Parts breakage/wear on M&P

[rupzuk]

Weedwhacker had a barrel almost break in two. It had a nice stress fracture right where the barrel meets the chamber (round part meets square). Granted he estimates closed to 100k on that barrel. That happened on factory ammo, no crazy squib type stuff. It was more than a little freaky to see.

I just saw my old (about 4 years old) M&P 40 do this...

I had sold the gun after about 6 months, with a low round count.

It worked great for me but I just didn't shoot it much.

The new owner shot it probably a few thousand rounds a year- at best.

Up until this weekend he hasn't had a problem with it except for the slide lock lever breaking on the right side over a year ago.

But this weekend... Actually it started last weekend...

He noticed the left front frame rail had about a third of it broken off.

The pistol looked normal and he decided to shoot a match with it.

Third round in on the first stage it self destructed in his hands...

The barrel had the exact ring crack you said- maybe an 1/8" of barrel was holding the two parts together. The barrel is manufacturered with a machined ring at this junction- if it was a shear bolt it broke exactly where it should have...

Anyway, on the last shot the barrel flexed enough to pluck the top of the slide off and launch the front site into space (we never did find it).

On closer examination you can see one side of the piece that came off the slide had a bit of a polished look to it leading me to think perhaps the slide cracked first, over time was flexing and eventually flexed enough to break the barrel - but I could be wrong-

The gun was shot with 40 major (175 ish on the PF) and never experienced an ammo problem.

Who knew...

Edited March 14, 2013 by rupzuk