I already knew that this particular pistol would group better than I'm capable of holding and it's been tried with most factory JHP's as well as a number of handloads. The only thing I've found that this particular pistol will not reliably feed with over 5 in the magazine are 200-gr. CSWC's, a rather staple diet for my 1911's. With everything else that I've tried, feeding/extraction/ejection have been flawless.
Speaking only for myself, I still do favor the single-action autos, specifically the Hi Power in 9mm and the 1911-type in .45 ACP, but were I unable to tote a single-action by rule or departmental policy, I believe that in .45 ACP, the P-220 would be my choice.
I didn't have much time to do a lot of shooting with it today, but managed a few slow-fire groups using a rest @ 15 yards and some Failure to Stop drills were repeated on my hand-drawn "Gort" targets that I use for such. These were done from a low-ready, with the first shot being fired double-action. (In the 15 yard slow-fire, all shooting was single-action.)
My particular P-220 groups a bit better with Remington 230-gr. Golden Saber ammunition, but the Winchester RA45T feeds slickly and averages roughly 857 ft/sec from this gun and groups plenty good in my opinion for its intended purpose.
For me, the P-220 was easy to handle starting each drill in double-action. A fellow had a PACT timer and the average for these starting from a low-ready was under 2 secs for the three shots in each drill.
Though I still prefer the single-actions, possibly due to 30 years of using them, I greatly respect the SIG-Sauer P-220.
It is my understanding that newer versions of this pistol are now available, but I have no experience with them. I might have to change that, but for now this basic P-220 serves well.
If interested, here are some more observations and personal opinions on the P-220:
http://www.hipowersandhandguns.com/Sing ... matics.htm
Best.