300 gr. Cast Bullet Loads in a Ruger Blackhawk 45 LC?

Lee S. Forsberg · December 13, 2015, 01:15 PM

Anyone have loading data for 300 gr cast bullets in a Ruger Blackhawk 45 LC?

Kosh75287 · December 13, 2015, 01:31 PM

7.0/Unique/300 Cast, if you want to stay within sight of factory pressures.

9.0/Herco/300 Cast for something a little more energetic

17.0 - 19.5/2400/300 Cast for the "3H", loading.

As with all reloading work-ups, start 10% below max and work up gradually. With 2400, 12.8 grains SHOULD give you pressures near or slightly above the SAAMI maximum. Your Ruger is very strong and will tolerate higher pressures, but I don't know how powerful you want the load to be.

If you're like me, when you start to increase powder charge in the work-up, your shooting hand will start complaining before the revolver will.

black mamba · December 13, 2015, 08:18 PM

Three good 300 grain loads for my 5½" Bisley are:

10.5 grains of LongShot with standard primer (950 fps),
13.0 grains of HS6 with magnum primer (1050 fps), and
21.0 grains of H4227 with standard primer (1100 fps).

Kosh75287 · December 13, 2015, 08:29 PM

I concur with Black Mamba concerning the IMR 4227. It's a very good powder for heavier-than-usual projectiles at faster-than-usual velocities.

Lee S. Forsberg · December 13, 2015, 11:00 PM

Thanks for the information. What diameter do you size cast bullets to for use in a Blackhawk?

Kosh75287 · December 13, 2015, 11:18 PM

I shoot my .45 Colt stuff from a Ruger Redhawk, so it might not be the same, but I think all mine come cast at .452". Double check this, but I think nearly all .45 Colt revolvers made after WWII have .452" chambers, bores and throats.

454PB · December 14, 2015, 02:08 PM

Some years ago, there were reported problems of Ruger Blackhawk .45 Colts having undersized throats. If yours has this problem, the only solution is to have the throats reamed. If your throats are .450", that's going to be the diameter of the bullet when it enters the forcing cone.....and the result is leading and poor accuracy.

It's easy to check, place a .452" bullet in the cylinder and push it through and out the front. If there is resistance, use a micrometer and measure the slug. If there is no resistance, you may have oversized throats.

The bottom line is that throat diameter determines correct sizing, not bore diameter.

I own both a 1980's BH .45 Colt convertible and a circa 2006 SBH Hunter, and both have .4525" throats and .4515" bores. I size all my cast boolits .452", and they shoot better than I can hold.

Lee S. Forsberg · December 14, 2015, 07:53 PM

Some years ago, there were reported problems of Ruger Blackhawk .45 Colts having undersized throats. If yours has this problem, the only solution is to have the throats reamed. If your throats are .450", that's going to be the diameter of the bullet when it enters the forcing cone.....and the result is leading and poor accuracy.

It's easy to check, place a .452" bullet in the cylinder and push it through and out the front. If there is resistance, use a micrometer and measure the slug. If there is no resistance, you may have oversized throats.

The bottom line is that throat diameter determines correct sizing, not bore diameter.

I own both a 1980's BH .45 Colt convertible and a circa 2006 SBH Hunter, and both have .4525" throats and .4515" bores. I size all my cast boolits .452", and they shoot better than I can hold.

You are correct reaming the throats is what needs doing. This is one of those revolvers. The throat diameters on both cylinders are .450". The bore looks to be about .448". Same as yours only smaller. Now to make the bullets small enough to pass through the throats. If the bore is smaller than the throats it may turn out to be accurate.

454PB · December 14, 2015, 09:44 PM

A .448" bore is unusual....but if so, you could still get acceptable accuracy by sizing the boolits to .450". That is assuming the cast boolit design allows enough lube groove after sizing, as some (especially Lee) have very shallow lube grooves.

I size a Lee 340 gr. FN designed for 45/70 down from an as cast diameter of .460" to .452" for use in my .454 Casulls, and they shoot well.

Lee S. Forsberg · December 14, 2015, 10:47 PM

Your right the lube grooves do tend to get shallow when sized from .459" down to .450". I made up for it with powder coat. Between the two I should have enough lube.

December 13, 2015, 01:15 PM	#1
Lee S. Forsberg Member Join Date: July 31, 2005 Posts: 36	300 gr. Cast Bullet Loads in a Ruger Blackhawk 45 LC? Anyone have loading data for 300 gr cast bullets in a Ruger Blackhawk 45 LC?

December 13, 2015, 01:31 PM	#2
Kosh75287 Senior Member Join Date: October 15, 2007 Posts: 820	7.0/Unique/300 Cast, if you want to stay within sight of factory pressures. 9.0/Herco/300 Cast for something a little more energetic 17.0 - 19.5/2400/300 Cast for the "3H", loading. As with all reloading work-ups, start 10% below max and work up gradually. With 2400, 12.8 grains SHOULD give you pressures near or slightly above the SAAMI maximum. Your Ruger is very strong and will tolerate higher pressures, but I don't know how powerful you want the load to be. If you're like me, when you start to increase powder charge in the work-up, your shooting hand will start complaining before the revolver will. __________________ GOD BLESS JEFF COOPER, whose instructions, consultations, and publications have probably saved more lives than can ever be reliably calculated. DVC, sir. انجلو. المسلحة. جاهزة. Carpe SCOTCH!

December 13, 2015, 08:29 PM	#4
Kosh75287 Senior Member Join Date: October 15, 2007 Posts: 820	I concur with Black Mamba concerning the IMR 4227. It's a very good powder for heavier-than-usual projectiles at faster-than-usual velocities. __________________ GOD BLESS JEFF COOPER, whose instructions, consultations, and publications have probably saved more lives than can ever be reliably calculated. DVC, sir. انجلو. المسلحة. جاهزة. Carpe SCOTCH!

December 13, 2015, 11:18 PM	#6
Kosh75287 Senior Member Join Date: October 15, 2007 Posts: 820	I shoot my .45 Colt stuff from a Ruger Redhawk, so it might not be the same, but I think all mine come cast at .452". Double check this, but I think nearly all .45 Colt revolvers made after WWII have .452" chambers, bores and throats. __________________ GOD BLESS JEFF COOPER, whose instructions, consultations, and publications have probably saved more lives than can ever be reliably calculated. DVC, sir. انجلو. المسلحة. جاهزة. Carpe SCOTCH!

December 13, 2015, 08:18 PM	#3
black mamba Senior Member Join Date: September 13, 2011 Location: SW Florida Posts: 890	Three good 300 grain loads for my 5½" Bisley are: 10.5 grains of LongShot with standard primer (950 fps), 13.0 grains of HS6 with magnum primer (1050 fps), and 21.0 grains of H4227 with standard primer (1100 fps).

December 13, 2015, 11:00 PM	#5
Lee S. Forsberg Member Join Date: July 31, 2005 Posts: 36	Thanks for the information. What diameter do you size cast bullets to for use in a Blackhawk?

December 14, 2015, 02:08 PM	#7
454PB Senior Member Join Date: February 23, 2005 Location: Helena, Mt. Posts: 122	Some years ago, there were reported problems of Ruger Blackhawk .45 Colts having undersized throats. If yours has this problem, the only solution is to have the throats reamed. If your throats are .450", that's going to be the diameter of the bullet when it enters the forcing cone.....and the result is leading and poor accuracy. It's easy to check, place a .452" bullet in the cylinder and push it through and out the front. If there is resistance, use a micrometer and measure the slug. If there is no resistance, you may have oversized throats. The bottom line is that throat diameter determines correct sizing, not bore diameter. I own both a 1980's BH .45 Colt convertible and a circa 2006 SBH Hunter, and both have .4525" throats and .4515" bores. I size all my cast boolits .452", and they shoot better than I can hold.

December 14, 2015, 07:53 PM	#8
Lee S. Forsberg Member Join Date: July 31, 2005 Posts: 36	Some years ago, there were reported problems of Ruger Blackhawk .45 Colts having undersized throats. If yours has this problem, the only solution is to have the throats reamed. If your throats are .450", that's going to be the diameter of the bullet when it enters the forcing cone.....and the result is leading and poor accuracy. It's easy to check, place a .452" bullet in the cylinder and push it through and out the front. If there is resistance, use a micrometer and measure the slug. If there is no resistance, you may have oversized throats. The bottom line is that throat diameter determines correct sizing, not bore diameter. I own both a 1980's BH .45 Colt convertible and a circa 2006 SBH Hunter, and both have .4525" throats and .4515" bores. I size all my cast boolits .452", and they shoot better than I can hold. You are correct reaming the throats is what needs doing. This is one of those revolvers. The throat diameters on both cylinders are .450". The bore looks to be about .448". Same as yours only smaller. Now to make the bullets small enough to pass through the throats. If the bore is smaller than the throats it may turn out to be accurate.

December 14, 2015, 09:44 PM	#9
454PB Senior Member Join Date: February 23, 2005 Location: Helena, Mt. Posts: 122	A .448" bore is unusual....but if so, you could still get acceptable accuracy by sizing the boolits to .450". That is assuming the cast boolit design allows enough lube groove after sizing, as some (especially Lee) have very shallow lube grooves. I size a Lee 340 gr. FN designed for 45/70 down from an as cast diameter of .460" to .452" for use in my .454 Casulls, and they shoot well.

December 14, 2015, 10:47 PM	#10
Lee S. Forsberg Member Join Date: July 31, 2005 Posts: 36	Your right the lube grooves do tend to get shallow when sized from .459" down to .450". I made up for it with powder coat. Between the two I should have enough lube.