Curiosity got the better of me the other day, and I measured the length of a number of .224 50gr Nosler BTs. There was a spread of about 9 thousands of an inch between the longest and the shortest. I know that the seater presses on the ogive, so seating depth should be consistent so long as the shape of the bullets is consistent - which I believe to be the case. However I don't think the plastic tips are always exactly the same length, and that's a problem because that is one of the two surfaces I use to measure COL. I can't lock the seater die down - it's a Forster benchrest die and there is no locking mechanism. The die is the basic type, without micrometer adjustment. So how can I tell if I'm seating to the same depth every time I set up the press? How do other people get around this?

The thing is that I'm getting good results seating about 10 thou off the lands, but this variation could just about put the bullet in contact with the lands, which I don't want to do.

Patrick

Buy a comparator. The one I have is 6 sided with caliber specific holes. Slide it down over the bullet until it stops. Then you are measuring from a set point on the ogive to the base of the case. Sinclair and others sell them. Sean

You DO have a means to lock your die, both on the large pinch nut on the large threads of the die and at the seating stem. Read your instructions and follow them. You set the die on your press per the instructions then tighten the pinch nut on the die. On the seating stem, back it off and adjust slowly until you get the correct seating depth then tighten the nut on the stem.

What many reloaders do is to set up a dummy round for each bullet you use. Size a case, I use old worn out ones. Seat a bullet to the correct seating depth. Mark your dummy round with a Marks-a-lot and save it. Then, put your die in the press. Back off the stem. Put your dummy round in the press and run it up into the die all the way. Then turn the seating stem with your fingers until you feel it contact the bullet. Remove the dummy and seat a bullet in a charged round. Double check the seating depth. Usually you have to make a slight adjustment on the first one. When you do, lock down the seating stem and you're set for that bullet.

The easiest means of checking seating depths, and other measurements, is with the Stoney Point Chamber-All tool. It's mounted on a caliper and has both a comparator for the bullet and for checking the headspace distance on cases. That enables precise measurement of shoulder set-back sizing the cases.

The bullet length is of no consequence. you are seating off of the bullet where it comes to full caliber. The rest of the bullet tip is up inside the seating stem. It is the ogive/bearing surface area which determines seating depth,..don't read too much into the OAL measurement. If you take the two farthest apart bullets in the lot (shortest and longest), set the die and seat them,..then take the comparator and measure them,.....I bet your measurement from case head to ogive/full caliber is pretty darn consistent.

I had a problem with a Forster Ultraseater die in .223.
With very compressed loads, seating depth was erratic and with more compression, the bullet would get stuck in the die. There was then a ring cut into the bullet at the ogive.
I emailed Forster, and they sent me a new seating stem. It worked. I looked at both seating stems under a microscope, and the bad stem had burrs on the chamfer. I put the old stem in the lathe and polished off the burr and now it works too. I wrote to Forster and they said they would forward my finding to engineering.

I continue to believe that the Forster seating die is the best value in reloading.

If you`re trying to reset your seater to give the same lenght, try this, I read it on one of these sites so it`s not my idea but it works!
Adjust your die to give the cartridge OAL you want and be sure to set the lock nut so the die is always screwed in to the press to the same depth and leave it alone. Measure the die and seating stem OAL with your caliper when you`re happy. When you want to go back to that seating depth just set your seating stem to give that same die lenght.
I record the measurement on the box of bullets I set it for and double check the OAL when starting a new lot of bullets.

It`s still a good idea to have a comparator type tool (stoney Point) to double check your ammo.

[ 09-30-2003, 01:14: Message edited by: Ol` Joe ]

Measure your bullet lengths, about ten of them and you'll find quite a bit of variance. It doesn't really matter. The important measurement is the length from the bullet base to the widest part, where it contacts the lands. You're not going to go much beyond that regardless of the total length of the cartridge. Anything beyond where you touch the lands is projecting into the rifle and unsupported so it shouldn't matter. Just touch the lands lightly when you measure the overall length. Don't force the bullet into the lands or your pressure will increase drastically. Best wishes.

Cal - Montreal

Thanks to everyone for your thoughtful replies.

I now have a stoney point bullet comparator on order.

Bob338, do you use Forster dies? I have re-checked and there is no "official" way of locking them down. There is a further adjustment, other than those you mention, and that is the problem. However if I screw the adjuster right down, I can effectively lock it up - I am not sure that is how they intended it should be used. I have made up a number of test loads, and will see how well they work.

Patrick

I DO use Forster dies. However, my seaters are the Ultra Micrometer seaters which are a bit different though they adjust the same. Their sizing dies are particularly interesting with the expander up around the neck.

Do not trust the ogive to be the same in a new lot of bullets, just because the bullets are the same. I bought a comparator an found a big difference in bullet length, when measuring with the comparator and calipers. Conclusion: the ogive is not always the same.

Patrick,

I buy a large number of bullets of the same lot and slip in an empty case with some araldite in the neck when the press is set up as I wish. This is used as a dummy round.

Thereafter it is simple to set the dies up. I love Lee dies which don't lock and this works exceedingly well for me. Each time you use this be sure to use the same shell holder and to back off the seater before adjusting it back down on the dummy. This prevents inadvertant shortening.

Accurate +/-2 thou.

1894,

We seem to have come full-circle on this. Like you, I have made up dummy rounds - although I have to confess that Araldite has not been part of the equation. The idea of using the same shell holder is also very good.

The question is however, how do you KNOW that depth is +/- 2 thou? What dimension are you measuring, and with what equipment? This was the real point behind my original post.

I have now received the Stoney Point bullet comparator, and believe this will give me an accurate means of checking seating depth, plus lot-to-lot differences in bullets. For the record, their customer service was excellent - I received the equipment within about 5 days, which is not bad at all for a product ordered from the US.

Patrick

Patrick,

If I seat a bullet in a case then take the die out the press and set it back up again using the dummy method then the same bullet (obviously pulled in the meantime) will seat +/-2 thou measured the same way as it was measured before.

As I have a 6x scope that's good enough for me.

I use a Bulleye Seating Die from Z-Hat. I uses a micrometer and hase different floating sleaves for each cailber. The inital investment was a bit high, but when I want a new caliber die I just have to fork out ~15 dollars. It is also very repeatable.

[ 10-09-2003, 14:48: Message edited by: Newguy ]