Need help with consistent seating depth using seating die

[misterc01]

Is it a compressed load? I've had this issue when when I'm crunching powder.

as someone else mentioned, VLD bullets sometimes need a special stem, so you're not seating off the point of the bullet (not sure if the 120gr bullet would count as VLD??).

It's also really easy to get different measurements with the hornady comp tool, with just the slightest change in angle or pressure.

What he said - about the comparator!!!!

 

[30BR]

All,

I am not sure what is going on but when seating 120 grain Nosler Ballistic tips in my 7mm08 using my Forster competition seating die, I am not getting consistent seating depths to ogive when measuring with a Hornady comparator.

Call Forster, and ask for a seating stem for that bullet. They usually have a variant for most calibers that will cure the problem.

 

[coopersguide]

I have the same problems. I can tell when I have less neck tension when seating my lengths are shorter. I recently started using dry lube and it has helped. I am interested to see all the educated comments on this was well. I am still "sneaking up" on my desired lenght which works but is time consuming. ??????

 

[Tiny Tim]

Tagging in

 

[orange1948]

Good thread...following. Thanks

 

[AggieHunter]

I don't anyone has said anything about using a sizing die w/a bushing. It could be your case opening doesn't seat your bullet w/the same tightness for each round. I use a sizing mandrel from Darrell Holland to make sure my case opening stays consistent w/each round after I run it thru the sizing die. Yes it is an extra step, but I get a really good consistent fit on each bullet that is seated.

 

[Barrelnut]

Forster dies have very thin seating stems. Very high neck tension or compressed loads can crack the stem and will cause exactly what you are describing (I have done it). Look for a very fine crack on the side of the stem right at the area where it contacts the side of the bullet. You may need a magnifying glass to see it or feel it with your finger nail.

Brass that is annealed inconsistently can cause this.
Brass that has different shot counts can too, because the necks are work hardened differently.
Like said above, compressed loads can cause it.
Also, like said, bullets with varying base to ogive can do it, but doubtful with the quality of the bullets you're using.

All of the above in any combination can cause it. I sometimes "walk" the seating depth in by backing off the seating stem a few thousandths and seating/measuring for each bullet until it is perfect for each round.

 

[wonderman4]

I got a wild hair up my butt one day and thought I would measure some .308 150 gr Accubonds.

The results showed (for 100 bullets) that the ES was 0.003" for the 100 that I measured.

This measurement was from bullet base to ogive using a Hornady comparator.

 

[Vettepilot]

Lots of good responses here, but have you closely checked that your primers are all seated below flush?

Vettepilot

 

[epoletna]

Lots of good responses here, but have you closely checked that your primers are all seated below flush?

Vettepilot

Vettepilot:

Yes, I have closely checked to make sure primers are all seated deep enough.

 

[misterc01]

Do you have your forster seater die adjusted to the instructions that came with it? You will have a problem with seating depth consistancy if the sleeve (sliding die chamber) is at or near bottoming out. All explained in the fine tuning die directions and if you have done it correct disregard post, just leaving no possibility unchecked

Second that! I had similar problem and I was watching a video and the point they made was you have to properly se tup the die. I follwed their advice, and Savage 12BVSS point, and complety re-adjusted my die and go tthe consistency I was after.

 

[IHFarmer07]

Forster dies have very thin seating stems. Very high neck tension or compressed loads can crack the stem and will cause exactly what you are describing (I have done it). Look for a very fine crack on the side of the stem right at the area where it contacts the side of the bullet. You may need a magnifying glass to see it or feel it with your finger nail.

Brass that is annealed inconsistently can cause this.
Brass that has different shot counts can too, because the necks are work hardened differently.
Like said above, compressed loads can cause it.
Also, like said, bullets with varying base to ogive can do it, but doubtful with the quality of the bullets you're using.

All of the above in any combination can cause it. I sometimes "walk" the seating depth in by backing off the seating stem a few thousandths and seating/measuring for each bullet until it is perfect for each round.

^^^^this^^^^
Not annealing, annealing inconsistenties, neck thickness inconsistency all will do exactly what the op is got a problem with. The big one that I've had issues with the most is/was donuts!

After I found out about those and figured out how to take them out I have had no issues with seating depths with my forester seating dies I use, they are just as consistent as my Wilson in-line dies that I thought would fix things but didn't until I understood and figured out how to and what to do with donuts. Donuts cause a LOT of things and inconsistent neck tension is one of them.
Good luck

 

[epoletna]

Could you share with us how you recognize donuts (I've read about them and still don't understand) and how you remove them? Or post directions?

 

[sedancowboy]

One of the simplest thing to do is to cut a piece of brass in to length wise and look at it. There is a lot to be learned from dissecting a piece of brass. Donuts being one of them.