Thread: Glock blows up!
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Old 12-11-2009, 06:42 PM
Skip Sackett Skip Sackett is offline
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Exclamation Well noted point!

Quote:
Originally Posted by dennis40x View Post
That said the 9mm-Luger is considered to be fully supported in the Glock series 17 & 19 pistols. I’ve noted no meaningful dimensional difference between fired cases from the Glock pistols mentioned and S&W-MP9 pistols in regards to case expansion.

It should be noted that I’m not into reloading/fabricating +P or +P+ equivalents in either the 9mm-Luger or 45ACP.
Dennis,
Good points all, especially the later point. Staying away from those rounds that "Go where no man has gone before" is a sure way to stay away from having problems.

Some do and I'm not sure that that is a smart thing in this platform of firearm.

I think we all can agree that the way to keep problems from happening is to keep the pressure down. Usually that means a lack of performance. Not always, and that is the point that needs to be explained as well.

Here is the data from Hodgdon for the 180gr XTP with SR4756
Quote:
Cartridge: 40 S&W
Load Type: Pistol
Starting Loads

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Maximum Loads

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Bullet Weight (Gr.) Manufacturer Powder Bullet Diam. C.O.L. Grs. Vel. (ft/s) Pressure Grs. Vel. (ft/s) Pressure

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180 GR. HDY XTP IMR SR 4756 .400" 1.125" 6.1 957 25,200 PSI 6.6 1018 28,800 PSI
Look at the pressure of that bullet to get over 1000fps. Now look at another powder, one much faster.

Quote:
180 GR. HDY XTP Hodgdon Clays .400" 1.125" 3.0 727 26,000 PSI 3.5 847 34,300 PSI
On some charts Clays is considered faster than Bullseye, how much difference between the numbers on a chart is hard to ascertain, still..............

One can readily see that the pressure is higher for less performance. Now, if it was my firearm, with the knowledge that it had a partially supported chamber, I can tell you which load I would choose.
Note, .5gr of powder changes the pressure by over 8000psi. What happens if you go to 3.9gr? I can tell you, DON'T!

OK, that's the 40S&W. What about the 45ACP? Let's look.
A popular bullet weight for target shooter is the 200gr LSWC, we'll check them out.

Quote:
200 GR. CAST LSWC IMR SR 4756 .451" 1.225" 7.4 875 13,500 CUP 8.2 966 17,100 CUP
A maximum load gives pretty good velocity.

Now a much faster powder, again, Clays.

Quote:
200 GR. CAST LSWC Hodgdon Clays .451" 1.225" 3.6 759 11,800 CUP 4.3 888 17,000 CUP
Now the difference in pressure isn't that different. Look at the velocity. What will happen is this, someone will try to eek out that extra 78fps with this powder. What if your powder drop is +/- .1gr? It is possible that bad things are to follow folks, period.

I'm not trying to slam Clays. Like every tool available to us as reloaders, it has it's place. In light revolver rounds, very good.

Good points again Dennis.
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