MK2 vs MK IV Mags

Does anyone know if the older MK II mags are compatible with the newer MK IV guns Overall size and shape appears the same except for a molded burr looking protrusion in the right-front of the MK IV mags.

Thanks for your time... Chiefbg

22/45 and the other later MK III and MK IV that have the mag release button on the side in front of the left grip panel, the mag bodies and bottom s can be switched around and made to work, but it is the location of this mag release that determines which mag bodies will work with whatever gun......... the early bottom ( European) release,'standard', MK I and MK II there is no "notch" on the left side of the mag body..............

Dan,
Thanks for the reply, You are exactly right, Had I used my brain a little I would have seen that.That burr is what holds the mag in place. Again, thank you for taking the time to straighten me out... Chiefbg

The Mk II mag will work in Mk. IV if you hold it in place while shooting, not ideal situation, but can be done if necessary.

cjs1945 said:

The Mk II mag will work in Mk. IV if you hold it in place while shooting, not ideal situation, but can be done if necessary.

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I've never tried it but will MkIII/MkIV magazines work in a MkII? Will the "heel clip" magazine release work with their baseplates?

22/45 Fan said:

cjs1945 said:

The Mk II mag will work in Mk. IV if you hold it in place while shooting, not ideal situation, but can be done if necessary.

Click to expand...

I've never tried it but will MkIII/MkIV magazines work in a MkII? Will the "heel clip" magazine release work with their baseplates?

Click to expand...

Yes they will, but, you may experience the mag getting hung up in the mag well. I have heard of some fellows using a 4 or 3 in a 2, and only having to wiggle it some to get it in or out. You can modify a 3 or a 4 mag by removing the catch "burr", but then it would not latch into a 3 or 4 of course, but would work in the Mark 2 and later Mark 1.

I have used Mk. IV mage in MK II a few times with no problems, they don't come out quite as smooth, but shoot OK.

cjs1945 said:

I have used Mk. IV mage in MK II a few times with no problems, they don't come out quite as smooth, but shoot OK.

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As I recall MKII mags hold 8 rounds and I'd wanted 10 round mags for a 3-gun competition. So I ground off the two "burrs" on a MIV mag and then the mag dropped out easily when I used in my MKII.

I didn't want to mess with my MKII mags because I believe they have a high resell value.

Matthew Duncan said:

As I recall MKII mags hold 8 rounds and I'd wanted 10 round mags for a 3-gun competition. So I ground off the two "burrs" on a MIV mag and then the mag dropped out easily when I used in my MKII.

I didn't want to mess with my MKII mags because I believe they have a high resell value.

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No, MkII magazines hold 10 rounds just like MkIII and MkIV magazines. The early Standard Model and MkI magazines held 9 rounds.

22/45 Fan said:

cjs1945 said:

The Mk II mag will work in Mk. IV if you hold it in place while shooting, not ideal situation, but can be done if necessary.

Click to expand...

I've never tried it but will MkIII/MkIV magazines work in a MkII? Will the "heel clip" magazine release work with their baseplates?

Click to expand...

Yup! Mark III magazines will indeed work in a Mark II, I've actually tried it. The "nub" on the Mark III magazines, for the Mark III style latch/release, will hangup slightly, but they will work and work OK with the Mark II pistol magazine release, and feed just fine. It's ALWAYS best though, to use the proper magazines designed for your specific pistol.

SGW Gunsmith said:

It's ALWAYS best though, to use the proper magazines designed for your specific pistol.

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No argument with that. My question was more academic interest than intent to use the "wrong" magazines. I was just wondering how "backward compatible" newer Ruger magazines are.

Matthew Duncan said:

cjs1945 said:

I have used Mk. IV mage in MK II a few times with no problems, they don't come out quite as smooth, but shoot OK.

Click to expand...

As I recall MKII mags hold 8 rounds and I'd wanted 10 round mags for a 3-gun competition. So I ground off the two "burrs" on a MIV mag and then the mag dropped out easily when I used in my MKII.

I didn't want to mess with my MKII mags because I believe they have a high resell value.

Click to expand...

I am in error. My original post stated MK II and I should have written MK I.