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JSmitty's picture
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Location: Eunice, NM
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New to reloading

I am just getting started reloading and was wondering why you would crimp or not crimp a case.

Thanks  James

Critter's picture
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Crimping a case will depend

Crimping a case will depend on what you are shooting.  If it is a rifle case there is usually no need to crimp a case since the neck tension will hold the bullet in place.  But if you are reloading for a case such as a .30-30 that is to be used in a tubular magazine then a slight crimp may be needed to hold the bullet since it will have some pressure from the case above in in the magazine that could drive the bullet down into the case by either the spring tension or under firing the rifle.  Now if you are shooting a pistol then a crimp is usually needed to hold the bullet in place under recoil unless you are reloading for a semi automatic and then either no crimp or a tapered crimp may be needed since the round usually head spaces on the edge of the rim.  If you look at most pistol bullets they will have a chanule that you can crimp the case into to hold the bullet where most rifle bullets will not have one.   

Don Fischer's picture
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Often heavy recoil rifles are

Often heavy recoil rifles are crimped to keep the bullet from moving under recoil. In handguns cases bullets must be crimped to bring the load up to pressure also. So with a handgun it does two things. When the bullet is crimped, rifle or handgun, pressure will be elevated. How much, I have no idea. If you look at rifle bullets, you'll see that some have a knurled grove around them. It is the crimp grove. But a lot of people seat the bullet to that grove and don't crimp. They think thats where the bullet is supposed to be seated, not true. Now if you use a bullet without that grove and try to crimp it, you won't get much if any crimp and just may colapse the shoulder of the case. As you go the bit farther the crimp requires, there's nowhere for the case mouth to go, as into the crimp grove, so what it does is stays where it's at and colapses the case shoulder.

I use a lot of Hornady bullet's and many have that crimp grove on them. But the length of my magazine and throat allow me to seat the bullet way out past that grove. Doesn't matter as was said the tension on the neck holds the bullet. In dangerious game cartridges I think they do crimp everything. Never shot one though.

JSmitty's picture
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Location: Eunice, NM
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Thanks for the info, I am

Thanks for the info, I am loading for my new 7mm-08 in an encore. I loaded 25 rounds in .5 gr increments, just havent had a chance to get out to shoot yet. I did shoot 16 factory loads when I got the gun togather and was very pleased with the gun. If I do my part it will shoot moa so I cant complain.

Thanks James

Don Fischer's picture
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The 7mm-08 is not a handgun

The 7mm-08 is not a handgun cartridge, you don't need to crimp to keep up pressure. To measure the distence to the bolt face, think frame face. Just close the action and drop down the rod.

JSmitty's picture
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Don I am a little thick in

Don I am a little thick in the head, so I am not following what you ment. What I did to get the length of the cartridges I loaded was make them the same as the factory Hornaday superformance that I had ran through it to set the scope.

thanks

Don Fischer's picture
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If it works for you it works.

If it works for you it works. But that will not tell you what your chamber is doing. Most likely your's would not be shorter than any factory loaded cartridge. What it might be is longer. If it is then what you would have is a bullet having to take a longer jump to enguage the lands. By knowing where the are in relation to the bolt face, you can adjust that distence from the bullet to the lands in fine tuning the load. Sometimes it does make a difference in accuracy. By getting the Hornady/Sinclair tool to measure with you can measure that distence. With my method I don't know what the distence is but I do know where the bullet is. The seating plug in your seating die is designed to enguage the bullet where the ogive is.

JSmitty's picture
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Location: Eunice, NM
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Got it, thanks

Got it, thanks

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