Hi Alan and welcome. These late models run well. The trick is to leave then stored with the bolt locked back when new. The bolt spring is stiff, and this will mitigate a lot of the recommended break in time and facilitate even low power load cycling. When loading the magazine, ensure that the case rim on the top round is ahead of the case rim on the bottom round to prevent rim lock or stove pipes. Also, if inserting the magazine on an open bolt, not to over insert the magazine. Excellent details here: youtube.com/watch?v=UbqGrDd18GY ----------- Cheers, stay safe and enjoy!

A lot of the problems with the tar 12mp tar 12p comes from using low brass ammo during break in. Also using ammo below 1300fps. Once the gun has ran about 500 rounds the issue clears up. Ensure magazines are loaded properly. Store with an open bolt. Cycle the gun manually without a magazine helps with the breakin period