^^These^^ It's not that unusual for a seating stem to impart a kind of ghost mark where it contacted the bullet jacket. Only a mark, not an indentation. But those shown in the pictures above, that's an actual impression into the bullet. A deformity in the bullet. Which implies excessive pressure.
I've read those words, but it's kinda hard to understand how that ring in the bullet could've been made without taking something more than the ordinary amount of force. If the inside of the case mouth doesn't have adequate chamfer, this could be a cause. During the seating process, the bullet stops against the edge of the mouth, then force from seating overrides the resistance of the sharp edge. When this is done, the operator of the press usually feels a bump but the bullet keeps on seating. The other thing that would cause that kind of requirement for extra force might be the resistance of the case mouth on the sidewall of the bullet, called the "pull" or more simply put, the friction. As new, unfired cases, it might be that the necks are undersized.
I took it apart, and not seeing anything that seems wrong to me... at the moment. Im going to explore the idea of excessive neck tension before I decide anything....
Im going to explore this a little bit before I reload another set with this die again. I might seat with my old die (Redding) and compare. I also now as of today, have some fireformed Nosler brass that was in the picture I posted to resize and see... maybe the new Nosler brass was just too tight or thick neck or something. I dont know yet...
www.nosler.com
Digging into their website, Forster actually addresses this very topic and identifies that there are too many different types of bullet profiles as the cause of possible indentations from the stem.
www.forsterproducts.com
I agree and would think the force needed to create that deep of a ring might also collapse and bulge the neck of the case as well. I have had this happen in the past when roll crimping .30-30 and a case slightly on the 'long side' got a little more pressure than necessary and bulged the neck or shoulder of the case.
No idea but I have loaded many 1000s of SP, RN and lead bullets as well with the stock stems and other than maybe a light 'shadow' ring on the bullet from the stem I have never experienced anything like you have!
after reading their website, they have a dedicated article to this very subject (flag 1) and looking at their design sketch they only contact the bullet at a specific point...
thats what Im thinking now that I have some that are fireformed I can test the neck tenstion idea from sizing.. I think. Load one if it leaves a mark then I'll go back to my old seating die and probably order the RCBS matchmaster one to replace the Forster seating die.
I use the Redding Competition Seaters and have a standard and VLD stem for each. Even so, I've had to use some polishing compound on a bullet from time to time and grind it in the stem a bit to improve the fit. There are a wide variety of bullet profiles out there.
this tells me that Forster is not alone in the huge variety of bullet profiles, thus its not a design issue but probably worth buying a custom seating stem....
Amen. I don't think it's normal that you should require a seating stem with the exact concavity to match the ogive of the bullet.
I can understand your frustration. You think you're at a point where you can go ahead and load up some ammo and something else creeps up on you. I've been there many many times. The learning process never ends it seems in the arena of reloading, and especially reloading for long range accuracy.
Exact, maybe not but there can be a huge difference between the profile of a match grade bullet and a hunting style.
I wont give up on the new Forster die just yet, a nod to @BigGame above indicates this isnt a design issue and a specific seating stem is not uncommon. I wouldnt mind buying one if thats what it takes.
