Hornady seating dies pressing ring into bullets, 300 win mag

[fordj]

Hi guys,

A friend who's reloading for 300 win mag and is having an issue with seating the bullets.

He has the RCBS press setup and is using Hornady full length sizing dies and seating dies.

With the seating die, when he seats the bullet their is a very distinct ring pressed into the bullet. Even to the point of shaving off a hair thickness ring of the bullet when seating.

Any suggestions what's going wrong? Bad die? Bad process?

Thanks.

[fordj]

Loading 180gr Accubond bullets if that has anything to do with anything. Thanks.

[Apollo]

I don't have any personal experience with the Accubond Bullets but looking at the description and the problem your mate could have one or two possible causes.

The Accubond by it's description sounds to have a Tangent Ogive but is described as a Long Tangent and looks a bit like a Secant type Ogive.

The part about shaving a ring of brass sounds like the neck tension is possibly heavy but more important is your mate deburring the inside of the necks properly and/or not enough. There is available what is called a "K&M Tapered Neck Reamer" (available from BRT Shooters Supply) that puts a shallow angle on the inside of a case neck. Especially very handy when seating any calibre flat base bullet and makes the initial entry of any bullet a lot smoother when the seating starts.

The Hornady Seating Die probably has a Tangent Seating Stem and the leading edge is a lot sharper than the longer taper on the Secant Seating Stem and does not tend to leave a mark on the likes of VLD style bullets. I don't know at this stage if a Secant Seating Stem is available for the Hornady Die but if it is would be well worth swapping it out for these style bullets.

It may just be a combination of all factors. Tight neck tension, inside deburring not sufficient and wrong seating stem.

[Norton]

I'm casting my vote for neck tension and not chamfering the inside of the neck.

If he's got the RCBS rock chucker kit? It comes with a hand chamfering tool. Find out if he's using it, but I think probably not...

[Chronos]

I'm casting my vote for neck tension and not chamfering the inside of the neck.

If he's got the RCBS rock chucker kit? It comes with a hand chamfering tool. Find out if he's using it, but I think probably not...

Regardless of neck tension the seating stem should not make point contact with the bullet.

I'm going with Apollo in this one, I had similar problems with my dies when I changed to High BC target billets with a longer (pointier) nose

Chronos

[Manimal]

Have him try another die if possible.

I use the RCBS dies and have tried a dozen different bullet types, including Nosler Accubonds and Ballistic Tips and the Berger VLD's and none have any mark on them from the die.

[bunnybuster]

Try backing the die off half a turn and try one,Ithink the seating die is crimping the case into the bullet.

Be safe BB.

[fordj]

Thanks for the replies guys.

Looks like it might be a few of the factors you guys have mentioned above.

We seated a couple of bullets paying particular attention to chamfering and lubing the necks and the problems got better, but there is still a mark. So it looks like seating stem is playing a part in the problem too.

Will track down another type of die for testing and see what the result is.

Thanks all.