.45 acp KKM Barrel

I've been shooting a .45 KKM barrel with lead 200 gr Magnus lswc. I've had excellent, no outstanding results at 50 yds with it. I haven't Ransomed it yet, but I'm getting really tight clusters and am calling all my shots. I've used 3.8 gr - 4.0 gr BE & 3.8 gr - 4.2 gr 700X with similar results. Using .469" crimp. I load with .030" shoulder out of case. I don't measure OAL.
So in my opinion you can't go wrong with this barrel/ammo combination. Last night in practice I shot a 194 SF with two 8's.
Jon

Shouldn't any quality barrel made to national match standards do well? Ive had good luck with Barstow , kart and colt made to NM specs.

I'd like to think so, but I've heard people say don't use a kkm if you shoot only lead. So I've been finding out for myself. Mine likes lead. Will be building another kkm gun soon.
Jon

Jon Eulette wrote: ... Using .469" crimp....

I have heard that crimp measurement several times.  But when I load either a 180 gr or a 200 gr LSWC (lately from Dardas) and measure the (Starline) case where the base of the bullet is, I get a consistent 0.471" or 0.4715" diameter.  So wouldn't a .0469" crimp actually cause the case to cut into the bullet?  I heard that deforming a lead bullet is a no-no.

Thomas

joy2shoot wrote:

Jon Eulette wrote: ... Using .469" crimp....

I have heard that crimp measurement several times.  But when I load either a 180 gr or a 200 gr LSWC (lately from Dardas) and measure the (Starline) case where the base of the bullet is, I get a consistent 0.471" or 0.4715" diameter.  So wouldn't a .0469" crimp actually cause the case to cut into the bullet?  I heard that deforming a lead bullet is a no-no.

Thomas

If you are shooting good slow fire scores, I wouldn't be worried at all about a .001" to .0015" difference in my crimp. Spend the time training.

I use .469 because. I also shoot shortline powder puff loads. I need the tighter crimp to get good pressures with the lighter loads. And it's working at 50 yds as well. So if it's deforming the bullet that's only going to happen at the crimp location which is at front of bullet near the shoulder. The crimp will open during firing.  I haven't had good luck going bigger.
Jon

Thanks Jon for the insight.  I too shoot shortline powder puff loads and the brass practically dribbles out of the gun (and I am using the lightest spring made for the gun).  So once this year's season is over, I might experiment with a tighter crimp for the short line load.  No issues with the long line load, so I will leave that crimp alone (it is easy for me to change crimp since I use Redding Competition Pro micro adjustable crimp dies).

have you measured the dardas bullets, ive found even though a company says .452 sometimes they are larger or smaller. .469 gives a good powder burn, some guns wont reliably work with over .470 if the have match chambers. If yours is doing well. no need to change

I've seen a lot of match chambers and .470 should work in all of them! Without naming names I've worked on pistols by 2 of the premier BE smiths in the country and their minimum dimension chambers will easily function .470 crimped catridges. Jacketed bullets are running .471-.472! Might want to look at OAL as culprit and not crimp diameter. Too many BE shooters seat out to far for lead and get lead ring in chamber that will cause far more issues than crimp.
Jon

Jon Eulette wrote:...Too many BE shooters seat out to far for lead and get lead ring in chamber that will cause far more issues than crimp.
Jon

Good info, I was wondering if the chamber leading was normal or not.

Are you using cast or swaged Magnus bullets?

Cast. I do have some swaged Magnus' to try. That leading should never be there. Some guys try compensating for out of spec chamber headspace by seating farther out. Does more harm than good.
Jon

Whoops, I was thinking of the leading that appears midway in the chamber at the top from the feeding of the round.

I've been shooting the swaged Magnus 200 ever since I weighed a sample of them and found how low the weight deviation was.

Load a cartridge into your chamber then pull it and look to see if tip is deformed. If it is your chamber ramp isn't relieved enough and its forcing cartridge into chamber deforming bullet hard enough to lead chamber.
Jon

Jon Eulette wrote:...  Might want to look at OAL as culprit and not crimp diameter....

The attached image may be hard to read, but it shows my bullet seating stem on top of a finished cartridge.  The bullet is a 180 gr lead SWC.  Basically, I seat so that the top of the shoulder of the bullet is just a hair or two above the case mouth.