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Old March 3, 2009, 03:31 PM   #1
Brian Pfleuger
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Glock Slide Weight

I'm wondering about the slide weight on the 26 and 27. Just the "bare" slide, minus the barrel and guide rod. If you're scale is precise enough it would be interesting to know the weight with an empty cartridge.
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Old March 3, 2009, 07:31 PM   #2
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Old March 3, 2009, 09:32 PM   #3
jdncsu
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definitely not the most accurate... but my kitchen scale reads 11.9 ounces for my 27 slide.

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Old March 3, 2009, 09:38 PM   #4
David the Gnome
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I'd weigh my 26 slide if I had a scale to do it on.
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Old March 4, 2009, 01:04 PM   #5
goodspeed(TPF)
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Heya "Pete".

The 9mm slide is just a hair lighter. There is more mettal removed from the front of the slide. I dunno where the heck my scale is but here is a pic for ya.
Attached Images
File Type: jpg 40L9mmR.jpg (229.2 KB, 35 views)
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Old March 4, 2009, 01:42 PM   #6
Brian Pfleuger
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Alright, thanks guys.

I'm trying to determine if there is any justification for another threads assertion that Glock should have used different spring strengths for the different calibers.

It appears that the slides are very close in weight, my 33 comes to 11.8 ounces. So, the 40 and 357 are essentially identical. That's the easy part.


Now the complicated part. Basically, I'll have to estimate because of all the complex variables. The bullets all exit identical length barrels at different speeds meaning that the amount of time the force is applied to the slide is different. I'll have to assume that the gun is bolted down because, if it's held, there are too many unknown possibilities for motion that would effect the distance the slide might travel relative to the frame, ie "limp wristing" and a solid base ensures that the maximum speed and momentum are applied to the slide.

Anyway, if it's true that modern guns are essentially designed around "+p" 9mm ammo then the difference in power levels is not significant enough to need more spring in the "larger" chamberings.

115gr +P 9mm = 454ft/lb
124gr 357sig = 503ft/lb
165gr 40SW = 485ft/lb

So.... basically, the 40 might justify a spring that is 6% stronger than the 9 and the 357 might be 10% greater.

Alright, if the 9 has a 16 pound spring then the 40 should have a 17 and the 357 should have 17.6, let's say 18.

My initial assertion is probably correct. The 16lb spring is probably heavier than needed for the 9, about right for the 40 and slightly light for the 357.

Anyone concur? Anyone read this far to see what I was getting to? Anyone care?
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Last edited by Brian Pfleuger; March 4, 2009 at 01:54 PM.
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Old March 4, 2009, 02:02 PM   #7
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Interesting thread.

What about the G29 or G20? Now we have ammo that runs in the 600 - 700 range. I have a number of factory ammos sitting on my shelf rated in that range; not to mention reloading.

As I have only owned Glocks in the 10mm and .45ACP this is not my area of expertise and experience. Perhaps someone more knowledgeable will take up the torch here.

Good luck!
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Old March 4, 2009, 02:08 PM   #8
goodspeed(TPF)
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Don't forget to take into account the other "variable" which is slide mass. This exists on the 10mm "-VS-" .45ACP and the 9mm "-vs-" .40S&W/.357SIG..

All else being equal, greater slide mass will alter the "recoil impulse" of the pistol. Delaying unlocking of the breech.

Keep in mind that the shorter the barrel/slide length the less this slide mass needs to differ (say for example .40S&W -vs- 9mm) as the bullet leaves the barrel sooner and pressure drops subsequently faster than on a "long slide" version. So the "percentage" of difference in slide mass between similarly sized Glock pistols will be greater on longer barreled Glocks than on shorter barreled ones.
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Last edited by goodspeed(TPF); March 4, 2009 at 02:20 PM.
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Old March 4, 2009, 02:27 PM   #9
AZAK
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Let me add this to the mix:
Quote:
One myth I almost forgot to debunk: recoil spring weights have virtually NO effect on unlocking in 1911-style handguns. Pistolsmith Ned Christiansen has tested this, to the point of firing a 1911 with no recoil spring at all, and the effect on unlocking was negligible. This falsehood was possibly based on the fact that recoil spring weight does seem to effect lock time in Glocks.
http://www.geocities.com/mr_motorhead/10tech.html

Good article - 10mm Tech notes. I think that it is worth the read. (page seems to take forever to load, but it does load eventually; maybe it is because I am in Alaska?)

Just when you thought that it might be "that" simple, along comes just one more thing...
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Old March 4, 2009, 04:42 PM   #10
Alleykat
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The only "justification" one needs is a rudimentary understanding of h.s. physics. This ain't rocket science! If you can't understand that slide speed is governed more by recoil spring strength than by slide weight, then you're not going to grasp the physics involved.
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Old March 4, 2009, 05:10 PM   #11
Brian Pfleuger
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Quote:
This ain't rocket science! If you can't understand that slide speed is governed more by recoil spring strength than by slide weight, then you're not going to grasp the physics involved.
I majored in physics, thank you. I would have thought that my previous post, while not complete in the sense of complex math and every possible variable, made it fairly clear that I have a decent grasp of the concepts involved.
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Old March 4, 2009, 05:49 PM   #12
jdncsu
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2 semesters of physics for engineers at my state's land grant institution was enough for me


for s's and g's my G30 slide weighs 15.7.
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