You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
Can you crimp a bullet too much?
- Thread starter Cableman
- Start date
- Status
-
Not open for further replies.
Frohickey
Member
Yes. You can crimp too much where you start deforming the bullet shank (the cylindrical portion of the bullet).
Crimps should be as uniform as possible, and most revolver bullets have crimping grooves on them. For heavy recoiling loads such as 454Casull, you definitely want a firm crimp since bullets could move under heavy recoil.
As to accuracy, some guy with a rifle was experimenting with pulled bullets, either pulled with pliers, so that there were marks on the bullet ogive (the sloping/tapering portion of the bullet), and there wasn't a large degradation in bullet accuracy with that compared to deformations in the bullet base (the bottom of the bullet where the hot gasses hit). The experimenter also did some intentional damage to the bullet, such as filing one side of the bullet base.
Essentially, you want a concentric bullet, so that when it is spun by the rifling, its not out of balance
Crimps should be as uniform as possible, and most revolver bullets have crimping grooves on them. For heavy recoiling loads such as 454Casull, you definitely want a firm crimp since bullets could move under heavy recoil.
As to accuracy, some guy with a rifle was experimenting with pulled bullets, either pulled with pliers, so that there were marks on the bullet ogive (the sloping/tapering portion of the bullet), and there wasn't a large degradation in bullet accuracy with that compared to deformations in the bullet base (the bottom of the bullet where the hot gasses hit). The experimenter also did some intentional damage to the bullet, such as filing one side of the bullet base.
Essentially, you want a concentric bullet, so that when it is spun by the rifling, its not out of balance
P95Carry
Moderator Emeritus
Agreed with Frohickey ... my base-line tho is .... concentricity ............ the one thing the Lee factory crimp allows you is .. a heavy crimp if needed .. even if no cannelure or convenience grease groove.
On firing .. gas pressure will almost for sure expand that case mouth and ''free'' the bullet .. anyways. So long as indent on bullet or any '' shaving'' (unlikely IMO) ... then all will be well.
My main consideration is crimp limitation to suit the round's requirement ....... concommitant with minimizing case mouth work hardening ...... and thus case life.
Crimp ...... enoughj .... but no more.
On firing .. gas pressure will almost for sure expand that case mouth and ''free'' the bullet .. anyways. So long as indent on bullet or any '' shaving'' (unlikely IMO) ... then all will be well.
My main consideration is crimp limitation to suit the round's requirement ....... concommitant with minimizing case mouth work hardening ...... and thus case life.
Crimp ...... enoughj .... but no more.
P95Carry
Moderator Emeritus
Horribly true 444 but .. generally that only happens when crimping with seating .. whereby it is heavy pressure down the long axis of the case which does the forming.If you get too carried away you can buckle the case.
The Lee uses a collet principle and so much more side thrust .. and a lot less risk of buckling. Not to say it won't or can't but .... much more unlikely IMO.
FireInTheHole
Member
I've ruined some perfectly good 9mm and 40 jacketed bullets by applying too much crimp...
I am contemplating whether or not the purchase of lee CFCDs for both calibers is in order... (for workup loads)
I've only run into problems with the single-stage... factory set crimp on the SDB is much more forgiving.
I am contemplating whether or not the purchase of lee CFCDs for both calibers is in order... (for workup loads)
I've only run into problems with the single-stage... factory set crimp on the SDB is much more forgiving.
Many of the IPSC guys seem to think of crimp as just returning the brass to the pre-expanded size. That is to say that there is not any brass pushed into the bullet. This seems to yield better accuracy. Really what is the point of crimping. The neck tension should hold the bullet in for all but the hottest calibers. I dont really crimp on anything except 41mag and up. Neck tension will more than hold 9mm-45acp. After that you are just working your brass more which causes less accuracy and shorter brass life.
stans
Member
Crimping revolver rounds is generally a good idea, especially with heavy recoiling loads. Revolver bullets tend to pull out of the case under recoil, this usually does not happen with semi-auto's. With semi-auto's, case neck tension must be sufficient to prevent the bullets from being pushed deeper into the case during feeding, or a cannelure can be rolled into the case at the base of the bullet.
Peter M. Eick
Member
I would argue that in most cases the average reloads I have seen are OVER crimped, not under. I know I have been guilty of this in the past. It is just to easy to give the old crimper an "extra little twist" and wham there goes your accuracy!
I disagree. I think a good firm crimp increases accuracy by providing a more uniform and complete powder burn.
As a side note: I almost never buy factory ammo and when I do, I usually don't examine it. Last night I was playing around with a speedloader and grabbed a box of Winchester .38 special 158 grain lead HPs ("the FBI load"). I noticed that Winchester seems to put about the same amount of crimp on these factory loads that I do-which is pretty heavy.
As a side note: I almost never buy factory ammo and when I do, I usually don't examine it. Last night I was playing around with a speedloader and grabbed a box of Winchester .38 special 158 grain lead HPs ("the FBI load"). I noticed that Winchester seems to put about the same amount of crimp on these factory loads that I do-which is pretty heavy.
P95Carry
Moderator Emeritus
I'm with 444 here ...... a strong crimp, per se, cannot as I see it cause innacuracy ... unless as we brought up earlier, there is bullet deformation leading to lack of concentricy.
BUT ... the BIG factor with crimping and I expect 444 will concur ..... is consistency of crimp. No use having 50 rounds in a batch all having variable crimps .... then you might see, not so much INaccuracy but .. inconsistent accuracy .. ergo .. poor groups.
This why although another operation .. I do feel that the Lee Factory crimp gives a big plus in that regard.
BUT ... the BIG factor with crimping and I expect 444 will concur ..... is consistency of crimp. No use having 50 rounds in a batch all having variable crimps .... then you might see, not so much INaccuracy but .. inconsistent accuracy .. ergo .. poor groups.
This why although another operation .. I do feel that the Lee Factory crimp gives a big plus in that regard.
I have the Lee Factory Crimp dies in a variety of calibers.
I just tried the Redding Profile Crimp die after reading "WeShootTo" tout it for several years now. I only have it in one caliber and haven't had a chance to really play with it much yet (.45 Colt).
I just tried the Redding Profile Crimp die after reading "WeShootTo" tout it for several years now. I only have it in one caliber and haven't had a chance to really play with it much yet (.45 Colt).
I'm with 444 here ...... a strong crimp, per se, cannot as I see it cause innacuracy ... unless as we brought up earlier, there is bullet deformation leading to lack of concentricy
I am curious if you have ever tried this to make sure since it is basically the opposite of what most major IPSC competitors will say. I have never specifically tried varying the crimp and shooting groups to see. I doubt most people have.
In IPSC, most competitors are shooting autoloading pistols. I do not put a heavy crimp on autoloading pistol ammo. Most autopistol cartridges headspace on the case mouth. You don't want to heavily crimp them.
The guy that started this thread was asking about the .45 Colt cartridge; a revolver cartridge. I normally crimp my revolver ammo pretty heavily.
The guy that started this thread was asking about the .45 Colt cartridge; a revolver cartridge. I normally crimp my revolver ammo pretty heavily.
Peter M. Eick
Member
In my defense I was thinking autoloaders. I was not thinking about revolvers.
My experience with others reloads is nearly exclusively for autoloaders and there, I still think, that most reloaders over crimp and deform the bullet. I have seen it to many times to think otherwise.
As to revolvers, I profess not enough experience to know.
My experience with others reloads is nearly exclusively for autoloaders and there, I still think, that most reloaders over crimp and deform the bullet. I have seen it to many times to think otherwise.
As to revolvers, I profess not enough experience to know.
Desert Eagle
member
The best thing about the Lee Factory Crimp Die is that it post sizes the round when you crimp to take out any bulges from seating the bullet. Far as I can remember I've never collapsed a case with a Lee Factory Crimp Die but I have with regular dies. I have the Lee Factory Crimp Die with all my dies except the .50AE.
DE
DE
- Status
-
Not open for further replies.
Similar threads
- Locked
- Replies
- 14
- Views
- 1K
- Replies
- 12
- Views
- 1K
