Fired subject gift from wife over the weekend. New purchase from dealer. If there are any viewers with same, then check your fired casings for damage.
Rifle loaded, chambered, fired, and ejected as expected, with no indication fo problems. 5.45x39mm rounds are all Russian made (steel case, berdan primers). Shot 12 rounds (NIB, Wolf, non-corrosive, 3.45x39mm, 60gr hp); first ammo it ever fired by a customer owner. Way too cold for more, so I habitually pocketed spent casings, cased it, and planned to clean it after getting back home the day after. While walking the dog, felt the spent casings and gave them a quick look. 9 of the 12 casings were severely expanded at the bottleneck, 1 had a large split in the neck, and 2 had shiny finish at neck where bottleneck starts.
Immediately contacted S&W, and told to send it back for evaluation.
Barrel stamped 5.45x39mm, and other box markings said same. S&W phone tech confirmed SN matched 5.45x39mm as well.
I left as is, and sending back as soon as box arrives from S&W.
Casings gave the appearance of fire-forming to a longer casing. This can't happen if chamber is cut to 5.45x39mm dimensions, and using correct ammo; and if shell doesn't seat with closed bolt, then it isn't supposed to fire (that's what the forward assist is for). M&P 15 is typically a 5.56x45mm round (M-16 round). Fire-formed appearance looked eerily similar to what a 45mm casing would be. I'm guessing the barrel was correctly cut to 5.45mm (saw no barrel damage), but chamber somehow cut to 45mm vice 35 mm. Loaded OAL of both cartridges is nearly identical, so, the bullet of a 5.45 round in 45mm chamber would meet barrel at about the same point. I may never know from S&W what they find, but figured this forum might be interested in the information if others have this new rifle (only been out a very very short while).
My thoughts are that since it shot well, with no loading or cycling problems, then other owners may not notice the problem because the casings are not reloadable. Were I not in the habit of policing my casings, I'd have probably left them where they lay, and been oblivious to the problem.
If I'm correct about the reason for the problem, then it certainly won't be confined to just one barrel. First thoughts might imply that it isn't a major safety problem, but extended firing without knowledge of the problem may set up situation for significant failure (i.e. portion of separated case lodges in barrel and sets stage for obstruction explosion).
When I get resolution, I'll let the board know what I'm told. My suspicions may prove wrong, if somehow maybe the firings took place when bolt wasn't fully closed. Rifle has not been disassembled, but checked for proper functioning and no obstructions prior to firing.
Rifle loaded, chambered, fired, and ejected as expected, with no indication fo problems. 5.45x39mm rounds are all Russian made (steel case, berdan primers). Shot 12 rounds (NIB, Wolf, non-corrosive, 3.45x39mm, 60gr hp); first ammo it ever fired by a customer owner. Way too cold for more, so I habitually pocketed spent casings, cased it, and planned to clean it after getting back home the day after. While walking the dog, felt the spent casings and gave them a quick look. 9 of the 12 casings were severely expanded at the bottleneck, 1 had a large split in the neck, and 2 had shiny finish at neck where bottleneck starts.
Immediately contacted S&W, and told to send it back for evaluation.
Barrel stamped 5.45x39mm, and other box markings said same. S&W phone tech confirmed SN matched 5.45x39mm as well.
I left as is, and sending back as soon as box arrives from S&W.
Casings gave the appearance of fire-forming to a longer casing. This can't happen if chamber is cut to 5.45x39mm dimensions, and using correct ammo; and if shell doesn't seat with closed bolt, then it isn't supposed to fire (that's what the forward assist is for). M&P 15 is typically a 5.56x45mm round (M-16 round). Fire-formed appearance looked eerily similar to what a 45mm casing would be. I'm guessing the barrel was correctly cut to 5.45mm (saw no barrel damage), but chamber somehow cut to 45mm vice 35 mm. Loaded OAL of both cartridges is nearly identical, so, the bullet of a 5.45 round in 45mm chamber would meet barrel at about the same point. I may never know from S&W what they find, but figured this forum might be interested in the information if others have this new rifle (only been out a very very short while).
My thoughts are that since it shot well, with no loading or cycling problems, then other owners may not notice the problem because the casings are not reloadable. Were I not in the habit of policing my casings, I'd have probably left them where they lay, and been oblivious to the problem.
If I'm correct about the reason for the problem, then it certainly won't be confined to just one barrel. First thoughts might imply that it isn't a major safety problem, but extended firing without knowledge of the problem may set up situation for significant failure (i.e. portion of separated case lodges in barrel and sets stage for obstruction explosion).
When I get resolution, I'll let the board know what I'm told. My suspicions may prove wrong, if somehow maybe the firings took place when bolt wasn't fully closed. Rifle has not been disassembled, but checked for proper functioning and no obstructions prior to firing.
