My first two range trips with my new MP10 have not gone very well. Here is a pretty detailed thread in hopes contributors might have some tips before I consider contacting S&W.

New M&P 10 (stock) with Nikon M308 scope. 95 rounds fired thru the firearm with FTF on reloads but not factory loads. I have two stock SW 10 round mags and one 25 round Magpul. Here is the sequence of firings and symptoms for the first two range outings with the new the rifle. When FTFs were encountered I tried switching magazines and the problem seemed consistent regardless of the mag used:

Range Day1:

A. 12 Factory Winchester 150 gr: NO issues

B. 10 Home Loads: 168 Hornady HPBT and IMR4064 new PPU brass with 41.3gr: First three cycled fine and then 7 FTF. Brass ejects but bullet left in mag (short stroke? Not enough lube? Both?)

C. 8 Factory Winchestor 150gr: No issues

D. 5 Home Loads (above): All FTF

Firearm brought home, cleaned and lubed. I reloaded both the Winchester once fired brass and the once fired PPU brass with 44 gr of IMR4064 thinking my initial loads were too light to cycle the MP10 (no gas block adjustment so I tweaked the powder load)

Range Day2:

Control group 1: 150 grain Winchester Factory: No FTF

Control Group 2: 10 rounds new PPC brass of 165 grain SPBT with 41.3 grains of powder The first three rounds were perfect, then problems started and they 100% FTF

Control Group 3: 10 rounds of once fired PPC brass reloads with 44 grains of powder. Mixed results: 50% FTF

Control Group 4: 6 rounds of once fired Lake City brass with 165 grain bullet and 43 grains of powder. 100% FTF

Control Group 5: 20 rounds Once fired Winchester brass with 168 grain bullet and 44 grains of powder. Mixed results: Some of these rounds really got crunched while jamming at the feed ramp. The cases were badly damaged and beyond the ability to chamber.

Control Group 6: Once fired PPC brass with 168 grain bullet and 44 grains of powder. Mixed Results: estimate 75% good, 25% FTF

Notes: Upon cleaning the rifle the second time, I noted lots of brass shavings in the bolt chambering area and 50 percent of the fired brass had dents/scrapes near the shoulder and on the case neck. Feed Ramp? New Mags?

My Questions: The forum notes indicate that a breakin of at least 200 rounds is needed and lots of lube. The forum notes on the reload topic also indicate that too much pressure on reloads can cause FTF. However, with a lighter load, it seems the rifle short strokes to the point where the bolt carrier does not even go back far enough to catch the next round from the mag. More powder results in jams at the feed ramp.

Is the recommendation to pump another 100 rounds thru the rifle before tuning reloads?

Should I consider polishing the feed ramp?

Should I consider a power switch?

Side note: I am new to SA Rifle reloading (but not to pistol reloading, I have 8K rounds of pistol reloading bench and range time for 9mm all the way to 50AE). I have done much research on the rifle round reloading minutia and case guage/length/headspace importance. I use Dillon xl650, case guage and carbide dies.

Thanks in advance for offered tips.