.40 is to 10mm as 9mm is to.....?

[herkyguy]

I'm no wildcatter myself, but has anyone ever explored the possibility of an elongated 9mm case that would have the same velocity bump as 10mm does over .40 ammo?

Seems to me that an average 180 grain bullet gains about 300 fps with the 10mm, usually hovering around 1300 fps, whereas the .40 tops out, on average, around 1000 fps.

Other than .38 Super (which doesn't seem to offer as significant of a bump in velocity) is there anything that could push a 9mm 115 grain bullet to velocities approaching 1500 fps??

With the renewed interest in the 10mm, it got me thinking.....

 

[DeanV]

How about the 9x23?

Does not look like finding manufacturer ammo is going to be an option for it though.

 

[WestKentucky]

38 super, 9x21, others that I don't immediately recall.

 

[ATLDave]

38 Super +P can be loaded up into that range. That's pretty much what all the Open gun guys in USPSA/IPSC run. And have for decades.

For instance, Western Powder's data can get a 115 .38 super +P with AA#7 to just under and over 1500 (depending on the specific bullet). Their 9 +P data tops out in the mid-1200's.

http://www.accuratepowder.com/wp-content/uploads/2010/09/WesternLoadGuide1-2016_Web.pdf

 

[GRIZ22]

Add 357 SIG to the list. Seems like people keep trying to reinvent the wheel.

 

[SHOOT1SAM]

The title & the OP seem a bit backwards to me, as the 10mm came first, then the .40. The 10mm isn't a bump over the .40; the .40 is a reduction of the 10mm.

That being said, to answer the OP-the 9X25 Dillon, a 10mm necked down to 9mm, with factory ammo from DoubleTap (the big brother to the .357 SIG, A .40 necked down to 9mm).

Sam

 

[agtman]

I'm no wildcatter myself, but has anyone ever explored the possibility of an elongated 9mm case that would have the same velocity bump as 10mm does over .40 ammo?

Well, it's not an exact relationship.

That being said, to answer the OP - the 9X25 Dillon, a 10mm necked down to 9mm, with factory ammo from DoubleTap (the big brother to the .357 SIG, A .40 necked down to 9mm).

Sort of agree.

The .40S&W is a "10mm Kurtz" - more akin to the relation between the .380 cartridge (9mm Kurtz) and the 9mm Parabellum. But the .40 case itself isn't structurally "necked down" to hold the .40/10mm bullet. Both cartridges can use the same weight of slug up to 200gns, despite the 10mm's capability of propelling all of them to radically different max velocities.

The 9x25 Dillon took a true 10mm case and necked it down to hold a range of 355/9mm bullets (initially 95gns to 147gns, IIRC). All of them can be propelled to insane velocities, and the 9x25 is credited with being the first cartridge to finally put some nads on the 9-minimeter.

 

[eldon519]

9x23

 

[Dragon breath]

It's called a .357 magnum.

 

[OilyPablo]

9x25.

 

[ApacheCoTodd]

... as .38(+P?) is to .357.

Though their respective developments are reversed.


Todd.

 

[Jim NE]

There was a Walther P1 on gunbroker recently that was chambered in 9 x 21. To my surprise, I was able to find ammo online.

 

[SHOOT1SAM]

But the .40 case itself isn't structurally "necked down" to hold the .40/10mm bullet.

Yep, I didn't say that-said the .357 SIG is a .40 necked down to 9mm.

Sam

 

[agtman]

Yep, I didn't say that -said the .357 SIG is a .40 necked down to 9mm.

Didn't say you did, just pointing it out .... But the necked-down aspect is disanalogous to the OP's gambit, since neither the 10mm, nor the .40, nor the 9mm use necked down cases.

And while it's not a perfect analogy in terms of the "velocity" part of the OP's query, if you go from the 10mm -> the 40, then with the 9mm (9x19) you'd go to the .380 (9x18), or perhaps even to the 9mm Makarov (9x17). The caveat with the 9mm Mak, however, is that it's not truly a .355 diameter bullet, but .386, IIRC.

Other than .38 Super (which doesn't seem to offer as significant of a bump in velocity) is there anything that could push a 9mm 115 grain bullet to velocities approaching 1500 fps??

Again, if you're not picky about case design (straight-walled, tapered, bottle-necked, or necked-down), and just want to max-out a 9mm bullet's velocity, check out the fps/fpe specs of the 9x25 Dillon from a 5" or 6" barrel.

 

[herkyguy]

9x23 seems impressive, but some issues with availability and reloading headaches according to Shooting Times.

http://www.shootingtimes.com/ammo/cartridge-review-9x23-winchester/

 

[goste]

9 mm. winchester magnum, aka 9x29, came out in the late 70's, early 80's, was supposed to push a 115 bullet, to 1500 fps. was pretty much a non starter right out of the gate.

I do belive it was beat by the 9x23, and the .356 tsw

 

[Sistema1927]

Going the other direction, I would say: "Just as the .40 S&W is to the 10mm, the .380 is to the 9mm Para."

 

[ny32182]

OP needs to clarify whether he is including necked cases or not. The way I read it was he wanted a longer (nearly) straight walled, rimless case, like the relationship between 40 and 10mm. If that is true, the best answer is probably 38 supercomp.

Also, I know virtually nothing about 9mm Mak, except that they do occasionally slip into my 9x19 brass supply, and run through the loading operation just fine, and seem to hold tension on a .355" bullet just fine too. I don't catch them until/unless I gauge and find them sitting below flush.

 

[agtman]

9x25 Dillon: 125 gn FMJ bullet: over 1500fps from a 5" barrel; over 1600 from a 6" tube.


See: http://www.gunblast.com/9x25Dillon.htm

 

[Arkansas Paul]

One major difference in this idea is that the .40 was not enlongated to create the 10mm, as is being suggested with the 9. The 10mm was shortened to create the .40 S&W.

So enlongating a 9mm would be backwards in relation to the comparison that is being drawn.

I would agree with Dragon breath, that the .357 mag is close to the equivalent.

 

[SSN Vet]

9x23

 

[herkyguy]

Thanks for the replies. I guess I'm most impressed by the 9x23, even with the scarcity of options and problems with reloading. I see the point about an inverse relationship, but I was primarily thinking about a straight-walled elongated 9mm, not necked down 10mm.

I've been seeing a lot in the magazines about 10mm lately and it seems to indicate a growth in interest in high power pistol cartridges.

With a more powerful 9mm, maybe it would still allow for the capacity of a 9, but the oomph of a powerhouse like the 10mm. Seems to me from the replies that some cartridges already exist, just not as prominent as the 10mm.

 

[Mainsail]

The .357sig gets close to those numbers, although as mentioned it is a necked down case (it's not a necked down .40s&w case though).

The neck down case is a benefit as it makes for more reliable feeding; so win-win.

Also it's available on the shelf in most reasonably stocked ammo retailers.

 

[gwpercle]

Been done...9 X 29
9 mm Winchester Magnum , AMT chambered their Auto-Mag III for it. It shot a 115 grain bullet at 1450 fps .
Never got popular and is now so obsolete only us old shooters can even remember it !
Gary