Just wondering - would it be possible to convert a 9c to a 40 by changing the barrel and clip?

Nope. 40 barrel won't fit in the 9 slide without modification.

you might be able to buy the 40 slide/barrel/mags to fit it.

wdk535:

Most people will tell you to buy an aftermarket (Storm Lake) barrel when going from .40S&W to 9mm. You may be able to go the other way with their .40 barrel, but I can't say for sure.

(The .40 to 9mm thing is because the breech face on the .40 slide is a little different than the 9mm, and the Storm Lake barrel is supposed to allow better for that. Just repeating what I heard.)

Anyway, I'd call them, or a Storm Lake supplier (Brownells?) and see what they think. The magazines will interchange (you need 9mm mags for 9mm, .40 mags for .40!). IMHO, if you're going to buy a slide and barrel, you probably should just buy the whole gun.

I have put a 9C slide on a 40C frame, and vice versa, with their barrels and magazines, with good luck. Matching the breech face and the barrel is the key. However, the 9mm barrel and breech face are definitely different.

Regards,

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Stu.

Short of swapping the entire slide to a 40, there is no way to do a 'drop-in' swap from 9mm to 40. The tang on the barrel (the part that has the loaded chamber indicator hole) is wider on a 40 than a 9, so it will not physically fit in the slide. A factory 9mm barrel will fit in a 40 slide, since the 9mm tang is narrower, leaving a small gap on either side - some will argue this is bad, others insist that it functions reliably. A 9mm conversion barrel has the extra-wide tang of a 40 and thus locks up just like a 40 in a 40 slide.

Confused yet? You will be.....

You could always take the 40 barrel and grind down those tangs in order to make it fit into the 9mm slide. Some of the 9mm Shield owners have already done this.