1700+ fps out of a 40 S&W = Too Hot!

[alucard0822]

Since I have some free time at work, I checked the loads for 40 versus 10. Longshot isn't even mentioned in the 10mm section, and it's actually slower than the 40 load. ???

found this for 10mm out of notes, think it's old data from Nosler

135gr Nosler 13.2gr max Longshot - 1542fps

The "new" 11.5gr 40S&W load claims 1434FPS

Thing is especially for auto calibers, you don't really know your velocities till you test them. Have had a few suprises that were way over published velocities and showing overpressure, while still under max load, and others that were anemic at max with plenty of room to go. have seen data change, and some data get passed down or worked up by others, there is data everywhere, some good, some bad, part of the reason working up is so important. Especially when it comes to cult favorites like 10mm, there are probably more good loads a knowledgeable reloader worked up for a forum or magazine article than have ever made it onto the big manufacturer's websites.

 

[jimbobborg]

found this for 10mm out of notes, think it's old data from Nosler

The "new" 11.5gr 40S&W load claims 1434FPS

Thing is especially for auto calibers, you don't really know your velocities till you test them. Have had a few suprises that were way over published velocities and showing overpressure, while still under max load, and others that were anemic at max with plenty of room to go. have seen data change, and some data get passed down or worked up by others, there is data everywhere, some good, some bad, part of the reason working up is so important. Especially when it comes to cult favorites like 10mm, there are probably more good loads a knowledgeable reloader worked up for a forum or magazine article than have ever made it onto the big manufacturer's websites.

Thanks. I have a new 10mm coming in soon, so I can get back on this. Although I think I'll get another for testing loads like this. No point blowing up a $2000 pistol.

 

[atblis]

I've come to the conclusion one should get a chronograph and stop adding powder once the published velocity is reached. If you're seeing velocities higher than you expect, most likely the pressures are higher than they should be. Problem is, published velocities are not always useful due to different barrel lengths and or a test platform that isn't comparable to your platform.

I am considering picking up a strain gauge pressure measuring system. $700 or so if I remember correctly.

 

[atblis]

7" KKM 40 S&W barrel for the Glock 40 on the way! It'll be interesting to see how much velocity I gain going from a 4.6" to a 7".

 

[jimbobborg]

I've come to the conclusion one should get a chronograph and stop adding powder once the published velocity is reached. If you're seeing velocities higher than you expect, most likely the pressures are higher than they should be. Problem is, published velocities are not always useful due to different barrel lengths and or a test platform that isn't comparable to your platform.

I am considering picking up a strain gauge pressure measuring system. $700 or so if I remember correctly.

You also need to look at what brand of brass and primers that the publisher is using. Winchester pistol primers are for both standard and magnum rounds. For the 10mm, most recommend Norma brass for hot loads.

 

[atblis]

Who recommends Norma brass (actual published loads based on pressure testing)? I know many people on the internet do, but I've never seen published data that recommends Norma brass. On top of that, Norma 10mm brass is ancient history at this point. I don't think it's been made in over a decade. I'd say Starline is now considered the safe bet.

 

[jimbobborg]

Who recommends Norma brass (actual published loads based on pressure testing)? I know many people on the internet do, but I've never seen published data that recommends Norma brass. On top of that, Norma 10mm brass is ancient history at this point. I don't think it's been made in over a decade. I'd say Starline is now considered the safe bet.

I have some 25 year old books somewhere My 10mm brass is quite a mixed bag. I'm at the point where I'm thinking about cutting down some 6.8 SPC brass and trying that out.

 

[atblis]

Might/could buy 10mm Magnum brass and cut it down. What are you trying to do? If you're planning on staying close to or inside of the SAAMI pressure, there's really no need for beefed up brass. Starline will do that just fine. Really this whole mess with blowed up guns is due to Glock's crappy chambers, early Federal brass, and or people trying to make 10mm in to 41 Magnum.

 

[jimbobborg]

Might/could buy 10mm Magnum brass and cut it down.

I'm looking at going with small primers, and the base of the 6.8 is beefier than standard 10mm brass. That's for when I get a 610 again.

 

[BUFF7MM]

7" KKM 40 S&W barrel for the Glock 40 on the way! It'll be interesting to see how much velocity I gain going from a 4.6" to a 7".

I've got to ask so I'll quote this post, but what exactly are you trying to gain by the increase in velocity? And how do these loads group for accuracy?
I guess I'm more for groups than speed.
I'm not trying to bash with this post just trying to understand from the other side of the spectrum.

 

[atblis]

Planning on doing some plinking at 50 yards, 100 yards, maybe longer. It also makes cans and water filled bottles explode nicely. Just a range toy really. Some extra noise and muzzle blast makes it more interesting. Ultimately, I plan on shooting mostly 357 SIG out of it. The recoil is much much milder than the 135 gr 40 S&W loads.

 

[BUFF7MM]

Planning on doing some plinking at 50 yards, 100 yards, maybe longer. It also makes cans and water filled bottles explode nicely. Just a range toy really. Some extra noise and muzzle blast makes it more interesting. Ultimately, I plan on shooting mostly 357 SIG out of it. The recoil is much much milder than the 135 gr 40 S&W loads.

Cool.
You want some nice fireballs, Bluedot is your friend, definately turns your handgun into a fire breathing dragon.
Here's some loads for it, I'm sure you've already got this but I'll just set it here.
http://handloads.com/loaddata/defau...&Weight=All&type=Handgun&Order=Powder&Source=
Bluedot 10mm load

 

[atblis]

10mm is fun isn't it?

My morning entertainment

The effects of a Nosler 135 out of a 10mm on waterbottles. Summer plans are for gator-aide bottle filled with colored water.

 

[BUFF7MM]

They are fun aren't they.

 

[atblis]

Let me know if the pictures don't show up. Still trying to figure out how to use Google photos.

Ruhh Rohh. Squeezed off a round and the mag blew out the bottom of the gun. Got a little carbon on the trigger finger from hot gasses. Asides from a missing extractor, the gun pulled through with no apparent damage. The magazine's notch for the mag catch is a little marred up but still works. So now I am trying to figure out what happened and how to proceed.

-For starters, the velocities I am getting are too high (even after reducing it). I suspect I have batch of Longshot that's a little faster/hotter than normal. So even though I am at a published max load, I think pressures are too high (well obviously duh).
-I don't believe it is wholly attributable to variation in the thrown charge though this may have contributed. I pulled some rounds and measured powder charges. There was some variation, more than I care for +-0.2 gr. I've chronographed these plenty, and the velocity variation could be better, it wasn't terrible. I have plenty of check-weights and do use them regularly so I don't suspect the scale was off.
-Leading up to this case blowout, a few rounds fired immediately previous to it were severely bulged (see 3rd picture). Earlier in the day I had been shooting the same ammo in another Glock as well as the this one, and had been inspecting the brass as I went looking for issues (mostly single loading though). When I was satisfied everything was okay, I proceeded to simply shooting and then...kaboom.

I am leading towards bullet setback increasing pressure for a couple reasons. I didn't observe the case bulging with the other Glock which also has never exhibited feeding issues. This Glock 40 has had some feeding issues.

So basically my best theory is that I was already at high pressures, a little bullet setback and... Classic 40 kaboom scenario.

When they're not blowing the magazine out of the gun and sending the extractor in to a low earth orbit, this is what a 135 gr Nosler at 1800 fps does to a 2 liter soda bottle.

 

[redeemed.man]

pics are showing up, YouTube link is bad

 

[atblis]

Thanks, working on it. Delete the quote if you would please as it won't get fixed when I edit the original.

 

[Shoobedoo]

Cool.
You want some nice fireballs, Bluedot is your friend, definately turns your handgun into a fire breathing dragon.
Here's some loads for it, I'm sure you've already got this but I'll just set it here.

I have never used Blue Dot in 10mm, but I probably burned 10 lbs of the stuff in .44 magnum. Blue Dot has been around for a long time, I can remember loading it when it still said Hercules on the powder can, it was designed primarily as a magnum shotshell powder that also had pistol applications. BD can get squirrelly on you with pressure spikes as you begin to approach max loads, so watch carefully for signs of excess pressure if you're trying Blue Dot to get max or near max velocities. I never found BD to be "flashy" but I never shot it out of an auto pistol. Power Pistol has a reputation for producing the fireballs you speak of, it's an excellent powder for .40 so I imagine it would do well in 10mm also.

 

[ten75ice]

I don't get the point of this, just go shoot a rifle.

 

[atblis]

I bet you're a lot of fun at parties.