Saturday, March 5, 2016

10mm Auto vs. 40 S&W

Jeff and I worked together for the first fifteen years of my career.  We still keep in touch.
"In Michigan, female bear range from 100-250 pounds, while adult males weigh between 150-400 pounds."  Source.
Jeff plans to retire and to move up to the Eastern Upper Peninsula of Michigan.  Jeff likes walking in the woods with Buddy, his geriatric, yellow lab.  Jeff decided that he needed to research handguns for personal protection.

The Eastern UP is known to have large black bears that are not very afraid of humans and a few mountain lions.  The video shown above gives a good feel for what woods are like in the Upper Peninsula.
This bear weighed over 500 pounds.  Source.
My friend's house is next to the house of member of his county's sheriff's department and that fine officer took Jeff firmly in hand.

They went out to the range last Tuesday and Jeff got to shoot about 12 different handguns.  Offerings included 45 ACP, 40 S&W, 9mm, .357 Magnum.

He shot the big guns well.  He really struggled with the most concealable handguns.  He said, "Joey, some of those guns I had two fingers wiggling around in the air.  The handles are just too short for me to hold."

He shot the semi-autos just as well as the .357 revolver.  The officer had him do several rapid fire and reload drills and Jeff became convinced of the merits of the semi-auto.  Writers far better than me have observed, we don't choose our guns so much as they choose us.
Extended capacity magazines offer additional capacity.  That might be awkward while driving but almost transparent while walking in the woods.

He now plans to buy a Glock 20 in 10mm.  He also plans to buy a 40 S&W replacement barrel so he can switch between the two based on ammo cost and availability.

I don't see the utility of the 10mm over the 40 S&W.  According to Hodgdon's reloading data a reloader can wring 1160fps out of 180 grain bullets with the 40.  Stepping up to the 10mm increases that to 1290fps.  For what it is worth, most 10mm "factory" ammo with the 180 grain bullet only advertise 1150fps.

Hitting even the largest of bears with the 40 S&W factory offerings in 180 grains at 1000fps will tend to re-order nearly any bear's priorities.

The officer also showed Jeff several different holsters.  A firearm does you little good if you lose it while canoeing, or after you slip off a beaver dam or during a scuffle.  Many holsters offer secondary retention features.  Jeff seemed to gravitate toward the Blackhawk Serpa design.  I shared Old NFO's observation that this kind of retention mechanism is vulnerable to being locked up by sand.  Jeffy is going to give that some serious thought.

Is the 10mm worth the hassle over-and-above a vanilla 40 S&W?  Clearly it is to Jeff.


  1. General consensus among instructors I respect, and others who've looked into that setup it is to stay away from the SERPA design. Check out Tam's blog for a good demo why not.

    The Safariland ALS system is more reliable and about the same cost for a very good holster with lower chances of negative outcomes.

    1. Thanks Aaron. I passed that on to Jeff via email.