why are so many commercial 10mm rounds so weak?

[glenwolde]

This is my understanding as well. D&D, the developers of the original Bren 10, shopped around for an ammo maker and Norma was the only one to step up. D&D spec'd 200 gr at 1200 fps fully expecting something like 200 gr at 1100 fps.

Only problem was Norma delivered on the original spec and the ammo gained a reputation of beating the guns to death.

I think that neglects Jeff Cooper, who was already working on the 10mm when D&D approached him for advice and they combined efforts. The design was Cooper's.

Cooper's original specifications called for a 200gr bullet at 1,000 fps.

 

[BillBro]

Does it really matter who developed it,and why, or when, or with who ( though I think Cooper should be recognized as the originator). Ive always disliked the 40s&w cartridge for my own reasons. The 10mm is a glorious round and I will continue to enjoy mine no matter the who, why, how or when of it. To me its as versatile as any other and more than others that can do many things well. A 135gr jhp at 1650fps up to a 200gr hst or GD at 1250fps and weights and velocities beyond those. Really? I know some 10mm hater will want to, have to argue semantics. And not every 10mm has an unsupported chamber and drops mags. My Dan Wesson Silverback has over 5 thousand absolutely trouble free rounds through it now and its a beast. It has never given me a single problem, and its stock except fir the occasional spring change for really stout loads.

I suspect all of the posters above are partially correct in how the 10mm came to be . All of the things being argued probably happened putting the 10mm round where it is today.

 

[Dave Lively]

Maybe one of the Peter Stahl guns.

Maybe not. The 10mm Springfield Omega I owned had Peter Stahl stamped on the slide but I cannot remember if it was rebranded or just used something Stahl patented. It broke twice before I traded it for a S&W 610.

To be fair I bought it right after the 10mm cartridge was introduced and like many early 10mm pistols it was a 45 with a different barrel and recoil spring, not designed from the ground up to be a 10mm handgun.

 

[44wheelman]

Sorry to hear the stahl gun was a dud. My brother had one, I thought it was pretty cool (at the time). Lots of better options these days.