400 grain bullet, bolt gun, do you crimp and if so how much. Nosler Partition so there is a channel for crimping.

Crimp only if you can do it without buckling the shoulder. Federal nickel brass is hard enough for me to use the RCBS die crimp. Norma and Hornady both buckled. Invest in a custom crimp die otherwise. I crimp hunting loads to avoid recoil jamming bullets into the case. For the same reason I choose full/compressed loads...

I am very satisfied with the Lee Factory Crimp.

I always crimp big bores and DG cartridges.
I use a firm crimp, buckling of the shoulder should not be a problem if you adjust tge die correctly, simply place a case in the shell holder, raise the ram, screw the die in until it touches the case mouth, then adjust with a bullet seated to the correct depth. Once the crimp is firm on the bullet, adjust the seater plug to the bullet and you can seat and crimp in one pass. I seat the bullet deep into the cannelure, leaving only around .030" of the cannelure visible above the case mouth. The crimp should have a visible curl in on the cannelure.

Cheers.

I just seat and crimp in two different stages, haven't buckled a case doing it that way.

I do the same thing at Hitman with my 416 Rigby. This is for full house loads with 400 Gr. bullets. When I load reduced power practice loads with Trail Boss I don't bother with crimping.

Never bothered with crimping on either my 416 Weatherby or 416 Rigby Improved.

Both have been used in Africa with no problems at all.

I crimp the 416 Rigby.....use Redding dies and do a slight roll crimp. I tried not crimping and the bullets were getting hammered into the case while in the magazine.

Trim your brass to uniform length. You'll never buckle a case that way and can seat and crimp in one stroke.

I crimp my 416 Rigby as the projectiles get hammered back into the case. I use and swear by the Lee Factory Crimp die. I picked up one for my 375H&H but have not found I need it.

I crimp mine, with a rather heavy crimp.

I have a second set of dies that the sizer got wrecked when the worthless one shot lube failed, so I pulled the seating stem and use the second seater as a dedicated crimp die.

I haven't had any issues with case necks buckling with Winchester, Norma, Federal or Hornady brass doing it this way.

I am using Norma 416 Rigby cases & when I got 90 cases as custom loaded ammo, they were slightly short of min spec. So I could not use a trim die to make them uniform.

Then I found here on AR that I could crimp them as a second step using my Lyman seating die. This works well for me. Some of the cases have been fired 4 times and the cases have not stretched at all!

My loads drive a 400 gr bullet @ 2400 to 2450 fps. I did get one load to 2600 fps but dropped 4 grains to reduce recoil. I am getting 350 gr TSX to shoot at 2700 fps.

I don't crimp mine and have had no problems.

Karl

I have never crimped mine.


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I've shot a bunch and have never had one move. I think if they are moving, your sizer isn't quite right. I also like the Lee factory crimp dies, used them a lot on .30-30's.