Sorry ahead of time for the redundancy on this topic.

I've heard and seen several on this board make the comment "swap the barrels, you'll be fine." I'm a Glock convert and for mine to be completely reliable I had to exchange the ejector as well. Has anyone had issues with FTE without exchanging the ejector? It only makes sense to me to change those out, but hey, it should have been common sense to go with the M&P instead of Glock 1st.

Groo here
Are you doing this for cheaper range work?
If so then a FTE from time to time is just part of your training.
If for carry, don't, change to 357sig for carry and cheap 40 for the range.

Odd as it may seem. Those of us who have been converting the Shield for a few years now. Dont seem to have issues swapping between the 2. I personally had a few problems running the 9mm through the .40 mag. But of course a 9mm fixed that issue. As far as that, theres never ben any issues with the barrel swap that im aware of. At least noone here has spoken of it anyways.

MPC .357 Sig to .40c to 9mm using all OEM barrels just have to buy 9mm magazines. Zero problems. I do carry .357 for EDC.

Why do you suggest .357 Sig for self defense?

This is my M&P 40 to 9 conversion kit.



The 40 barrel and mag (lower) are OEM. I picked up the S&W factory 9mm barrel and mag (upper) from Midway.

To date, I've shot 974 rounds in the stock 40 configuration, and 994 rounds in the 9mm config. The conversion is simple.

I've had no FTEs in the the 40 config, and 4 FTEs in the 9mm config (1/248.5 = 0.4%). Normally, the 9mm cases are flying well over my head.

My practice is to config the pistol for 9mm only for range practice. I swap the barrel on the bench before I shoot, and I reconfig back to 40 before I re-case the gun. I always keep the pistol configured for 40 away from the range, including classes and carry.

I consider an FTE rate of 0.4% to be completely acceptable for range practice.

I put a storm lake conversion in my 40. I use 9mm mags. 0 problems.

Math is off. 0.4%.

Still not bad for just practicing, one for a little over 200 rounds.

Good catch!

I've got a KKM .40 to 9mm conversion barrel for my .40c.
No problems at all.