6.5x47 Lapua, Berger 130 Seating issues. Need Opinions, and Help

[Matt Pridachuk]

So I am having a weird issue, and I am about to pull my hair out.

Last loading session I loaded up about (300) 6.5x47 Lapua Virgin brass cases.

Berger 130gr AR-Hybrids
42.0 Grains IMR 4451
COAL 2.650
Off the Ogive 2.051
Velocity 2885

Forster Seating Micrometer die.

Went to a PRS class, and shot about 250 of the loaded rounds. Worked great no pressure signs, accurate, etc.

Now I am ready for the PRS season, and need to load the aforementioned now (once fired brass) with the same load after cleaning, prep, and charging with powder.

Now I seat the bullet, and it WILL NOT seat to the 2.650 COAL / Ogive 2.051 It only seats to COAL of 2.695 / Ogive of 2.096. I thought maybe the die got bumped or changed. So I took it apart, cleaned it, and re-installed it. Measured it and seated a few more rounds with the same results.

Then I wondered if the powder charge was wrong. So I took some of the previously loaded rounds, measured the 2.650/2.051, and then pulled the bullets. Weighed the charge and it was also 42.grains. Re-charged the cases, and took the bullets back to the press and seated them (Previous measured 2.650/2.051) Now when seated it goes to 2.695/2.096!!!!!

I can't figure it out. What am I missing, or what do I need to do to get to the old measurements, as those are what worked and I have all my data for before the match next week?

 

[Grimstod]

How did you clean your brass? Are you using stainless steel meadia? If so it stripped the brass of lubricant that Lapua puts on there and will alter your finished seating depth.

 

[Milo 2.0]

I'd say you need to get your neck tension under control, going to need more to hold that bullet.
I'd revisit your load too, based off experience and Quickload, you're pushing rather hard.

 

[dskogman]

That’s full Probably a compressed load pushing it back. Less powder, more neck tension, drop tube,

 

[Matt Pridachuk]

Yep, it is a compressed load, but as I said earlier, no signs of pressure, flattened primers, flow, etc.

The cases were sized with a Forster Full Length die, set to just bump the shoulder 2-thousandths, and then a mandrel to set neck tension. The same mandrel was also used when the brass was straight out of the box. I wouldn't think that one firing would change the neck strength to a point that it would not hold the bullet in place after being sized for just a second time?

 

[Milo 2.0]

Yep, it is a compressed load, but as I said earlier, no signs of pressure, flattened primers, flow, etc.

The cases were sized with a Forster Full Length die, set to just bump the shoulder 2-thousandths, and then a mandrel to set neck tension. The same mandrel was also used when the brass was straight out of the box. I wouldn't think that one firing would change the neck strength to a point that it would not hold the bullet in place after being sized for just a second time?

If you can recall, that new brass took quite a bit of force to seat a bullet, and duplicating neck tension of new brass is damn tough.

 

[Cloudrepair]

Could it be you may have created a donut and overlooked It?

 

[FatBoy]

any chance you have:
used a different shell holder in your press than the one you used initially?
Used a different lot of bullets?
Have a new caliper or have you changed the ogive insert of your measuring tool?

If the ogive of the bullet isn't getting a raised ring of copper, or you're not crushing it you CAN seat it deeper. If you seat it deeper and it pushed back out, you have your answer. Something has changed, probably not the brass.

 

[Dusty Stevens]

Humidity has made your powder adsorb more moisture and its pushing your bullets- or- You didnt say if you actually tried to adjust your seating die to put your bullet where you want it? Maybe a diffrrent lot of bullets and your die only contacting one point is different on this box of bullets.

 

[FeMan]

Is your seater a Forester as well? If so, I have had the knurled keeper nut on the stem come loose every once in a while and leave me wondering why I cant adjust the seating depth down. When this happens, you turn the indicator but the stem does not move with it. Check to make sure that is good and tight. If it came loose, make sure you run the stem down a turn or two at least before you tighten the keeper nut.

 

[Matt Pridachuk]

Thanks for all the advice guys!!! I guess a clear head when I came home from work today helped. I took one of the "long" rounds, and then adjusted the seater to seat the round to the depth I wanted it. I then took an unloaded round, and seated it. It seated to a the proper depth. So I guess for some reason when there is powder in the case I did not have enough "pressure" on the seating stem to press the bullet to where it needed to be be. Once I set it again, I began reloading several rounds, checking every round, then every three, then every five, and finally every 10-15 until I made my 300, by the end I seated everything to the depth I wanted to within 1/2 a thousandth either direction.