Problem after Seating Bullets

[montana]

I thought I had a seating problem when I got my first Grendel. My case would fit in my case gauge after sizing but would not fit after I seated my bullet. I backed my seating die out and it still would not fit. After much frustration I realized my chamfering tool wasn't doing its job. After I made sure my case was being chamfered correctly my problems ended. The shoulders on my Horn cases were being pushed out of spec by the tight fit from seating my bullets.

[45r]

Ok, the dust has settled from Christmas. I took two cases and sized and prepped them as usual and seated bullets without powder or primers. The necks measure .290, which jives with the Hornandy loading book. However, the shoulder to body dimension is .429, 4 thousands over the spec in the book. I don't know if that's too much or not. And they have to be pushed into the case gauge with a bit of force, but they will seat the the prescribed safe depth. I can't yet measure headspace, which will tell me if I can or should push the shoulder back some more. How many votes does the Hornady headspace tool get?

What thinks the horde?

The hornady headspace tool works well.

I always use it and wish I had bought one from the beginning.

It helps with accuracy and not overworking your brass.

I wouldn't be without one now.

[wajm]

Yeah, I did check the cases after prepping them. The seater die is set one revolution away from touching the case mouth. I wonder if the sleeve in the seater die might be hitting the shoulder, thus deforming that area. Probably not, but I will check that out. Thanks.

I do believe you missed an important step in diagnosing your problem. Correct me if I'm wrong.

After you sized and prepped these cases, did you check them in your gauge before you seated the bullets. If not you need to go back and try this.

If they do not fit the gauge with no bullet then you Know you have a sizing issue. If they do fit the gauge with no bullet, then you know you have a seating issue.

My guess would be that you have the seating die screwed to far into the press and you are applying an unwanted crimp, thus buckling the case.

If you had a Headspace issue you would not be able to force the case into the gauge further. It would stop where it stops. Sounds like a crimp bulge to me.

If it is a sizing issue, then your die may be out of spec. My Forster was, had to replace it with an RCBS.

[wajm]

Thanks for the endorsement on the headspace tool. It will allow me to check the cases before and after sizing. Thanks.

The hornady headspace tool works well.

I always use it and wish I had bought one from the beginning.

It helps with accuracy and not overworking your brass.

I wouldn't be without one now.