200gr SWC in 45 Colt Using GreenDot: Quickload Check?

[rjrivero]

I found a recipe for 200gr SWC in an application for .45 Colt. It's off the Alliant Website.

Click here.

They call for 8.3 grains of Green Dot with CCI 300 primers. So I went ahead and plugged this into QuickLoad.

Could someone who has quickload make sure I'm not missing something?

The max pressure shows to be WAY too high for SAMMI Specs.

The Lead bullet measures: .647 long .452 Diameter. (I had to enter this manually.)

Thanks for the back up.

RJ

[AlaskaMike]

So when you plugged the numbers into Quickload, what did it come back with?

[Unclenick]

The Alliant load looks warm for an old gun. At about 19,000 psi predicted, the first thing that occurred to me is that they substituted .45 ACP pressure limits for .45 Colt by mistake. I've found a couple of warm loads in Alliant's data in the past, so that isn't impossible. It could also be a typo. With your bullet and their COL QL thinks 6.3 grains rather than 8.3 grains would produce the claimed ballistics.

Another possible source of error is that there are a lot of .45 Colt revolvers with throats large enough for the old .454 caliber bullets, but with the .451 post war barrel groove diameter. Lead bullets are soft enough that this allows the gun to shoot either pre or post war size ammo. A .452 bullet fired in such a loose throat could, indeed, have considerable gas blowby that reduces pressure and that may be what Alliant used?

Keep in mind that QL was developed for bottleneck rifle cartridges and is not as good with straight wall cases. The manual includes an example of a straight wall case that had to be given a false 7% extra capacity before the program predictions matched performance well, and I have run into one .500 caliber chambering that needed that. However, it is not enough to account for two grains of Green Dot.

In the meantime, since that 6.3 grain prediction comes close to matching Alliant's claimed ballistics, start there, and check it with a chronograph. Use that as feedback for QuickLOAD. For a given barrel length and powder charge weight and bullet, you'll find that pressure and velocity have a direct relationship. Just expand or contract the case water capacity artificially in the program until you get a velocity match, then see what the pressure prediction is? It will be pretty close. Use the chronograph at 15 feet from the muzzle to match Alliant's measurement distance.

[rjrivero]

Thanks Unclenick. Will do exactly as you suggest. I realize that Quickload isn't Gospel, but I find when something looks "fishy" it's best to discuss it before testing it.

Too bad my chronograph is older than I am. It may be less of a chore to set it up if it wasn't quite literally an antique.

[Unclenick]

Sounds like my Oehler. Two lamp stands and pole and three screens to run wires for. It's still the accuracy standard, though the CED unit seems to be just as accurate for me and is more flexible.

A setup tip: I take the bolt out of a rifle and prop it up on bags so its sight is aiming at the target. I then put a laser bore sighter in it. I walk out to the chronograph move the setup around until I can see the laser on my palm in the middle of both screens, where I want the bullets to go.

No reason you couldn't do that with a Revolver. You can open the cylinder on a DA or remove it on an SA to ensure the RO that all is safe. The rifle is a little easier to bag, though. You just have to put it up high enough to match your bagged handgun position afterward.

I also stick a range safety flag (ECI; empty chamber indicator) in a rifle action while I do this. The flag is to remind me to take the sighter out of the muzzle before I load and shoot. With a Sharpie I wrote on it "take the laser out". I've seen a couple pictures of barrels blown by those who forgot.

[rjrivero]

Thanks again, Unclenick. I appreciate your sage wisdom.

I've been thinking about this issue all day, as it sits in my craw a bit.

I wonder if the powder prediction part of QuickLoad was done at "usual operating pressures" or at handgun pressures.

Green Dot, being a shot gun load, is probably intended to be used at 1200-1500 psi. When we use it in a handgun cartridge, we are asking it to burn in an environment of 20,000psi (give or take).

I've heard of some guys experimenting with Lil Gun to make short barrel .223 loads for use in AR pistols and SBR's which would be asking that particular shotgun powder to operate around 55,000 PSI.

I wonder if the operating pressures will effect the burn rate and therefore the peak pressures.

The Chrono won't lie.

[rjrivero]

I forgot to mention above, I also took a few mintues to talk to the folks at Alliant.

The good-ole boy on the other end of the phone assured me that "He's a seasoned reloader, and I don't see anything wrong with 8.3grains of Green Dot behind a 200gr LSWC. That sounds about right."

I was asking if they had the PRESSURE data with their loads. They did not. He did assure me that Speer had done the testing for that load and it would have to be below the 14000 psi threshold.

It may very well be, but as I said above, the Chrono won't lie.

[Unclenick]

The shotgun pressures are missing a one in the 10,000's place. Here are the SAAMI maximums in PSI (MAP):

10 gauge 11,000
12 gauge 11,500 (except 3-1/2 in.)
12 gauge 3 1/2 in.14,000
16 gauge 11,500
20 Gauge 12,000
28 gauge 12,500
.410 Bore 2 1/2 in. 12,500
.410 Bore 3 in. 13,500

SAAMI max for the .45 Colt is 14,000 psi, as you say, and the CIP max is 110 MPa or 15,954 psi. So the cartridge really is only a little above shotgun range.

Regarding the Alliant load, be wary. Speer is famous for hot loads historically. They cleaned up their act on a lot of their old data, but many of their pressures are calculated and are to be taken with a grain of salt. For example, we had a thread not long ago by a fellow using one of their .243 Win loads in a Handy rifle. The rifle kept popping open and the velocities were about 200 fps above the manual velocities. IIRC. He'd checked the gun latch for wear and correct lock-up, and it was fine.

Using the method I described in the earlier post in this thread, I figured he was at about 77,000 psi. That explained the velocity and the popping open. It was basically a proof load. He'd called Speer and they continued to claim the load was safe and they stood by it even after he explained what he'd found.

The Speer manual says their .45 Colt loads were developed in a Colt SA Army revolver, not in a pressure test barrel in a universal receiver. So I doubt it was pressure tested. That revolver could have the loose chambers I mentioned or a big barrel/cylinder gap or other factors that lead to lower pressure than you'll get. So, 6.3 grains and a chronograph still seems to me to be the way to go. Work up slowly.

[zippy13]

rjrivero,

FYI: 8.3 of Green Dot is the load that's printed in Alliant's Reloader's Guide.

[Unclenick]

That's where he got it, but in the online version; they match. But by Alliant's own admission, it is actually a load developed by Speer, and sure enough it is in the Speer manual, too.