I own a full size M&P9, looking to pick up a compact now. Should I go 9mm or.40 ccal?

I would stay with 9mm.....

 

Not really a fan of .40

I would also suggest staying with 9mm.

9mm

Commonality of ammunition and magazines. Go with the 9mm.

9mm for sure. There is nothing a .40 does that a 9 won't, other than cost you more and give you more unnecessary snap to deal with.

I have a Shield in 9mm and a full size M&P40. I say go for the 9mm.

 

The biggest reason (although a bit silly) I got the 40 was the standard magazine held 15 which isn't an issue for your compact. My secondary reason is I feel I have more room to fiddle with reloading recipes for IDPA with the larger .40 case. It's easier to make power factor with a 180gr pill and some fast powder than a 147gr or even lower.

I have a Shield in 9mm and a full size M&P40. I say go for the 9mm.

 

The biggest reason (although a bit silly) I got the 40 was the standard magazine held 15 which isn't an issue for your compact. My secondary reason is I feel I have more room to fiddle with reloading recipes for IDPA with the larger .40 case. It's easier to make power factor with a 180gr pill and some fast powder than a 147gr or even lower.

 

How do you like the Shield?

I like it a lot

This is what I did.

 

I picked up a used M&P40 Fullsize at the Bullet Hole a couple of years ago. I redid the trigger w/ the Apex sear, radiused/polished the firing pin safety and polished all trigger related contact points. Gotta say, the trigger is pretty nice now. Also bought an M&P 9mm barrel and a bunch of 15rnd 9mm mags. When I go to the range, I usually shoot 9mm. However, there are times, like now, when 9mm isn't the easiest to find and .40 is out there for purchase. While accuracy is not match (not many service pistols are), it is easily good enough to practice SD shooting.

 

Off all the .40's I've fired, the M&P handles the .40 the best (includes CZ75, Gen 2/3 G22, Gen 2/3/4 G23, Beretta 96, Sig P229/P226, HK USPF, XD40). Also, places like http://sgammo.com tend to carry government overruns of high quality HP for prices that sometimes rival FMJ prices. I've never seen those kind of deals on 9mm/.45.

 

I'm not trying to make the argument for the .40. While the M&P handles the .40 very well, I'm not that big of a fan shooting it. I prefer to shoot 9mm/.45. However, I like having a pistol that uses the same round as the majority of LEO's (local/fed), and that is available and on the shelves during political crazyness. Also, in regards to shooting it, I've found that if I go and shoot the .40 during multiple consecutive range sessions, I get used to it and don't find it as offensive. The downside is that the FMJ ammo is about $3-$4 more expensive per 50 rounds.

 

I've never fired the Compact model in .40, but was amazed at the minimal recoil in the 9mm model.