Just purchased a Caspian frame, custom ordered Caspian slide, several parts. All in stainless steel. Does anyone have some good suggestions on this build that has done it before? This would be my first. The frame and parts will come in tomorrow and the slide is 3-8 weeks out. Thanks in advance!

P.S. This is the commander style in .45acp. What mags would work in it?

Call Aaron @ Tripp (877.837.9445) and order one Gen II Cobra Mag. Tell him what you're building and let him explain what options you have. (7 vs 8 round, welded base, poly bumper or alloy base.) I'll make you the same offer I have made to those who ask for a mag recommendation; If after you evaluate the Cobra mag and still are not convinced its the best 1911 mag out there, I'll buy it from you including shipping.

I've tried them all and after the Tripp's I have never looked back.

From an earlier post;

By a magnitude!

http://i695.photobucket.com/albums/v...DSCF1433-1.jpg

From L to R; Tripp Cobra, Wilson 47DOXB, Wilson ETM 500B, Tripp Cobra

Find the weld on the Tripp.

http://i695.photobucket.com/albums/v...DSCF1437-1.jpg

From L to R; Wilson 47DOXB, Wilson ETM 500B, Tripp Cobra

http://i695.photobucket.com/albums/v...DSCF4314-2.jpg

Notice the fluid stampings of the Tripp mag on the left and right. The .45 case head sits square against the back wall of the Tripp mag, the Wilson is rounded and forces the round forward when it presents for stripping. AND, the Tripp mag feed lips are CNC finished.

http://i695.photobucket.com/albums/v...gs/TvW-1-1.jpg

This photo shows the slide stop interface. The Tripp mag on the bottom uses a hybrid follower with a metal interface where the Wilson on top uses a poly follower interface. The Wilson shows witness-marks where the slide stop engages the mag when empty. This mag is six month old and speaks volumes as to this critical area.

As a retired engineer, this is how my mind works while looking at new products. When a company makes guns and mags that go into them, the mag becomes an area where they can cut production costs. When the company only makes mags, their entire R&D budget is used on mags. Think about that!

If your 1911 mags have poly followers be sure to check them each time you load. Should this area wear out, your slide will not lock open when empty!

You asked Dave, and I answered with the reasons why I only use Tripp Gen II Cobras for carry!

Do I need officer or gov't mags for my commander?

Government mag.

The Government and Commander both use the full size receiver.

The Officers, Defender, New Agent and CCO use the compact size receiver.

Order Kuhnhausen's books on the 1911.
Have plenty of refreshments
Have plenty of patience.

My brother in law did the smithing on my Caspian, there are few things that may require some machining. Here's mine it's a full size Government Series 70 so it has a very nice trigger compared to my Colt or Remington but their not bad but both are Series 80. I have the Caspian Commander slide and receiver in my wish list.
http://i186.photobucket.com/albums/x.../SAM_1130a.jpg
http://i186.photobucket.com/albums/x...p/SAM_0879.jpg

Canebrake, I just bought a colt mag for it to start off. The colt mag looks very similar to the Tripp mags. I will look at getting one or two after I finish.
Danf_fl, I just added the book to my cart for my next order from Brownells.
Rjgnwdc, I have already had to file some pieces to make them fit. Such as, mainspring housing to frame pin hole, trigger, and grip safety. On the grip safety, I have filed a lot of steel off to fit. On the back of the frame, the tail is kind of pointed, was yours? I have yet to hear anyone with this.
How hard is it suppose to be to put the mainspring housing to frame pin in? That spring is 23#s. Is that too high and I should cut a little off, or fine. I am wanting a trigger pull between 3-4.5 lbs.

For some extra bucks, you should have ordered ED Brown's CD, too. There is info on how to fit a grip safety, aftermarket trigger, and more.

Never cut a spring. If you need a reduced rate, buy one. Kuhnhausen has spring rates in his books.
The trigger pull is a combination of sear spring, sear mating with hammer, disconnector resistance, hammer resistance, sear resistance, and main spring. Pins for the hammer and sear should fit with no slop but not tight that they do not allow movement.

Keep us informed on your progress.

This is it so far. Staked the plunger tube, fitted the mainspring housing, and fitted the sear/hammer. I also removed one link from the 23# mainspring. I could not get the pin past the pin retainer, even with a hammer. I still had to tap it with a hammer, but it actually went in this time. (hint: never compress the mainspring with a semi-sharp object. Stabbed myself right in the webbing between two fingers. Lesson learned.) I found these grips at my lgs and had to snatch them. The mag I have feels kind of loose/long, meaning it wiggles a little when it is inserted. Does that do that just because there is no slide on it?

That could be loose without the slide. Mag follower is not pushing against anything.
Reminder: Do not drop the hammer without having all parts (including slide and slide parts) installed.