40S&W Bullets Tumbling???

NorthernPF

NorthernPF

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Hey Guys,

Here is my predicament. This is the first time that any of my hand loads have tumbled. I just shot a competition and it was noticed that my bullets were key holeing. Just looking for some advice to possible solutions. I'm shooting 180gr Lead Cast DRG Bullets on top of 5gr of Win 231 (~875fps). OAL is 1.100"

Thanks for any info
 
5.0 grains of 231 is a max load for a jacketed 180 and it's faster than 875 fps(947 fps), according to Hodgdon. OAL is a tick short too. So something about your load isn't right if that velocity is accurate. No .40 S&W cast data on their site.
However, keyholing is caused by undersized bullets, oversize barrel, excessively low velocity and, with cast bullets, a lack of lube. If this is something new, you may have leading like Spawn-Inc. suggests. Mind you, leading is caused by trying to drive a cast bullet too fast. Using a jacketed load with a cast bullet will do that.
 
One thing to consider is that the barrel is getting leaded up. If there are still lead deposits in the rifling grooves, then the grooves may not grip the bullet enough to get the proper spin. If the bullets aren't spinning at the proper speed, then you will get keyholes.

I would thoroughly clean out all traces of lead in the barrel every 100 to 150 rounds and see if that works.
 
Bullets I'm using measured at 0.400"

My Lyman 49th says that for a 175gr Cast bullet (I use 180gr but it's as close as I can get) using Win 231 Min is 4.3gr and Max is 5.8gr. Thanks for the info guys. I'll try to put my OAL at 1.125" to see if that helps and I'll ease up on the crimp a bit.
 
NorthernPF

I know this guy whose initials are bigedp51 who had the same problem because he was pushing lead bullets down a funny shaped Glock barrel. :bangHead:

"This guy" switched to plated bullets with the stock Glock barrel and the problem vanished. :rolleyes:

40SampW001_zpsfc7e7b54.jpg


And don't let words "CZ pistol" throw you off below, on rifles and handguns you can tweek the overall length of the cartridge to improve accuracy.
READ what the poster "Wobbly" has to say and picture about seating length

How to determine Max OAL for a CZ Pistol
http://www.czfirearms.us/index.php?topic=34225.0

And then this guy found out at lower velocities even lead bullets can work in that silly metric Polygonal barrels.

Make Right With a “.40 Lite”
Light-recoiling .40 S&W loads for action shooting
By Paul Scarlata

http://www.handgunsmag.com/ammo/ammunition_40lite_091806/

P.S. sunray is now posting at our American CMP (Civilian Marksmanship Program) reloading forum. Can you tell me if this is a Canadian plot to lower American reloading standards or did you guys just deport him. You have no idea what it felt like to see him posting there, the Doctors are still treating me for depression and helped me from committing suicide.

sunray some reverse psychology about your stupid posts in a American reloading forum for people who shoot at Camp Perry's National matches.

 
You left out a lot of information
Gun/ barrel length etc
875 fps is this estimated or measured with a chrony

at what distance is it key holeing ?

are you getting leading ?
did you actualy measure the lead bullet or go from information on the box ?

the length of the round you use depend on the shape of the bullet and other factors

if it passes the plont test and it fits in the mag and feeds ------> that is the length you should use --- and --- it will vary from gun to gun from one bullet to another
 
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