P-12 Conversion Thread

[gandog56]

STI slide is already on the way.  Found one that a gunsmith had ordered and the customer didn't like and got it for $170.

EGW FPS is a must, plus a 25 lb mainspring to tame the slide.  Based on Ned Christensens testing this should put the frame batttering back in to the same realm as 45 ACP is.  Plan on a 20 lb recoil spring.

All Para frames are already cut for a ramped barrel.  The Clark/Para cut in fact   No frame milling required as it is already cut for the barrel I want.

I plan to build a whole new top-end, not re-using any of the 45 acp top end.  This will give me a multi-caliber set-up.

Magazine is the area that I see possibly being a real challenge.  I don't see a huge challenge on the feeding end of things, as the mags in my current P16 work fine and I expect/hope they will feed a commander length top end just as well.

No, the issue is the other end.  I will have to modify a magazine to get the right length.  Plan right now is to use a Mec-Gar body I have that has good feed lips for Para 40/10mm but a blown out base.  I plan to chop it to the correct length and rebend the bottom to properly hold the base pad.  That may prove to be a challenge.  Or not.  Just not something I have done before.

Hmmmm, my brand new Fusion Firearms 10mm came equipped with only a 20 pound spring, although they also provided me with some other poundage springs in case I needed to go higher. I haven't so far.

[REDLINE]

Hmmmm, my brand new Fusion Firearms 10mm came equipped with only a 20 pound spring, although they also provided me with some other poundage springs in case I needed to go higher. I haven't so far.

What claimed poundage are the additional weight springs they sent?  Ultimately I'm wondering if any of them are over 24#, as that generally seems to be the heaviest readily available for my G20.

[sqlbullet]

Hmmmm, my brand new Fusion Firearms 10mm came equipped with only a 20 pound spring, although they also provided me with some other poundage springs in case I needed to go higher. I haven't so far.

Are you talking about the recoil spring?  Generally this is the one that mfg include different strengths of, not the mainspring, AKA hammer spring.

[gandog56]

I was.....and I believe the heaviest 10mm recoil spring i have seen for a 1911 was 26 pounds.

[sqlbullet]

Wolff makes a 28 lb recoil spring for 1911's.  Way stronger than I would want on my gun.  I am a big believer in flat bottom firing pin stops and stout mainsprings before upping the recoil spring.

[gandog56]

Firing pin stops and stout mainsprings won't help you if your slide doesn't return all the way. Recoil spring will.

[sqlbullet]

If an 18.5 lb spring doesn't return your slide all the way, you have serious issues that need addressed in your gun.  If a round doesn't go into battery relatively easily, it shouldn't be forced.

[gandog56]

Correct poundage spring means I DON'T force it. And 18 1/2 is the LOWEST spring I've ever heard of.

[sqlbullet]

1911 springs for full size in a standard 45 ACP is 16 lbs.  National match guns with shoot target loads ship with two springs...a 16 for full power and a 14 lb for target loads.  Ace 22 conversions, 9mm, 38 super and the rare 38 special all shipped from the factory with 14 lb springs.

Wolff sells 1911 recoil springs as light as 7 lbs.

18.5 lbs (some say 19lbs) is standard for 10mm and 40 S&W, and is considered my most non-10mm enthusiasts to be a very stout recoil spring.  At 22 lbs most experts agree you are subjecting the slide lock pin and corresonding frame holes to some degree of battering that will eventually deform the frame.  May take several 100K rounds though, so most users don't worry about it.

[gandog56]

I'm talking 10mm, not .45 ACP.

[sqlbullet]

Armscor shipped their latest 10mm with a 16lb I believe.

[gandog56]

Only way for that is to have a slide that weighs less than normal for something of that pressure. Makes me wonder how durable they will turn out to be.

[dasatelliteguy]

Any more news on this conversion sqlbullet? I am planning the exact same thing myself and was curious how you made out? Would love to see more pix and details about what you have done. Thanks!