10mm Conversion Lab - C'mon in Y'all

Well, my 4566TSW project is on the back burner until I get some parts back from Houston so, I'll proceed to mess with some other stuff.

What we have here is a couple old 40xx uppers. As you can plainly see, one's a 4013 and the other a 4014.



Both are early versions with the fat 0.290 staked guiderod, one being aluminum and the other stainless with a single roundwire recoil spring.


Narrow barrel hood/tab and standard three dot low-mount Novaks.



What were gonna do here is turn both of these into 10mm pocket rockets. And along the way fix up a few more things; Lots of cleanup, new sights, cut for spring loaded decocker, sort out a new recoil assembly, and a bit of polish here and there. And of course re-chamber the barrels to 10mm auto.

First order of business, I'm going to see to the recoil spring setup. Big surprise... Were gonna use a ISMI spring I'm not going to cut up any factory parts for this so I'll be making the guiderods completely from scratch.

Now since the flatwire spring runs on a quarter inch diameter guiderod, I will need to do something about those huge holes in the end of the spring tunnels.

I know!... lets make some bushings.

I have a couple stubs of 416 stainless in the bin I think will do nicely. So lets dust off my little lathe and make some swarf.

Here's a piece in the chuck indicated to withing 0.0005". This is a leftover piece from the last time I made some bushings. I think I can squeeze one more out of this. I've already faced the part and turned the OD down to 0.427 to fit the 4013 slide.


Need to deepen that hole first. Spinning the part at 500rpm and using a 1/4" cobalt bit here.


Ramp up the speed to 1375rpm and cut the shoulder back seventy thousandths and reduce the diameter down to 0.297 to fit tight in the 4013 slide.


Got it cut to the right size so now we'll part if off the stub. I stuck a little piece of rod in the tailstock chuck and ran it into the stub to capture the part when it comes free. Slowed the speed back down to 500rpm and ran the parting tool in there leaving flange about .050 thick.


There it is.


There's not enough meat left on that stub to cut another one so I need to set up another stub to cut the bushing for the 4014. The dimensions on that 4014 are also a bit looser so I need the cut the bushing a couple thousandths larger in the diameters to get a tight fit.

Here's the second stub already indicated in and I'm facing off the hacksaw marks at 1375rpm.


A little more drilling.


Splash on some layout dye and scribe my reference line. This time I'm only cutting back sixty thousandths since the 4014 is about 0.010 thinner than the 4013 is at the front of the spring tunnel.


Gettin' there


Good enough, lets chop it off.


All done. While they look identical, the one on the right is a couple thousandths bigger in both outside diameters to fit the looser 4014 tunnel.


When installed it'll look something like this.


That concludes tonight's episode For the next installment well get started making the guiderods. Assuming my order from Mcmaster-Carr gets here.

Cheers
Bill

Yes! Yes! Yes! Yes!

Another BMCM pictorial step by step thread!!!!!!!!

<-------- runs and gets popcorn

I LOVE these threads!!!!!!!

Nice!

10mm pocket rockets. You HAVE to like this!

I love these swarf making threads

Way to go! I just set up my subscription to this thread, things were getting a little boring.

And, now that your geared and tooled up for the 10mm conversion; maybe that surplus 4013 slide & barrel (I want to have Melonite treated) that I have for a future 1066SSV has potential to become real.

What can, or do you plan to do anything with the barrel caliber markings?

Well, the barrel marking are a ways off yet but for safety sake I have been thinking how to go about taking care of that. Since this is a "NO Welding allowed" zone I believe the best option is to cross out the 40 with an "X" marking punch them move aft a bit towards the hood and stamp 10mm. In any event the barrels need to be clearly marked. Once the chamber is cut to 10mm, shooting 40S&W in there ist verboten!

So, an 1066SSV eh? Very cool Do I need to clear another spot on the bench?

Cheers
Bill

Glad to see you take on this project & documenting it for us!

You know this means we're going to have to start a "BMCM Lottery" with one lucky drawer winning this same conversion as the grand prize ??

.

BMCM said:

...Once the chamber is cut to 10mm, shooting 40S&W in there ist verboten!...

Cheers
Bill

Click to expand...

Um...aaaaactually...you can still shoot .40S&W out of a 10mm...
it just requires some serious brass brush cleaning of the chamber to remove
all the crud one builds up from shooting a box or three of .40S&W thru it

Until you clean it, not a good idea to try and chamber 10mm...
it just gets stuck...

In the interest of safety I'm going strongly to disagree with you there.

The only place where it's remotely safe to shoot 40S&W in a 10mm chamber is in a 610 using moon clips. And even then, once the chambers get dirty 10mm may not want to chamber fully until some cleaning is performed. Not so much a problem in a revolver but in a semi it's an entirely different matter.

Both of these cartridges are intended to headspace on the case mouth. Thus the only thing holding the case head against the breechface in a correctly cut chamber is the cartridge case itself.

Now consider when you load 40S&W into a chamber cut for 10mm Auto. The 40S&W case is 0.142 inch shorter than the 10mm case. What does the 40S&W headspace against? What keeps the 40S&W from falling 0.142" further into the chamber away from the breechface? What holds the 40S&W case against the breechface where the firing pin can actually reach the primer? Performing all those functions that it was neither designed nor engineered for is your pistol's extractor. I'd expect the extractor's lifespan to be greatly reduced and that's not something I'd want to gamble with considering the availability of replacement extractors these days.

The chief reason I say this is an unsafe practice is the possiblity of the gun blowing up in my face...
Say for example we shoot a bunch of 40S&W in our shiney new 10mm chamber. Now it's good and dirty, possibly with some gilding metal or lead or copper scraped off the projectiles on the way out and some firing residue built up in the chamber. Now were all out of 40S&W and decide to switch over to some 10mm Auto without thoroughly cleaning the chamber first. Well all that debris built up in the chamber has caused a short chamber or insufficient headspace condition. Insufficient headspace is a very well known cause of slamfires and out of battery detonations in self loading arms. Not somewhere I ever want to go!

I'm not at all saying this is how you treat or care for your arms. What I am saying is if we make it known and tell folks it's ok to mix and match calibers & chambers any which way as in if it fit it shoots, then sooner or later someone's gun is gonna blow up and someone is gonna get hurt or worse. And if we told that someone that it was ok to do that then we are at fault. or at least partially so.

In my view this is no different than shooting .380 in a 9mm parabellum chamber or 7.62Nato in a 30-06 chamber or .45GAP in a .45ACP Chamber. Just Dont!

So, I stand by my statement and re-iterate;
Once the chamber is cut to 10mm Auto, shooting 40S&W in there ist verboten!

Above all else...Safety First Gentlemen!

Cheers
Bill

The Gun Zone -- 10mm v. .40 S&W FAQ

Incidentally, I disagree with the author of the above article concerning the Springfield Omaga also. Please, if you can, name ONE 10mm autoloader manufacturer who states in writing that it's OK to fire .40 S&W ammo in a 10mm chambered autoloader. Just one will do!

Bruce

That's why I specifically mentioned cleaning it before switching back to 10mm...
Its the kind of thing one should only do in a serious pinch...

Kinda fits into the "just because you Can do it, doesn't mean you Should" category...
which I should have said after mentioning you could

I have trouble making things with Legos.

Hot diggety you-know-what!

Thanks, Master Chief, for treating us to another conversion thread!

[ame]https://www.youtube.com/watch?v=arZdeg_fL-I[/ame]

Interesting thread,...I can see why the step-by-step pictorials are popular. I've often considered doing this conversion to both the 4053 and to my Mauser M2 .40 which is another .40 built on a .45 frame that can well take the 10mm. But every time I look into performing the conversion, I wonder if there's an easier way.

For the record, I shoot almost no factory loaded ammunition whatsoever. Other than .22LR and military surplus ammo, all my shooting is done with personally loaded ammo. With that thought in mind, rather than the full conversion to 10mm I wonder if it wouldn't just be easier to long throat the .40S&W chamber, rip out the magazine spacer, and then long-load .40S&W to something closer to 10mm specs. I'm sure it would require at least the 180gr slug to do it, but that's what I'd be loading anyway. Continued shooting of standard .40 in the modified chamber would no longer be an issue and the long loaded souped up .40's wouldn't pose a danger in any unmodified pistol that couldn't feed them through the magazine.

I think it'd be cheaper to scrounge up a second barrel to re-chamber than have PTG or Manson grind a custom reamer to push the throat forward. Most of these conversions I've seen done took a lot less work than what you're gonna see here. I'm just doing it my way Why? because

At the moment we're waiting on my "care package" from McMaster-Carr to get here then we'll get rolling on making a couple new guiderods. Ought to be here tomorrow

Cheers
Bill

After personally seeing and shooting several pieces of Bills work and reading his threads, I'm convinced the Bill way is "the way" for things that go bang

Well, all my goodies have been delivered. Actually the order was split into two shipments and half of it was "ninja delivered" on my porch early last night. Anyway, I have everything on hand needed to resume work.

So next up we're gonna be making these parts. That guiderod measures 0.236" in diameter is the correct part for most any of the 3-3/4" barrel compact 45s ie. 4516-2, 4513TSW and several others. The guiderods I'm going to make will be a proper quarter inch in diameter.


The conical spring will be fairly straightforward I think. I found a part that is nearly identical and will just need tighten the coil on one end so it'll snap onto the plunger.


I decided to start with that little plunger thingy. Loaded up the "Caveman CAD software suite" and created this precision blueprint to reference while messing about on the lathe. Bonus, I can stick it to the wall behind the machine Who doesn't love post-it notes


That round nose on the end of the plunger measures at 5/64" radius. I have a radius turning tool however, I think I'll just do this with a file and check it with the radius gage instead of setting up the radius turner just for this little thing.


Over on the lathe I have a foot of 5mm Hardened & ground 416 stainless steel rod in the headstock. Getting that dialed in with the four jaw chuck.


Total indicated runout about 0.0003" That's three tenthousandths of an inch. Not bad

I'll be back later...time to make some chips.

Cheers
Bill

Picking up right where we left off...

Taking a cut to bring the OD of that 5mm rod down to about 0.176"


Now the that the diameter is right we'll put some layout dye on there and mark where the shoulder is to be. I line up my tool bit to that mark by eye then set the carriage stop so when turning I can simply run the carriage right into the stop with the power feed and not worry about missing my mark or overshooting.


This is the last cut here as we take off the last 0.008" to bring the diameter to 0.129"


Looks good to me


Spin the thing back up and after a little file work, we have our 5/64ths radius.


Now a little more dye and mark the rod 0.800" back from the shoulder. That's where we part off the first one.


Slow the machine down to 500rpm, apply a little bit of cutting fluid and run the parting tool in there briskly.


We're about one fourth complete making the plungers now.


Now loosen the chuck and advance the rod to make the next one. Once it's indicated in we repeat all the above steps. Here's plunger #2 about to be parted off the stock.


Now we un-mount the chuck and install a collet to hold the unfinished plungers. You can see there's some more dye and a new mark. What we want here is set back the shoulder 0.120" and reduce the diameter to also 0.120". But first I'll take a facing cut to clean up the end of the rod and wipe the little nub off there.


Almost there.


That looks good, but... it still needs a 45° chamfer out on the end.


I'll do that with a file too.


Clamp the other piece in the collet, rinse & repeat and we have two plungers that are 90% complete.


That little groove on the short end which retains the plunger spring is left to do yet. I'll grind a tool to cut that tomorrow. I just re-mounted my grinding wheels with some precision drill bushings in lieu of those cheap plastic nested bushings so I need the dress & true the wheels again before I grind any tools.

The plungers didn't come out half bad.


And...



I'll finish these up tomorrow then get going on the guiderods proper.

Cheers
Bill

wow......just blows me away