Board Index Gear and Ammo Reloading

New Category!

For reloaders and related equipment such as presses, dies, trimmers, scales, and bullet molds.

Postby lrgcal4fun » Fri Jan 22, 2010 11:30 pm

Good question, they are the same diameter;) But just for the sake of celerity, lest some one miss understand... No one can't shoot a 10mm in a 40S&w. The 10mm is a longer and much more powerful (higher pressure) cartridge. I have heard of some who have tried the reverse, but because the head-spacing would be all wrong, I would never recommend trying it. One could end up with a face full of burning powder.
Posts: 216
Joined: Thu Jan 17, 2008 5:42 pm

Postby Mark4 » Sat Jan 23, 2010 3:37 am

Can one load the 40 cal to 10 mm specks and get the same power? Or trim a 10 mm case down to 40 cal specks?
Posts: 15
Joined: Fri Sep 11, 2009 4:03 pm

Postby judgeparker » Sat Jan 23, 2010 2:03 pm

hi Mark4

I can not stress enough how dangerous it can be if you deviate from the specs in the manuals. There is usually a very small amount of leeway on the top end but it's best to not play with it . Doing so can be very DANGEROUS.While some pistols can handle a little higher pressure some can not so it's best to always err on the side of caution. As for trimming a 10mm case down if the lower part of the case walls are not thicker in the 10 you probably could ,but why when the 10mm cases are more expensive and harder to find.
Posts: 136
Joined: Sat Dec 20, 2008 9:17 pm

Postby Mark4 » Sun Jan 24, 2010 6:53 am

I have a steady free supply of 10 mm.cases.

I am thinking they made both the 10 and the 40 just to charge more for both. I wonder why they were made at all when the old 45 cal is just as good. Granted the 40 may be a little better to control for the second shot.

My personal choice for CCW is the 38 super in a 1911 frame.

Iwonder what they were thinking?
Posts: 15
Joined: Fri Sep 11, 2009 4:03 pm

Postby judgeparker » Sun Jan 24, 2010 11:34 am

In a nutshell

The 10mm was created for the FBI because they found the 38 specials that their agents were carrying in their 357 mag revolvers were inadequate. Then the FBI discovered that the 10 was hard to handle by the smaller agents so the 40 was born. I have a Taurus PT-140 in 40 cal and second shot placement takes longer than my Rock Island 1911. Because the 40 so snappy in that lighter pistol. I can buy once fired 40 brass for $8.00 a 100 count I am not sure all the labor to cut the 10 down would be worth the effort. But then I am Kind of lazy. You could always just buy a 10mm pistol thats always fun.
Posts: 136
Joined: Sat Dec 20, 2008 9:17 pm

Postby Mark4 » Sun Jan 24, 2010 4:51 pm

I read that a gun magazine was first to suggest them both.

You know a 38 Super is not your regular 38. It falls in between the 357 and 9mm with just a small less powerful than the 357. It is hard hitting and controllable shot after shot. You wouls love it.
Posts: 15
Joined: Fri Sep 11, 2009 4:03 pm

Postby lrgcal4fun » Sun Jan 24, 2010 7:47 pm

Hay Folks, Ok, I'm going to date myself here but what the heck.

You can find good information on the 10mm in its original incarnation (the Bren 10) here http://www.bren-ten.com

In short Jeff Cooper, Thomas Dornaus and Michael Dixon developed the cartage and Bren pistol around 1978. In the early/mid 80's the FBI began the first truly scientific study of hand gun effectiveness. A summery is available here http://www.firearmstactical.com/hwfe.htm

At that time they decided on the 10mm in two different loadings. One that pushed a 180gr. bullet well over 1000fps. and another that pushed it about 950fps. The hot load was intended for swat and other high risk situations and the lighter was for regular agents on regular duty. S&W built a gun for them that was shipped with two recoil springs, so it could be configured as needed.

As judgeparker mentioned, this plan failed. Agents with mid to small hands just couldn't handle the pistol. The long cartridge made the pistol grip to big. The engineers at S&W realized that they could cut down the case and still get the 950fps specs (and better). Wham the 40S&W was born. Smaller cartridge, plenty of power, standard size grips, and a big hit with law enforcement.
Posts: 216
Joined: Thu Jan 17, 2008 5:42 pm

Postby lotsip81 » Sun Feb 21, 2010 7:38 am

I have read that before, but it is good to read it again. It is some great information that all interested in the firearms field should take the time to read at least once.

Thanks again
"Guns don't kill people, People do!"
User avatar
Posts: 637
Joined: Wed Feb 28, 2007 7:46 pm

Postby keyman » Sun Feb 21, 2010 7:31 pm

Does anyone have any figures . . . pro or con regarding the savings on loading your own ammo ? ?

I ordered some re-loading equipment yesterday, and intend to find out.
Posts: 303
Joined: Tue Oct 30, 2007 1:53 pm

Postby tkdguy » Thu May 13, 2010 2:06 pm

Keyman: I have been reloading for 17 years with a Hornady Projector circa 1994 and a Lyman Orange Crusher (for rifle rounds). Hands down reloading is cheeper, and if you work with it you will be able to refine the accuracy of your target or hunting shooting by finding the most effective formular for a given bullet weight, powder load and primer combination. Buy your bullets, power, etc in bulk; you will save big time. I can usually cut my groups down by 1 plus inches in my custom bedded rifles, and develope more powerful loads than factory. By example, I have a Winchester 70 .338 that will shoot 2.5 inch groups at 200 yards with handloaded bullets, but with factory it will shoot 2.5 inches at 100 yards. tkdguy
Posts: 36
Joined: Sat Mar 22, 2008 9:01 pm


Return to Reloading

Users browsing this forum: No registered users and 1 guest

Fatal: Not able to open ./cache/data_global.php