Leading-Things that make you go hmmm

Hal · June 3, 2000, 04:58 AM

FWIW, but interesting.
Two different load from my Trapper.

.44Mag 240 gr Hornady lead SWC/HP over a charge of Unique-approx 1000fps= heavy leading and keyholeing.

.44Mag 240 gr Hornady lead SWC/HP over a charge of 2400-approx 1100 fps=no leading and pretty accurate.

I need a chronograph. Oh, Dear are you reading this? Pappa's day is pretty soon. Pappa needs a chrono!

Seriously, the charge of 2400 is 17 gr, which should be enough to drive the slug faster than the 9.2 gr charge of Unique. The recoil of the Trapper pretty much says the 2400 load is warmer than the Unique. When I switch over to a jacket round using the Unique, I have a very accurate load that shoots mild. I always thought that leading was a result of velocity, even after reading some stuff that stated the leading resulted from the hot gasses melting the back end of the slug. Without actual numbers taken from a chronograph, it's mostly conjecture I guess, but still, interesting.

Chris McDermott · June 3, 2000, 03:26 PM

The load using Unique isn't sealing the bullet to the barrel (tech term is obturation?) and the hot gases are blowing by the bullet, eroding the bullet and causing leading and poor accuracy. The load using 2400 has a higher pressure that seals the bullet to the barrel, so no leading and better accuracy.
My loading manuals say that you are using the starting point loads, use 1 to 2 grains more of the Unique and see if the leading doesn't go away.

Paul B. · June 3, 2000, 03:28 PM

RAE. Interesting situation. I have an idea,but at best it is no more than a WAG. (Wild A$$ Guess)
First, the bullet in question is rather soft. Unique is a faster burning powder, and the sudden jolt may be causing gas cutting. #2400, being the slower burning of the two, may be giving the bullet a gentler start. Then to, the heat of the explosion from Unique may be generated faster, thus affecting the bullets base. Or maybe a combination of the two. If you could find a way to recover some of the Unique propelled bullets that are not too badly damamged, you might be able to determine if gas cutting, or skidding is the problem. A change in powders might help. I shoot a Winchester 94 carbine in .45 LC. I got anywhere from light to moderate leading with Unique. Changing to W-231 made leading almost non-existant.
Hornady bullets are swaged, so they have to be relatively soft. Maybe trying a hard cast lead bullet will cure the problem. You can probably get them the same size (.430 dia.) or go to .431 diameter, which is the size I use in my .44 magnums.
Don't know if this solves your problem, but it's something to think about.
Paul B.

**Bud Helms** · June 3, 2000, 08:16 PM

I swear to God, when I read the title to this post, I thought it was about leading the target. As in duck shooting. Imagine my surprise when the first thing that caught my eye was <BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>.44Mag 240 gr Hornady lead SWC/HP over a charge of Unique-approx 1000fps= heavy leading and keyholeing.

.44Mag 240 gr Hornady lead SWC/HP over a charge of 2400-approx 1100 fps=no leading and pretty accurate.[/quote]

[This message has been edited by sensop (edited June 03, 2000).]

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

June 3, 2000, 04:58 AM	#1
Hal Senior Member Join Date: October 9, 1998 Location: Ohio USA Posts: 8,563	FWIW, but interesting. Two different load from my Trapper. .44Mag 240 gr Hornady lead SWC/HP over a charge of Unique-approx 1000fps= heavy leading and keyholeing. .44Mag 240 gr Hornady lead SWC/HP over a charge of 2400-approx 1100 fps=no leading and pretty accurate. I need a chronograph. Oh, Dear are you reading this? Pappa's day is pretty soon. Pappa needs a chrono! Seriously, the charge of 2400 is 17 gr, which should be enough to drive the slug faster than the 9.2 gr charge of Unique. The recoil of the Trapper pretty much says the 2400 load is warmer than the Unique. When I switch over to a jacket round using the Unique, I have a very accurate load that shoots mild. I always thought that leading was a result of velocity, even after reading some stuff that stated the leading resulted from the hot gasses melting the back end of the slug. Without actual numbers taken from a chronograph, it's mostly conjecture I guess, but still, interesting.

June 3, 2000, 03:26 PM	#2
Chris McDermott Senior Member Join Date: March 30, 2000 Posts: 245	The load using Unique isn't sealing the bullet to the barrel (tech term is obturation?) and the hot gases are blowing by the bullet, eroding the bullet and causing leading and poor accuracy. The load using 2400 has a higher pressure that seals the bullet to the barrel, so no leading and better accuracy. My loading manuals say that you are using the starting point loads, use 1 to 2 grains more of the Unique and see if the leading doesn't go away.

June 3, 2000, 03:28 PM	#3
Paul B. Senior Member Join Date: March 28, 1999 Location: Tucson, AZ Posts: 3,800	RAE. Interesting situation. I have an idea,but at best it is no more than a WAG. (Wild A$$ Guess) First, the bullet in question is rather soft. Unique is a faster burning powder, and the sudden jolt may be causing gas cutting. #2400, being the slower burning of the two, may be giving the bullet a gentler start. Then to, the heat of the explosion from Unique may be generated faster, thus affecting the bullets base. Or maybe a combination of the two. If you could find a way to recover some of the Unique propelled bullets that are not too badly damamged, you might be able to determine if gas cutting, or skidding is the problem. A change in powders might help. I shoot a Winchester 94 carbine in .45 LC. I got anywhere from light to moderate leading with Unique. Changing to W-231 made leading almost non-existant. Hornady bullets are swaged, so they have to be relatively soft. Maybe trying a hard cast lead bullet will cure the problem. You can probably get them the same size (.430 dia.) or go to .431 diameter, which is the size I use in my .44 magnums. Don't know if this solves your problem, but it's something to think about. Paul B.

June 3, 2000, 08:16 PM	#4
Bud Helms Senior Member Join Date: December 31, 1999 Location: Middle Georgia, USA Posts: 13,198	I swear to God, when I read the title to this post, I thought it was about leading the target. As in duck shooting. Imagine my surprise when the first thing that caught my eye was <BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>.44Mag 240 gr Hornady lead SWC/HP over a charge of Unique-approx 1000fps= heavy leading and keyholeing. .44Mag 240 gr Hornady lead SWC/HP over a charge of 2400-approx 1100 fps=no leading and pretty accurate.[/quote] [This message has been edited by sensop (edited June 03, 2000).]