Gen 5 Glock 17 accuracy issues with 147 grains

[Vic79]

Recently picked up a Gen 5 Glock17, it seems to have issues when using 147 grain bullets. Accuracy just completely falls off a cliff. Is this due to most 147’s being sub sonic? Has anyone else seen this issue with Glocks 9mm shooting heavier bullets?

[ggammell]

What ammo are you using? And what kind of accuracy can you produce with other guns using the same ammo?

I’ve run 750 or so 147 AE through my new 17. Our whole agency uses it as training ammo with good results.

[Vic79]

Armscor.



The right side is Glock 17, the left is my Glock 22. This is 5rds from the 10,15,and 25 yards. 15rds total. The two hits on the left target that are out of the center silhouette are actually 9mm and happened on the 25 yard line.

I ran some 124’s through it and I can put ten rds in the center silhouette from the 25.



This is 10rds with my Glock 27 from the 25 shot after the first pick. Not the best , but I can usually do alright.
I thought I had a picture of the Glock 17 with the 124’s, but I guess not.

Sent from my iPhone using Tapatalk

[MegademiC]

Might just be that load. AE9FP (american eagle 147 gr) have always been accurate for me. Ive shot multiple 3” and 4” with it out if my stock 19.5 and a couple 2” groups with it out of a glock with kkm barrel (10 shot groups offhand at 25yds).

Its definately not the weight or a “glock” thing. Something specific to your gun, ammo, or combo of them.

Id can you replicate the test? Id do it at least twice, then try other 147 gr.

[ST911]

Recently picked up a Gen 5 Glock17, it seems to have issues when using 147 grain bullets. Accuracy just completely falls off a cliff. Is this due to most 147’s being sub sonic? Has anyone else seen this issue with Glocks 9mm shooting heavier bullets?

Pistol projectile weight means virtually nothing esp in common weights and standard service barrels. 147s are not only GTG but are among the top performers.

Hang a high demand target like a B8 bull and shoot 10 round groups at 25 yards. Shoot your chosen loads against each other for comparison and follow the crumbs. Mix some dummy rounds into the magazine to see how much of this is you.

[alx01]

If you have a caliper pull the bullet and check the actual caliber (bullet diameter) of 124 vs 147. It should be 9.02mm or 0.355". I've seen some 9mm with diameter as little as .353 (although 0.354 is much more common) and it would definitely cause a poor accuracy especially at 25m or further.

I haven't tested it myself, but I've heard that a slightly oversized 9mm 0.356" diameter rounds to be more accurate. Don't know if that's the case, but very well might be.

Edit: maybe just a bad manufacturing lot. Have you tested the same ammo (both 124 and 147) out of other 9mm?

[ggammell]

147 AE is also $2-3 cheaper per box.

[Vic79]

Unfortunately I’ve been struggling with the 17 for a bit. I just thought I was a weirdo for not shooting the 9 mm better than the 40. I had a coworker come out to help diagnose what the issue was. He shot 2 or 3 5 round groups with the 124’s he brought out, all hits were in the center silhouette 5/5 each time. So we both thought it was me. Before he left I asked him to shoot 147 Armscor through it, that is when we found out that it was not me. He went 2/5 with two rds not on paper.

The only thing we came up with was that 147‘s were sub sonic but from hearing from others on here that doesn’t seem like that should be the issue. I’m fairly new to 9mm so forgive the stupid question but are all 147 grain 9mm sub sonic?

I’m going to try to pick up some different 147s tomorrow and try those.

[ggammell]

For the most part most 147s will be about 1000 FPS so yeah, subsonic.

Also, Armscor advertises a muzzle velocity of 950, AE is 146 advertised. I think it’s just weak and the leak of velocity affects accuracy.

[Vic79]

“maybe just a bad manufacturing lot. Have you tested the same ammo (both 124 and 147) out of other 9mm?”


Plan on that tomorrow.