The future of 10mm

[Mike_Fontenot]

[...]
The culprit is relative initial case capacity.
[...]

Thanks.  I understand your point.  And thanks for that specific data on case-volume comparisons.  I would suspect that there might be some "wiggle room" in that effect by trying to use a mix of slow and fast powders, so that some burning continues during the bullet's trip down the barrel.  But maybe there are reasons why that isn't achieved ... perhaps because most ammo probably needs to work OK in snubbies.  Or maybe it's just hard to get consistency and stability that way.

At the other extreme is the simple calculation you can do by assuming that the pressure stays constant at the max-spec pressure during the whole trip down the barrel.  Of course, this would never be even approximately achieved in real life, for multiple reasons.  And even if it could be, the extreme blast as the bullet leaves the muzzle would probably upset the bullet trajectory.  But that simple assumption is useful to easily determine the upper limit to energy (even though the achieved results are nowhere near that limit).  By assuming a constant pressure, the force at all times on the bullet is just that constant pressure times the cross-sectional area of the back of the bullet, and the energy is just that force times the barrel length (or, more accurately, times the bullet travel length in the barrel).  The energy is always just the area under the force vs distance-down-the-barrel curve (a rectangular area in the constant pressure case, and a more complicated shape for the (real) variable pressure curve).  The constant-pressure calculation (at max spec) is what favors the 10mm vs the .357mag so much.

[sqlbullet]

I just did the math based on ma = F = pa

Using a hypothetical 180 grain load that chronographs 1350 fps at the muzzle, and using standard units I get a calculated muzzle velocity from a 4.6" barrel of 1,382 fps.

Bullet mass = .000888028 slugs
P₁ = 37500, P₂ = 3251, P_avg = 20,375
Area = 0.126289085 sq inch
Time in Barrel = 0.000493827 seconds

This gives us a theoretical velocity of 1430 fps, or basically 80 fps lost to friction.  That seems to check out pretty good actually.  Physics works...who knew.

[Buckeye 50]

Interesting.........  but perhaps    maybe you guys have too much time on your hands?   


Excellent analysis though.


Pat

[sqlbullet]

No, I don't.  That was a very quick and dirty, which is partially why I was surprised it worked out so well.

There are a bunch of factors I ignored, and my average pressure calculation is actually quite frankly wrong.  The pressure drops geometrically, but I treated it like a straight average.  But, I make up for it my not applying a correction factor for friction, loss of energy via heat, the rotational acceleration due to the rifling.  And it appears to balance out at least in this case.  If I had a bunch of time I would be working on a spreadsheet that would run this for a variety of different cartridges to see how well it applies there.

[cwlongshot]

Well, personally speaking,  I don't think its going away. I agree I feel its actually seeing a uptick not a big one mind you, but indefinably better, couple new makers offering it as well as new guns offered...

BUT If it does, I am stocked with brass and guns to keep me happy.  

CW

[REDLINE]

I believe;  Growing.  10mm ammo and firearms options are still on the rise.  I think it also continues to rise in popularity for woods carry as an alternative to heavier big bore revolvers that hold a much lower round count.  One guy I know bought a brand new 10mm firearm last week after I filled him in on the details of the 10mm Auto.  He had never heard of 10mm Auto before I talked to him and he is "a gun guy".  Another fella I clued in will have one as soon as he can get the funds together for a purchase.

The biggest issue I see at this time and since the beginning are some of the big ammo manufacturers (Remington, Winchester, Federal, Speer,.....) not getting on board with many mid-range or for that matter full-house 10mm loads.  The 175 grain Silvertip load by Winchester is the most popular offering that comes close to full-house but still isn't full power regardless.  If they would come around, especially in loads they market as "self-defense" loads, I believe it would be a big boost for 10mm Auto firearms and ammo sales.

One reason way too many gun enthusiasts shy away from 10mm Auto are the mistruths and lies floating around about it.  I think if most of that nonsense was cleared up once and for all the 10mm community might double and then some almost overnight. 

All in all though I'm happy to see 10mm as popular as it is and seemingly to me still growing in popularity with much more room to grow yet.  There are just so many people out there that don't even know of it that would own it if they did.

[The_Shadow]

One reason way too many gun enthusiasts shy away from 10mm Auto are the mistruths and lies floating around about it.  I think if most of that nonsense was cleared up once and for all the 10mm community might double and then some almost overnight.

Redline, glad to see you on.  Your statement about the mistruths has put many people off on the 10mm guns.  That and the continuous brainwashing in every publication that boast 1911 this and 45 that as being the "Holy Grail" all the while shying people away from the 10mm. 

One of the reasons our forum exist is to educate people about the 10mm guns as used by real people who actually bought and paid for them (not some loaner gun).  The 10mm ammo that we buy, load, shoot from these guns are our real experiences and not something you get from a magazine designed to sell you other products. 

The pull-down documentation and preservation section on this forum, has shown what is inside the ammo and what makes it go like it does.  While I pride myself for doing these, it is the people here, that shared the ammo for the documentations for study that make it possible for us the learn what exactly is being sold as purchased.  It was Intercooler that pursued his quest of what was inside and him pushing me to do the documentations that kick started this snowball rolling!  It was not something that was done on any of the other forums and it does set our forum apart having this information.

Many of us here had also been active on the 10mmTalk and GlockTalk forums and a host of other forums, to educate ourselves and others as we continue to share our vast wealth of knowledge all things 10mm.  Long 10mm live and grow with the introduction of new firearms chambered for the ballistics, power, and flexibility that this cartridge has to offer!

[gmerkt]

Nothing scientific, my own observation is that I see more 10mm stuff lately.  New Colt 1911 stainless DE, other 1911's, but many more Glocks in 10mm.  I think Glock has some credit due in the matter.  10mm brass found at the range used to be rare; not so much now.  And usually with a distinctive Glock primer imprint. 

[cwlongshot]

Nothing scientific, my own observation is that I see more 10mm stuff lately.  New Colt 1911 stainless DE, other 1911's, but many more Glocks in 10mm.  I think Glock has some credit due in the matter.  10mm brass found at the range used to be rare; not so much now.  And usually with a distinctive Glock primer imprint.

Most of the brass I get now was likely fired from a H&K. The fluted chambers leaves burn marks on the brass...

CW

[45BBH]

I think it will maintain its current position for a while, not too sure if I really see popularity growing unless you start to see major police departments switching over to it and the big 3 ammo companies producing viable self defense loads for it.  Because it lacks those things I do think the .40 is a better choice for the majority of people, plus when loaded warm, a .40 is only about 100 fps slower than a 10mm of equal barrel length...that's not much difference.   I like the 10mm but it's still not that popular and it's only really gained it's popularity since velocity/energy sell guns and many promote the 10mm like it's unbelievably powerful, which isn't true.  I mean how many times do you hear people say they expected the 10mm to recoil like a .44 Mag?? Seriously?!!! It goes to show you that many just don't know that they're talking about and can be fairly easily sold just about anything.

[Mike_Fontenot]

[...]
Because it lacks those things I do think the .40 is a better choice for the majority of people, plus when loaded warm, a .40 is only about 100 fps slower than a 10mm of equal barrel length...that's not much difference. 
[...]

I carry some 10mm Underwood JHP's that have energy in the high seven hundreds of ft-lbs.  I don't think you can find any .40S&W anywhere near that.

[The_Shadow]

One thing I see is the ammo companies trying to make the 40S&W loadings as hot as they can for the most part.  Pushing the limits of cartridge and firearms.  Powders being used are interesting as well, some being made by other companies than their own.

[sqlbullet]

...plus when loaded warm, a .40 is only about 100 fps slower than a 10mm of equal barrel length...

This is true only for light bullets.

By the time you get to 180's that difference in velocity has grown to 200 fps +.  And the 10mm keeps going up to 220-230 grain with very usable velocity, where the 40 S&W is just plain out of gas even with 200 grain bullets.

I have the opposite feeling.  Due to the larger initial case volume you can download muzzle blast faster than than velocity, which makes for a milder feeling gun.  Also, the longer action soaks up more momentum before it has to be managed as recoil and muzzle flip.  Finally, most 10mm ammo that general Joe public will buy is "practice" velocity that is mild, where as most 40 S&W ammo is loaded "warm".

I think most 40 S&W owners would find a 10mm far more enjoyable at the performance envelope their ammo performs.

[cwlongshot]

I like the 40, I feel it gets less respect than it deserves. But its no equal to the 10mm.

As stated some makers are indeed pushing the envelope with it, even offering a +P version. ??

I like my 40s with a 135-155 gr bullet and my 10MM at 180+. As stated the powder cap of the 10 wins out as weights increase and the smaller 40 simply don't have the displacement for the heavier slugs. Same story with the 40's offspring the 357SIG it will match the 357mag but ONLY with the lightest slugs, for the same exact reasons.

CW

[blaster]

I think the 10mm is increasing in popularity. especially among hunters. as mentioned above, it is a viable alternative to a heavy magnum revolver. if I wen't to Alaska I still might carry my .44 mag. but I have heard of a few locals up there who pack a 10mm instead of their .44s. anywhere out of big bear country it is plenty of gun for woods carry. I'm going to my camp in the morning and hope to try mine out on some hogs.
when I bought my Witness last Feb., my local gun shop could not find one thru any of his distributors. I looked on line and found only one! after I ordered it, i went back on their sight and sure enough, sold out! I probably bought the last available  Witness Steel  in the whole country. I almost thought i was going to have to get a Glock!