shocked by crimping by crimping berger

[Freedom2live]

Hello there hope all is well. I went to the range yesterday and there was a heated argument on crimping Berger bullets. One ol timer put his target on the guys face and showed him he crimps Berger bullet mandatory. To get most evenly burn and pressure rate. By looking at his target I was amazed . 410 groups at 200yds ... My question is this normal ??he was shooting 243 savage 12 bvss

 

[Reloader222]

I have never crimped any of my bottle neck cartridges, but I belief if you want to crimp, make sure the AOL is the same on all cases. I belief that neck tension is more important, therefor I size them, then neck turn all necks to 0.011" and then neck size again without the neck expander ball. This gives my loads an even jump from the cases. Had many holes in one on this method.

 

[Dr. Vette]

That makes me wonder how much better he do if he neck sized them only and didn't crimp them.

 

[Freedom2live]

Interesting.. I went again to the range this evening and he explained it in such details that made sense soon there was a crowd of on lockers. I think I will start cramping those 243 merger 105 old this week just for the neck of it.. I ll also lighten up on powder not know the pressures

 

[Freedom2live]

Another thing why does almost all factory cartridges come crimped ??

 

[westcliffe01]

Crimping is yet another source of variation and given that only 3-5 rounds fit in the typical hunting magazine, there is little concern of the bullet positions being moved by recoil forces in the magazine. The last bullet experiences N-1 recoils before it is loaded in the chamber (N being number of rounds in the mag). Why not do a simple test: Take your reload with the heaviest recoil and measure the OAL of each cartridge before you load it in the chamber. Then fire all but the last one. Take that one out and check its length again. If its length didn't change then all crimping will do is degrade your accuracy.

So just live and let live. If he wants to crimp his, fine. He may be spoiling the drag coefficient if he leaves a mark on the surface of the bullet too. Do you think the Berger reloading manual has anything to say about crimping ? I think not.

 

[Freedom2live]

Your right west. Berger says no need to crimp in my book..

 

[Lefty7mmstw]

Another thing why does almost all factory cartridges come crimped ??

Mainly so they don't get the bullets beat out of them shipping and getting run through autoloaders, pumps, and levers. They also often seal the ammo, which most of us have found isn't necessary either. The only rounds I crimp are pistol rounds and rounds for my bigger rifles. My 375 will loosen your fillings at 8# scoped, and my 405 is a lever so anything that can hang up the action will.