10 mm loads in 40 S&W!?

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Onty

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My apology for this silly question, but recent conversation with fellow shooter prompted me to put this question on the web:

He has one of those high tech 1911-s in 40 S&W and, out of curiosity (my knowledge about semiautos is miniscule, I am mostly in revolvers), I asked why he didn’t get 10 mm? If he wants Major load, wouldn’t make more sense to go with lower pressure 10 mm instead of higher pressure 40 S&W for the same power level. His reply was that used brass for 40 S&W is way cheaper than for 10 mm (very good point). And if he really wants full blast with 200 gr bullet, he can always grab proper magazine and the second barrel with longer throat, and load 40 S&W with powder charge and OAL of 10 mm. I asked about shorter case and reduced brass grip on the bullet, but he said that 200 gr bullet is long enough so this is not the issue.

Well, I am puzzled and any enlightenment will be welcome…

Thanks!
 
10mm brass is about five times the price of .40.:eek: Also a .40 to 10mm conversion will likely only require a barrel and recoil spring, the mags are good to go. For a $300 barrel and $10 spring you get a second caliber. I would have to agree with your freind on this one.

Dave
 
Most of it is right except that I doupt he can load the .40 at the same OAL than the 10 MM even if he seat them very long. Even then , he will not get the same power or velocity than the 10 MM can produce. The .40 major is already stretching the safe limit of that case, pressure wise.
Whatever, it will be easy for him to get the barrel, recoil spring and proper 10 MM brass to enjoy two calibers. The 10 MM is much more powerfull than the .40 S&W and a better proposition if you want or need more hump, within published limits and safely.
 
And if he really wants full blast with 200 gr bullet, he can always grab proper magazine and the second barrel with longer throat, and load 40 S&W with powder charge and OAL of 10 mm. I asked about shorter case and reduced brass grip on the bullet, but he said that 200 gr bullet is long enough so this is not the issue.
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I doubt that can do that safely; .40 case isn't long enough.

The truth is there aren't many 1911s in 10mm IIRC only two; Kimber and Dan wesson (which is not in production)
 
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IM_Lugger said:
I doubt that can do that safely; .40 case isn't long enough.

The truth is there aren't many 1911s in 10mm IIRC only two; Kimber and Dan wesson (which is not in production)
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Yes it is. I did just that using 180 and 200 gr plated bullets in .40 brass loaded to 10mm length. My gun was a custom Caspian using an STI bull barrel (ramped)

The barrel throat had to be relieved, but it worked fine. I had no need or desire to load anything higher than a 180Pf, but .40 brass held up I suspect better loaded long than the equivilent load with a normal OAL. Only sacrifice was more powder per case.
 
IM_Lugger said:
I doubt that can do that safely; .40 case isn't long enough.

The truth is there aren't many 1911s in 10mm IIRC only two; Kimber and Dan wesson (which is not in production)
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Not quite. Got a Colt Delta Elite sitting here factory chambered in 10mm with a spare barrel to swap it to 40S&W.
 
Anyone have a .40 barrel they'd be willing to part with for a song & dance? 10mm is EXPENSIVE, and I want something cheaper to feed my Delta... it never came with the second barrel since i bought used.
 
Grizz Axxemann said:
Anyone have a .40 barrel they'd be willing to part with for a song & dance? 10mm is EXPENSIVE, and I want something cheaper to feed my Delta... it never came with the second barrel since i bought used.
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'Willy1' had one for sale in the EE forums a while back for $95.00 shipped.;)

EDIT: I think it was for a Glock 20.:redface:
 
Most IPSC shooters who are "serious" about shooting 40 in a 1911 based gun have throated barrels and load to 10mm lengths or close. Its not difficult or dangerous... UNLESS you try to run those same loads in a pistol that hasn't been throated to accept them. THEN you're going to have an unfortunate experience.

So to make clear it is very possible to load 40 to 10mm lengths, but only do so if you KNOW your pistol has been modified to accept the load (this requires a gunsmith). Otherwise you're looking at the same situation as having a rifle bullet jammed on the lands - pressure goes through the roof.
 
The above advice is great. The following is a bit more background info.

The 10mm case is designed for a maximum pressure of 53,000 cup, but the 40 S&W case was designed to a lower pressure.

SAAMI max average pressures (psi) are
40 S&W 35,000
10mm 37,500

The 10mm case is substantially stronger and if you load 40 cases to 10mm pressures, they will not last very long.
 
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