I just picked up a new MK25 and a new MK25-10. They are both new, never fired with a light coat of oil. The MK25 was manufactured in late 2013 and the MK25-10 was manufactured in late 2014. Both came with the cert. that they are the genuine MK25 used by military. Both have the UID sticker. The MK25-10 is shipped with 10 round mags. I promptly sold those to someone in CA and replaced them with 15s.
The strange thing is the MK25 seemed some how different, some how better than the MK-10. I thought maybe that was in my head. But without looking at the UID sticker - I could repeatedly tell which one I liked better when picking them up. I inspected them closely inside and out for any differences. There seemed to be none. So I took the slides off and weighed all four pieces to look for weight differences on a decent scale. This scale is always in agreement with the Post Office scale. The total difference between the two is 0.04 oz or 1.3 grams - with the MK25 being the heavier. The difference between frames and slides were both 0.02 oz. I weighed them 3 times in oz and grams in different orders. The total weight was 32.27 oz and 32.23 oz (914.9 and 913.6 grams) with mag. I used the same mag. when weighing each pistol. Makes me wonder why the Sig website and others say 34.4 oz with mag. But more importantly, I can't figure out why the significant weight difference. I put enough oil on the scale to amount to 0.04 oz. No way it's oil. There was a sizable puddle on the scale. I googled 1.3 grams of gold (which would be denser and thus smaller than aluminum, any alloy or steel). Every 1.3 gram nugget of gold I found for sale was just too big to be some sort of difference in machining. It's not like Sig has sloppy tolerances or sloppy machining. Does anyone know if Sig changed their design in the last year that would account for the weight differences? Does anyone know if there is some difference between a MK25 and an MK25-10 that is escaping me. Neither one of these is the CA or MA compliant versions with the ugly chamber indicator on top or the unwise mag. release safety. It can't just be a change in the alloy formula as that wouldn't account for the slide weight difference. ..and no, the difference is not a round in the pipe of the heavier one - lol. Any thoughts, any help is greatly appreciated.
Four .177 BBs weigh about 1.3 grams. If it's extra metal, then there is about 2 BBs worth of extra metal - either added by extra density or extra volume - in the slide and in the frame. That's just too much to make sense to me.
The strange thing is the MK25 seemed some how different, some how better than the MK-10. I thought maybe that was in my head. But without looking at the UID sticker - I could repeatedly tell which one I liked better when picking them up. I inspected them closely inside and out for any differences. There seemed to be none. So I took the slides off and weighed all four pieces to look for weight differences on a decent scale. This scale is always in agreement with the Post Office scale. The total difference between the two is 0.04 oz or 1.3 grams - with the MK25 being the heavier. The difference between frames and slides were both 0.02 oz. I weighed them 3 times in oz and grams in different orders. The total weight was 32.27 oz and 32.23 oz (914.9 and 913.6 grams) with mag. I used the same mag. when weighing each pistol. Makes me wonder why the Sig website and others say 34.4 oz with mag. But more importantly, I can't figure out why the significant weight difference. I put enough oil on the scale to amount to 0.04 oz. No way it's oil. There was a sizable puddle on the scale. I googled 1.3 grams of gold (which would be denser and thus smaller than aluminum, any alloy or steel). Every 1.3 gram nugget of gold I found for sale was just too big to be some sort of difference in machining. It's not like Sig has sloppy tolerances or sloppy machining. Does anyone know if Sig changed their design in the last year that would account for the weight differences? Does anyone know if there is some difference between a MK25 and an MK25-10 that is escaping me. Neither one of these is the CA or MA compliant versions with the ugly chamber indicator on top or the unwise mag. release safety. It can't just be a change in the alloy formula as that wouldn't account for the slide weight difference. ..and no, the difference is not a round in the pipe of the heavier one - lol. Any thoughts, any help is greatly appreciated.
Four .177 BBs weigh about 1.3 grams. If it's extra metal, then there is about 2 BBs worth of extra metal - either added by extra density or extra volume - in the slide and in the frame. That's just too much to make sense to me.
What's the tolerance on the scale?........thats somewhere around 2% difference, I bet you'd have to weigh at least ten of them before you found two under 1%.
