Crimp for a single shot?

handlerer2

New member
I need some advice.

I recieved as a Valentine and as a souvenir a Cooper Mdl22 VDM,6.5/284, 26",1/8. Beautiful walnut.

I've relocated to Ms Coast, so I have had to order everything I need. As soon as I recieve bullets I'll be ready to start reloading. I have to load the rounds I'll need to zero, so I want to do as right as possible for me.

So far I have recieved redding dies, two piece, trim die, 100 pieces Lapua brass, shell holder powder,rl22 and 4831sc, and bore guide. I ordered and mounted a Vortex Viper PST,FFP, 6x24 ect.

Let me note that I started reloading In 1976 for 30-30, then 7mag and 300WM, 7.7Jap and 9mm. I sold it all in the eighties and just since 06 have gotten back into it. I now load for 300WBY, 340WBY, 223, 44mag and now will start for 6.5/284.

This is the first single shot centerfire I have ever tried to reload for and need to know how much, if any crimp am I going to need? I have almost always reloaded for heavy recoiling or semi-automatic firearms, so crimping was necessary. Being a single shot there is no recoil setback, so would neck tension alone be adequate?

I'll be using the load that the guy at Cooper gave me when I called; 142gr SMK, 49gr RL22,start at 3" oal and work out. Only they used Norma brass and I'll be using Lapua.

I'm thinking I should crimp just to know I'm staying on coal when chambering. But is it really necessary?
 

dacaur

New member
Crimping with a lee factory crimp die improves accuracy. Many people who have never tried it say it doesnt, but 99% of people who have actualy tried a lee factory crimp die recomend them.....
 

dmazur

New member
I've reloaded for a Ruger #1 for quite a few years. Never crimped.

Neck tension is sufficient to survive normal field handling.

While I've never owned a single shot bolt-action, I can't believe there are any more forces involved in chambering a round than there are in a Ruger #1. You can drop one on a loading ramp and that aligns it with the chamber, does it not? There are no magazine rails to tune for a feed angle.

Also, most bullets for non-military calibers don't have a cannelure, so crimping can distort the bullet and adversely affect accuracy.

And, even if you find bullets in the weight you select appropriate for distance, if they have a cannelure, the fixed location of that will effectively prevent adjusting COL for the amount of jump your rifle likes.

I would proceed with load development for your very nice rifle and forget about crimp for this application...

Edited to add:

You should read this. The Lee FCD for rifle isn't the same die as the FCD for pistol. While the mandrel crimp isn't the same type of recoil-resisting crimp you are used to, I suppose it can be called a crimp. And there are definitely two "camps" concerning its use.

http://thefiringline.com/forums/showthread.php?t=471987&highlight=lee+fcd
 
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As this is a single shot rifle crimping is a moot point unless there is some deviation in the neck tension when seating the bullets and I would be greatly surprised to see this in Lapua brass . The primary reason for crimping is to reduce any potential bullet seating shift due to recoil on bullets stored in the magazine of a firearm. Single shot equals no magazine. Another good place to use crimp is where bullets need to be seated long in a case where freebore vs bullet setback has become an issue. It helps to replace the neck tension lost due to less bullet contact in the case neck and will tend to create a more uniform "starting pressure" when ignition of the powder breaks the bullet free from the case. I use factory crimp dies on all my repeaters and taper crimp on my .223 bolt gun tack driver.

10 Spot
 

NESHOOTER

New member
What I have noticed when crimping is not so much of movement or shift in a COL,.... but what I've enjoyed while crimping is less variance of SPEED-FPS and thus a tighter POI's down range. But each to there own the chrony doesn't lie.
 
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