primers on fireforming 280 ackley

[7mm looney]

question i have seen conflicting info on magnum or non magnum primers for fire forming

280 qckley brass using mid to low original 280 loads ?

just being cautious and curious. ;D

thanks for helping a internet blog newbie!!!!!

 

[TonyR]

I have fire-formed a bunch of 7X64 Brenneke which is roughly the same size case and uses the same powders as the 280AI and I always use standard CCI BR-2 primers. Otherwise I would use the Wolf Large Rifle Magnum primers instead. You should compare the headspace on an unfired and fired case to see if you need a false shoulder for fire-forming. Usually a hard jam is enough but I was getting about a third misfires with my Brenneke cases until I put a little false shoulder near the base of the neck and the problem went away. I am told that fire-forming with too much headspace stretches and weakens the case body near the case head even if the round goes of OK so I check now. My most recent lot of 6.5X284 Lapua brass had about 0.008 inches more head space than my first batch so there does not appear to be any general rule to follow. Just check and see what is going on with your chamber.

 

[bheadboy]

I use 9 1/2 and top 280 std loads with 140gr and it work great no lost cases

Bob

 

[bigedp51]

primers on fire forming 280 ackley

When fire forming cases use the primer you plan to use with your normal loads. Reading the primers is the real issue, if your pressure is too low the primers will not be flush with the base of the case. This also requires a work up load to find out at what load-pressure the case is filled out.

If you have reasonably tight headspace don't worry about diffrent primers and loads and fireform as bheadboy stated above.

If you have a RCBS Case Mastering gauge it will tell you if you have any stretching in the web area after fireforming and if you need to change your methods.

 

[Nik]

I will be fire-forming for 284 using 6.5x284 Lapua brass. Is it just a straight forward neck up to 7mm with 284 FL die, and fire in the 284 chamber rifle? Can I use a neck die instead? Thanks.

 

[TonyR]

I will be fire-forming for 284 using 6.5x284 Lapua brass. Is it just a straight forward neck up to 7mm with 284 FL die, and fire in the 284 chamber rifle? Can I use a neck die instead? Thanks.

I neck them up with expander mandrels in htree stages, the last being the mandrel sized for my neck turner pilot. I use an inside neck reamer to get rid of the donuts. Others just use a F/L die with an expander ball but I lost too many cases that way.