Has anyone had a similar problem and possible a solution?

I took my MPX K Black Copperhead, not the Tan one, to the range today and immediately had problems. After I put SIG mag in, the bolt stopped short of going into battery by .5 to .75 in. I tried the SIG 20 round and 3 35 round mags. The mags were not scratched on top. Eventually it went into battery.

It continued to happen over 350 rounds over the 4 different SIG mags and 4 types of ammo. Ammo was 9mm 125 grain, Federal American Eagle, Fed. Champion, Norma, and PMC Bronze. I tried downloading the magazines but that did not help.

This issue happened at round count 0, 148, 207, 250, 282, and 332.

When it happens I must lock the charging handle back, drop the magazine reinsert and try it multiple times before it will go back into battery. I tried putting some oil on the bolt carrier group but it did not help. I have 1 20-Round and 3-35 Round magazines. All from SIG Sauer.

The only time it does not wan to go into battery is when I insert a magazines. My gun was cleaned and lubricated before use.

Can you make any suggestions. I am very distressed about my new SIG. I had the larger MPX K and it only had this issue once in 984 rounds. ( I should have kept that gun.)

Thanks

I’d be calling Sig and asking for a label to ship it back to them.