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Old October 24, 2011, 11:17 AM   #1
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Join Date: July 28, 2007
Location: Central Ohio
Posts: 8,578
.357 Magnum for the Coonan semi-auto

In another thread, Deja Vu mentioned loading for his Coonan Classic. These days, I'm also feeding a Coonan. Not mine, this one belongs to my buddy, purchased on my recommendation. I really want mine, but the time isn't right at the moment. I hope that the time WILL be right in the next year. Until then, I have been shooting his.

On the Coonan website, there is a blurb for a page "under construction" that hopes to list some handloading data for the Coonan pistol. It even has a little quip that says,
Ammunition and Reloading Guide...coming soon…seriously, like soon, Dan and the rest of the ballistics team is working on it even as you read this!
Grrrr... this annoys me because it's been up for like a year and hasn't been updated. I even sent an e-mail to them and the guy who wrote back told me that yeah, they are busy as heck building handguns and haven't worked on that at all... but he also said that the pistol doesn't seem to finicky and runs well. The website notes:
Due to the wide variety of ammunition available in the .357 Magnum caliber, we recommend using Federal or Magtech 125 or 158 grain JACKETED ammunition. Other ammunition can be used, but some setup of the firearm might be required.
I'm happy to report that it mirrors my findings, too. Even so, I'd like to share some trials that have worked in the new Coonan pistol. And I hope that others will add their tests & results... be it a box-fresh new one or an old Model B or Cadet or what have you.

I started with 158gr Zero JSP's and ran them with 13.5 to 14.0 grains of Alliant 2400 with a non-mag CCI primer. I don't use mixed brass so each box of 50 is all the same headstamp, but I'll use any brass that works. All of these run with no hassle whatsoever. No "occasional" feed hiccups or ejection failures... these run 100% of the time.

I decided to give a test using a mid-range .357 load... the same 158gr Zero JSP's over 6.3 grains of Hodgdon Universal and these do not run in the Coonan. They just don't have the oomph to rack the slide. Some eject, most don't get that far and no new ones get a chance to get chambered. These loads are fun for fast shooting from a revolver, but won't run a Coonan.

I then decided to switch to a 125 grain load with the idea that I could save a few pennies with a lighter bullet weight, and yet still have all the fun of shooting .357 Mag from a semi-auto. This turned out to be a fine idea and I got great performance from 125gr Zero JSP's powered by anywhere from 15.0 to 17.0 grains of Alliant 2400... again, non-mag CCI primers.

I did put a box of 50 .38 Special handloads through the pistol with the included (and MUCH lighter .38 spring installed) and the gun ate these, also. They were 158gr Berry's plated flat point bullets loaded over 5.2 grains of Alliant Power Pistol. These fired, ejected and fed with no problem, but the whole operation just seems so S-L-O-W that it's like watching a firing sequence on video in super slo-mo. The slide reciprocates at such a speed, you feel like you are watching a long event. The feel is just really odd. Though I don't have a Coonan of my own yet, I'm not sure how much .38 I'll be shooting through mine because it's just not the same experience. But the pistol did run the ammo well, albeit just the 50 round small sample that I tried.

Currently, my buddy is running 158gr PMC JSP factory ammo through it and it's running all of those at 100%, too. Those loads give just the slightest bit more bump in felt recoil than my 125gr loads, but they don't have near the audible bark that my 125's offer.

Just the other day, I concocted my first trials with some Speer 125gr TMJ bullets. They have a different profile than the Zero 125's, but I started them at 15.0 grains of 2400 also. Haven't yet had a chance to try them.

All in all, the pistol is quite accurate and the function of it has been ridiculously good for a non-standard platform and magazines that are made nowhere else in the world by nobody else, ever.

As for shooting cast lead through a Coonan... well, it's not a gas-op pistol, so there's no concern with lead bullets mucking up any piston or port. I haven't tried it simply because I tend to stick to jacketed when working with bullets at this speed. I know many folks know how to deal with hard cast lead at speeds well over 1,000 FPS, but I have very little experience in that area.

So... maybe you find this interesting, or maybe you find a COONAN interesting! But either way, I'm hoping we can get at least a couple of Coonan owners & shooters to add their experiences to this discussion. Bottom line so far with the Coonan I get to play with... about a thousand rounds down range, maybe a half of it handloads or a bit more, and this pistol doesn't fight you much when you feed it. It loves to shoot, it isn't cranky, it's very accurate and it's incredibly fun to play with.
Attention Brass rats and other reloaders: I really need .327 Federal Magnum brass, no lot size too small. Tell me what caliber you need and I'll see what I have to swap. PM me and we'll discuss.
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