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Quick question about crimping
hehateme
Member Posts: 724 ✭
This might sound like a rookie question, or maybe I'm just losing my mind tonight, but here goes.. I am loading some 62 gr .223's, and my min. OAL is 2.250. Well the crimp groove sits above the case mouth at that length. No big deal, but out of curiosity, I look at FAQs on Speer's website, and find this :
"Q.
The rifle bullet I'm loading has a crimp groove, but the cartridge length recommended puts the groove out of the case. Should I change the seating length to make the crimp groove line up.
A.
No. Not all rifle cartridges require crimping. The groove on the bullet is positioned for those that need the crimp. If the recommended seating length puts the crimp groove above or below the case mouth, we determined that crimping was not needed. Having the crimp groove above or below the case mouth has no adverse effects on accuracy or performance."
The highlighted is what I'm having trouble wrapping my mind around.. I've always crimped all my rounds. I've always thought that it was needed especially for rounds that might be in magazines, being jumbled around, so the bullet doesn't get pushed back into the case inadvertently, etc. I've also felt that I got better accuracy with crimped rounds. Anyone have any thoughts on this? Should I not crimp my rounds because Speer determined crimping was not needed on this particular bullet? I don't see a problem with crimping them anyways, I really doubt it would cause any excessive pressure problems, right? As always I appreciate all help, comments and constructive criticism.
Thank you
Chris
"Q.
The rifle bullet I'm loading has a crimp groove, but the cartridge length recommended puts the groove out of the case. Should I change the seating length to make the crimp groove line up.
A.
No. Not all rifle cartridges require crimping. The groove on the bullet is positioned for those that need the crimp. If the recommended seating length puts the crimp groove above or below the case mouth, we determined that crimping was not needed. Having the crimp groove above or below the case mouth has no adverse effects on accuracy or performance."
The highlighted is what I'm having trouble wrapping my mind around.. I've always crimped all my rounds. I've always thought that it was needed especially for rounds that might be in magazines, being jumbled around, so the bullet doesn't get pushed back into the case inadvertently, etc. I've also felt that I got better accuracy with crimped rounds. Anyone have any thoughts on this? Should I not crimp my rounds because Speer determined crimping was not needed on this particular bullet? I don't see a problem with crimping them anyways, I really doubt it would cause any excessive pressure problems, right? As always I appreciate all help, comments and constructive criticism.
Thank you
Chris
Comments
True, not all rifle rounds require crimping. Those particularly subjected to life in a tube magazine do, i.e. the 30-30. Those in a box mag of 20 should also. But, those in a blind mag of 5 or so don't. Neck tension holds them just fine.
Also, I've never heard of the cannelure being placed above where the bullet is normally seated to so that it doesn't have to be crimped. That bullet may be intended for a different case such as the .222 Rem with the longer neck or the .22-250, same reason. If not timed correctly in the assembly line, it may have made its way out of the factory instead of onto a bullet line? I have heard that sometimes the cannelure is there to crimp the jacket down on the core.
As for accuracy, I will debate the thought that crimping "helps accuracy". It doesn't. Crimping puts extra pressure on the bullet and can introduce pressure differences from round to round. In lower pressure bullets such as the 30-30 it doesn't make as much difference. High performance rounds that are right on the edge (most hunting and competition reloads). In extreme accuracy loads not only is the no cannelure, neck tension is very light. Bullets are usually fired singly for this.