My Ruger Auto Pistol conversion Project

[Chev. William]

I have begun a project to convert a Ruger .22LR "Standard Auto" MKII Pistol to Center Fire and .25ACP Cartridge use.

The MKII Pistol was purchased used at the end of July 2018 and I received possession about two weeks later in accordance with California Laws and Regulations.

It came to me as a 4-34" Barreled pistol modified for target use with a Volquartsen molded Grip, with thumb rest and hand 'heel' support one piece wrap around.

This November I sent the Receiver-Barrel assembly, the Bolt assembly, a MKI 'takeoff' barrel for a measuring sample, a roughly 8" long Remanent L.W. Cr-Mo Alloy steel .25 Auto/6,35 Browning Pistol Barrel Blank, and my custom 'Straight Cylinder' Finish Chamber reamer with .2795' Body diameter to John Taylor Machine in WA for machining a new roughly 8" barrel and fitting it to my MKII Receiver.
John Taylor also said he would look into converting my Bolt assembly to Center Fire use.

John notified me via PM that he has assembled my parts onto his Grip frame and test fired my bolt, receiver and New Barrel.

John also reported he used Carbide End Mills to make the CF Firing Pin hole in the Hard Bolt.

Now I need to get onto the part of making a New Magazine to fit the Ruger grip frame and feed angle.
So far it looks like Beretta 'Bobcat M25' 8-shot or 9-shot magazines may be a good donor for my purposes. Probably need two or three cut up and welded together to make one long body Mag to properly feed and fit the Ruger Pistol as Ruger uses a Bottom rotating catch to hold the Magazine in the pistol, so magazine Length is critical to function.

Beretta "950" Model magazines also may be usable with the same length problems.

Both of these have a semicircular front edge and a square rear edge that will fit in the Ruger Grip frame.
A Beretta JM25 .25ACP Mag. with its more square front edge, does NOT fit.

Chev. William

[Petrol & Powder]

That's a cool project.

Is there enough room in the .22 magazine for a 25ACP cartridge? If so, it may be easier to change the shape of the existing feed lips on the Ruger magazine. If the Beretta 25 ACP mag is too fat to fit in the grip frame, you will need to open up the grip frame to accept a larger magazine. That means you have to fabricate a magazine and modify the grip frame.



Keep us updated, this sounds like a good project.

[Chev. William]

I have tried Ruger Pre-Mark, MKI and MKII magazines for .25ACP possible fit and none will accept a .25ACP cartridge because of the Body Contour full Length 'ribs' impressed into the Magazine sides to guide the .22 bullets and also 'trap' the Magazine springs in one part of the Magazine body.

A sample Beretta 7-shot .25ACP 'Bobcat' magazine fit 'easily' into the Ruger Mag. well and a Beretta "950" .25ACP magazine fits 'closely' in the Ruger mag well with the exception of the Base plate nose being too wide for the Ruger Well Mouth.

To my Eyes, it looks like I would have to either grind on the Magazine Base plate nose or Grind on the Ruger mag Well Base opening to get the "950" magazine to fit properly.
Perhaps I will buy a spare grip frame to experiment with. My Local Gun Shop does have a number of 'left over' Ruger Auto Pistol Grip Frames to choose from.

For Balance, I think I should stick with the Steel Ruger Grip frames and not use one of the aftermarket Aluminum Alloy grip frames available for the Ruger Auto Pistol.

Best Regards for Thanksgiving 2018,
Chev. William

[Moleman-]

The grip angle and consequently the magazine angle on the Ruger MKII is more than many other 22's. How does the grip angles of the Bobcat and 950 compare to the MkII? I wonder if a 22/45 would match the angles of the 25ACP magazines better.

[Mk42gunner]

I've been thinking about this magazine alteration off and on since I first read of your idea. Since you have identified a couple of donor mag bodies that can be altered to fit the well, the next big issue is going to be feed speed, i.e. does the magazine spring have enough stored energy to push the next round in place to feed in time for the bolt to strip it out of the feed lips?

I don't think the Beretta springs will work since it sounds like they will be too short. Maybe the Ruger springs will, and that is what I would try first; since it sounds like you will be using one for the base of your custom mag. It has been several years since I held a Ruger .22 mag in my hands, is the magazine spring a round coil or is a rectangular spring?

Robert

[Outpost75]

John is a skilled machinist and clever mechanic. I have greatly enjoyed the "Infamous Bunny Gun" and rook rifle projects he has done for me, as well as my James Bond Bunny Gun.

Attachment 230850

I look forward with great anticipation to reading about your conversion.

[Chev. William]

I have seen both Round coil spring (in the front portion of the Ruger Magazine) and Rectangular Springs (in the rear portion of the Ruger Magazine); so that is a possibility.

Perhaps also the Beretta Spring might work; as I will, due to California Regulations, need limit my Magazine to ten rounds capacity yet the overall length would allow a few more possible.
This would indicate a 'filler' below the Follower and Spring to limit the capacity, and an eight round Spring should feed up to ten rounds reliably.

Yes I will need to reform the Feed Lips and angle them to match the Ruger feed angle. That will need to be done BEFORE trim and Weld as the overall length is Critical to proper feed Position. The Ruger Standard Auto grip frame has the Magazine catch at the Bottom of The Mag. Well so it rotates to catch on the bottom of the Base Plate.

I am thinking that a Steel Form Block fitted to the inside of the Beretta Magazine body with the Ruger Feed lip inside contour and angle will work as a "Form Buck" in reforming the Top fo the Beretta donor body.

Then, a Copper Welding Block,. also fitted to the Beretta magazine body insides and made with the Ruger Feed lip angle and an overall length longer than the finished welded body. would hold the parts in alignment while minimizing the inside weld bead for TIG welding by an Aerospace qualified welding shop.

I used this process (Copper weld Jig) to make single stack .45 Win. Mag ten round magazines for a M1 Carbine conversion.
Each Magazine body weld cost $10 at the time.

Chev. William

[Petrol & Powder]

Could you cut the impressed "ribs" out of the Ruger .22 magazine so that there was greater width inside the Ruger mag ? That way you would still have the required length and the angles of the feed lips and base plate would still match the Ruger grip frame.

[dverna]

Could you cut the impressed "ribs" out of the Ruger .22 magazine so that there was greater width inside the Ruger mag ? That way you would still have the required length and the angles of the feed lips and base plate would still match the Ruger grip frame.

Exactly what I was thinking. If that would work it would be a simple modification

[Chev. William]

Petrol & Powder,
The Two ribs, one on either side, are deeper than the thickness of the side metal and extend almost the full length of the Magazine.
Internal width of the Ruger Magazine is about .250 inch which will not allow the .25ACP rim of .304"-.307" diameter to enter.

It is a Good start on a Magazine for .22 Ladybug-Repeater conversions.
Sadly, it does not look like a good candidate for a .221 Askins magazine either.

Chev. William

[Chev. William]

My Ruger MKII .25ACP barrel is completely machined and is going out for Bluing Finish.
I am Planning on sending John Taylor a second 'Installment' on the costs soon.

Chev. William

[NoZombies]

I'm looking forward to seeing how this works out for you, I've got little to add, but I'll be watching!

[FergusonTO35]

I LOVE weird projects like this. Eagerly following!

[rking22]

Same here, just so I can watch the proceedings!

[Chev. William]

the afternoon and Evening of November 30th I was able to use the Facilities of my Friends Special Effects shop to begin making the Jigs and Tools to remake Beretta 950 .25ACP magazines into ones that will fit and function in my Ruger MKII Pistol conversion.

First items are the welding jig pieces that go inside the bodies during welding.
Two pieces of 1/8" thick Copper bar and a Piece of rolled Steel sheet stack up to fit the inside of the Mag. Bodies but required grinding down in width and beveling/radiusing of one edge of the Copper bars to match the inside Full radius curve of the Bodies. This was accomplished by the end of the shop time available.

Still to be determined are the Clamping and aligning portions of the Weld Jig.

Also still to be fabricated are Form Blocks to reform the Feed Lips and Angle to match the Ruger Feed Angle.

Chev. William

[Chev. William]

December 4th, I mailed a Check to John Taylor Machine in WA to pay the remainder of my bill to convert a Ruger Bolt to CF and to machine my Barrel blank to fit The Ruger MKII Standard Auto Pistol Receiver, plus the estimated cost to finish Blue the New Barrel.

Now to Wait Patiently for the Blue work to be completed and the parts shipped back to me.

So Far, I have about $832 invested in this Conversion project including the cost of the Used Ruger Pistol, the Barrel Blank, and John Taylor's Machining work.

I still need to modify magazines to fit the Grip frame and feed .25ACP cartridges.
To date I have invested about another $100 in parent magazines and raw material to make my tools and Jigs from.
I am planning to use cut and welded aftermarket Beretta "950" .25ACP 8-round Magazines as the parent basis, cutting two up to make a longer one to feed in the Ruger. The work needed is to first rework the bullet feed lips and angle to work in the Ruger, then cut and weld to make the correct overall Length required to fit the Ruger action; and finally make a "Blocker" to limit the Magazine capacity to 10-1/2 Rounds (the half is to allow inserting of a full (10 rounds) magazine into a closed breech Ruger Pistol action).

I have Started with making the 'weld jig' parts to align and protect the Magazine sections form oversize inside weld beads. Still to be made is the Clamping portions of the weld Jig and also the 'Form Block" to form the New Feed Lips over.

Today is Overcast and Rainy her and expected to rain tomorrow also, hopefully it will NOT start any Mud Flows in the recently Burned areas, I don't think the burned Area Victims would need further misery added.

Chev. William

[JMtoolman]

How about cutting the rib of the ruger clip with an end mill? Something like a 3/16 th in end mill cut from the outside of the magazine from top to bottom of the indent. It would take a bit of the radius out of the inside of the mag on both sides. The cuts could be wider if more of the material needed to be machined away. It would also make the spring and follower and the loaded rounds easy to see. Just a thought from an old machinest. Best regards, the toolman.

[Chev. William]

JMtoolman,
That Approach has been considered and set aside for the following main reasons:
1. Rim Diameter of the .25ACP is greater than the width of the Ruger .22LR Magazine.
2. Body diameter of the .25ACP is greater than the width of the Ruger .22LR Magazine.
3. Impressed ribs of the Ruger Magazine further reduce it working width; but do reduce the Friction of .22LR cartridges movement in the Magazine.
4. Ruger Factory Magazine springs are cylindrical Coil type guided by the ribs to stay in position.

Luckily, Ruger made the Grip Frame Magazine Well of such dimensions that a Beretta "950" .25ACP magazine body will slide into it. Perhaps Bill Ruger was thinking of the possibility of marketing a .25ACP version in the future?

Chev. William

[Chev. William]

Happy News!!!

Today, December 10th, I received back my receiver with the Mounted .25ACP custom barrel and the CF converted Bolt along with my Two 'takeoff 4-3/4" Ruger Barrels and My custom chamber reamer.

The Barrel machining and finish is lovely with a finished length of 8-1/8 inches and the Muzzle is threaded 1/2-28(UNEF?). the Thread protector is knurled and Blue in finish, the Cleaning Crown protector is also knurled and blued. John made and fitted a Square front sight that is also finished Blue. The Color match to the receiver looks exact under interior Lighitng, it was already dark out when they were delivered so I will wait until tomorrow to view it in Sunlight, if it is not overcast tomorrow.

I(note on the two Ruger "Takeoff" 4-3/4" barrels the thread is apparently 'clocked' to start about even with the Extractor slot and the 'seating shoulders' are of Two different lengths, possibly to adjust for variations in receiver and barrel machining.

John's Invoice included with the items was dated 11/16/2018 and the 'Terms" listed is "Due Yesterday" But since I mailed the check for the remainder on December 4th, I guess he is happy too.

Now to get an Adjustable Rear Sight installed and make the magazines for the Firearm.

My Christmas Came early this year!

Chev. William

[Catshooter]

What a fun project man!


Cat