300 win mag bullet seater problem

jerm8352

Member
Jul 24, 2013
144
2
Hello again guys. Time for the reloading newbie to beg for more help.

Anyways, I have been trying to reload 300 win mag now. When I try to seat the bullet, I am getting ALOT of resistance, and it feels like the bullet is getting stuck in there. This only happens with 180 grain bullets. I use some 150 grain with cannelure just to find seating depth and these bullets seat fine and feel fine when seating. However, whenever I try to use the 180 grain bullets, its back to stuck. I thought maybe because the 180s were longer that it was pushing up against the powder, but it does the same with empty cases as well. The 180 grain bullets seat fine in a 30 06 case but have the problem in the 300 win mag. What could the problem be? I am using 180 nosler partitions and ballistic tips and the 150s that work fine are hornady gmx. I use all hornady equipment. I tore the die apart and everything looks fine. Thanks for the help!
 

Musket Man

Veteran member
Jul 20, 2011
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colfax, wa
Are you sure the crimper isnt hitting the brass before the bullet is seated? Are your case lengths consistent? Are they tight all the way or just when they are almost seated?
 
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jerm8352

Member
Jul 24, 2013
144
2
The case lengths are consistent and it is tight all the way. Almost like the bullet is getting stuck in the die but only with the 180s. I backed the die out quite a bit but it didn't help. Thanks for the reply.
 

Colorado Cowboy

Super Moderator
Jun 8, 2011
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Dolores, Colorado
If you have a micrometer, start by measuring the od of the 180 gr & the 150.gr. they both should be the same, .308.
If they are the same then you probably have a die adjustment problem.
 

Musket Man

Veteran member
Jul 20, 2011
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colfax, wa
If you have a micrometer, start by measuring the od of the 180 gr & the 150.gr. they both should be the same, .308.
If they are the same then you probably have a die adjustment problem.
I thought of that but he said those bullets load fine in 30-06 cases so I would assume it is not the bullets.

I wonder if they are not starting straight into the case for some reason?
 

jerm8352

Member
Jul 24, 2013
144
2
Well.... I am an idiot. I must have forgotten to chamfer and deburr the case mouths because after doing that they work fine. I did already have about 15 round that I really, had to apply pressure to finish. Thay should be fine for plinking right?
 

Musket Man

Veteran member
Jul 20, 2011
6,457
0
colfax, wa
Well.... I am an idiot. I must have forgotten to chamfer and deburr the case mouths because after doing that they work fine. I did already have about 15 round that I really, had to apply pressure to finish. Thay should be fine for plinking right?
Glad you found the problem!
 

woodtick

Veteran member
Feb 24, 2011
1,492
0
Jim Bridger County, Utah
Well.... I am an idiot. I must have forgotten to chamfer and deburr the case mouths because after doing that they work fine. I did already have about 15 round that I really, had to apply pressure to finish. Thay should be fine for plinking right?
I would try them and see if they'll chamber if so shoot a couple see if they blow the wrinkles out! I've done this when fire forming some really weird wildcat rounds. As long as you don't split the cases you should be fine.