What is the diff. Is one better, are they interchangable.

The 10 is a more powerful round, closer to the 45acp. It also has more recoil and is getting harder to find ammo.
The 40 is a nice balance of smaller round and reduced recoil, plus its everywhere.
I prefer the 40 for the above reasons cited. Many will disagree and I cant fault their opinion as the 10 would have been a very nice round if it woulda taken off.
The FBI dropped it and pretty much killed it.

The difference is about like the 38 verses 357mag. They cannot be interchanged in an auto but can be in a revolver. I shoot alot of 40's in my 6 1/2' 610 S&W. They shoot very well and less recoil. I sold my Colt Delta Elite Gold Cup which shot great but they are hard to find and I was to cheap to want to wear out a high dollar auto. Still have a 40 auto and the revolver. I enjoy shooting these more than a 45 but it is just a preference thing. Once fired brass is really cheap. Like $10-12 dollars a thousand. Once fired 10 is a little harder to find and will usually run $35-45M.

.40 the 10's a good round, but if it was that good it would still be around.

Whats wrong with the old .45 or 9mm, tried and true. I had a .40 was'nt impressed

The purpose of the 40 is it is almost a 45 but will fit into the compact frame size of a 9mm gun.

The 10mm is a full sized full power handgun cartridge meeting the legal deer hunting power requirements in many states.

The 40 is just what the headstamp says.

40 Short+Weak

This has been gone over before, extensively.  The 10mm is not 'dead', and the 40 is most definitely not 'short and weak'.  40 is a better carry round 'cause it fits in a 9mm sized gun, is cheaper and easier to find.  10 is a better hunting round, also shoots through hard cover like cars better.  Both can outclass the .45 with the right load.

This topic always brings out the "manly", types (big guns and small penises), who badger their limp wristed brothers for not having the balls to shoot a "real" gun. If I can't do it with a 40 then I need to be running like hell the other direction.

Which one is better.....whichever one you are hit with.  With proper placement, the results will be the same.

i heard the 10mm is like a 41mag in an auto case, and that the 10mm was 36% more powerful than a 45acp.
the 40 is more or less a compromise between a 45 and 9mm, almost the best of both worlds.
ive heard people putting 40cal in there 10mm auto guns, i would never reccomend this, and even IF IF IF its safe the accuracy would SUCK, the very least you would probably shorten the life of the chamber throat, and make it more difficult to chamber a 10mm.
you can buy a bar-sto 40cal barrel to stick in your 10mm guns

I have heard some people refer to the .40 as the 10mm "Short". it is much like the examples given. Much like a .380 is to a 9mm

I used to carry a 40 S&W for about two years and I still wouldn't feel poorly armed with one, but I went to 45ACP for a couple reasons:
1)you can't count on any handgun round to expand in a human body and when they do expand it is usually close to the point where they would exit the body, so it's better to go with a round that is larger to being with
and
2)the 45ACP recoils differently than the 40.  While the 45ACP has more of a "push" than a kick, the 40 has the muzzle-flip and sharp recoil of the 357 Magnum.

As for 10mm, it is a fine caliber, very versatile and I wouldn't mind owning one, though I don't right now.  But it takes a lot more practice to master than either the 40 or 45 and kicks like a 41 Magnum in its hotter loadings.

Speaking as the owner of 4 10mm guns and 2 .40 guns.--

1.  The 10mm is close, in it's hottest factory loads to a .41 mag.  It does exceed several of the .357 factory loads.

2.  The .40 basically came about when the FBI wanted to download the 10mm due to recoil concerns.  I agree with what the designers of the .40 did--why down load a large cartridge in a large frame handgun when you can make a smaller cartridge in a smaller frame handgun?

3.  I still wouldn't use the 10mm for hunting--my Smith 10mm's (pre-sellout of course), Glock 10mm and Delta Elite are not what I consider accurate enough for hunting handguns (the round itself is OK, just the guns aren't 50-100 yd rounds).  I would prefer a Ruger Super Blackhawk in .44 Rem. Mag. as a hunting handgun.

4.  For self defense, I think the .40 is a little better, just due to the more manageable size (I have "medium" sized hands) of the guns (Sig 229 and Glock 22).  The 10mm will more than do if you practice with it.

5.  For fun, shoot a Winchester Silvertip or Norma round out of the 10mm.  Nice size fireball from the silvertip and both have a pretty good recoil for an autopistol (not as much as a .357mag, but definitely more than a .40, 9mm or .45).


I think the IDEAL reason for a 10mm would be in a carbine.  Then it would be practical to have a pistol in the same caliber.  I would love to see a caliber conversion for an UZI, MP-5, AR-15 rifle in that caliber (with CHEAP, RELIABLE mags--the conversions I have seen have a reputation for being unreliable and/or expensive mags).

Ok, the 10 was designed for the Bren 10 and in full power loads it even beat that gun to death.  That is when the FBI asked for the lower power rounds, so you end up with wasted case volume which is not good either. then came the 40.  If I need to shoot something the 40 will not stop I going to reach for something bigger than a 10 anyway. But the 10 is a cool round in full power. Good balistics but you need a gun that will stand up to it.

Ron

Glock 20 designed for 35,000+ full power 10mm rounds. Options include factory porting and a 6" barrel.

I think the 10mm is going to fall into the same category and follow the same road as the .41 Mag.  It was designed to be the "ultimate" defense caliber in an autoloader, but it still had some limitations.  It needs to be chambered in full-sized guns and it generates more felt recoil than most other popular defense cartridges.  I doubt it will ever "die," but rather become, just like the .41, a hobbiests' cartridge.

I just picked up my fifth 10mm today, a Olympic Arms CAR-10.  I could have picked one up in 9mm, .40 S&W or .45, but I really like the ballistics of the 10mm (plus I'm an old Miami Vice fan!).  I got the flat-top version with the picatinny gas block and have outfitted it with a C-Moore sight as well as a Bushmaster flip-up front sight and an ARMS flip-up rear sight.  I'm thinking about modifying a tacblock to accept M3 greasegun mags, but have to do some more homework on that to see if it's a worthwhile project.  Once I'm done with it and have worked up some loads for that 16" barrel I'm going to take it out to the Oregon high dessert and see how close I can call in those coyotes!