I'm sure it wouldn't be a big deal if the RSA was replaced with the updated one. But I wonder if having the counterbored version might offer some benefit to use of alternative RSAs to fine tune the weapon to different loads (like making a caliber conversion to 9mm)... not sure on this.

jonconsiglio
01-08-11, 23:00
I wouldn't really worry about it. I'd just buy what was there like I did. I figured if it didn't work, I'd change a spring and be fine. Sure enough, that's what I did. I don't care for caliber conversions and there's really no fine tuning unless you're shooting competition and handloading.

For me, I know any of springs I have will work fine for carry and defense, it's just weaker ammo that has caused me a very, very few issues - but I was also using extended mags.

I'd have no concern with carrying it with the unmarked spring with my carry ammo.

DHart
01-08-11, 23:23
Jon... good points and I tend to agree with you... I could be giving it more deliberation than needed... although I'm also thinking about how the counterbore option might impact RSA choices when converting the G22 to 9mm... so a slightly different set of considerations than running the Gen4 G17 for defense use.

I'm sure either choice can be made to work, one way or the other. What I'm very drawn to is the new frame... I really like that!!!

Robb Jensen
02-05-11, 05:05
I don't believe there would be any difference between a Gen 4 non-counterbored with the "021" and a Gen 4 counterbored with the "02" spring.

Mine has been great over 4,000 + rounds. I personally have never experienced the spring hanging up, which is the reason for the "021" spring and the new counterbore.

The .40 Glock 22 Gen 4 with non-counterbored slide uses the newest spring for this slide and is marked 0 1 1 and 9mm Glock 17 Gen 4 non-counterbored slide is 0 2 1. The muzzle end of the spring cap is different and allows it to be easily removed from the non-counterbored slide. My Glock 22 Gen 4 is running fine with the original unmarked spring but I know a few people who have had some difficulty with removing the springs from the slide.