TTI +4 basepads not fitting on nickel-plated MecGar mags

[ClangClang]

I just ordered some TTI basepads my my Mec Gar 17 round tubes, but they don't fit on the nickel-plated mags, only the AFC mags. I'm assuming this is due to the added thickness of the nickel plating. The photo makes it seem like I'm only shy by a hair width, but due to the chamfered edge of the retention pin, it's actually a surprisingly large gap. Using a set of okay (but not great) calipers, I reckon I need another 0.018 - 0.022 inches of depth before the pin can be raised.

 

I spoke to TTI customer service and they recommended using a punch to dimple the mag tube inward, but I am pretty sure that will induce feeding issues when the follower snags on the dimple.  At this point, I'm thinking that sanding down the exterior of the magazine tube would be a better option. My plan would be to sand "front strap" of the mag tube where it slots into the basepad so that the tube sits further forward in the rails of the basepad (see the orange colored section below) and then if necessary, some more sanding on the "backstrap" right where the pin is located. 

 

Anyone care to give feedback or comment?

 

 

[sfinney]

Is your colored in area on the front of the mag actually making contact with the pad? Or is it the rails of the mag not sliding far enough forward in their slots? Have you given iit a good whack to fully seat it? Looking at your pic I don't think you'll get enough movement by just sanding the plating off.

May be you could squeeze the tube front to back in a vise (lightly)?

[ClangClang]

1 hour ago, sfinney said:

Is your colored in area on the front of the mag actually making contact with the pad? Or is it the rails of the mag not sliding far enough forward in their slots? Have you given iit a good whack to fully seat it? Looking at your pic I don't think you'll get enough movement by just sanding the plating off.

May be you could squeeze the tube front to back in a vise (lightly)?

 

Yup, the mags are definitely fully seated into the basepad. I tried giving them a good wack, but no dice.  I like the vice idea, I hadn't thought of that.  I might give that a shot first before sanding.

[ClangClang]

Vice seemed to work!  The tube was originally 1.262" front to back, and after being squeezed it's down to 1.251" and now the basepad fits as long as I use something solid to push the pin.  As an additional data point, the width of the tube started at 0.802" and it expanded to 0.810".  It's now a little tougher to slide the basepad on, but not to the point that it's problematic.  I'll run this mag at the range to fully test it before squishing all my mags, but I think it will be fine.  I may wind up needing to sand the front and back of the follower a bit, but that's pretty easy.  Thanks for the suggestion!

 

Edited July 17, 2018 by ClangClang

[Trinimon]

I'd mark where the exposed part of the pin meets the base when fully in then pull the retaining pin out, run it on the grinder or dremel to put a flat spot on it. 

[Brooke]

I agree I would have taken a little off the inside of the pin rather than work on the mag itself. Actually I just bought several TT +4 pads to be used on the AFC 17 round Mecgar mags. I had 1 of 20 that had the same problem you describe.

 

19 of them assembled slick as hell but that 20th one required some sanding on the pin.

[magpulled]

I noticed on my nickel were hard to get on. I think I broke the corners on the front of the mags and that worked for mec

[jbecker]

Quote

 

Hi

I have the same issue on a couple of regular 17 round mags, the TTI basepads fit on most but one of TTI basepad had trouble, I just used a small file on the TTI push dowel to give it a little flat spot. and then it fit fine