Duty ammo choice with primary and backup sharing ammo

[98z28]

I have just ordered an M&P 40 compact to work as a backup to my full size M&P 40 on duty. I chose the M&P40c because it can share magazines with my primary. It is now time for me to replenish my duty ammo supply and I have the M&Pc to think about. I work for a small agency, so this is at my own expense. The expense sucks, but the up side is that I can use whatever ammo I want. I have for years carried a j-frame as a backup to my issued Sig, so shared ammo choice is a new concern for me.

Here is my question: What ammo should I choose that will perform well from both my primary 4.25" barreled handgun and my backup 3.5" barreled handgun?

In the past I have used whatever is on DocGKR’s approved list that I could get cheapest. This past year I used Speer Gold Dot 180 gr. However, I am thinking that some of the approved loads may not do so well out of a shorter barrel and there may be a compromise. Maybe a lighter load would fare better out of the shorter barrel while still performing well out of the longer barrel, such as the Winchester Ranger-T 165 gr.

I was surprised that I could not turn up any threads on this since choosing a backup that can share mags with your primary is such popular advice. I am guessing my search-fu is weak, so any help is greatly appreciated. Or maybe I am just over thinking it.

Thanks!

[Beat Trash]

The difference in velocity between the 3.5" barrel of the M&P40c and the 4.0" barrel of the M&P40 is not enough to worry about in my opinion.

I'd pick a loading that gives the performance I need in the environment I work in (If you do alot of vehicle stops such as a Highway Patrol, then vehicle barrier penetration is an issue). Find one that is priced right, and is also currently available.

I'd use a duty loading that is the same weight and velocity as your practice and training ammunition. Safe point of aim and felt recoil for both.

Dr. G. Roberts' list is a great resource. Check it out.

I'd use the same loading in both and not worry about the .5" of barrel difference. The 180 gr Speer Gold Dot would be a good choice. So would the Federal 180 gr HST loadings.

Stay Safe...

[DocGKR]

Most of our testing is out of a 4 inch barrel, there is no difference in performance for a 9 mm or .40 when dropping 0.5" in barrel length...

[tpd223]

We have had shootings with G26s and our duty ammo and not noted any problems, and I know of OISs where the issued 180gr Gold Dot has worked well over in KC from G27s, I wouldn't worry about it.

[kmrtnsn]

Federal XM40HB, 155gr.

[CoryCop25]

Stick with the 180 Gold Dots. My duty is a G22 and my backup is a Kahr K40. They perform very well in both and have excellent ballistics. The Lawman 180gr practice is identical in poi and felt recoil. After testing, most departments in my area use this ammo. The performance difference was minimal to the higher priced ammunition (Black Hills, Hornady TAP).