Forster 223 micrometer seater variances?

[kyotekiller25]

Why am I still seeing up to almost a .010" variance in seating depths from the ogive, when the bullets are all within +/- .001"? Starting to drive me nuts. Thats why I bought this seater over the basic RCBS seater in the first place. Cases have all been trimmed to length, bullets are sorted to above specs. Shouldn't that put them all within the +/- .001" when being seated?

It's taking waaaaaaay to long to seat them to my specific depth. I basically am having to seat them all .015" long, then measure each one and reseat numerous times until the correct depth is hit.

 

[Straightshooter1]

Why am I still seeing up to almost a .010" variance in seating depths from the ogive, when the bullets are all within +/- .001"? Starting to drive me nuts. Thats why I bought this seater over the basic RCBS seater in the first place. Cases have all been trimmed to length, bullets are sorted to above specs. Shouldn't that put them all within the +/- .001" when being seated?

It's taking waaaaaaay to long to seat them to my specific depth. I basically am having to seat them all .015" long, then measure each one and reseat numerous times until the correct depth is hit.

Need waaaaaay more information :
What press are you using?
What bullets are you seating?
What's you're bass prep like? Cleaning procedure? Annealing? Number of times fired?
How much powder fills the case?

 

[jpjulian]

Check to see if your seating stem is flared or maybe cracked.

 

[kyotekiller25]

Rockchucker press, 75g ELDMs, just your normal basic brass prep, 1x fired lapua brass, no annealing, and not a compressed load. 24.7g N540 at 2.485"

 

[kyotekiller25]

Check to see if your seating stem is flared or maybe cracked.

Its brand new, I wouldn't think so.

 

[kyotekiller25]

Brass prep is pretty simple. Couple swipes on inside neck with nylon brush, decap, fl size .002" bump, trim to length, primer pockets cleaned, then inside/outside chamfer. That's all I do. I see way better variance with the same process on my 6 creed with 108 eldms and 7-300 win mag with 180 eldms and a cheap basic rcbs seater...

 

[Straightshooter1]

Rockchucker press, 75g ELDMs, just your normal basic brass prep, 1x fired lapua brass, no annealing, and not a compressed load. 24.7g N540 at 2.485"

Sounds to me like you need a different seating stem that better fits that 75gr ELDM, as well as those others. The standard seating stem profile often causes issues like this with ELDM bullets.

 

[jpjulian]

Its brand new, I wouldn't think so.

It's still worth looking at the stem. I've had 2 Redding stems crack on me. Take the die completely apart, clean and lube, just to be sure.

 

[bpm990d]

I'd clean the die. When you take out the seating stem, you can polish it up pretty good with Flitz or Mothers or some other metal polish. I did take a 90gr Sierra and put some diamond lapping compound and lapped the stem to better fit the bullet.

I make sure the internal sliding parts of my die is lubricated with just a little bit of super lube.

Also make sure you chamfer the inside of the neck with a VLD tool.

 

[jelenko]

What powder, how much, what bullet and what COAL?
I'm wondering if the load is compressed. If so, I get significant variations in seating depth.

 

[KMW 1954]

What powder, how much, what bullet and what COAL?
I'm wondering if the load is compressed. If so, I get significant variations in seating depth.

Looks like they answered those questions back at posts 4, 5, 6,

 

[Doug Beach]

Pull the stem, and drop a bullet into it. If the point of contact is the very tip of the bullet nose, rather than a point on the ogive, there’s your problem.

 

[jelenko]

Looks like they answered those questions back at posts 4, 5, 6,

I even read those posts. Too early, not enough coffee.

 

[PopCharlie]

I believe @jpjulian is correct. I'll bet a dollar to a doughnut it's a cracked seating stem. The Forster seating dies are known for this. I had 3 seater dies that all cracked. You may need to look at it with a magnifying glass. I switched to LE Wilson inline seaters and an arbor press.

PopCharlie

 

[wedgy]

Are there marks on the bullets from the stem ? As stated either the bullet point is bottoming out on the stem or they are binding in the stem and pulling out when you are on the down stroke. Polish your seating stem with some lapping compound( you don't need to watch the whole 30 minute video, put the stem in a vice, chuck a bullet in a drill, add lapping compound and spin).

Also possible the die isn't set up properly.

 

[ASbobcat]

Why am I still seeing up to almost a .010" variance in seating depths from the ogive, when the bullets are all within +/- .001"? Starting to drive me nuts. Thats why I bought this seater over the basic RCBS seater in the first place. Cases have all been trimmed to length, bullets are sorted to above specs. Shouldn't that put them all within the +/- .001" when being seated?

It's taking waaaaaaay to long to seat them to my specific depth. I basically am having to seat them all .015" long, then measure each one and reseat numerous times until the correct depth is hit.

Checked 75grELDM in my Forster Ultra Micrometer seater stem. Full ogive contact without touching bullet tip. These stems are very deep, designed for VLD ogives.
Forster dies are at least as accurate as Redding or RCBS equivalent.

 

[DHD]

I believe the likely cause has been addressed concerning the seating stem. Another possible cause is squeaky clean (grabby) case neck ID. An example is wet tumbling with SS media or ultrasonic cleaned brass.

I use more Forester micrometer seaters than any other seating dies. I always check if any possible bullet I may use does not bottom out (top out?). I also will polish the ID of the stem with a felt tip loaded up with Flitz or SemiChrome to a high polish.

If the bullet isn't bottoming out in the stem, have a smooth surface inside the stem, the case neck is also smooth, and seat with a smooth consistent motion you should have consistent depths to the ogive.

I haven't experienced a cracked stem myself so I don't have anything there.

 

[Kracken McGraw]

I have had to polish out most of the seating stems on my Forster seaters so they want mark the bullet.

 

[ronemus]

Forster is good about shaping their stems to fit almost any bullet; the only one I've had bottom out is a Badlands Precision .338 285 gr ICBM (copper monolithic). They are much longer-lived than the Redding I started with; the stem belled and galled the sliding sleeve (not a compacted load). I haven't had a Forster stem bell, but they do crack - they usually make a small snap at the start of the down stroke when that happens. Fortunately, replacement stems are available on Forster's web storefront and aren't very expensive; I keep a couple on hand for each of my seaters.

 

[divingin]

Most seaters hit way above the actual ogive (the point that will contact the rifling.)

You said you were getting variations in the Base to ogive; how is the OAL (or was that what you were referring to as being within .001"?) If it was, measure the base-to-ogive of several bullets, and subract that from the bullet OAL length. Variation in an ogive to tip (or more accurately from ogive to the point the stem hits the bullet) will likely end up as cartridge base to ogive variation.