Hi Folks,

I have searched high and low, and have not found good answers to some questions on caliber and magazine type for the heavy metal and he-man classification of 3-gun.  I have the rifle and shotgun for this division squared away, with an iron-sighted ArmaLite AR-10 (either 1959-production Portuguese or modern A3) and a Benelli Nova Tactical.  

My question is on the handgun.  I know that traditionally, the rule has been that the handgun must be a single-stack pistol in .45 ACP with magazines of 10 rounds or less.  Then, there are the endless variations that are discussed often, like double-stack .45 ACP being allowed, with the Glock 21 becoming the most popular sidearm for this event.  I have also seen references that other large-calibers being acceptable, like .44 Magnum and any .45 (.45LC, .455 Webley, .45 GAP, etc.).  Then there are those that mention .40 S&W being permitted now, and talk about any cartridge reaching a certain power-factor, such as 10mm, .357 Magnum, or .357 Sig (with a high enough velocity) being permitted.  

I am a huge believer in training and practicing with one system to gain as much competence as possible, as I see competitions as a means to become more proficient with the gear I would actually use in a defensive situation.  Therefore, I am hoping I would be allowed to use my go-to duty handgun (the only handgun I own), which is a Gen 4 Glock 31.  I both carry and practice with my own handloads, which push a 125gr bullet (Gold Dot for carry, Flat Point FMJ for practice and large animal defense) at 1450fps, so I am well within major power factor.  However, if that is not allowed, one route I am considering is to get a Gen 4 Glock 37 complete slide assembly/upper and ejector for the 31 and converting it to .45 GAP for the competitions.  This might actually be more costly than just getting a Glock 37, given how low the demand is for them, but my wife is not big on me getting another handgun, and she, being an avid shooter herself, is a stickler for caliber consistency.  She and her parents (she is Chinese, so they have followed the custom of her parents moving into our house now that they are retired) all carry .357 Sig (32s for the women, 31s for the men).  

My other option seems to be picking up a cheap .45 ACP, like a Kahr CT45, a Glock 36, or a Springfield XDS 4.0 with the 7-round magazines.  I am not too fond of the idea of having to support a .45 GAP platform, and I still have a large amount of .45 ACP stockpiled - as well as brass, primers, powder, and bullets - from before my wife forced me to dump the Glock 21 when the whole family went to .357 Sig.  I might be able to convince her to let me drop 300 on one of the aforementioned .45 ACP pistols, and the fact that those are all single-stacked would mean that I would be the safest as far as rules go.

Basically, if anyone can point me to rules that would allow a .40 S&W, .357, or double-stack magazines, I would really appreciate it.  Also, I am thankful for your advice on what the best course of action is for me getting back into the big bore game, if that is what I have to do for competition.