Confused about Crimping rifle rounds


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REL1203
July 29, 2010, 10:34 AM
OK, so i am new to reloading, just built my bench, and mounted my new LCCT press, and so far i love it, but i am confused in the crimping stage. Right now I am set up to reload .308, .223, and 9mm, but am only planning to reload immediately for 308 and 223. My confusion comes from me, in both calibers, having both Bolt guns, as well as Gas operated Semi-auto. In 223, I have a Rem 700 Tack Driver, as well as a DDM4 and Bushmaster M17. In 308, I have a Tack Driving Rem 700, and a DPMS SASS. I understand in my bolt guns I dont need to crimp as long as I have proper neck tension. For the Semi Autos, i believe I am supposed to crimp. I have a nice new set of Dillion 308 dies that include a Taper Crimp, which I think is supposed to be a slightly better crimping method, but I dont know how much am I supposed to apply. Should i screw down the die till it touches the shell holder and then take the loaded cases all the way into the Taper crimp die? Is there anything i can look for on the case to tell if I am doing it properly?

For 223, i use Lee Dies, and have the Lee Factory Crimp Die. I believe once again, i dont need to use it for my Bolt gun, but for the Semi-Auto, i need to use it. For this one, i think i am supposed to put the die down till it touches the shellholder, then like 1/2 turn more, and then run the bullet all the way into it....

I am more confused by the Taper Crimp die since i havent used one before, but any tips will be greatly appreicated.

Thanks

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Hondo 60
July 29, 2010, 11:37 AM
Looks like you have it right.
Many reloaders say you don't have to crimp .223 at all. But I read "The AR-15" by Patrick Sweeney & he has an accuracy chart that shows he did better by crimping.

I WAS going to test the difference on my chronograph yesterday, but I shot it.
(see Imbicile! http://www.thehighroad.org/showthread.php?t=535756)

USSR
July 29, 2010, 11:57 AM
I understand in my bolt guns I dont need to crimp as long as I have proper neck tension. For the Semi Autos, i believe I am supposed to crimp.

You do NOT have to crimp loads for semiautos. If you can grasp a loaded cartridge by it's body and press the bullet down hard against a table top and it doesn't move the bullet, then you have enough neck tension for a semiauto. If not, you simply need to polish your expander ball (reduce it in diameter) to increase your neck tension. The only loads that I would crimp would be loads with extreme recoil (African game loads), or loads to be used in a rifle with a tubular (under the barrel) magazine.

Don

243winxb
July 29, 2010, 12:40 PM
No Crimp needed. but check your expander buttons. Expanders need to be .002" or more under bullet diameter. Measure the neck of the sized case before and after bullet seating, has the seated bullet pusher the neck out larger by .002" ? If so, your good to go.

loadedround
July 29, 2010, 01:00 PM
I have never crimped any semi auto round, be it 223, 308 or 30-06. Proper neck tension alone holds the bullet in place. Have been loading 30-06 rounds for my NM Garand for over 20 years now w/o problems.

rbernie
July 29, 2010, 01:17 PM
I use a Lee FC die on all rifle rounds regardless of the platform that will shoot them. My own testing with my own loads and my own firearms supported the notion that using the FC die was the easiest path to good accuracy and low SD/ES.

There may be paths that give better results (e.g. lots of attention to equalizing bullet pull via neck turning and such things), but they require far more time and their benefits for my 'field use' needs was incremental at best.

Crimping is not 'needed', but in my testing it worked better than no crimping.

JimKirk
July 29, 2010, 01:58 PM
I never crimp(roll or taper) rifles any more, I'm saying a regular crimp, not a Lee FC crimp as I've never used the Lee FC. I found it to be easier to get better groups with out crimping for rifles. As USSR and others have said, neck tension alone is good, if you have it right. YMMV

Jimmy K

jwr_747
July 29, 2010, 08:44 PM
the saying "your milage may very" applies to reloads.I went thru about a thousand rounds of handloads for my K-31's. 2 out of 3 rifles have better groups when a Lee FC die is used...jwr

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