it really doesn't matter what the outside of a Bulgarian magazine looks like or from what Bulgarian factory it was made in, internally they are all the same design.
Not so; the Arsenal ((10)) "waffle pattern" magazines have metal-reinforced feed lips and locking lugs, while the ISD "slab-side" and "bullet" magazines do not.
You should have sent them back to US Palm. That was definitely a manufacturing defect. I have only read of that happening to one other person and he got them replaced by US Palm. Remember, just as a comparison, Magpul had a whole batch of bad mags too and they are still the current standard AR mag for most guys.Not much to say really. **** happens. I bought them in a package deal and really liked them until they broke. No idea how old, what generation or prior use really. I used them as training mags and both broke within a month, 4 or 5 range trips of each other. I also used them to do reload drills so who knows. The bottoms broke off of both of them.
I am relatively new to the AK but I have had Pmags for my AR go through much more abuse and not fail. I kind of expected the same with the US Palm.
I did not say they were junk just that I believe my money is better spent on the heavier, surplus steel magazines. I have yet to break one of them or had one fail. I may try some again some day who knows. I definitely want one of the US Palm Grips.
There was a guy on the saiga 12 forum that did a comparo between the uspalm and the ((10)) along with others. He did all sorts of stuff like soaking in salt water, drop tests, and so forth. The ((10)) and uspalm were on par with each other as far as durability. The price point was significantly different, with the palm costing a bunch more, and the us parts count was 0 vs 3 so that was another swing factor. The Palm mags have come down in price.
Botach has them for 26.95$ and free shipping. BHI is having a clearance for 25.00$ don't know about shipping.
((10)) mags are available from sks man for 25$ in 3 colors ($33 at kvar).