As promised my Pmags arrived today. At first look there are some difference that make me think they will feed all right with the heavyweight bullets. Externally there are no real exciting differences. They stated there were tactile differences so you can tell them apart without looking. To me it is hard to feel the missing ribs as any real difference. They do have the different markings top and bottom to denote the 300 Blackout and 7.62 x 35 designations.
Internally there is a different black follower and it is marked 300 to differentiate. Now to the notable difference. The internal rib that has been interfering with feeding the heavy bullets is very different. Comparing by caliper I see the rib and wall thickness is .140 versus .180. The rib is smaller in length and bearing surface by moving the end closest to the rear of the cartridge forward making it shorter in the forward to back dimension. It looks very similar to the modifications I did to my standard Pmag by thinning the rib to get it to feed 247 grain without issue.
When loaded with 247 Grain NOE they do sit straight and normal unlike the unmodified 5.56 pmag on the left. These do seem to stack better than the modified magazines.
Sorry about the slight out of focus images, to get close up images like this I had to freehand a macro rig I normally would have used on a tripod. I really should have focus stacked the images but I did not have time. When used like this the focal plane gets very very narrow. In case anyone is interested in what it took to get close in like this I was trying 12mm and 20mm macro tubes on a 18 to 105 lens with dual YN560 flashes on a D300. I had to step down the image size a lot to fit on the forum.
Last edited by Boolit_Head on Thu Sep 14, 2017 11:41 pm, edited 1 time in total.
I received my 3 magazines yesterday too. Haven't done anything with them yet except look at them. Thanks for posting pictures. When are you going to the range with them?
Not sure, my wife caught the refurbishitis virus and I spent last weekend doing sheet rock. More is planned in my future. Not sure when she who must be obeyed has me penciled in for some free time.
DMIINC wrote:I received my 3 magazines yesterday too. Haven't done anything with them yet except look at them. Thanks for posting pictures. When are you going to the range with them?
DMIINC wrote:I received my 3 magazines yesterday too. Haven't done anything with them yet except look at them. Thanks for posting pictures. When are you going to the range with them?
Boolit_Head wrote:Not sure, my wife caught the refurbishitis virus and I spent last weekend doing sheet rock. More is planned in my future. Not sure when she who must be obeyed has me penciled in for some free time.
Jbhurley wrote:Has anyone had any problems with standard 5.56mm mags? Do these mags really fill a need?
Take a look at the pictures, with a heavy bullet the ribs of the 5.56 mag can cause stacking problems. In the third picture those are NOE 247 grain bullets loaded in the mags. You can see the 5.56 mag on the left is not stacking in a manner that will allow proper feeding. With the lighter bullets they do not interfere with the ribs and don't see this problem.
I know the feeling. Good luck.