"opening" The Mag Catch Hole On A Mag

[iweiny]

So I am getting my wifes STI 10 rd mags all tuned up. We pretty much have figured out a lot of the problems she was having. One of the final things I would like to try is take some material off the "top" of the mag catch hole such that when the mag is full and her slide is closed the mag will go in a bit easier. (Right now they go in but they are tight and I don't think that slaming them in is a good idea.) I know that this will make the mag sit a bit lower, and there might be feed issues if I take off too much... (So I am going to proceed with caution.)

My question is what tool do people use to do this. I have a couple of small files but this really seems like a long process. I am planning on dropping by the hardware store for a dremel bit which will fit in there to use. Also I want to polish this really well so it does not wear on the mag catch. Does this sound like a good way to go?

Thanks,

Ira

[cpty1]

I would suggest you stick with the file(s). Awful easy to take too much off with the dremel. You can always take off more, but you can't put it back on if you go too far. You shouldn't have to take off that much anyway...I wouldn't think.

[Loves2Shoot]

If you don't have an MBA in Dremelogy I would stick with the file, sandpaper, and stone approach.

[shred]

Are they all like that? Would it be easier to lower the top of the mag catch instead? Even if you go the Dremel route, you'll probably need to use a grinding stone and not a metal bit-- mags are made of some hard steel.

[Powder Finger]

You won't make a difference untill you start getting 1/4 to 1/2 of the case diamater extra space. Plus it's lowering the position the round feeds from.

[iweiny]

You won't make a difference untill you start getting 1/4 to 1/2 of the case diamater extra space. Plus it's lowering the position the round feeds from.

Powder finger,

If I read your response right I have already altered the follower such that the top round will compress sufficiently to allow the mag to catch when full. (This allows the top round to be pushed down into the mag.) But I have found, by taking too much off, that I am at the limit I can do with the follower.[*] What I would like now is like maybe a 1/128" or maybe 1/64" of play. This should not alter the feeding that much.

Perhaps a file is in order. But the little filing I did seemed to help little.

Thanks for the responses, does this help explain?

Ira

[*] Basically we found that the follower when all the way at the bottom was "bottoming" out at the bottom of the mag when full. By taking a good 1/8" or more off the bottom of the follower I got the spring to compress enough to allow insertion. It is hard to explain but worked well. However if I take any more of the follower off, while it fixes the problem, it allows the follower to kind of float funny when empty and we are having some drop problems. So I have just about found the optimal amount of follower grinding.

PS I guess I should add that these are STI mags in an SV gun. I started thinking of this solution when I was told that the 2 guns are slightly different. Is that true?

Edited January 24, 2006 by iweiny

[TCK]

I would say that a Dremel tool is our worst friend and a gunsmiths best friend. If I hazard to guess, I would say dremel tools have sent more work to gunsmiths than anything else.

Its a hell of alot easier to remove metal than it is to put it back. Time is something we all have lots of, stick with the files and stones and dont be in a rush.

[Tman33_99]

Mag Catch is $30 give or take. Mag Bodies are $50 each give or take. I would work on the mag catch. Much easier, quicker, and cheaper to get back to square 1 if you screw up than with mag bodies.

Just my 2 cents.

[Nolan]

PS I guess I should add that these are STI mags in an SV gun. I started thinking of this solution when I was told that the 2 guns are slightly different. Is that true?

Ira,

The grip frames are identical. Last I heard they were molded in the same molds then the SV grips had the STI logo milled off. I don't know if that's still true or just an urban legend.

The STI and SV mag catches are quite a bit different. The STI mag catches have a very squared off bottom face and the SV are tapered, or is that the other way around?

Nolan

[shred]

PS I guess I should add that these are STI mags in an SV gun. I started thinking of this solution when I was told that the 2 guns are slightly different. Is that true?

Ira,

The grip frames are identical. Last I heard they were molded in the same molds then the SV grips had the STI logo milled off. I don't know if that's still true or just an urban legend.

It definately used to be true, though I've heard rumors of another mold lately. I have STI/SV grips in various stages of the 'conversion', obtained by a guy that worked there and was thinking of going into the painted grip business.

Drop an end mill into the STI logo, insert SV logo plate, done. Molds are expensive and since both companies started from the same one and share the same basic patent, I'm betting there's a share-the-mold deal as well.

Nolan is correct that there are a number of other differences however-- mag release, trigger bows, etc, etc.

[Powder Finger]

not sure which size mag you are doing but if you want to try i would go with TMAN33_99's

idea as it's always better to go after 1 part mods for $$$ and Consistency(only have to 1 right not 6) Also i would add that when i shot a lot i used big extra power wolff springs cut to hold just barely 19 rounds of 38 whatever then loaded 18 only every time. If i needed 19 i used the +2 basepad mag (set up the same way) point is the mags always work the gun will work every time stopped counting rounds with out a jam @ 25,000. I know people want to run a 24 round corse with a 25 round mag & not reload but there is always(almost) a place to do a load. Not sure if that's what your doing it for but that's my 1.5 cents.

[Brazos Custom]

The mag catch from STI and from SV is a little different. I usually recommend if someone is using STI mags in a SV and having problems to swap out to an STI mag catch and quite often that solves the problems.