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Elkins45
02-12-2013, 12:13 AM
This photo is of a 200 grain 40 caliber boolet from a mold I designed on the Mountain Molds website. My design goal was to create a heavy 10mm boolet that took up the least amount of room inside the case as possible. In other words, I tried to design it to be as short for the weight as possible. It's a 75% (.300) meplat and is significantly shorter than the RCBS 200 grain design I was using previously.

Due to the relative cost and scarcity of 10mm cases I bought a 40 S&W barrel for my Glock 20. That opens up some interesting possibilities in that the barrel will chamber a round with a COAL that would never fit a standard 40 S&W magazine but will easily fit inside the longer 10mm magazine of the G20. The photo shows a dummy round with a boolet loaded out much farther than I could get away with seating it in a 10mm case. I arrived at this length by gradually seating it deeper and deeper until the head was flush with the barrel hood when dropped into the chamber. The dummy round fits into the 10mm magazine at about the same length as a regular 10mm round does.

This raises the possibility of maybe getting heavy bullet performance from the 40 barrel that more closely approximates 10mm performance since there's now more powder space available due to the long seating length. I'm going to experiment (very cautiously, I assure you) with seeing if I can exploit the extra COAL. Bullet setback is a fear, of course, but by concentrating on slower powders at first I might be able to prevent that possibility by loading to near 100% density.

Surely I'm not the first person to contemplate going down this road? Anybody have any results they would like to share about shooting "40 longs"? I should add that the chances of me shooting these 40 longs in a regular 40 are nil, since they won't fit in the magazine and also because I don't own a 40 other than the Glock barrel.

http://i292.photobucket.com/albums/mm35/elkins_pix/IMG_0599_zps67409f00.jpg

Lloyd Smale
02-12-2013, 06:37 AM
neat project but if your fooling with a glock i hope your 40 barrel has a supported chamber if your running hot loads. Ive seen a couple of them go kaboom when the cases blew out.

popper
02-12-2013, 12:46 PM
Interesting, 40 cases in a 10mm. Will they feed OK? You could crimp into the lube groove for setback prevention. You're only gaining 10% weight over a normal 180 for the 40.

Elkins45
02-12-2013, 03:00 PM
neat project but if your fooling with a glock i hope your 40 barrel has a supported chamber if your running hot loads. Ive seen a couple of them go kaboom when the cases blew out.

I'm familiar with the phenomenon, unfortunately. Here's my first Glock 20, which was the victim of weak brass and heavy loads:

http://i292.photobucket.com/albums/mm35/elkins_pix/Rcrack.jpg

http://i292.photobucket.com/albums/mm35/elkins_pix/Lcrack.jpg


Interesting, 40 cases in a 10mm. Will they feed OK? You could crimp into the lube groove for setback prevention. You're only gaining 10% weight over a normal 180 for the 40.

To be clear the GUN is a 10mm but I'm using a 40S&W conversion barrel (Lone Wolf) to shoot the rounds so there's not a headspace issue. I have no idea how or even if it will feed because this powerless dummy round is the only one I've assembled yet.

I wish somebody made a 40 conversion barrel for the S&W 1006---this experiment might be less costly in a metal framed gun if things go bad!

davidalyn
02-14-2013, 10:02 PM
United State Practical Shooting Association (USPSA) shooters have been loading 40 caliber longs (some as long as 1.240) for years. I have experimented with 225 gr, 200 gr, and 180 gr long loaded 40 caliber rounds. Most of my ammo was loaded to 1.200 OAL. Most 40 caliber barrel throats need to be lengthened to accept rounds that long. I would be more than happy to do my best to answer any questions you may have.

Oreo
02-15-2013, 12:20 AM
Fyi, I'm going to be designing a boolit for just this kind of application. I'll be having Miha make the molds as a group buy. If any of you guys are interested let me know and I'll send you a PM when I get the buy posted.

Elkins45
02-15-2013, 12:31 AM
United State Practical Shooting Association (USPSA) shooters have been loading 40 caliber longs (some as long as 1.240) for years. I have experimented with 225 gr, 200 gr, and 180 gr long loaded 40 caliber rounds. Most of my ammo was loaded to 1.200 OAL. Most 40 caliber barrel throats need to be lengthened to accept rounds that long. I would be more than happy to do my best to answer any questions you may have.

What guns are they shooting them in? I would think the magazine length on most 40's would be the limiting factor. What powders are most popular for this application? I'm thinking of starting with AA#9.

davidalyn
02-15-2013, 07:00 AM
What guns are they shooting them in? I would think the magazine length on most 40's would be the limiting factor. What powders are most popular for this application? I'm thinking of starting with AA#9.

Just to ensure that I don't lead you astray, long loaded 40 caliber rounds are not pushed to 10mm velocities and are not fired in 10mm chambered barrels.

Many folks are shooting 40 caliber or 10mm (with 40 caliber chambered barrels) 1911 single stacks, 1911/2011 40 caliber or 10mm (with 40 caliber chambered barrels) double stacks and Glock 10mm (with 40 caliber chambered barrels).

Since the 1911 was designed to feed rounds loaded at a OAL of 1.270, many people think they run (feed) better with long loaded rounds. All magazines used obviously must be large enough front to rear to accommodate the long rounds. 10mm mags for the 1911 single stack, all 1911/2011 double stack mags start life with enough room front to back unless a spacer in inserted to push shorter rounds forward and I don't need to tell you about Glock 10mm mags. The extra cartridge length allows shooters to use faster burning powders (less perceived recoil) while lowering the pressure (hopefully less chance of a Kaboom, even though many have occurred).

As for powder used, let me check and see if we are allowed to post links or reference other web sites, because there is a ton of information out there.

I could not find any prohibitions for linking to other websites so....check out the following:

http://www.brianenos.com/forums/index.php?showforum=73

Oreo
02-20-2013, 10:44 PM
I'm designing a boolit just for this application. If anyone is interested in participating in the group buy (Miha) here's the discussion thread:
http://castboolits.gunloads.com/showthread.php?185257

jmbaccolyte
03-20-2013, 07:03 AM
Elkins45-
I have been interested in this idea myself, even bought some Winchester AutoComp powder for the experiment. I chose WAC because its charge weight is less than most of the others with similar performance. Bullet setback shouldn't be a fear with the proper sizing die; my Dillon die (and some others- EGW comes to mind) creates an hourglass shape that looks great on women- but I digress. This shape keeps the bullets from setting back into the case.

At present I'm shooting (about 4K rounds so far) a mild practice load in .40 S&W cases with 180 grain moly-coated bullets with 3.2 grains of Clays at 1.23" OAL. And a somewhat stronger load (about 3K rounds, so far) is 5.5 grains of WST with the same bullet and OAL, which yields 945fps out of a 4.75 inch barrel. I shoot a large frame Tanfoglio in .40 S&W with 10mm magazines. Evidently they use the same barrels for .40 and 10mm and just cut the chamber for proper headspacing for either length case. The rifling leade or free bore or whatever (just before the bullet touches the rifling) must be the same, because mine passes the "plunk" test without the bullet touching the rifling at this length.

Keep us advised of your results!

HATCH
03-20-2013, 08:01 AM
I wish somebody made a 40 conversion barrel for the S&W 1006---this experiment might be less costly in a metal framed gun if things go bad!

some were made but you really have to look.
I have been looking for a couple months for my 1066

jmbaccolyte
03-21-2013, 08:32 PM
Hogdgon's website shows the .40 S&W (at an OAL (overall cartridge length) of 1.125") using a 200 grain jacketed bullet and 4.8 grains to 5.2 grains of Win AutoComp powder. The high end charge operates at 32,000 psi.

For the 10mm (1.26" OAL) using the same bullet and AutoComp powder, the charge weight varies from 6.0 grains to 7.0 grains. Interestingly, the pressure at 6.0 grains is listed at only 26,000 psi at the longer OAL. Clearly increasing the internal volume of our 40 Long by increasing the OAL to 10mm lengths (and thereby duplicating the internal volume of the 10mm) greatly affects the pressure levels.

I and others have sectioned both cases and found the case web thickness is the same. With a properly supported chamber, this should be quite doable. Just go slow, use a chronograph and use a 10mm recoil spring or one of those Sprinco recoil reducers.

PS: If you've fired a few rounds with your new bullet, how does it feed? It looks very nice.

Any Cal.
03-21-2013, 11:55 PM
I and others have been running .40 Longs w/ 10mm data for a long time now. If you do it in a .40 barrel you will probably need to have it throated, as the rifling will limit the length you can use. My load for the last 1200rds or so has been a custom 230g boolit @ 1135 fps in .40 brass, loaded to 1.260 oal.

More info later.

Any Cal.
03-22-2013, 04:01 AM
OK, there is an old thread about a similar subject here...http://castboolits.gunloads.com/showthread.php?162043-Hot-40SW-loads-in-10mm-converted-to-40SW

My input was in posts 16 and 17, I'm going to paste them here rather than retype it.


What I was doing was basically like mstarling, loading to 10mm dimensions and charge weights using .40 brass. It allows more room for powder in the .40 case, since you aren't consuming so much space with the bullet. You are trying to duplicate a 10mm load exactly, but using a bit less brass around the body of the bullet. I will see if I can get a pic to illustrate, but remember, these are not going to be .40 spec, they won't fit in the mag or feed, they will require 10mm length mags and a 10mm chamber or a .40 chamber throated extra long. It is NOT just a matter of upping the powder charge in a .40, that is a good way to blow a gun up...



Alright, here is a pic to illustrate...
64985


Same powder charge, same bullet, same OAL, just a different case length. The case will no longer headspace on the casemouth, but on the extractor. On some guns, doing this is a BAD idea. On the Glock, seems to be fine. The case on the .40 is basically identical to the 10mm case with the exception of length, some claim stronger due to the smaller primer.

-Edit- Those boolits are puuuuurrrty 'cause :castmine: Unless those were some I had laying around, in which case someone else cast mine...

jmbaccolyte
03-22-2013, 08:10 AM
Any Cal- very interesting thread you referred to. I shoot a large frame Tanfoglio (in the early days it was a CZ 75 knock off, but they've since branched off with their own improvements. Once of which is a large frame design that is chambered for 10mm and .45 ACP (as well as 9mm and .40 S&W). Another is a hard chrome frame for the Witness Match and some of their other models. Evidently they use the same barrels for .40 and 10mm and just cut the chamber for proper headspacing for each length case. The throat, rifling leade or free bore or whatever its called (the area just before the bullet touches the rifling) must be the same in both calibers, because mine passes the "plunk" test without the bullet touching the rifling when loaded at 10mm lengths. If I use 10mm magazines then if works great for mild practice loads and mid range (powerwise) loads. Headspacing is not on the extractor, but on the case rim with the .40 S&W barrel as it should be.

What powder are you using for your loads?

Another thought are the polymer frames like the Glock are more forgiving than steel frames of the tearing forces involved when the case web blows out on a less than fully supported barrel chamber or not?

jmbaccolyte
03-25-2013, 08:21 AM
My barrel seems to fully support the case and it has an integral feed ramp.

Is anyone who has done this willing to talk about loading data?

davegalesr
03-25-2013, 09:28 AM
Elkins45 - hop your hand looks better than the Glock after that blowout?

Any Cal.
03-25-2013, 01:48 PM
Load data is the same as 10mm if you keep the OAL the same. Most cases are the same internally other than primer size between .40 and 10mm, so there isn't any difference. Don't do it unless it is in a Glock or a chamber that fits the round correctly, as some people get some really hammered rounds in other guns/chambers.

Other than that, Longshot and Blue Dot are your friends, and some people like #9, except you burn a lot of it.

jmbaccolyte
03-26-2013, 07:06 PM
Thanks Any Cal.