Lapua .284 brass problem

[expiper]

Post # 16 is spot on your resized dye and your chamber are not working in concert together. Remember there is more to achieving proper cartridge fit to the chamber than headspace. The cartridge must fit radially as well as longitudinally for proper brass life and sealing of the gas inside the chamber of the rifle. I have used Kiff Reamers for many years with much success while using Redding full length bushing type S dies you need to do a lot of measuring and figure out if the chamber is too big or the dye is too small compared to virgin brass as Dave says the smoke on the outside of the cartridge case is a dead giveaway. There's too much clearance and probably not enough pressure. You can't just mindlessly squeeze cartridge brass into some random dye and say the bolt closes on my cartridges so they must be OK and not end up with problems like this. ...Roger.

 

[MikeRu]

Did you check headspace measurement when the brass was new? I’ve seen brand new brass be say .006” to .007” shorter on headspace vs a different lot and or vs a different brand.

That doesn’t mean the brass is bad.

So from what I’m getting out of it is the brass is stretching more for some reason and or being worked to much on resizing after firing.

What powder charge are you loading it to and what bullet are you loading? You gave your velocity and you don’t think it’s a hot load etc… But that doesn’t mean it‘s not.

I’ve run the 284win with what I will call hot loads. I pushed it hard and after 3 firings the Lapua brass primer pockets you could tell where getting loose after those three firings. I wouldn’t use the brass after that. Again doesn’t mean the brass is bad… I was just pushing it to hard in this case. I’ll guarantee my loads were past 65k. Probably more around the 70k to low 70k range.

You could have a combination of things going on.

Later, Frank
Bartlein Barrels

Like Frank said—what bullet?

 

[Dave M.]

So Dave, I’m just getting into 284 Shehane, my first experience with a wildcat, necking up, fireforming, etc.
Let me see if I’m grasping this, you jam into the lands on seating and use a reduced load to avoid overpressure when fireforming?
My experience so far was all pistol, 308, and 6.5PRC.
Thanks,

Ray

I typically run 2gr less than my standard charge when fireforming, unless I need the brass to be fully formed after one firing (which is very difficult) in which case I will run my standard load.
Dave