.357 compared to 10mm?

Not open for further replies.

I suggested an auto vs. revolver test because that's the point of using the two different rounds - a powerful auto against a powerful revolver.

I also suggested 5" and 4" respectively because that would equal about the same amount of rifled barrel, since the auto loses an inch to the chamber. The cylinder gap we can't help, it's built in. But the auto is loosing velocity to the recoiling barrel, so too bad.

I'm just trying to come at this in terms of "What's more powerful: a .357 Revolver or a 10mm Auto?" Sure, there are 10mm revolvers, but that's a pointless application of 10mm if you are shopping for power. But the underlying point of this thread is to determine if you can fire a more serious round out of a G20 or a Model 19, and which to pick if power is the deciding point.

In terms of the bearing surface problem, 10mm would have LESS bearing surface than .357 bullet of the same weight, not more. For any given weight, the wider the bullet, the less of it is on the outside diameter.

If you say 10mm wins, so be it. But this doesn't seem to be open and shut in everyone's mind.
Some people are asking why are we making this comparison?

I was CURIOUS. I was not curious about how the factory loadings of these cartridges compare; I know how they do. I was wondering what each of these cartridges can do with handloads and strong guns.

You want two test platforms? Well, mostly loads like this would be used for hunting anyway, so how about this: a GP100 6" and a Glock 20" with a KKM 6" Hunting Barrel, heavy recoil spring, maybe a shock buff, etc.

I'm not talking about service style guns, or how a K-frame Smith compares to a box stock G20. I'm talking about how both of these rounds can perform in big strong guns that would more likely be used for hunting.

If you think the discussion is silly and pointless, then why read the thread and take the time to type replies? Hell, folks, I'm on summer vacataion; I don't have anything better to do! :neener:

Anyway. A GP100 can, with Georgia Arms' DeerStoppers, push a 158 grain bullet to 1475 FPS. Is there any comparable load that a 10mm G20 with a 6" barrel could do? Maybe with a 155grn. .400 cal bullet?
I'm willing to bet there is no "six inch barrel 10mm auto" data. Load manuals usually print velocities with typical pistols, which is 4.5" or 5". That extra inch is going to increase velocity, but who knows how much?

A 155gr .400" bullet isn't comparable in application to a 158gr .357 bullet. You'd want to compare a 180-200gr .400" bullet to the 158gr .357 bullet to get similar sectional densities (with the 180 a little lower and the 200 a little higher).

In that light, we have the Cor-Bon 180gr JSP hunting load at 1,320 ft/sec from a 4.6" barrel vs a G.A. 158gr GDHP at 1,475 ft/sec from a 6" barrel.

G.A. looks pretty good, until you consider that extra barrel length. With 6" of barrel, the 10mm will chrono at over 1,400 ft/sec. At that point the muzzle energies are virtually identical: 783.21 ft-lbs for the 10mm and 763.12 ft-lbs for the .357. Sectional densities are about identical, the 10mm is of course a bigger bullet, and the 10mm has a bit more momentum too.

Careful Glock 20 handloads worked up for 6" aftermarket barrels routinely exceed 800 foot-pounds with HEAVY bullets. Search the "10-Ring" at Glocktalk.com and you will find alot of hot load data for 10mm auto. 800-X is generally considered the "ultimate" 10mm powder, with the caveat that you have to measure each charge by hand, since it doesn't meter for crap.

From the chrono data I've seen, hot 10mm loads (using lots of slow powder) gain 50-100 feet per second per inch of extra barrel length (I'm talking handgun barrel lengths here, not going from a 16" to 18" carbine...).
Back to my earlier question, though. If full sized autolaoders (yet smaller than Desert Eagle type weapons) can lay out the same power as a large revolver, why on earth is anyone complaining about .45 Super being too hard on guns?
Because the "guns" in question aren't built for anything more powerful than ACP?

I hadn't heard complaints about USPs.
I dunno. I'm still gonna say that out of a Blackhawk or a huge Desert Eagle, you can get more out of .357 than you could out of a 10mm Glock. The frames are just larger and stronger. If nothing else they'll certainly be able to handle larger amounts of hot ammo than a G20 or Delta Elite.

And I've heard of 158 grains @ 1600fps being done out of a Desert Eagle or a Blackhawk. Can you replicate that in a G20 (even with a fully supported, 6" hunting barrel) without damaging the gun?
The original question was about handloads, not factory ammunition and to answer that I say yes. In fact the 10mm can be loaded close to the power of the .41mag.>> Majic

This depends upon how you define 'close'. The 41 case is max 1.290" , the 10mm .992" The 41 is a little wider. At equal pressures, the 10 is not close to the 41, though they could be brothers in the same safe, and are both orphaned from department acceptance of their police loads, which shared similar philosophies.

..Is the 10mm as close to the 41 as the 41 is to the 44? By the phrasing of this question, I securely entered the territory of this thread.

Nightcrawler, I've re-read much of this thread, and I can't quite put my brain around what it was you really wanted. Your questions seem to have an agenda behind them. What was it you wanted to buy? What was it you wanted to do?

The DE was not neccesary to contain the power of the 357. I think there are 10mm autos which would do well with the 10.

Personally, I think the 10 and 357 are well matched, though not the same beast.


The .357 loads you're talking about, are they within SAAMI pressure? If not, it's not a good comparison.

If you chambered a .30 carbine Blackhawk in .32 ACP, how hot do you think you could drive it. An extra 200 fps? More?

Blackhawks and DEs are built for .44 Magnum power and pressure, and are just goofing around in smaller calibers. It shouldn't be surprising that they "handle" overpressure loads in lower calibers.

But compare the abuse of a purpose built .357, like a 19, and a purpose built 10mm, like a G20. Do you really expect the Glock to break before the Smith? How many broken G20s have you heard of?

You can build an auto to whatever power standard you want. The Grizzly was mainly mazzive because of the magwell, not the components that contain pressure. A weapon truly built for 10mm will handle the full range of design pressures fine. (A Delta Elite is not "truly" built for 10mm, it is a rechambered .45).
A Delta Elite is not "truly" built for 10mm, it is a rechambered .45

That's not ENTIRELY true... the Delta Elite has an extra-heavy slide, for instance, for the specific purpose of keeping slide velocites down.

However, it is also true that the Delta Elite didn't exploit alot of simple changes that can make the 1911 platform much more viable for hotter cartridges like 10mm Auto. For instance, if you use a flat-bottomed firing pin stop (like the original Browning design, oddly enough), you can delay unlocking and lower slide velocities considerably. That lets you lower the recoil spring weight, and save the gun a beating in both directions. I wonder how different the history of the Delta Elite would be if Colt delivered them from the factory with a modified firing pin stop and a 20lb recoil spring on a steel (not plastic) plug? For want of a nail and all that...
The original Norma load was supposed to be a 200-gr. bullet at 1,200 fps. That's a pretty hefy 640 or so ft. lbs.

However, some Norma factory stuff I shot out of a Delta Elite across a chronograph pushed VERY close to 1,300 fps, somewhere in the 1280s.

That's almost 730 ft. lbs of energy at that point. No wonder the Norma ammo was so tough on the Delta Elite frames.
The problem with Delta Elite frames was fixed early on by milling away part of the left-side frame rail where the cracks were prone to happen. The modified frames (almost all of the Delta Elites produced, by the way) will generally last pretty much forever.

Delta Elites were pretty far from "optimized" for the caliber, but they were (and still are) alot better than people, especially those who got brainwashed by gun rag hysteria, give them credit for.

Of course, $13 can do your Delta Elite alot of good... :D

The .357 loads you're talking about, are they within SAAMI pressure? If not, it's not a good comparison.

I don't know. What does that have to do with anything? NATO-spec 9x19mm ammunition isn't within SAAMI specs. Cor-Bon .45 Colt certainly isn't either. (SAAMI specs for .45 Colt are especially skewed, since they're set up for SAA clones and such.) As long as it doesn't damage the gun or balloon the brass, what difference does it make?

Okay, then. From the answers I've gotten, I'll conclude that 10mm and .357 magnum are, in fact, essentially equal in performance capabilities, within SAAMI specifications and beyond. For maximizing performance, some .357s have the advantage in that their frames are actually designed for .44s and such, but given the same setup (i.e., a 10mm Ruger Blackhawk, if one were to be made) one would assume that 10mm would continue to parallel .357's performance all through the spectrum of loads.

MY 10mm ammo seems to impact targets with FAR more authority than any .357 Magnum i've ever shot.

I know some guys here in Idaho that have taken deer and
black bear with the 10MM. They used to own .44 Magnums,
but found that the TEN killed just as quickly, or even better!

I've read that on other forums and even in books. I do
consider the .357 Magnum minimal for Whitetail. The 10
and .41 Magnum an even better choice.

My 10MM Witness gives me TEN shots, a quicker reload.. in
a package not much bigger than a CZ75.

The G20 gets my respect, it is just a bit to big in the grip for me.

If i was still into Revolvers, a four-inch 610 would get the nod.

10 x10MM It's all you really need:)
The big numbers for the .357mag comes from platforms with 8" barrels, while number for the 10mm comes from 5" barreled platforms.

Actually that's not quite true, at least about using 8" barrels with the 357. 173 gr LSWC @ 1,500 fps is what my 5.5" Redhawk does with published data from Hodgdon. Using data from Alliant my 4" GP100 will do 1,386 with that bullet.

But to really compare the 357 and 10mm as calibers you'd need to load and shoot them in similar or identical platforms, something like a 5" 610 and 5" 27 Smith, or a Delta Elite and a Coonan. Then you could maybe get an idea about which caliber has an edge.
6.5" Ruger Blackhawk:
125GDHP handload (hot)- 1677fps
158GDHP handload (hot)- 1522fps
180WFN Handload (hot)- 1416fps
200WFN handload (hot)- 1338fps

G20 w/6"KKM:
135JHP- 1834fps
155GDHP- 1689fps
180XTP- 1511fps
200XTP- 1466fps

These are real loads that I worked up, the recipes are in the 10Ring at Glocktalk.


Not open for further replies.