The probable reason you're getting a variance in you OAL is because of the crimp you applied. You are probably actually swaging the brass with such a tight crimp. I don't use Lee dies, but I know many people who do and have no problems with them. Your problem in this case is your crimp, it's way overboard. As I said in the previous post, theses rounds should be perfectly safe to shoot. Make sure, when loading large capacity magnum rounds that you don't use less powder than is reccomended. The powder you are using is fairly tolerant of lower power loads, but WW296, H110 is not suitable for less than published loads. The best way to get a good, uniform, crimp is to seat the bullet and crimp the case mouth in two seperate steps. Seat the bullet so the top of the cannelure is just visible above the case mouth with no crimp. Using the same die, or another specific crimp die if you prefer, apply the crimp without the seating stem contacting the bullet. Your press and dies should serve you well for this caliber, the smaller press usually becomes an issue when you start full length resizing large rifle cases. If you want to invest some money in your hobby, get a digital reloading scale and a high quality powder measure, in that order if you want precision rounds. Most pistol powders will flow like water though a good powder measure. The digital powder scale is the biggest advancement in reloading in the last 15 years in my opinion. You might want to try a Redding Profile Crimp die if you want to use a different crimp die, a lot of people use the LEE factory crimp die and like them also. The crimp should taper into the cannelure, or crimp groove on a cast bullet, nothing more. The amount you taper it in is what you're looking for here. If you want rounds with the same OAL, you're going to have to trim your brass to the exact same length, as it almost never comes from the factory that way.Trimming the case also make the case mouths square, which allows for a good even crimp, which supports consistent combustion, which supports low velocity spread, which make for accurate ammunition. After brass has been trimmed, it needs to be inside and outside chamferred, but you should have a case chamfer tool even if you don't trim the brass, they come in handy. I would suggest a power trimmer if it's in the budget, because trimming brass is a tedious chore and the power trimmer makes it go by more quickly and easily. Since you load on a single stage press, you should also get a primer pocket cleaner to remove the residue from the primer pockets. There are many things you can do to get the utmost precision out of your handloads, but it all starts with sound techniques. You shoul practice your loading, once you are comfortable with the basic procedures you can look to enhance the consistency of your ammunition in order to increase accuracy. A chronograph is an invaluable aid in determining the quality of your ammunition. I use a Oehler Research Model 35 and like it, many shooters use the Chony, I have not used one of those. If the load shoots well and is consistent, you know you're on the right path. You can actually see a difference in your loads consistency with some of the different loading practices in my experience. I haven't loaded for the Casull, but there are over 25 die sets in my loading room, and most of it crosses over from one caliber to the other. Everything that you can make as close to exactly the same as you can, withing reason, will enhance the accuracy of the ammunition. All the shooting (testing) helps your skills, that's the most important thing. I would keep the 50 pieces of new brass seperate from the initial 50 you loaded, unless you plan to trim them all. Once your dies are set properly and firmly installed into your press, with all adjustments tight, you shouldn't have to mess with them during a single run of ammunition. Sorry to ramble with no particular direction here, hope it helps. The biggest thing you can do to ease into reloading is to buy a good manual, I'd suggest a Hornady in your case, and read the "how to" section front to back once or twice. In the case of the 454, you will want to stick to data to the letter, as this is a handgun round that works at rifle pressure levels and different bullets of the same weight occupy different amounts of the case capacity. This could turn a starting load into a max load when using a bullet that takes up more case capacity than the one specified in the data you're using, even it is the same weight.. I'm not trying to scare you away from it, just giving a safety tip.