Bassnbow
Well-Known Member
I'm going to fire form new brass for a 280 ackley and have an option of several different bullet weights. Does a heavier bullet or lighter bullet work better when fireforming, or does it matter?
bullet weight for fire forming brass??
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Whatever is cheapest, give it a slight jam and send it
quigley257
Well-Known Member
I use whatever I have on hand as it's more about the pressure generated. I choose middle of the road doses of faster burning powder with the understanding that the cases won't be fully formed until the 3rd loading or thereabouts. Yes, absolutely seat your bullets long to keep the case head pushed against the bolt face to avoid excessive stretch.
Bassnbow
Well-Known Member
Great, so a slight jam creates more pressure and helps form faster?
QuietTexan
Well-Known Member
Are you forming 280 Rem cases to 280 AI, or were the cases bought as 280 AI cases? This is one AI where brass is readily available in the AI form.
Bassnbow
Well-Known Member
it is new 280AI brass
quigley257
Well-Known Member
No need to fire form if it's already AI brass. Just load and shoot per normal load developement.
I fully understand what you are saying. However, your thoughts on using the cream of wheat method or just a fast powder and some TP to keep the powder secure? I have a 243AI coming soon and I'm contemplating using just the powder and TP. I have done AI's before but I want to try the method I stated above. Just because.
quigley257
Well-Known Member
I've never used the COW method for forming. Many people do it with great success. I have always loaded and fired bullets. Many AI cartridges are extremely accurate during forming plus it allows you to do barrel break-in at the same time.
I've used the COW method in a 223ai. I used dried out used coffee grounds instead of cream of wheat..... it smells better burnt
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I'm going to use the false shoulder method necking 270win brass down to 25sherman one of these days.
If your case of going from 280 to 280ai id jam the bullets. BUT BUT BUT if your 280AI chamber is set up properly then it should be about .004-.005" shorter than a standard 280rem chamber and have all the "crush" built into it. Take a sharpie and color the case neck and shoulder of an empty case and chamber it. It should show a "crush fit" line at the neck shoulder junction. You can still jam bullets but if it's a "true" ackley improved chamber it should be hard to close the bolt on factory standard 280rem cartridges.
If you have 280ai headstamped brass then is already 98% fire formed to your 280ai chamber. If it's standard 280rem virgin brass then I would jam a bullet in the lands and use a 75% charge. I don't load to max in virgin brass or really any brass for that matter. Keep a cleaning rod handy and if you have to unload a unfired cartridge do it with the muzzle pointed up as high as possible depending on your shooting range rules. Jammed bullets like to stick in the lands sometimes and nobody wants a magazine full of powder.
So do your ladder or OCW load work up with all virgin pieces of 280ai or 280rem brass. Find your "virgin brass" load with the first 25pcs or so then you could load up the next 75pcs of virgin brass with your "virgin brass max/ideal" load then shoot all of those 75pcs. If it's a new barrel then by the time you get all 100pcs shot your barrel should be broke in and you could play with the load from there if you wanted to squeeze out the most speed and accuracy.....which who doesn't lol.
I had been under the impression that you had to fire form before you did a real load work up in an AI chamber.....you don't. @lancetkenyon explained it to me like this.......You have a fire forming load AND a formed load. Both can be very accurate and the only difference is one is faster than the other due to the increased powder charge.
So yes your D.O.P.E. at longer ranges will be different but you shouldn't be trying to make 700yd shots on a deer with the first 50-100 rounds out of the rifle anyway.
My bone stock bergara 300prc gained 60fps on the 4th box of hornady precision hunter down the tube. That's a difference of elevation correction of 0.4mils at 1000yds. I know that's not exactly the same as blowing the shoulders out on an AI case but it still relates. All but about 25 rounds of the first 100 shots out of my 300prc were made on coyotes,hogs or cull deer out to about 200yds. Fire formING loads don't have to be "wasted" on paper or steel .... just keep the shots close-ish.
.I'm going to use the false shoulder method necking 270win brass down to 25sherman one of these days.
If your case of going from 280 to 280ai id jam the bullets. BUT BUT BUT if your 280AI chamber is set up properly then it should be about .004-.005" shorter than a standard 280rem chamber and have all the "crush" built into it. Take a sharpie and color the case neck and shoulder of an empty case and chamber it. It should show a "crush fit" line at the neck shoulder junction. You can still jam bullets but if it's a "true" ackley improved chamber it should be hard to close the bolt on factory standard 280rem cartridges.
If you have 280ai headstamped brass then is already 98% fire formed to your 280ai chamber. If it's standard 280rem virgin brass then I would jam a bullet in the lands and use a 75% charge. I don't load to max in virgin brass or really any brass for that matter. Keep a cleaning rod handy and if you have to unload a unfired cartridge do it with the muzzle pointed up as high as possible depending on your shooting range rules. Jammed bullets like to stick in the lands sometimes and nobody wants a magazine full of powder.
So do your ladder or OCW load work up with all virgin pieces of 280ai or 280rem brass. Find your "virgin brass" load with the first 25pcs or so then you could load up the next 75pcs of virgin brass with your "virgin brass max/ideal" load then shoot all of those 75pcs. If it's a new barrel then by the time you get all 100pcs shot your barrel should be broke in and you could play with the load from there if you wanted to squeeze out the most speed and accuracy.....which who doesn't lol.
I had been under the impression that you had to fire form before you did a real load work up in an AI chamber.....you don't. @lancetkenyon explained it to me like this.......You have a fire forming load AND a formed load. Both can be very accurate and the only difference is one is faster than the other due to the increased powder charge.
So yes your D.O.P.E. at longer ranges will be different but you shouldn't be trying to make 700yd shots on a deer with the first 50-100 rounds out of the rifle anyway.
My bone stock bergara 300prc gained 60fps on the 4th box of hornady precision hunter down the tube. That's a difference of elevation correction of 0.4mils at 1000yds. I know that's not exactly the same as blowing the shoulders out on an AI case but it still relates. All but about 25 rounds of the first 100 shots out of my 300prc were made on coyotes,hogs or cull deer out to about 200yds. Fire formING loads don't have to be "wasted" on paper or steel .... just keep the shots close-ish.
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birddog 68
Well-Known Member
This is the correct answer for AI brass. No jam needed or wasted components!
BillLarson
Well-Known Member
If your chamber is cut to match the brass.......
fire forming may not be nessacary..... Test to find out...
Many.... Many..... important matches have been won with NEW unfired brass.....
fire forming may not be nessacary..... Test to find out...
Many.... Many..... important matches have been won with NEW unfired brass.....
purpledragon
Well-Known Member
Also, the heavier the better.....jmho
This! No need to overcomplicate it unnecessarily.
