Roll crimp

[ian45662]

Can cast boolits be roll crimped? Should crimping be done in a separate operation?

[iron mule]

yep to the first part
and either way you prefer or what works best in the gun you are shooting them in
i prefer to crimp in a separate operation but it is not necessary just depends
mule

[462]

Crimp in a separate operation to eliminate any possibility of lead shaving.

Roll crimp for revolvers and taper crimp for auto-loaders. Except for .30-30 in the Winchester Model 94, I don't crimp rifle boolits.

[thegreatdane]

I'm currently in the process of setting up my progressive for 357 mag (roll crimped). Based on experience loading 357 in a single stage press, I'll be seating and crimping in separate operations using separate stations.

I had a few seat-crimp bulges which were no fun. Hopefully this will keep that from happening again. I hate it when your hard work won't chamber. It seems a real waste.

[prs]

Revolver rounds typically have booltis with the crimp groove in them and to avoid boolit distortion or work hardening your brass all that is wanted is to just barely seat the brass onto the lead in that groove and no more. Same for tube magazine lever or pump action rifles. Its a deal where less can be more.

prs

[405]

Revolver rounds typically have booltis with the crimp groove in them and to avoid boolit distortion or work hardening your brass all that is wanted is to just barely seat the brass onto the lead in that groove and no more. Same for tube magazine lever or pump action rifles. Its a deal where less can be more.

prs

That's pretty much what I've found works best.

Also, can't disagree about the idea that certain types of applications may or may not require or may require different amounts or types of crimping. For those guns/actions/loads that are either very light recoiling or are single shot I use no crimp at all. At the most for those no-crimp types I set the seater die to only remove the bell from the mouth and no more. The only full roll or tight Lee FCD crimping I do is for the heavy recoiling tube magazine guns or really heavy recoiling bolt action guns shooting jbullets with a crimp groove. And yes, using a separate crimping die is easier. Using the seater die to first seat the bullet then backing out the seater stem, readjusting the die body to roll crimp works but is a pain.... as it requires having to re-set both functions of the seater die each time a new batch of cartridges are loaded.

Some powder/load combinations may call for a crimp to get the powder up to pressure for best results but I don't go there for my cast bullet shooting and really haven't seen the need for it with the powders I use for jbullet loads. Those that I crimp are to hold the bullet against rough handling or recoil and not to get the powder up to pressure. And, it's fairly easy to apply too much roll crimp and actually loosen neck tension or induce variable tension in their loads- defeating the whole purpose of the crimp to begin with.

[Russ in WY]

Ditto on what prs said about the crimp groove on the boolits for revolvers.. With a crimp groove I have had success using both methods , seating & crimp in one operation & also crimping as a separate step. You will need 4 dies to do it separately tho if you also bell the case mouth to help with starting the boolit. My 2¢ Russ.

[ian45662]

Thanks for the info. So for k31 I really don't need to crimp unless ofcourse the rifle seems to shoot better with crimp

[mike in co]

Thanks for the info. So for k31 I really don't need to crimp unless ofcourse the rifle seems to shoot better with crimp

me thinks with the quality of the k31, current powders and boolit designs, i would find accuraccy long before i tried a crimp...


mike in co

[Silent]

I don't really crimp my 9mm pistol loads past making the leading edge of the case straight again. If I don't do that, the rounds will not chamber in my 9mm properly. I do the minor crimp on the 9mm with the boolit seating die. I do crimp all of my 30-30 loads, and thats done in a seperate operation.

[Larry Gibson]

If it's not a revolver or a tube fed rifle I seldom fine a crimp benificial to accuracy. If one is having consistent ignition problems then a change of powder or a dacron filler is in order.

I seat and crimp based on the size of the crimp groove. Some grooves are big enough to allow seating/crimping in the same operation. Other crimp grooves won't w/o shaving lead, then 2 seperate operations are then used.

With revolvers using magnum loads (.357, .41, .44) of 2400 or H110 I use as heavy a crimp as the groove allows and get the best ignition consistency. I also use .002 - .003 case tension on the bullets. With medium or light revolver loads and with tube fed rounds I like to crimp so the case mouth is against or almost against the bottom of the driving band at the leading edge of the crimp groove. this prevents and shifting back during recoil in the tube. I also just crimp enough so the outside edge of the case mouth is flush with the outside edge of the driving band. Doing such I've not had any problems with cast bullet setback using heavy full speck loads with 311041s in any M94.

Larry Gibson

[RobS]

I've found that crimping in a separate stage makes for easier set-up and can be more cast boolit friendly. I also like that I can adjust the amount of crimping without messing up my seating depth and IMO feel that it works better especially for crimping magnum loads.