I finally got around to doing a Google search for STI Heavy 10 and here I am.
All I ever shoot/carry is a 1911 so I decided to add a 10 mm 1911 to my "bureau of alcohol, tobacco and firearms". (No I don't smoke. At least not anymore)

The man I bought mine from said he'd only shot about 100 in it and it looks it.
He also said that there were only 20 of the Heavy 10 1911's made so ron556's comment of 30 built kind of rings true.

I was looking for a 10 mm to shoot bowling pins with and found this one on gun broker about a year ago. 10 mm cases are not what you find every day at the range and since it is considered to be a 40 caliber magnum I decided to play around with 40s in it before I got set up to load tens.

I've not shot any tens in it yet but since the extractor holds the case back against the breech face in a 1911 I decided to give that a try. It works.
I've shot 380s in my 9 mm 1911, not that they work the slide but at least I can burn whatever 380s I happen to have and punch holes in paper. I also discovered that the Wilson 45 caliber magazine feeds the 40s in the Heavy perfectly.

I've been knocking bowling pins off of the 3 foot deep table with my 45 and found that the 460 Rowland load works very well in my Dan Wesson K03, 45 ACP. Pushing a 255 grain Keith SWC at 1000 is quite a handful which is why I decided to try the 10.

I load my 40s with either 170 or 200 grain bullets at 1000 FPS and they seem to work fairly well on the pins at 25 feet. I can push the pin off the back of the 3 foot table very well.

No matter what I'm shooting, I anticipate shooting as many 50 during each course of the bowling pin tables. Five pins, two 8 round mags, for four tables, first course of stock service pistol and the same for the Open pistol. Yes it's punishing but it's good practice and whether I'm shooting the heavy 10 or the 460 I deal with it.

All of my 1911's have a 3-3/4 pound trigger, all smooth and of course crisp. The heavy ten has a 2-1/2 pound trigger and when I'm shooting pins, occasionally I will light off a shot when I'm not ready. I reset during the recoil excursion. I will either have to increase the trigger weight on the 10 or decrease the trigger on my other 1911s. As mentioned, my KO3 is also my EDC which also handles my bowling pin loads.

What I don't understand is why there's such a heavy recoil spring in the Heavy and also in my STI 2011/45 ACP.  Seems like it's 25 pounds while my K03 has an 18 pound spring.

I'd ordered a mag from BROWNELLS and explained the Heavy 10 to the technician there (He'd never heard of the Heavy 10) and for some reason he sent me a double stack mag which obviously does not fit. That was when I tried the Wilson 45 caliber mags which I use in my K03 and they work in the Heavy. Not right but still, if it's a stupid idea but it works then it isn't stupid. Put that in your pipe and smoke it...

I don't know whether I prefer the short high recoil impulse of the 40/10 or the long heavy pendulous shove of the 460 Rowland. When I'm tired, the 460 will dislodge the gun from my left hand and I have to re-grip.

Welcome to the Forum Rogrrr
I enjoy shooting my Delta Gold Cup quite a bit
Try looking for some Chip McCormick, Shooting Star Mags
https://www.midwayusa.com/product/1006123895

Welcome to the forum. Interesting range report. Just a friendly suggestion, get a .40 barrel if you plan on shooting them through the STI regularly. You're putting undue stress on the extractor and it's not really designed to function that way. You risk bending the internal extractor out of adjustment or chipping the face. Unreliable ignition of the .40s and jamming can happen. Neither are desirable during a pin shoot.

FWIW, I shot pins every Thursday for years with my Delta Elite. At the time I was using Montana Gold 180gr hollow points @1200fps. I wish I had known about the RMR 180fmj bullets at that time. Much cheaper and they have a very wide meplat.

Wilson 47D mags (.45acp) will run in many 10mm 1911s. I've only had one that it did't work in. Wilson makes 10mm 1911 mags and they run beautifully. Tripp research is another good choice.

Congrats on your find!

Quote from: Graybeard on June 11 2020 05:16:44 AM MDT
[SNIP] get a .40 barrel if you plan on shooting them through the STI regularly. You're putting undue stress on the extractor [SNIP]

[SNIP] Montana Gold 180gr hollow points @1200fps. I wish I had known about the RMR 180fmj bullets[SNIP]

Congrats on your find!

Thanks for the warm welcome here.
While I appreciate your caution about shooting the 40 in the 10mm barrel, I don't understand how this is hard on the extractor. As I understand it, the case comes up from the mag and slides into/under the extractor hook, not springing it in any way.
I would be open to a bonafide explanation of the mechanics of this 'problem'.
I'd forgotten the model number of the Wilson mag. Yes, it's a 47 I use.

I wasn't aware of the RMRs and will look into them. I do like a wide meplat for pins. I'd been using a Vance 255 grain Keith SWC as my 460 load and like it. I'd also like to find a Keith SWC in 9mm but nobody makes one, only round nose which leaves a ragged hole. I happen to like a clean hole in the paper.

I've used the search function here but haven't been able to find how to set notifications, like other boards provide, for email notification of a post to a thread I've subscribed to. Is that option available on this board ?

I had a computer intrusion recently which wiped out all of my data. YEARS of gun info. That's hard to swallow.

The controlled feed you describe is exactly correct. The 10mm chamber in your barrel is designed to headspace on the mouth of the case. That's what stops the round from going any farther into the barrel and what takes the energy from the impact of the firing pin. When you fire 40s the case mouth isn't touching the end of the chamber. The round is basically dangling on the extractor. So it's like hitting the primer with a little hammer and instead of the case mouth preventing the round from moving forward, the extractor is now taking that stress. Which is not what it was designed to do.

That said, yes, it can work that way. But you risk losing proper tension on the extractor and possibly chewing up the extractor hook. Too much dangle and the 40s may not get enough hit from the firing pin, as well.

Internal extractors aren't terribly hard to replace or properly tune. Personally, I hate to DQ in competitive events because of surprise gun or ammo problems. It's pretty easy to swap barrels, but not as easy to replace or retune an extractor during a pin shoot.

Congrats again on your find!

Quote from: ROGRRR on June 10 2020 09:35:27 PM MDTI was looking for a 10 mm to shoot bowling pins with and found this one on gun broker about a year ago. 10 mm cases are not what you find every day at the range and since it is considered to be a 40 caliber magnum I decided to play around with 40s in it before I got set up to load tens.

Like Greybeard said:  you can do this, but it's not best practice. 

If you simply want lighter loads, then I would just load/buy light 10mm ammo. 

You can buy 10mm cases to reload (though they're not as cheap as .40), or somewhere on this forum revolverguy has posted a bunch of chrono data for various 10mm loads, and it would be easy to pick one that's on par with .40. 

Graybeard, Thanks for the well-reasoned explanation. I'd not thought of it that way and it gives me lots to think about. Your suggestion of the 40 barrel goes a long way with me.
I do a heavy crimp on my 9 and 45s so I'm wondering if maybe I'm crimping too hard on them. I set my dies this way since I'd had several failures to lock in battery and it was EXTREMELY hard to pull the slide back to extract the shell, as if the bullet was engaging the rifling, even with proper COAL. I seated the bullets a bit deeper and set the crimp die several thou further down. Solved that problem. I can now see the crimp roll on the mouth.
I'm also just setting up my 650 to load both 40 and 10 so I'm wondering how much crimp to do there. I'd guess I should remove the barrels from my 1911s and crimp an empty case and see how they seat in the chamber. What are your thoughts on that ?

I'll check around for the loads Bimmer mentioned. I use a #49 Lyman load manual. I use either Bullseye or Universal.

In my experience taper crimping is much easier to setup than roll crimping and works as well.

Quote from: Sneed on June 12 2020 02:14:56 PM MDT
In my experience taper crimping is much easier to setup than roll crimping and works as well.

I'm using Dillon dies and I don't know if they are taper or rolled crimps. I can see the shape of the crimp, whatever it is.

Definitely can get the problems you described from too much crimp. If the round doesn't headspace correctly the bullet could start to engage the rifling or, more likely, the brass slightly is pushed beyond the end of the chamber. Even a tiny bit would cause the slide to be difficult to open. That shouldn't cause a failure to go into battery unless the cases were too long.

Some friends of mine, last year, both had some factory 9s that were made out of spec. The brass was too long. The slides were ramming them a little past the end of the chamber and they wouldn't go fully into battery. It was extremely hard to rack them out of their guns.

No heavy crimp should be required for rimless auto rounds. Basically you just want to remove the flare (bell) from the case mouth. Making up a dummy round, no primer or powder, and doing a "plunk test" is an excellent way to test you hand loads. Just see if it drops right in the chamber and you can hear/feel it hit the end of the chamber. Then easily drop back out.

Another thing to do is check for case neck tension and potential setback. Once you've set your crimp die and made your dummy round, push the bullet against something hard and make sure the bullet doesn't move into the case. If it doesn't, it's perfect. If it does, it could be brass that isn't taking the resizing, a die the isn't properly resizing, or an expander that's expanding the brass a little too much. Heavy crimp can possibly alleviate that, but now you're back to not properly headspacing.

I use Dillon dies, mostly, too. They are taper crimps for auto calibers. Others may disagree with this method, but this is how I set up my crimp die. Once the dummy round is at the crimp stage I lower the die until the bell is almost gone, visually. Then I continue with 1/4 turns, running my thumbnail down the side of the case until I can't feel the bell catching anymore. Add another 1/4 turn and get out the calipers to check I haven't gone beyond crimp specs. Plunk test and done. It probably took me longer to type that than actually do it.

Hope this helps and good luck with it Let us know how that baby shoots with some real 10mm stuff!

p.s. Highly recommend Starline brass for your 10mm loads. It's made with reloading in mind, starts out a little soft and work hardens over time. Their manufacturing tolerances are excellent.

Graybeard
Knowing about fatigue from overflexing I don't like to flare my case mouths much. Just enough to allow the base to start into it. Now that I'm using Acme beveled base bullets I don't need as much flare.
I'm wondering about your method for setting crimp. 1/2 turn is about .035 which, to me, is a lot when crimping. I typically go less than 1/8 turn from when I feel the die contact the case mouth. That seems to retain the bullet satisfactorily, for me.

Overall, I like how the gun shoots. Like all 1911s, accuracy is good (better than _I_ can shoot) and function is reliable for what I'm doing. Pin shoot tomorrow morning and if I can load some 10s today, I'll run it and report. The only thing I'll change will be to add a magwell. I've already added an enlarged mag button and extended slide lock. I do this to all my 1911s.

I think we're pretty close on the idea of setting up the crimp die. When I said I couldn't feel my thumbnail catching, I mean not catching on the sharp outside edge. There's still a tiny bit of flare there. Then I add 1/4 turn. I would agree that 1/2 turn after all flare was removed might be too much. I still plunk test and put the calipers on them to record my specs if anything needed to be changed.

Good luck in the pin shoot. I really miss doing that!