CS40 Conversion To 10MM

[JohnHL]

CS40 and CS45 magazines have the same exterior dimensions.

Swap slide, barrel, and magazine and the CS40 is now a CS45 and vice versa.

One of the reasons I like my CS40/45 so much!

John

 

[oldman10mm]

CS40/CS45 mags are externally dimensionally identical. The CS40 is modified internally.

 

[BLUEDOT37]

That's cool!

Too bad S&W figured that one out too late in the game.

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[oldman10mm]

That's cool!

Too bad S&W figured that one out too late in the game.

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???

They did know that ! They created the CS40 from the CS45 platform.

 

[BLUEDOT37]

Yes I understand. What I implied, but you must have missed, was too bad they didn't do that earlier on other models, ie, make the mags/magwells the same size.

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[BLUEDOT37]

Reamer & Go/No Go gauges

Measured from the rear of the tab to the chamber mouth, that's correct. Keep in mind though, your measurement with the depth gauge will not be as accurate as when measuring using the proper drop in chamber gauge set.

With the Go/No Go gauges it more fitting, than measuring.

Ream the 40 S&W chamber until you can just fully seat/lock the barrel smoothly into the slide with the Go gauge (nominal .9920" long) inserted, but the No Go gauge (nominal 1.0040" long) will not allow it.

On my 4013 barrel the top of the Go gauge was about .002" below the end of the hood, when inserted into the newly reamed 10mm chamber. The No Go gauge extended beyond the end of the hood.

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[tlawler]

EAA....Grrrrrr

Right now, I'm still playing with my Mauser M2 10mm conversion. I figured out the .40 mag followers were binding and I couldn't get more than 8 rounds to feed properly, so I swapped in a follower from one of my EAA Witness 10mm mags and it took care of the problem...hand feeding anyway; I still need to get to the range and try it out live fire.

Ordered some mag followers and other stuff from EAA a week ago. They charged my card almost immediately, then I get an email this morning that they were "just preparing" my shipment and happened to notice that they didn't have any mag followers and didn't expect to get any in stock maybe ever. But they would ship my other items pronto. The whole reason I placed the order was for the dang followers. I said don't bother and refund my money pronto. This is a company that is right across the state from me and they're just now getting ready to process my order a week after I placed it? I'm sure I'll have to wait a couple of weeks for a refund. *end rant*

On a better note, I did find a source for the S&W 3rd gen buffers, even though they're discontinued, and ordered three of them. The company is in Miami and I got those a couple of days ago. Just waiting on the spring from Numrich...Oh, and I found another CS40 locally. It's DAO and hasn't been shot much and it came with 4 mags! All for $475. My plan it to ream one barrel, so I'll have 10mm and .40 capability in either DAO or conventional DA.

Update: got home and my springs were here. I thought I had gotten them from Numrich, but it was actually Midway. I ordered a 22# and a 20# P239 spring. I took down the DAO and put the 22# in it. Wasn't hard at all, and racking the slide isn't too hard, but noticeably stiffer. I got the 20# because it was mentioned too and if I don't use it in the CS, I still have a P239 that could use a new spring. Haven't tried a buffer yet. I might do that tomorrow.

 

[BLUEDOT37]

1013 Mag Followers

It's done, and finally got to the range today for the first shots with my 10mm converted CS40 today...
I used followers from the S&W 1076, but had to cut the sides down a bit to clear the 'humps' near the top of the CS40 mags.

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Question on gutting the magazine:
Is the follower the only thing you cut down on the sides? The hump at the bottom rear of my magazine keeps the 10mm follower from fitting. Does this get ground off? I do not see any weld spots on the inside of the magazine.
Any info is appreciated!

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For those converting the 4013, 4053, I remember having issues with the crimps on the sides of the magazines that secure the spacer interfering with the follower. Had to take a pillar file and remove some material off of the protrusion from the inside of the mag body in order for the follower to work smoothly.

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Since this thread has ended up with related info on converting both CS40s & 4013/4014/4053s I'll add this item from my recent 4013 conversion:

On my initial test firing, after reaming the spare 4013 barrel I got from Numrich & modifying the 4013 mag, I had two times where the slide did not lock back after the last round was fired.

Apparently I missed some of the previous notes on using the 1006 followers in the modified 4013 (1013) mags. Some semi-related work on a second 4013 I just bought had me noticing the differences/revisions in 4013 followers & it dawned on my to look closer at the position of the 1006 follower in the 1013 mag.

First off, two things, the mouth/opening of the 1006 mags are are slightly wider than the mouth of the 4013 mags. The depth & width of the lower bodies are the same. Secondly, the notch/opening on the left side of the followers (where the follower pushs up on the slide stop's arm) are slightly different too, the 1006's opening being longer vertically (distances "A" & "B" noted in my attached pic).

So the 1006 followers go freely to the top of their mags but the 1006 followers are too wide to go freely to the top of the 1013 mag (see attached pics).

S&W apparently saw a similar issue (?) on the 4013 mags & revised them to have a slight chamfer to the top left & right sides (notation "C" in my pic), because of the rebated lips on the mags, to allow them to freely feed to the top.

(Note: the 4013 mags evolved, as typical of others, & there are several versions. I used the ones without the additional vertical indention to hold the top round.)

The 1006 followers are ~.440" wide across their top while the 4013 "chamfered" followers are ~.390". By carefully chamfering the corresponding points on the 1006 followers (notation "D" in my pic) to ~.400" wide the (1013) follower will freely go to the top of the 1013 mag.

Without this full range of movement the follower can't forcefully push up the slide stop to consistently lock the slide back on the last round irregardless of spring force.

I chamfered mine by first making a reference line ~.170" down from the top of the follower to give it a similar chamfer (notation "C" & "D"). I used a low speed Dremel mini-sanding drum & a small long nose Vise-grip plier, loosely clamped in place, to provide a guide & restrict where I cut. I later used a small fine cut file to smooth out the surface.

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On my mag I was able to use a 1/4" chisel to separate the spacer from the back of the 4013 mag & it just popped out as I carefully drove the chisel deeper. The spacer appears to be held in place by indentions, not tack welds, that were easily minimized to not interfere with the follower.

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[tlawler]

Took the plunge!

I finally finished gathering all of the bits and pieces I needed to complete the CS10, springs, buffers, go/no go gauges, etc. Decided to go ahead and do it over the weekend, despite several interruptions (I was on call and have needy teenage daughters with no transportation of their own). I now have two CS40s, my original TDA and a DAO I picked up locally a few weeks ago. I decided to use the barrel from the DAO because the caliber marking strike is noticeably shallower than the other barrel, so I figured it would be easier to fill in/remove when I get to that step. I got as far as finishing the reaming and fitting phase of it so far. Next, hopefully during the week, I'll get the spring and buffer installed and get to the range with it.
I started out slowly just like I did with the M2 and took just a few thousandths at a time, which amounted to about 10 to 12 180 degree turns with the t-handle. I would run a patch through the barrel from muzzle to chamber and measure after each set of turns. This way, I became consistent with how far I was going each time and felt confident I wouldn't overshoot my measurement. I checked the chamber with several .40 cases before I began and the rims ranged from .008" to .003" below the hood, so I knew where I needed to end up. I took it down to where the gauge was .005" above the hood and would reassemble the barrel and slide on the frame and check lockup. The difference between not locking and locking was only about .001". I stopped when I was either flush or maybe .0005" above the hood with the gauge, but three different cartridges I tried were .002" to .004" below the hood. In the first two pictures, you can see where it would almost go into battery, but it was evident from the guide rod protruding that lockup was incomplete. Next two show full lockup. I'm using CS45 mags and easily hand cycled two full mags through it. I can't wait to go out and try it!

 

[tlawler]

Here are a couple more pictures showing the go gauge at various depths. Last picture shows my ending depth. I stopped when just short of what the final chamber depth will be so I can go by ten thousandths until I get it exactly where I need it to be.
As a side note, I found another Mauser M2 .40 that I plan on converting and giving to my son in another year and a half when he turns 21. He loved shooting the first one I converted, and I'll be able to play with it a lot until then. They are really fun guns to convert and shoot. And accurate and CHEAP too!

 

[tlawler]

I contacted Tony South at Micro Precision Welding and got a quote of $35 a barrel plus shipping to fill in the caliber marking.

 

[themissingwhisk]

Great post, tlawler! It's threads like these, those that add some closure and that follow through all the way to the end, that make this forum what it is. Thank you!

 

[tlawler]

Installed the buffer and 22# spring. I should be all ready to go. I might take it to the range tomorrow since I'll be driving right by the big outdoor range at the WMA on my way home. If not then, definitely this weekend.

 

[tlawler]

Got it to the range this weekend for a test. Although it didn't go as well as I had hoped, it was encouraging. I loaded 100 rounds with 7.5 gr of bluedot, since I wanted something without a lot of power. I probably should have brought some factory too, but didn't, as I was pressed for time dealing with my daughter's upcoming prom(I can't wait till she gets her license!) I could run 3 or 4 rounds through a full CS45 mag, then the 4th or 5th round would fail to fully chamber. I'd clear it, put another full mag in and same thing. I noticed that the round I'd pull out of the chamber would have a nick just below the tip. I manually cycled a few rounds and noticed as I'd get a few rounds down into the mag, the rounds would skew left and get nicked on the left side of the barrel and maybe the loss of momentum would cause the out of battery condition. Do I need to reshape the feed lips of mags, or possibly make other mods to them? I have a few 10xx white followers that I thought I'd try out. I've been re-reading BLUEDOT37's 4013-1013-1016 thread and came to the conclusion that it is most likely magazine related. I would have liked to tried some factory ammo to discount my reloads as a cause. I did notice I can't lock the slide back with the buffer installed. I took the buffer out after the first two mag attempts, to see if that had any bearing on it. The buffer fits well, but I'm thinking it may be too thick since it's made for a full size 3rd gen. I'm going to shave it down a little thinner in small increments to see what kind of effect that has. Shooting wise, it did well. Accuracy was about the same as it was with .40, which was really good. Case ejection and feed(at least for the first couple of rounds) seemed normal. Stay tuned...

 

[BMCM]

My advice for what it's worth....

First of all, lose the buffer. That little plastic sphincter is of absolutely no benefit and induces short stroking. I contend that a gun properly sprung has no need for a buffer at all and I would never, and I mean NEVER use any arm equipped with a plastic buffincter for any serious purpose.

The principal wear area in these little aluminum frame 10mm conversion guns is the frame's camming lugs where a buffer has zero effect. This lug wear is common among all the aluminum frame guns regardless of chambering. That's why it's so important to keep healthy recoil springs in these guns. While an all steel pistol can tolerate a weak recoil spring without self destructing, an aluminum frame will be chewed up at the camming lugs in due time.

Every time you fire, the slide & barrel travel together rearward rather briskly about 1/8 inch until the barrel is halted by the camming lugs in the frame and tilted downward unlocking the breech. The frame will wear out at the camming lugs long before any battering at the impact abutment becomes an issue. and I reiterate, a buffer has zero effect on wear at the camming lugs.

Ejector...
You'll want a p/n: 230190000 ejector in there. This part is common among all the 45 & 10mm guns. The 40's often have a longer ejector in there, either 234340000 or 237400000 which can cause issues clearing the chamber as stuff (brass & live rounds) tend to catch on the barrel hood. This would be further compounded by short stroking due to a buffer in the gun.

Magazines...
I don't recommend messing with the feed lips. Fresh springs and a properly tuned 10xx white follower is all you should need.

From your description, I assess your recent feed problems due to short stroking with underpowered loads. In this case I envision your slide is halted and on it's way back into battery almost before the magazine can lift the next round and present it before the breechface.

Recoil Spring...
You'll want the measure the gun to insure there is sufficient space to allow full travel of the slide without stacking on the recoil spring. You slide should be brought to a halt by landing on the frames impact abutment under spring control. If the spring is too long for the gun, the slide will impact on the spring once it has compressed solid. This will quickly weaken and wear out the spring in addition to short stroking the slide. If you like, PM me and we can get on the phone and I'll walk you through how to measure the gun and adjust the spring if necessary.

Cheers
Bill

 

[BLUEDOT37]

I agree, that load (of slow powder) would be a light load even in a 40S&W, worse in the 10mm case. I used (3) levels of Power Pistol loads in mine to get a feel for how things were operating; 7.5gr to start, 8.5grs as mid power, & 9.5gr as a full load (on a 10gr. max.) with a 165gr JHP.

You can go the measurement route like Bill mentioned but I've always found I can tell by fully racking the slide rearward by hand, listening & feeling the difference in doing it without the barrel/spring in and with them in.

You can also pencil mark a reference point where the slide stops, fully rearward, without the barrel/spring in & compare that to where it stops with it fully assembled.

If it bottoms out on the spring it'll be a dull metallic sound, & feel, but will be sharper & clearer when it bottoms out on the frame abutment.

Don't know what magazine spring you used but a 10xx mag spring would give you more power in that short mag. Just cut a turn off at a time to get the fit wanted.

What recoil springs are you using in it?

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[tlawler]

What recoil springs are you using in it?

A 22# Wilson Combat flat wire spring. The same one listed in the original post.

 

[tlawler]

Another range report...this one much better.

Got the CS10 back out to the range today. My son is down from college, so we took it and my pair of 1006's for some range fun. At the suggestion of BMCM, I gave it a good lube job with some heavy molybdenum disulfide grease. I ordered a new 4516 ejector also, but opted for the cheap and slow shipping, so I haven't received it yet. With only the lube job, 22# Wilson combat spring, and a few CS45 mags retrofitted with 1006 white followers, I started getting much better results. I had loaded up the rest of a bunch of 180 grain flat points over 10.0 grains of blue dot as well as about 150 Hornady 180 grain HAP(not sure exactly what they are, but look like critical defense HP's) that I bought off of a guy on Florida Gun Trader, also over 10.0 grains of blue dot. Interestingly enough, I was getting much better feeding from the HP's. We both shot several mags that ran all the way through and locked back properly when empty. The only failures we had were failure to go into battery, and those were nearly exclusively with the flat points when one would glance off the left side of the barrel hood near the end of the mag. All together, we put more than 200 rounds through it with a total of maybe 10 or 12 hiccups. Not nearly the reliability you would need for a carry weapon, but I'm getting more hopeful. Next up is installing the 4516 ejector and I'm going to convert just one of my CS40 mags and try it to see if it has any effect on my flat point feeding issues. Also I'll install some heavier cut down 1006 mag springs. Stay tuned...

 

[tlawler]

Hmmm...a conundrum!

I received the ejector late yesterday and disassembled the CS10 this morning to replace it. After I pulled it out, I realized it was identical to the new one. I double checked the numbers and on brownell's site it is listed as a 4516 ejector. Could someone have changed it in the past, or did some of them come with the shorter ejector installed? One things for sure, I'm learning a whole lot about the disassembly/reassembly of 3rd gen semis as a part of this exercise.

 

[BMCM]

You're good... that 23019 part is the correct 10mm ejector also found in all the .45ACP guns among others. You just needed to make sure that's the part you have in your CS10. The longer ejectors (two part numbers) often found in the 40S&W guns can cause ejection faults. You have the right one and now a spare

Cheers
Bill