Lee Factory Crimp/Cast Bullet Modification

crimp

I have never use the Lee crimp die on pistols.I do use it on rifle.many are dropping the pistol die.I have never had to resize my loaded rds.I roll crimp all my pistol rds.there was no taper crimp when I started loading,so I never saw reason to change.

I dont need to resize my loaded rounds either, even in my Smith which has tighter chambers than anything else I own. I like the rifle die as well, and it has made a big difference in accuracy in my 444 Marlin. I started with the roll crimp too, but, I like the pistol die, and the performance I got from the crimp, but, went I went to the larger cast bullets it just ruined accuracy. I think the crimp alone is worth keeping the pistol die for, so I just modified the die to suit my needs. At least others have an alternative to dropping the die altogether...

Correct heavy crimp for Lee Factory Crimp for pistol, and Lee collet crimp for rifle dies. I would like to thank Gun 4 Fun for seeing the trouble I was having posting photos on this forum, and taking the time to walk me through the steps. Its nice to know that there is somebody here who cares enough to help out a fellow forum member!!! Thanks G4F!!!!!

How are you adjusting your dies, flat? To me that is an exorbitant amount of crimp. Just me though. I have gotten by for years with much less and to me that means brass life.

I do like the looks of that bigger 44 case though. Never shot one yet, maybe that will be my next firearm! Same molds, same type of rifle only with real rifle performance!

I could go for that.

Glad to help . I have been following this thread with some interest.

I know the picture thing can be a little frustrating until you get a handle on it, and I was more than a little curious as to what your loaded cases looked like. I am always up for learning something that is new to me.

The big Marlin round, and the .45/70 are both impressive looking rounds, especially when compared to handgun rounds. I have not loaded for the .444, but I have quite a bit of experience with the .45/70 in a couple of different rifles.

Your crimp certainly looks like it'll hold the bullet in place, both from jumping crimp, and from setback, both of which can be very costly in a life or death situation when hunting dangerous animals.

SC; On the Lee crimp. G4F has it right, this type of crimp if applied correctly will stop set back and jump. It will also aid in ballistic uniformity/accuracy. Just about everybody I know who are serious lead shooters, accuracy buffs, and (like G4F mentioned) those that hunt large dangerous game with rifle and handgun, use this type of crimp.

The crimping groove on most cast bullets is about .050 to .060 or so. On most cast bullets, the top part of the groove is a flat/square edge that sits under the nose. The bottom part of the groove is a bevel.

The key to getting the proper heavy crimp is to allow the swage of the crimp at the mouth of the case to sit against the flat/square edge of the crimp groove beneath the nose of the bullet, and then to apply enough pressure to the crimp to allow the lower portion of the crimp to pinch the bevel on the lower side of the crimp groove. You will know when you are there by the pressure that is exerted by your press, and when you see a near vertical swage on the case mouth. (see my previous photos).

What you will end up with is a swaged crimp that is as wide as the crimp groove on the bullet. This is the ideal crimp for this type of die............also, I have used these dies for years, and have cases that I have used for years and many loadings.....well over 20 with one set of 100 cases that I use for 44 Mag testing purposes. I have never had a case mouth crack or any case issues, and, I have never annealed the cases.

I believe I read that you are now working with the 45LC in a handgun? If so, set your dies up to size in this manner and then go to your starting load and work up.......I think you will like the benefits of this type of crimp, especially for the top end loads! Use this crimper die as an extra/seperate step. Seat your bullet in your regular seating die, and allow that die to roll the bell of the case mouth back to its vertical position. Then go on to the Lee Die to apply the final swaged crimp. If you are working with compressed powder charges, allow your regular seating die to apply a light crimp to hold the bullet until the Lee die completes the crimping process.

Here is a photo of my 444 Marlin. I built this rifle 2 years ago. I shortened the barrel to 16.5", and lapped it to a perfect .4305 chamber/.4300 muzzle dimension. I shoot cast .432 sized bullets. I also modified this rifle to take an oversized COL. The standard for the 444 in the Marlin is 2.580. After reworking the cycling spaces (which requires parts modifications/TIG welding, etc), retiming the action and giving everything a precise fitting and polishing. The action is now "butter smooth". This rifle will now take a 2.655 COL. That is an increase in 5 grains of powder, uncompressed! This gives me the power of the 404 Jeffrey/400-450 Nitro Express 3" with like weight bullets. I also bedded and freefloated an MPI Kevlar/Graphite stock and finished it off, added a reworked WWG Happy Trigger and WWG Bearproof Ejector, and a Longhunter one piece firing pin. The rear peep, front post, and scope rail is by XS Systems, the rings are Warne Optima Quick Detachables, and the Scope a Leupold 2.5 Ultralight. This gun weighs 6.2 pounds field ready, and is short and very handy in the thick environment that I hunt in...and best of all it is a "one holer"!!!......The revolver in the photo is my New Model Super Blackhawk that I just finished up on. Birds Head Grip, cocobolo grips, 4" barrel...the works. I carry this in a weak side crossdraw holster that was made for me by Alan at Chisholms Trail Leathers. It is the Ranger Flat Top Crossdraw, and for rifle carry it is ideal...keeps the handgun out of the way of the rifle...carries close and tight to the body, and allows for draw with either hand....This gun is also set up for lead, and shoots one hole groups.

FT-

could you post some more pictures of your crimps, both before and after? I am curious about this style crimp. I don't see anything wrong with them, but I don't use them either, so maybe I can learn something new here.

flat top said:

I load oversized cast bullets in my handguns...normally .431, .432

I also like the Lee Factory Crimper, and use it with a heavy crimp for my 44 Mags.

The Lee Factory Crimper has a a carbide collet insert in the base of the die, and that insert is used to size the loaded round before the crimp takes place....according to Lee, to allow the loaded cartridge to fit standard sized chambers, and to reduce crushing of the cartridge during the crimping process. The only problem with this collet is the fact that it WILL size down an oversized cast bullet. A buddy of mine reported that his Lee Factory Crimp Die was sizing down the case/oversized cast bullets as much as .002 therefore negating the oversize condition of the bullets and affecting accuracy.

I ground the collet in my die, to allow a .432 seated bullet to "slip fit" the collet. The die collet no longer "sizes" the rounds that I crimp, and it works properly and gives a nice uniform and square crimp, and will not crush the cases during the crimping process regardless of the size of bullets that I am working with.

Grinding the carbide collet by hand is very hard, to impossible, but any good machine shop that has a cylindrical grinder could accomplish this task.

Because of the amount of folks that shoot cast bullets on this forum, I though (that if this has not been mentioned before), that it should be posted for your info.........

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Very Good Tip Thank you

Scrapper; I hope this hint comes in handy....

G4F; Your photos: 1. Case belled and bullet ready for seating in the standard seating die. 2. The bullet is seated, and the bell has been reduced to near verticle. 3. The Lee Crimp die (used as a seperate operation) applies a firm crimp to the case mouth. Notice that the crimp is near verticle, and will not allow the bullet to jump or set back, because of the crimps "fit" in the crimp groove of the bullet. This is the "ideal" crimp for this type of die.

I love the looks of that crimp which is why I'm going to get one for my 460 Mag. I should get one for all the cartridges I load, 454 Casull, 45 Colt, 40 S&W.

Thanks for all the tip as they are greatly appreciated.

FT, what is that blue band, and where did that brass bullet come from?

Scrapper; If you like the looks of the crimp, you will really like its performance!

G4F; PM sent.

Thanks for that info. That is really cool!

flat top said:

Scrapper; If you like the looks of the crimp, you will really like its performance!

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I hear that loud and clear I'm sure it help the powder burn much more completely before the bullet cuts loose. I understand the slower burning powders like the crimp.

Scrapper; The powder "will" burn more completely, because the crimp helps charge to charge uniformity. It really shows up on the Chrono (more uniform velocities/lower SD's), less unburnt powder, and on paper...tighter groups! Remember, always back off your favorite load if you are going to change to this type of crimp, and then work back up. In some cases I have found that the load does not change, and in other cases it does, by a bit.....so, it is best to err on the side of caution, especially if you are pursuing maximum performance loads. This crimp is not the end all for absolute accuracy. It is just a part of what needs to be done to achieve those one hole groups, but, myself and others have found by comparison, that this crimp is the best crimp going.

Thanks flatop, I'm going to get a chronograph one day and that's when I'll try changing what I'm loading now (460 S&W Mag with 200 gn Hornady FlexTip Win 296 @ Hornadys minimum recommendation, using WLR).

Right now I don't have a way of checking velocities so as long I hit the target with at least 4-5" groups free hand @ 50 yards with my 8 3/8 460 Mag with open sights I will stay with those loads. I still have to try bench resting and I also have a scope (Bushnell 3200 Elite) to try out. I'm working slow cause I currently have a trouble getting to the range.

Patience is a virtue

Well, I guess I still don't get the NEED.

Well, I thought I would give this type of crimp a try with my regular Lee dies.

Guess what? It looks just like the one from the modified factory crimp die. So, I ask again, why go to the extra work?

The one on the left is a 45Colt with a H&G #502, 240gr Keith bullet designed for the 45AR, the one on the right is a H&G #503, 250gr Keith (THE Premium Keith bullet) in a 44Mag case.

To note; I have never used this heavy a crimp in any of my handloads. I will have to now to see if there really is any difference in performance. Like I noted above, I don't work the case mouth this much as #1: I had adequate accuracy from my loads, #2: Working the case mouth this much means shortened brass life, period, #3: Once you get to single digit SD what more do you need?

But, just to show I have an open mind, I will try this crimp with some of my loads and see if they improve or not.

Still don't see why I need to grind out a LFCD to get these kinds of crimps. I just never set them this deep before.

smith crazy said:

Well, I thought I would give this type of crimp a try with my regular Lee dies.

Guess what? It looks just like the one from the modified factory crimp die. So, I ask again, why go to the extra work?

The one on the left is a 45Colt with a H&G #502, 240gr Keith bullet designed for the 45AR, the one on the right is a H&G #503, 250gr Keith (THE Premium Keith bullet) in a 44Mag case.

To note; I have never used this heavy a crimp in any of my handloads. I will have to now to see if there really is any difference in performance. Like I noted above, I don't work the case mouth this much as #1: I had adequate accuracy from my loads, #2: Working the case mouth this much means shortened brass life, period, #3: Once you get to single digit SD what more do you need?

But, just to show I have an open mind, I will try this crimp with some of my loads and see if they improve or not.

Still don't see why I need to grind out a LFCD to get these kinds of crimps. I just never set them this deep before.

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Great pics Skip. Now we know that a "modified FCD" is lurking inside each seating die. All you have to do is turn the die in further. Voila you have a modified FCD and case life reducer in one easy step. Ingenious!!

Scrapper; Good luck!!!