Dasher Fireforming Process

[Keith Glasscock]

I have always looked at the process steps required to prep brass. The order of those steps, in my opinion can influence the outcome.

Take for instance Dasher fireforming. Cases fail at the shoulder occasionally. Those failures can be dangerous due to escaping gasses.

These two cases show what would have been two case failures. I have not fired all of the remaining cases (about 300 total) to see if I'll have any more failures, but the order of operations saved me from two bad experiences. Both of these opened up during annealing.

So, my current order is:
Skim turn necks
Expand to .257
Anneal (aimed at the shoulder)
Neck size to .266
Load and shoot - 30.5 Varget .007 into the lands

 

[JRS]

Those cases appear to be beyond well done, from heat.

 

[Keith Glasscock]

As we are all becoming aware, the oxidation color on brass is not a good indicator of annealing. Trust me, they were not overheated. They really aren't as dark as the photo appears. The color, less the blue line, is identical to how they went in.

On that subject, after cleaning, there is no indication at all that the cases were ever annealed - by me or Lapua.

 

[22DASHER]

Are you sure they didn't look like that when you opened the box up from the factory? I had 4 in one blue box recently that looked like that straight from the factory...toss em and move on

 

[waterfwlr]

That is a defect in the brass, straight from the factory. There was a topic here on the forum not that long ago.

 

[ridgeway]

Look at every brand new case and cull out any shoulders that are folded like that. They won't survive fireforming. Contact Kevin Thomas and he might be able to send you replacement cases. The last lot of 500 I went through....2-3 bad cases were the average per box of 100.

 

[savagedasher]

Look at every brand new case and cull out any shoulders that are folded like that. They won't survive fireforming. Contact Kevin Thomas and he might be able to send you replacement cases. The last lot of 500 I went through....2-3 bad cases were the average per box of 100.

I have the same success number. Larry

 

[Phil]

Contact Kevin Thomas and he might be able to send you replacement cases. The last lot of 500 I went through....2-3 bad cases were the average per box of 100.

This was my thought as well, I would see if you could get them replaced before I tossed them in the recycle bin.


Phil.

 

[dmoran]

In +11-years of using 6BR Lapua brass (several 1000's), I've hardly ever opened a box that didn't have a couple defects.
Seen a few in other Lapua calibers as well, but not as typical as found in 6BR boxes (only seen them in Lapua brass).
Donovan

 

[JamesnTN]

Look at every brand new case and cull out any shoulders that are folded like that. They won't survive fireforming. Contact Kevin Thomas and he might be able to send you replacement cases. The last lot of 500 I went through....2-3 bad cases were the average per box of 100.

I wouldn't hold my breath on Kevin getting back with you anytime soon. I sent him a few defective 6.5-284 cases that were so bad out of round they wouldn't even clean up on neck turning them. He said he'll send them to the factory for inspection and that's the last I've heard of that.

 

[Gabe22BR]

My experience as well on the 6br cases.

 

[Keith Glasscock]

Look at every brand new case and cull out any shoulders that are folded like that. They won't survive fireforming. Contact Kevin Thomas and he might be able to send you replacement cases. The last lot of 500 I went through....2-3 bad cases were the average per box of 100.

I wouldn't hold my breath on Kevin getting back with you anytime soon. I sent him a few defective 6.5-284 cases that were so bad out of round they wouldn't even clean up on neck turning them. He said he'll send them to the factory for inspection and that's the last I've heard of that.

I had a similar problem a couple of years ago. Kevin came through in the end. You have remember that during the summer he is bouncing from match to match. Once the factory says that the cases are out of spec. Kevin arranges for replacements. Send him an e-mail to ask how the investigation is going.

 

[DJSBRS]

Whatever process you choose to use, refrain from using Lapua lot# P00726201

I lose about 25% due to bad folds and thin thickness in the shoulder both inside and out.

DJ

DJ's Brass Service

 

[Keith Glasscock]

Where these folds were not immediately visible from the outside, has anyone tried bore scoping the brass?

 

[Geno C]

They are visible from the outside. I unfortunately didn't catch it till I stuffed a bullet in... I'll see if I can dig up a pic

 

[expiper]

Not to be contrary with the above post saying to avoid lot# P00726201,,,I just fire formed 200 6mm Dashers from that lot and had NO case failures or problems,,,,just sayin,,,,its all in how you do it and the luk of the draw,the 200 that I purchased just happend to NOT have those folds !!!,,,Roger

 

[Keith Glasscock]

I started working the process thing because case failures can be dangerous. That said, I had 3 case failures out of 88 formed so far. Examination of the remaining bras under magnification gave me an additional 5 that I won't shoot because they have a groove/crease/line longitudinally on the shoulder.

So, I have 10 bad cases (assuming my culls are actually bad) out of 300. A 3.3% failure rate isn't that bad when you consider that all of them would have likely been fine as straight 6BR except for the two that opened up during annealing.

Everyone please remember to wear good eye protection when shooting! A jet of hot gasses can ruin ones vision forever!

 

[Geno C]

Here you go. I happens with 6br Lapua brass. Sadly just the nature of the beast until they come up with a solution

 

[dkhunt14]

I never fireform any of them with the crease. They always blow through leaving crud and hot gases that can cut the chamber. Matt