I have been reading the reloading book and ran across the need for a heavy roll crimp for my .475 and .500. Im lost.. does this require any special dies other than the set of 3 I ordered? Or is it just a different process?
Thanks in advance.

your seater die should seat AND crimp. it is best to do it in 2 seperate operations though, rather than adjusting it to seat and crimp at the same time..

I just roll the crimp until the groove is filled, call it moderate or normal. Over crimp and the brass tries to press into the lead. Brass can also buckle and bulge below the crimp. That will break your case tension.
Depend on case tension to hold boolits, crimp is just an aid.
I use Hornady dies, seat and crimp at the same time. I will not use the extra crimp die if the boolit is too tight to enter it.

I also use the Hornady dies for the big bores but in my experience I’ve found the expander plug to be just a tad on the large size. I purchased the Redding expander die for the 500 Smith & 475L, as you can remove the expander plug and polish it down, so nothing will touch your case until you put that small bell on the case mouth. I feel I get the strongest case tension in doing so but others don’t think I gain much, if anything, by doing this. I put a fairly heavy crimp on the 500’s and 475L, which 430Man may call moderate.

What I can tell you is,I have the dies from Lee(3 die set) for my .500,If I apply too much crimp it flares the case, too large at the base part of the bullet,and I can't put it in my Encore it just won't fit,but in a revolver cylinder it probably wouldn't be a problem.But anyway,my Lee die applies plenty of crimp for the .500 S& W.If you need a heavy crimp,after you seat your bullet unscrew your bullet seat part of your die and you should be able to get all the crimp you want,you would have to do this-a 4th step-after you have seated all your bullets.

My very heavy loads have led me to a couple things to help keep a uniform held bullet in the case thru the recoil of the previous rounds being shot. The first thing I do is use an old combo die, it is a 45 colt acp rcbs set. I have another set marked 45 colt 454 casual. and a third set marked 460 S&W. the later 2 seem to size the case a little larger than the 45 acp 45colt set, as this set leaves the bullet slightly enlarge the portion of the case it sets in. then the next thing I do in these three calibers is use a redding profile crimp die, and a heavy crimp, I crimp as heavy as I can as I dont over crimp but use a very heavy crimp! This is very important for accuracy at extended revolver range. The most important thing is to keep the bullet with the exact same tension for all shots in the cylinder. I think a strong crimp is more important with cast bullets even in a single shot, I always crimp my cast bullets in my single shot, I don't crimp my jacketed loads in my encores, but it is still important to keep all tension the same from round to round. One other thing I have seen many do with crimped revolver brass is not keep an eye on case length!! this is very important as there will be no way to control crimp and seating tension with cases longer and shorter from one to another. This is what I do with all my revolver calibers and over the years I have had excellent results from 32 long to 460 S&W!!

I have a set of Lee dies and when I load my 454 I seat and crimp at the same time. I never had a problem with the bullets moving forward and dragging on the forcing cone. That also goes for accuracy. I do have the 4 th. die that crimps only. I never buckled a case when seating and crimping together. Maybe I am one of the lucky ones? I've been reloading for only 4 yrs. but I have never had any problems.

Whitworth brought some factory .454 loads to shoot. I looked at them and asked why the crimp was so hard. They were REALLY crimped.
Boolits pulled like crazy when we shot.
None of my hand loads pulled at the same pressures and velocity.
I have trouble with an extremely heavy boolit in another caliber, I don't know how to hold the weight unless you pin the boolit in the brass. Can't beat inertia with any brass. There is a limit and crimp will not help.

430,

You obviously need to watch more of the old westerns. If you do you will see the cowboys punch/sling the gun forward when they shoot. This gets the gun moving forward to put all those bullets back in place ;^)

Seriously, I am with you on looking at 454 factory rounds. I have some flavors that I could not begin to get that much crimp without seriously distorting the bullet. I have run enough XTP's at fairly stout velocities, and the crimp I needed was no where near what came on a few of the older factory Hornady ammo I still have on hand. I actually have 3 dies set up for sizing. My lee for plinker lead loads, my RCBS for my 250/1100 fps loads, and a Redding for the upper end. Each die actually places a different style of crimp, and I place a lot of value on neck tension, with use of the proper "just enough" crimp.

Craig

I have had good luck with Lee Factory Crimp Dies for revolver rounds. Back in 2008 I tested the crimp by firing four rounds (335 gr CPB w/25 gr W296 @1300 fps) in my .454 BFR, leaving the 5th round in the cylinder then reloading and firing four more. After the first four rounds there was no change in the cartridges OAL. After 4 more rounds (8 rounds total) being fired the bullet moved forward .010" in the case. I didn't fire any more rounds at that point since I didn't want to risk locking the cylinder up, but I think it would have taken several rounds for that to happen.