Differences between Glock Gen 4 and 5 barrels

[GJM]

I was moving a Glock Store heavy tungsten guide rod sold as “Gen 4/5” between a Gen 4 and 5 this afternoon, and realized how different the barrels are.

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[1Rangemaster]

I was in a GLOCK Armorer course just a while ago, and saw there were many changes between the 4th and 5th generations. Nothing really wrong with the earlier generations, but the Gen5 pistols can demonstrate a noticeable improvement in performance-part of that due to the “marksman” (their term) barrels.
I’m ok with earlier generations of GLOCKs. But what I put on almost every morning is one or two GEN5s. I have seen the difference in accuracy and noted it.

[Noah]

The Glock 17 Gen 5 switched to Glock 19 locking geometry.

[rob_s]

The Glock 17 Gen 5 switched to Glock 19 locking geometry.

Does that means Gen 4 and Gen 5 G19 barrels wouldn't have the same differences between them?

[Noah]

Does that means Gen 4 and Gen 5 G19 barrels wouldn't have the same differences between them?

The gen 4 and 5 19 barrels are still different in terms of geometry- the gen 5 does away with the slope at the barrel hood where the top of the locking hood interfaces with the slide and goes to the simple right angles that the 17/34 have always had, as well as most G19 gen 1-4 aftermarket barrels.

[Noah]

In theory, you can put a gen 5 17 barrel in a gen 5 19 since they now share the same locking block. This is why gen 1-4 17 barrels are not at all compatible with a gen 5 17.

[JTQ]

Do the older barrels give a few extra feet per second velocity over the Gen 5 barrels?

[Noah]

Do the older barrels give a few extra feet per second velocity over the Gen 5 barrels?

Why would they?

[JTQ]

Why would they?
Polygonal rifling

[Noah]

Polygonal rifling

Gen 5s still have polygonal rifling, it just produces slightly more pronounced markings on the fired projectile.

[LockedBreech]

I still like and trust my Gen 4 17 enough that it will stay my nightstand home defense gun as it has for 3 years, but my main work/carry guns are Gen 5s now except for my M2.0 Shield. I do find I see the accuracy improvement.

[blues]

I still like and trust my Gen 4 17 enough that it will stay my nightstand home defense gun as it has for 3 years, but my main work/carry guns are Gen 5s now except for my M2.0 Shield. I do find I see the accuracy improvement.

My Gen4 G17 shoots like a champ. I'd not replace it without actual cause to do so.

[LockedBreech]

My Gen4 G17 shoots like a champ. I'd not replace it without actual cause to do so.

Agreed, plus mine was built on my birthday, I can't ignore fate like that.

[lordhamster]

Gen 5s still have polygonal rifling, it just produces slightly more pronounced markings on the fired projectile.

I was under the impression Gen5 went w/ lands/grooves:
https://www.recoilweb.com/inside-the-glock-gen-5-129141.html#:~:text=The%20barrel%20has%20changed., rifling%20results%20in%20increased%20accuracy.&text=The%20Gen5%20barrels%20can't,Gen4%20or%20any% 20previous%20generation.

[BigT]

I was under the impression Gen5 went w/ lands/grooves:
https://www.recoilweb.com/inside-the-glock-gen-5-129141.html#:~:text=The%20barrel%20has%20changed., rifling%20results%20in%20increased%20accuracy.&text=The%20Gen5%20barrels%20can't,Gen4%20or%20any% 20previous%20generation.


Nope the GMB is still a Polygonalish style barrel.

[g45c]

Evidently my targets are too close because I don't see any difference in accuracy. At what distance are you seeing accuracy difference and how are you judging the difference? Shooting from a machine rest? I'm shooting 3/4" target pasters at 7-10 yards and hit more than I miss and I'm confident when I miss I'm the weak link, not the gun or the ammo.

[GJM]

Evidently my targets are too close because I don't see any difference in accuracy. At what distance are you seeing accuracy difference and how are you judging the difference? Shooting from a machine rest? I'm shooting 3/4" target pasters at 7-10 yards and hit more than I miss and I'm confident when I miss I'm the weak link, not the gun or the ammo.

My sense is based on 25 yards. The reason I say sense, is that I am not a bullseye shooter, but I regularly or semi-regularly shoot groups on the head of a USPSA target to evaluate me, my aiming system and zero, my ammo and my pistol. This has gone on for the last ten years and involved many Gen 3, 4 and 5 Glock pistols, in various barrel lengths.

Some observations, all anecdotal, so take them as such. Definitely in Gen 3, and somewhat in Gen 4, I found the 26/19/17 to shoot smaller groups than a 34. Across Gen 3, the pistols seemed more ammo sensitive, with a load or two in the 2.5-3 inch at 25 yards, and many loads printing larger groups. Gen 4 pistols seemed to have more loads in the 3 inch range than Gen 3, but many loads more than 3 inches.

The Gen 5 pistols have shot almost all loads good, and the 34 pistols seem as accurate as the shorter barrels. The first load I tested in multiple G5/34 pistols was 115 American Eagle and it was 1-5-2 inches, off hand at 25. Shooting Gen 5 19/17/34 pistols, I see no difference in accuracy between them and the VP9 and CZ Shadow 2 pistols, I have lots of experience with. Simply put, with the Gen 5 pistols, there is no reason to pick another brand based on accuracy, assuming you know how to work a Glock trigger. A s a side note, the same can be said about the Gen 5 in how it ejects/extracts, and how easy it is to reload.

From my source at Glock, I understand there are multiple differences in the Gen 5 barrels:

1) there is a target crown

2) there is a different finish internally

3) ahead of the chamber it is tighter

Google turned up this comparing Gen 3 to 5, which is consistent with my anecdotal observations.

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