Longest OAL for full size polymer witness 9mm magazines

[jmbaccolyte]

I am thinking about buying a full size polymer Witness in 9mm. Can I load the 9mm out to 1.161" OAL and still fit in these mags? EAA lists the mags as EA9MP10 Full Size Polymer #101922. How do these mags differ from the steel witness mags?

[Skydiver]

I am thinking about buying a full size polymer Witness in 9mm. Can I load the 9mm out to 1.161" OAL and still fit in these mags? EAA lists the mags as EA9MP10 Full Size Polymer #101922. How do these mags differ from the steel witness mags?

It should hold that long a round considering that SAAMI specs for 9mm is 1.169".

Edited May 1, 2012 by Skydiver

[littletoe]

the mags will hold them fine but the barrel may not........seems like they need around 1.150 to feed properly.....of course that may change with bullet shape too

[jmbaccolyte]

Thanks. So the worst case is that I'll have to have the barrel throated a little. I appreciate it. Do you know how these magazines differ from those for the steel witnesses?

[Nealio]

the mags will hold them fine but the barrel may not........seems like they need around 1.150 to feed properly.....of course that may change with bullet shape too

To feed or chamber? I run 1.135 now for reliability (keep the noses away from the end of the mag) and 115's and 124's both feed fine (plated and TMJ).

Thanks. So the worst case is that I'll have to have the barrel throated a little. I appreciate it. Do you know how these magazines differ from those for the steel witnesses?

FYI: You will need to run .355" bullets unless you want to open the throat on the gun (which I don't know why you would want to). I have ran Berry's, Xtreme, and Speer TMJ in 100, 115, and 124gr and they all were fine.

I tried some PowerBond .356" bullets and they would drag on the throat of the chamber in both the polygonal and groove rifling barrels. The bullet would get pulled out of the case if you tried to eject a live round no matter how short I loaded them.

[littletoe]

to chamber....sorry . they tend to stick in the rifling sometimes if longer

[jmbaccolyte]

I ran across some older Vihta-Vouri (misspelling?) loading data on the 9x21mm cartridge and without going into the reason that cartridge was developed, it occurred to me that here we had Open Class pressure tested loading data for the long loaded (1.61" OAL) 9x19mm cartridge that amounted to mid-range .357 magnum power levels, but in a much thinner, lighter handgun that holds 14-16 rounds. However, after thinking about it, I realized that a Witness Polymer in 10mm would make more sense.

Edited May 2, 2012 by jmbaccolyte

[Nealio]

Why not a Witness in .38 Super?

[jmbaccolyte]

That's a good idea, Nealio. I wouldn't be straying so far from SAAMI standards. I guess, though that the brass supply is limited to new. Probably not much departmental once fired available. Do they make the full size polymer witness in .38 Super or would that be a top end swapout?

[Nealio]

I don't know if they make one or not, but you could easily swap out the top end to make one (as long as you have the large frame poly).