I got my 10mm conversion kit ($245 straight from EAAcorp.com) for my Witness .45 in on Wednesday and finally had a chance to take it out to shoot.  There was some concern, originally, since the slide to frame fit was tight! and the action would not run through smoothly.  Mostly I think this was due to the black permacoat of the slide being rough and sticky from the packing lubricant.  After cleaning the slide several times with MPro7 cleaner, and leaving it well oiled along the slide rails for the night (MPro7 gun oil), I took the barrel and spring assembly out and ran the thing by hand for about an hour until it loosened up.

The factory spring for the Witness is 14lbs.  Way too light for the 10mm or .45 rounds.  I use a 16 lb. in the .45 configuration and went with the 20 lb. from Wolff for the 10mm.  It was more than adequate to suck up a bunch of the recoil.  I should be getting a conefit guide rod from Henning Walgren in Colorado in the next few days.  The design increases the amount of surface contact between the frame and guide rod, to lessen the battering the frame takes.

Here’s a quick clip of me changing the .45 slide/barrel for the 10mm…

I shot a box of the Blazer 200gr. 10mm, which moves at about 1050fps.  Essentially, it’s a .40 S&W cartridge.  After that, I traded up to the 180gr. Double Tap hollow-points, which move at 1400fps.  Not much more kick, and delivers 717ft-lbs. at the muzzle.  Lastly, the Double Tap 200gr. with a velocity of 1250-1300fps, depending on where you’re reading the specs; 680ish ft-lbs. at the muzzle.  The last two cartridges are easily in .357 magnum to .41 magnum ranges.  A bit more jump at the muzzle on the 200gr., but nothing serious.  I can’t believe the FBI complained about the recoil on this cartridge in the 1980s.

Here’s what it looked like…

Here’s a pic of the Witness in his 10mm configuration:

Accuracy was on par with the .45acp at ranges up to 15 yards (I was more interested in function for this outing) — groups at 7 and 10 yards were in the 2-2.5″ range.  At 15 yards, a 10-round group was about 4″ without taking my time between shots.

I’m a fan of the Tanfoglios in .45, and now I’m delighted to finally have a new 10mm that works well.  The conversion kit system of the Witness is a nice idea for people looking to have multiple calibers on the same, ergonomical platform.