Help with bullets jumping crimp

[Bob58]

I have two 629-4 .44 magnums for which I am working up hog hunting loads (locals in the area I plan to hunt tell of 600+ pound wild hogs - sounds awful heavy to me.) I have several 280g WFNGC bullets that I believe are from an LBT mold. New full length sized Starline brass, Federal 155 LP magnum primers, and 20.5g of VV N110 (less than the book max) gives me 1250 fps with this bullet. I think this should be adequate for the game anticipated, even the 600+ pound version with an attitude, if the bullet is placed properly. I am crimping the case into the bullet crimp groove with a Redding profile taper crimp die. The mouth is being belled using the powder station die on a Dillon 550B, so that no expansion of the case, where the bullet seats, is being performed. When a bullet is seated, there is a clearly larger case diameter where the bullet is, compared to the case just below the bullet. Consequently, I suspect that neck tension is high.

My problem with this load is that the bullets are jumping crimp. With a fully loaded cylinder, I fired five rounds, then took the 6th (unfired) round out of the cylinder, and measured its length. The length had increased by 0.025", with the case mouth now at the base (lower part) of the crimp groove. The cylinder was still spinning freely, so this wasn't tying the gun up. Nevertheless, with game that has the potential for doing damage to the hunter that wild hogs have, I don't want any lengthening of the unfired rounds in the cylinder.

I'm not sure I can adjust the Redding profile taper crimp die down much further. Is there a "best" die for producing a crimp that a heavy bullet will not jump? Or, should I see about purchasing a smaller body diameter die, with the hope that the increased bullet pull from a case sized with such a die won't jump crimp? Are custom sizing dies available, to size the case to a smaller diameter prior to seating the bullet, and thus increasing case tension on the bullet?

I've not tried to develop heavier loads like this before, concentrating on target / plinking prior to this. My son-in-law is set on going after some of these hogs, however, and I could use some help with this bullet jump problem.

Thanks,

Bob58

[STP]

Bob,
If your seating to the crimp groove you might try a seperate seater/roll crimp die, adjusted to only apply the roll crimp. The sized cases will need to be of uniform length as well.

Kinda takes the fun out it... (speed-wise)

[felix]

Bob, it is always best to have more case compression than a harder crimp. First, get a smaller diameter expander plug and use that. The downside of more compression is boolit distortion, and to overcome that problem to some extent is to have a seating die which is smaller than typical. Oftentimes the die on-hand will be OK when larger diameter boolits are used. The use of a roll crimp die can be used, provided it is not used to crimp hard. Crimping hard usually does not help your situation, and can tear up the boolit upon case exit. The factory crimp die offered by Lee can be an advantage when you are crimping on the body of the boolit rather than in a crimp groove. Your application calls for mechanical reliability and solid ignition equally, and only accuracy over a very limited range. (Loading for single shot rifle would lessen the mechanical reliability requirements considerably. ) ... felix

[cohutt]

Along the lines of Felix's suggestion, check your current powder funnel / die settings.

What you want is to set the powder die to be as high as possible in the toolhead where you still get the full powder drop from the powder bar. In other words the powder bar has to be pushed back far enough to reliably pickup a full powder charge.

There is some leeway in this setting- once you have the die deep enough to get a full drop, any incremental turns down adjust the amount of belling/case mouth expansion. It is possible to have it so far down that the case splits.

.
Short version= unscrew powder die a little, weigh drops, if ok, check belling. keep raising until either the powder drops light or the belling isn't sufficient to seat the bullet without shaving lead.

(ramble ramble ramble. )

This isn't the best explanation, i only had a minute to post this

[Ghugly]

Try cleaning the lube from the body of the boolit. Even with the crimp you are depending on the friction between the boolit and the brass. If you are lubing the mouth of the case.......don't. I suspect that there is a limit as to the weight of the boolit and the powder charge for a given revolver. The lighter the revolver, the more it wants to jump back and leave the boolits sitting there. Lead grips? :mrgreen:

[Bass Ackward]

Sometimes people have trouble creating a good crimp. Most of the time it's because of their brass. But die adjustment is critical too.

A light crimp that is in contact with the bullet is much stronger than a heavy crimp that is not. This occurs most with older brass that doesn't fold, but rounds in to look like a good crimp. It also occurs when seating the bullet too deep in the case before crimping. My guess is this is why you lengthened and stopped where you did on the last cartridge.

Adjust your die to allow the crimp to .... finish .... seating your bullet as it folds in. New brass would be most flexible for this which is why some guys chuck their brass after 5 re-loadings.

If you can image what I am saying, it will leave the top part of the crimp groove visible. This may require a separate crimping step without shaving. This way you have metal to metal contact along the whole crimp groove taper (for strength) instead of a nice looking crimp at the top of the groove that is maybe touching nothing until it slides forward.

[Ghugly]

Be careful out there. I've seen what a 500lb boar did to a pack of dogs that had it cornered. I was at the Vet's office when they brought in the survivors. That was 40 years ago and the memory is still pretty clear.

[44man]

No matter what you think, you do not have case tension. The grease grooves should show on the loaded round. I use a moderate crimp from .44, .475 and 45-70 and do not have boolits move. Over crimping will not help, neither will removing all lube as I leave as much on the boolit that I can. I hate dry boolits!
The redding crimp die is great but will not solve an over expanded case. I use nothing but Hornady dies because the dimensions are correct. I also use the Redding crimp die.
I have .44 cases that have been loaded at least 40 times without a failure. I recently shot several 1" groups at 100 yd's with these cases. I use 330 gr boolits with 21.5 gr's of 296.
I read about some guys that only use virgin brass for IHMSA. They buy new for every shoot---How rediculous can you get?
Bass is right where you need to see a little of the upper groove showing before crimping.
Too much is made of the crimp, it does not solve problems but case tension does.
I see where you use mag primers---WHY? I use nothing but the Federal 150's in the .44 and .45. I don't move to mag primers until I go to the .475 and 45-70.
Listen to Felix, he knows!

[happy7]

Bob, you mention that you use a Redding profile TAPER crimp die. As far as I know, all Profile Crimp dies provide a roll crimp, not a taper crimp. Redding does make a taper crimp die for the 44, but I believe you do want the profile crimp die, not the taper crimp. So I am not sure which you have.

If you are using the Dillon 550 powder funnel, it does in fact expand the case (not just bell the mouth) for seating the bullet and this expansion is not adjustable short of a custom powder funnel.

[shotstring]

I don't really understand the problem here. First, if you are using a taper crimp for hot 44 loads, that isn't a very good idea in my opinion. The 44 was created to take a roll crimp, and I have loaded thousands of super hot 44 and 357 loads using nothing but a 1 step bullet seating and roll crimp operation with a standard carbide die. These have proven to be very accurate loads with some of them being down right tack drivers. This also includes some very hot 45 long colt loads. I have taken them right up to developing pressure problems, and then had to back off a bit, but I only remember one time where bullet jumping was a problem, and that was due to too light a crimp.

I understand where people can be concerned about bullet deformation and shaving from too heavy a crimp, but handgun bullets are far more forgiving than rifle bullets that way. I think you have to really get carried away before the crimp will destroy both the bullet and your accuracy.

Starline brass has a reputation of being excellent brass, but it also has the reputation of being a softer brass case. It may not hold a bullet quite as tightly as some other brass. I know of many people that don't use starline for max loads because they claimed it just seemed to work better and hold up better on the mid range loadings. Just what I have heard....can't verify that last bit one way or the other.

[MakeMineA10mm]

My problem with this load is that the bullets are jumping crimp. With a fully loaded cylinder, I fired five rounds, then took the 6th (unfired) round out of the cylinder, and measured its length. The length had increased by 0.025", with the case mouth now at the base (lower part) of the crimp groove. The cylinder was still spinning freely, so this wasn't tying the gun up. Nevertheless, with game that has the potential for doing damage to the hunter that wild hogs have, I don't want any lengthening of the unfired rounds in the cylinder.


Guys, let's back up a minute here. He's got the "coke-bottle" bulge where the heel of the bullet has expanded the case greater than the neck-expander on the Dillon machine made it. He has a Redding Profile Crimp die maxed out. There should be no load on Earth that jumps that combination. Beartooth Bullets sells some 340gr WFN cast bullets that are successfully loaded without jumping crimp, so this one shouldn't be an issue...

Lastly, I point to the part of the quote that I bolded above. It appears that the bullet has moved forward JUST UNTIL THE CASE'S CRIMP "CAUGHT" THE BOTTOM EDGE OF THE CRIMP GROOVE... That's called - everything is working fine, in my book. Am I missing something here??????

Bob - I suggest you do the same test as you stated above with loading 6 rounds, and shooting five of them. THEN, measure the 6th one. THEN, mark the base of that case with a black felt-tip marker. Load five more fresh ones, and carefully fire them off (so you don't shoot the 6th one that is marked with a marker). Take that one out and measure it again. Then, do the whole test one more time. After fifteen rounds, measure that 6th round's OAL and let us know how it's going.

I noticed you said the bullets are "jumping crimp," but how are you defining that? Your description just one line lower sounds like the bullets have just moved forward until the crimp on the case mouth has run into the top edge of the driving band that makes up the bottom of the crimp groove. That is NOT jumping crimp. Jumping crimp would mean the case mouth is NO WHERE in the crimp groove - like down in the middle of the driving band or a lube groove. This may be all confusion based on semantics. Do you have pictures of the rounds?

[Lloyd Smale]

little trick ive done on dillons when my 475 bullets with shallow crimp groves have jumped crimp its to go to a .512 powder funnel and just set it so it barely bumped the top of the case. It puts a very short but pronounced flair in the case that way that allows good bullet starting but doesnt expand the case in any way. you could try the same with a 45 colt powder funnel. Another thing you could try is to size your bullets .001 bigger. If your sizing .431 try .432. Some bullet designs are just more apt to jump then others. Espcially ones with shallow crimp groves. Another problem can occur form crimping (especialy if your seating and crimping in the same operation) If your die is sent to cimp to high in the crimp grove when you put your final crimp on the bullet you are actually pushing to top lip of the case into the top of the crimp grove and it can actually open up the crimp slightly. this again is more prevelent in bullets with small crimp groves., Try just backing off your seating die a 1/4 of a turn at a time and see if it helps. It may take one of these suggestions or a combo of a couple to help you out