Shooters Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter #1
I just bought a set of RCBS dies for the .45 Colt. I believe the RCBS seating die does a roll crimp. If this is so, can I use my Dillon .45 ACP taper crimp die to do the .45 Colt and leave the RCBS seating die backed out so it does not crimp at all?

Thanks
 

·
Super Moderator
Joined
·
9,551 Posts
Why? What are you feeding?

Normally, a taper crimp does a great job of keeping the bullet from telescoping back into the case (which is what magazine fed firearms want to do as the bullet smacks into the feed ranp). With revolvers, the force acting on the bullet tries to jerk it out of the case forward (the cylinder of a revolver doing a good imitation of an inertia bullet puller as the gun fires), which is what a roll crimp is best at stopping.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #3
I am shooting a 255 grain cast bullet in a Ruger .45 Blackhawk at fairly low velocity. I am using 8 gr. Unique. Don't do any formal shooting with it, just plinking. Thought I would not have to be so picky with case length if I taper crimped.
 

·
Super Moderator
Joined
·
13,431 Posts
But in the mean time, it depends on your brass. .45 Colt specs allow it to be about three and a half thousandths thicker than .45 ACP brass. If your rounds will fit in the Dillon die, then yes, you can use it to taper crimp. With light loads that should be OK. Just watch for any sign the bullets are coming out and sticking out beyond the end of the cylinder. That will jam a revolver right up.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #6
Thanks for all the replies. I tried it and it works. I will heed your advice and watch for any signs of bullet movement.

Greg
 

·
Registered
Joined
·
4,740 Posts
I am shooting a 255 grain cast bullet in a Ruger .45 Blackhawk at fairly low velocity. I am using 8 gr. Unique. Don't do any formal shooting with it, just plinking. Thought I would not have to be so picky with case length if I taper crimped.
With the load you're shooting, don't expect much growth in case length. I shoot 9 gr. Unique with the same bullet and there just isn't much change. You can probably make the case (no pun intended) that you want to extend casemouth life by taper crimping but .45 Colt brass is not that difficult to obtain. As previously posted, taper crimp is designed to prevent bullets from being pushed into the case. Roll crimp is designed to prevent bullet from coming out of the case. IMO, with revolver ammunition suggest you use the roll crimp just like factory ammunition. Just my dos centavos, YMMV.
 

·
Super Moderator
Joined
·
13,431 Posts
I am reminded of a past exchange with William Iorg in which he reminded me that old time bullseye shooters used roll crimps for best accuracy from the .45 ACP in the 1911. The roll crimp actually is the universal one, since it prevents either setback or inertial bullet pull. The taper crimp was popularized solely on the proposition that it extends case life (which it does; I've had up to 50 load out .45 ACP cases taper crimped, while roll crimped mouths often start splitting after just half a dozen reloads). But the accuracy thing is another consideration. A roll crimp increases start pressure more than a taper crimp does. That can improve ignition consistency and velocity consistency, depending on your powder and primer. You need to try both in your particular gun to see what shoots best for you?

Marshal is correct about case growth. It really only happens in cartridges fired at chamber pressure above about 30,000 psi or so. The pressure has to be high enough to stick the brass to the chamber wall against rearward pressure on the head to cause stretching. In lower pressure handgun loads the whole case backs up under pressure, and you often find cases actually shrink slightly with each load cycle from the sizing die flowing the brass back. My .45 ACP target load cases shrink an average of about half a thousandth per load cycle. So, if you identify your shortest .45 Colt case and grind the tip of a Lee trimmer down so you can trim them all to that same length, then load and fire them all the same number of times, you should find the lengths stay pretty well matched.
 

·
Registered
Joined
·
4,740 Posts
I am reminded of a past exchange with William Iorg in which he reminded me that old time bullseye shooters used roll crimps for best accuracy from the .45 ACP in the 1911. . . The taper crimp was popularized solely on the proposition that it extends case life (which it does; I've had up to 50 load out .45 ACP cases taper crimped . . .
I believe the American Rifleman once tested both the roll vs. taper crimp in .45 ACP to determine which gives the better accuracy. For the life of me, I cannot recall which one came out on top, however, loads which give a one hole group from a Ransom rest do not necessarily look the same when fired one-handed during the rapid fire stage of bullseye shooting at Camp Perry. My wobble area alone would negate any super accurate ammunition I could possiby load. My point being that we can pursue accuracy to the nth degree but at some point, other factors come into play.

The fact that you get over 50 reloads with the taper crimp in .45 ACP is, in my limited experience, phenomenal. Most of my brass gets trashed at 25 or so reloads simply due to the number of casemouth splits I have already experienced and the ones that are potentially on it's way.

As to taper crimping the .45 Colt, it's doable but why add another step in the reloading process that could result in the bullet jumping the casemouth and tying up the revolver? I believe the ammunition companies have a good reason for putting taper crimps on semi-auto ammunition and roll crimps on revolver ammunition.
 
1 - 9 of 9 Posts
Top