I purchased a BPP MP5 40 from the classified section on here a few weeks ago. It was built off a German parts kit, but it didn't come with the bolt and carrier group. I ended up buying a brand new German, bolt, carrier, and recoil rod from HKparts to complete it.
Today was my second time shooting it and I didn't even get through one magazine before I had an issue. I was doing some 3-5 round bursts with factory Blazer Brass 180 grain ammo, everything was running smoothly until about 20 rounds in I had a malfunction. As you can see in the picture the back of the case completely separated and now part of the casing is jammed in the chamber. How do I get it out of there without damaging the barrel or chamber? I tried pushing it out with a wooden dowel but it kept slipping off.
Of all my years shooting I've never had this happen. Is this an issue with the ammo, or should I be concerned about a problem with the build by BPP? Thoughts?
I would just scrub the chamber out well to remove any brass shavings or pieces that may be left. I've seen case seperations on other calibers but not on 40 S&W (I am sure your not the only one). I would tend to say it was more of a bad case than the barrel itself
This can happen when the case thins out after reloading or if you got a bad batch of factory ammo where the brass is out of spec for some reason. I saw this recently in some 115gr Swiss Geco factory ammo in 9mm. The case sheared like in your picture where the case webbing thickened towards the base of the case. Whats funny is in my outing it happened in several different 9mm ARs but the same ammo ran fine in my mp5 but i could still see the line where the separation was occuring in the AR with an unfired cartridge upon close inspection. I returned the ammo and got a refund.
Do you have pics of the unfired ammo that you were using?
Looking at your pics, the front of the case has some bright wit marks between the flute marks on the brass. That is a bit unusual as my spent cases don't exhibit this but it may be due to the bullet crimp used on the case. Change up your ammo and see if you still have problems. I am willing to bet its ammo related.
Last edited by flybynt; 04-11-2015 at 04:22 AM.
Thomas Jefferson -
"When government fears the people, there is liberty. When the people fear the government, there is tyranny."
"Those who hammer their guns into plowshares will plow for those who do not."
I have had the same problem with that exact same ammo in my MP540. That Balzer brass is very thin once you look close at it.
Thanks for all the info, that puts my mind at ease. I guess I won't be buying Blazer Brass in .40 s&w anymore.
You get what you pay for, we have has multiple instances of case head seperation with the "BLAZER BRASS" ammunition............It is cheap for a reason