Crimping

[keys85]

I guess this is more of a poll...but, I have 4-piece set carbide reloading dies for my pistol rounds. I can seat and apply crimp in one step, or crimp\resize case in a separate step.

I was wondering how many of you crimp in a second step vs. applying crimp during the seating process. This pertains to straight walled cases such as the .45 ACP and .40 SW.

I've done it both ways. I have not recorded to see if any one way was more accurate than the other. Pro's and con's of each?

The only positive element I see in applying the crimp in a separate step is that A.) Differences in case lengths allow every round to receive the same amount of crimp B.) There's no risk of bulging the case or deforming the bullet C.) The process also resizes the case so if a round which wasn't flared enough got a bullet jammed down in there, the die will correct this and reduce the likely hood of a jam in a tight chambered gun. However, with a mild crimp setting on the seating die this is unlikely to happen. Opinions please...

[Nnobby45]

Strongly recommend seperate steps.


When a die is trying to crimp the bullet while it's being seated, bullet scraping results, along with a weaker crimp. If you turn the die down to crimp harder to secure the bullet, it scrapes the bullet more!

Only thing worse than such a set up is a die that sizes the case mouth and flares at the same time, since the case is sized, flared, then pulled back down thru the sizer!

In order to have any flare left, the flare must be very excessive so some will spring back after it goes down and gets sized again.

Yes, I realize that many thousands of these dies were made and have been used for a long time, and that they produce ammo adequate for practice, at the expense of shorter case life.

Combination dies saved time in the age of the single stage press. No more--not in the age of the progressive where the xtra die station can utilize a seperate crimp die without any time being lost whatsoever.

[Threefeathers]

for handgun the last step is a taper crimp.

[keys85]

Would you recommend that I adjust the seating die to take out the flare, but not crimp, or should I keep .001 or .002 flare on the case mouth prior to crimping phase?

[cerberus65]

I seat and crimp in two steps.

For operations that are adjustable I like doing just one at a time. I'm fine with resizing and decapping in one operation - there's nothing to adjust there. But adjusting the bullet seating depth AND adjusting the amount of crimp together? Brain starts to overload. But I'm pretty new to reloading. Maybe I'll change my mind as I go along. Doubtful though, I really like to keep things simple. :-)

[Steve in PA]

I've been reloading for about 18 years now, seat and crimp in the same step. Never had a problem.

[BigJakeJ1s]

I seat and crimp in one step for roll crimped 45 colt with no problems. But that may be a big difference between roll and taper crimped techniques; I don't have any experience taper crimping.

If you can get it to work in one step on a single stage or turret press, why use two steps? On a progressive, assuming you have enough stations for a powder check plus separate crimping, the "cost" of separate crimping is nil, and it is more tolerant of non-uniform case lengths.

Andy

[T. O'Heir]

"...seat and crimp in the same step. Never had a problem..." Ditto, only longer. Set up the taper crimp die to seat and you'll have no problems.
"...a mild crimp..." That's plenty. You don't need a huge crimp. Just enough to hold the bullet in place.
"...crimp\resize..." Those are two steps using two dies. You'd never resize and crimp in the same die. The sizer die resizes and decaps. The crimping die seats and crimps.

[Nnobby45]

I've done it both ways. I have not recorded to see if any one way was more accurate than the other. Pro's and con's of each?

Pro: If you have a single stage press, you save time by eliminating having to run all those cases thru yet another die stage.

Con: No bullet that is being seated and scraped (crimped) at the same time is likely to be more accurate than a proper roll crimp as a seperate stage. Progressive presses have that 4th station for a reason, and the die applies the crimp to secure the bullet after it's seated. Not during. For taper crimp dies, the case mouth only needs to be straightened , since the case tension secures the bullet.


Pro: For those who already have a two stage die that seats and crimps, you can use it without having to buy a new one.

[T. O'Heir]

"...a proper roll crimp..." No roll crimping for either the .45 ACP or .40 S&W. Taper crimp only. They both headspace on the case mouth.
"...two stage die that seats and crimps..." It's not a two stage die. It's a regular die. You take the seating plug out of the seating die and set it up in the taper crimp die. Works just fine.
Crimping, especially a roll crimp, is detrimental to accuracy. The taper crimp has more to do with reliable feeding than anything else.

[Nnobby45]

You take the seating plug out of the seating die and set it up in the taper crimp die. Works just fine.

Take the seating plug out of the seating die and "set it up in the taper crimp die"? I don't understand. Why would you put a seating plug in the taper crimp die? Or did you mean remove the plug and then use the die for taper crimping?

As long as the bullet has sufficient tension, you can get by with very little roll crimp. If the bullet has a cannelure (crimp groove), the roll crimp can be crimmped into the groove enough to help secure it without being enough to hurt accuracy IMO. Not sure how much a heavy crimp affects accuracy.

Most factory ammo is well crimmped-- especially in heavy calibers, and accuracy can be quite good. Unless the bullet is damaged by the crimp, the bullet should be ok once it enters the bore and gets to spinning. When loading low recoiling .38's, I roll crimp very little, since there's no chance of bullet setback from recoil.

I just started loading .44 Spec. and the Dillon taper crimp die is designed to impart a slight roll crimp, also.

[abber]

Since a taper crimp is only supposed to close up any extra flare applied earlier, How would it scrape the bullet if done properly? By properly, I mean the correct amount of crimp, as well as deburring the mouth of each case. Don't get me wrong, I am no expert. I have been reloading roll crimped ammo for about 17 years, but I am new to the taper crimp arena, and a little frustrated with it. The Speer reloading manual suggests that one step seating and crimping is believed to improve accuracy (although it does not go into any detail as to why). I put only 100 rounds of factory ammo through my .40 before I started reloading for it. My first 100 reloads were with Speer Gold dot bullets. I forget the exact weight and style. These performed flawlessly with a one step seat and crimp. I then bought some bulk once-fired brass, and 3000 pieces of 155 grain rainier lead safe bullets, and set out to load some reduced price ammo. I was afraid of tearing the plating on the Rainiers, so I went to a 2 step seat and crimp. I may have crimped too light, because I was getting feed jams with the first 200 of these. Probably about 1 in 20 or so. Quite unacceptable jam ratio, IMHO. I did the next 200 the same way, but with a more agressive crimp. I probably had about 1 in 40 jam up on these. I have now done 200 more with a medium crimp, but done in a one step seat and crimp. I have yet to try them out, but I have arranged to trade a buddy of mine at work 50 pieces of these, for 50 pieces of factory ammo he has. We are going to compare notes after shooting our respective loads. I want to know if he has any trouble with my ammo in his gun, which he has put well over 2000 rounds through, and says he has never had a single feed jam. Should be interesting to find out how we compare. Anyway, having said all this, I welcome any further suggestions, because like all of you, I am an absolute perfectionist with my loads, and I love reading the collective wisdom and experience offered by all you percussion addicts out there.

[BigJakeJ1s]

Even for a roll crimp, done properly, there is no scraping. Think about it. The distance from the seater plug to the crimp ring is constant during seating. So the case mouth is rolled into the bullet (preferably cannelure) as more of the case body underneath the mouth it is pressed upward onto the bullet. Once the crimping begins, the vertical position of the case mouth never changes relative to the bullet during seating.

Andy

[HOGGHEAD]

Separate step. I am in no hurry. Tom.

[JAYBIRD78]

I've had no problems with a RCBS dies and I'm on a single stage so it "saves" time.

I use a lite crimp regardless anywhooooooooooooooo.

[T. O'Heir]

"...Why would you put a seating plug in the taper crimp die?..." Turns the taper crimp die into a seating die. You seat the bullet and crimp in one step. You using a progressive press? I'm not and that may be where the difference lies.
"...without being enough to hurt accuracy..." The gasses have to overcome the crimp before sending the bullet on its way. That is detrimental to accuracy. Target loads, like .38 Special 148 grain WC's using 2.5 to 2.8 grains of Bullseye, need no crimp whatsoever. Case tension is enough to hold the bullet in place.
"...1 in 40..." That's not acceptable either. Check your case and OAL lengths.

[Ben Shepherd]

Keys85, you mentioned 40 and 45 specificly, so- where I you-

With both calibers, seating and crimping can be done in the same step, with no damage done to the slug. Calibers the require a roll crimp, especially a heavy crimp, are best done seperately.

With 45 ACP, assuming that you have quality brass(IME avoid remington and A-merc like the plague), you should only need a slight crimp.

With 40, you want a firm taper crimp. Reason: 40 S&W is a high pressure round, the powders used in this cartridge are more efficient and cleaner burning at high pressure. While neck tension should be the majority of the resistance to movement, a firm crimp helps hold the slug until the powder has built up a good head of steam.

[Nnobby45]

You'd never resize and crimp in the same die. The sizer die resizes and decaps. The crimping die seats and crimps.

Now there's a statement I can readily accept! Sizing and crimping the case before you seated the bullet would be a faux paux---but impossible to commit, since no such die exists.

All right, look. For a single stage press, where saving time is an issue, the dies that seat and crimp at the same time work. Avoid the die that sizes and bells at the same time like the plague.

For a progressive press, use the 4th station for the seperate crimp operation. A die set, like Dillon's, comes with it, anyway.

I guess there's nothing wrong with a single stage for pistol loading. Sometimes I forget that not everyone likes to shoot as much as me for semi-auto. For loading stuff like .44's, .45 Colt, .454 Casul (good grief),etc., one doesn't shoot as much ammo, and there's no hurry.

[Hawg]

I seat and crimp together. Have for over 30 years. No problems.

[mrawesome22]

Avoid the die that sizes and bells at the same time like the plague.

LOL That would have to be some sort of two piece die huh? LOL

[LHB1]

I understand the theoretical advantage of seating and crimping in separate steps/dies but have been reloading .45 ACP since 1964 using RCBS 3 die sets and seating/crimping in one step. Have had no problems with feeding or function in my 1911 pistols, including several years of Bullseye competition. These days I use RCBS 3 die set with Taper Crimp seater/crimper die.

[TEDDY]

the idea of the crimp die is to crimp cases that are different length.I roll crimp as I believe it feeds better and have never had a jam with a proper made cartridge.I do not go on the thery of seating cast bullet loads on mouth.
I load with bullets first groove crimped in middle.all the guns that I have worked on that jammed from reloads were caused by not taking the flair out.and a crimp cured that.

[Nnobby45]

Quote:
Avoid the die that sizes and bells at the same time like the plague.

LOL That would have to be some sort of two piece die huh? LOL

Ha, ha, LOL.
Die #1 of the two die set sizes the case mouth and flares at the same time. The case is sized and flared going up, then pulled back down thru the sizer which, of course, would have to remove flare--unless the flare is so excessive that some will spring back after it's pulled through the sizer. Such excessive flaring of the case amounted to a case torture test. I believe that die has been obsolute for a while now.

The second die, of the 2 die set, would seat and crimp as we've been discussing. I imagine more recent combo seat/crimp dies are better designed than those used in the OLD two die sets going back a few decades, since a number of posters have been using such dies with success and haven't been experiencing problems with scraping the bullet while the dies attempts to crimp and seat at the same time.

[DWARREN123]

I reload 40 S&W and use the Lee 3 piece carbide set. I have not had any problems so far after many, many rounds.

[joneb]

I load with a single stage press and mostly seat and crimp in one step, but if I encounter trouble with fragile bullet noses I will seat and then crimp.