Consistant seating depth...

[20PPC]

I just started shooting mid range 600 yards and am experiencing problems getting consistant seating depth in the case.
I'm shooting a 6BRA chambered by Ronnie Long, Lapua brass, Varget, Federal primers and 105 Berger Hybrids.
I cannot get 2 bullets in a row to seat the same depth, I sent the Wilson seater stem to Ronnie because it was was not making the consistant proper contact on the bullet.
He opened it up a slight amount and polished it to what now appears to be perfect contact with the tip of the bullet.
I've measured BTO on the bullets and all of them appear to be within + - .0015 yet when seating I'll get .004 - .010. difference.
Needless to say 2 1/2 hrs later " actually longer " and only 75 rounds loaded is getting to the point the hassle of loading is outwaying the enjoyment of shooting.
Any advise would be appreciated.
Dave

 

[CharlieNC]

Do you feel seating force differences as well, associated with depth?

 

[Bc'z]

Your seater shouldn't be in contact with the tip what so ever.
You already know that the BBTO measures good, try sorting some by OAL of bullet in .003 increments.
Once you have a few sorted try loading them and measure your CBTO

 

[Jeff Porter]

Long shot but look close at the seater stem. I was getting weird seating results with a Forster die and the seater stem had a fine crack in it. As neck tension varies, the crack would open up on stiffer necks and leave the bullet longer than desired. I got a new stem and problem went away.

 

[Sandstorm]

Annealing after every firing, trimming your brass.?

 

[6.5 forever]

Make sure you are using the same smooth stroke when seating. I can push my bullet in further if I push hard and bounce my press handle. Precision tools are fantastic but it is still important to FEEL a operation.

 

[mikecr]

I cannot get 2 bullets in a row to seat the same depth

Same seating depth,, same CBTO,, or same OAL?

I sent the Wilson seater stem to Ronnie because it was was not making the consistant proper contact on the bullet.

What do you consider proper contact?

I've measured BTO on the bullets and all of them appear to be within + - .0015 yet when seating I'll get .004 - .010. difference.

Do you understand that BTO means nothing to seating?

How deep are you seating bearing? Into donut area?
Are you annealing in some way?
What are the seating forces feeling like?

 

[20PPC]

Do you feel seating force differences as well, associated with depth?

No, seating pressure appears equal but I am not using a force gage but one may be in the future.

 

[20PPC]

Annealing after every firing, trimming your brass.?

I have not annealed, only 3 firings on the cases.
I had problems with my Annie and it went back for repair otherwise I would have annealed them all.

 

[Eagle Six]

I've measured BTO on the bullets and all of them appear to be within + - .0015 yet when seating I'll get .004 - .010. difference.
Dave

Dave I confused on this statement. Your base to ogive is +- .0015 using a comparator gauge correct? So what/how are you measuring seating to get .004 -.010? Is that base to bullet point?

EDIT: Sorry Dave I mis-read, you are measuring base of bullet to ogive and then cartridge base to ogive, got it.

 

[Coyotefurharvester]

Mike, what did you mean by- BTO means nothing to seating-?
I re-read it, bullet base to ogive, ok clear now.

 

[Mike TackleBerry]

Are you using a le wilson chamber type seating die?

 

[piie]

How much case fill? Perhaps slightly compressed load?

 

[rebs]

I have the same seating problem, I will try all recommended

 

[Sandstorm]

I have not annealed, only 3 firings on the cases.

I think ther's part of the problem for sure.

 

[rjs1230]

Try seating .050 long then measure if they stay the same then take them in another .010 till you get to your seated depth . Bullet base might be sitting in the middle of donut or on the powder .

 

[fisherman987]

Unfortunately, just like OAL and BTO, the point where the seating stem contacts the bullet can be different on every bullet. If you measure that point ( let's call it BTSO, base to seating ogive) and then sort your bullets accordingly, then the overall loaded length should come out to be the same. If you don't, then the overall length from cartridge base to seating ogive of the bullet will be the same for every cartridge, but the overall length will vary. The easiest way to come close without actually measuring all these is to sort all your bullets by overall length. The other measurements run fairly proportional to the overall length, especially Berger bullets and good custom bullets, so you should see the overall loaded length become more consistent. Accuracy one sells a tool for sorting bullets by OAL which is very fast and easy to use.

 

[JFrank]

Meplats can vary up to .010, if your seater stem is making contact with the meplats that seems a likely cause, ( if you haven’t already ) drill out the center if you have to and brush the case necks with a nylon bore brush prior to seating. Your seater stem should make contact about the .174 mark, if you have a .17 cal comparator insert? You could use that to monitor seating consistency.
Lack of annealing is a unlikely cause , doughnut an unlikely cause, compressed varget seems unlikely as well.

Good luck

 

[jelenko]

the overall length from cartridge base to seating ogive of the bullet will be the same for every cartridge, but the overall length will vary

But, isn't the base to ogive distance the important one?

 

[Pete Wass]

But, isn't the base to ogive distance the important one?

yes.