Glock 9 to 40 conversion?

[Bobby Hated]

I've put some 40 uppers on 9 frames and I keep getting light strikes. It's happened with both compact and full size frames. Are the triggers on 9 and 40 frames set different or something? I cant figure out why I keep getting light strikes. It happens like 1/20 rounds, which is way more than acceptable.

Thanks

[Port Authority]

Glock website.

Downloadable materials.

Download Parts Order form (certified armorers) WordDoc.

Look for parts, springs and things, and compare.

I'm told that up caliber don't seem to work as readily as down caliber.

Extractor and ejector troubles.

Port

[JohnCCW]

^ What he said.
All manufacturers had issues redesigning their 9mm to work in 40S&W.
Mostly was due to the slide speed, and the extra beating the 40 dishes out.

[Bill Steele]

I believe the only difference (within a category like compact 19/23 or subcompact 26/27) are the slide components and trigger housing (ejector).

I would look at all of the usual suspects regardless of what caliber the frame started out as, clean striker channel, new stock weight striker spring, stock striker, etc.

If you are shooting reloads, seat your primers firmer, or take them back to the reloader and tell him to seat his primers firmer.

[Bobby Hated]

How would an extractor or ejector produce a light primer strike? FAIL

Glock website.

Downloadable materials.

Download Parts Order form (certified armorers) WordDoc.

Look for parts, springs and things, and compare.

I'm told that up caliber don't seem to work as readily as down caliber.

Extractor and ejector troubles.

Port

[Bobby Hated]

How would the slide speed and the extra beating that a 40 dishes out produce a light primer strike? There is no slide speed or beating if the round doesn't discharge. FAIL

^ What he said.
All manufacturers had issues redesigning their 9mm to work in 40S&W.
Mostly was due to the slide speed, and the extra beating the 40 dishes out.

[Voo]

The only thing I can think of is that perhaps the locking block is slightly different for each caliber? It might position the barrel slightly 'forward' relative of the breech-face?

Beyond that, it could be a tolerance stack between your striker and trigger bar simply not pulling the striker far enough rearward. I've swapped trigger bars before between my glocks with varying degress of success- in one the trigger was crisp and in the other it turned to mush.

You might want to simply try cleaning the striker channel (if you haven't done so) or simply replacing the spring. But yea, that's weird. The frames between the 17, 22, 34, 35 are the same. There are specific parts for each but they shouldn't affect the striker..

[Bill Steele]

Does it happen with various types and brands of ammo, or all the same source? If more than one source, that eliminates the primers as the source of the problem. If always the same source, it very well could be primer related and not gun related.

[ElDub1950]

First questions would have to be - do the 40 uppers work fine on 40 lowers? Are they stock Glock uppers or aftermarket / modded? New? Used?

Basically, just asking if you know you're starting with perfectly working uppers.

And as others mentioned, are you sure it's not just your ammo?