antelopedundee
Well-Known Member
Usually [at least for the 6.5-06 vs the 6.5-06AI] the AI max is about 3 grains more than the standard cartridge.
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How do YOU fire form Ackley Cartridges?
- Thread starter hankle
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That's what shooting a factory loaded parent cartridge is. Again, do not over complicate it unnecessarily.
cabelasken
Well-Known Member
I use a fairly heavy bullet and then enough powder to square off the shoulder. When I din't use enough powder, the cases needed two firings.
Mine will be 270AI. It looks to gain around 6 grains. It would be interesting to see. My 7mm mag shoulder moves .017 from virgin brass to once fired and was very accurate with virgin brass.
antelopedundee
Well-Known Member
I'd like to get my hands on some .270AI cases.
antelopedundee
Well-Known Member
If one has access to QuickLoad one can compare the same bullet at the same COL for say the 6.5-06 vs the 6.5-06AI and note the differences in load for each powder. Usually 2-3 grains higher and that's what I go buy when making up loads.
greenejc
Well-Known Member
What is your AI in, and does it chamber a factory round reliably? The factory casing should have a slight crush-fit in your chamber (the bolt should close on the factory round with a little bit of effort). If that's what you have, you can fireform your casing just by shooting factory rounds, or your reloads. You can also use pistol powder, cornmeal filler and bee's wax. But when I fireformed for my 8mm-06 AI, I just necked up from 30-06, loaded the rounds, and shot the standard 8mm-06 for practice, which gave me an improved casing afterwards. You can do this without stretching your brass as long as your chamber is done properly. As a matter of fact, part of the reason for the AI chamber is so factory ammunition can be used as an alternative for the AI ammunition. If you're using a 30-06 AI, you should be able to use standard 30-06 ammunition in it if your AI loads are unavailable, and it will have a minimal effect on velocity, without any effect on accuracy while giving you an Ackley Improved casing without basically wasting a LR primer on just fireforming. I'd just make sure my chamber has a crush fit with the factory casing and then I'd load practice loads in standard casings and shoot them until I had a good supply of AI casings. One or two hundred practice rounds and you're in business, and if you need more casings, you just repeat.
The OP is in the process of building a .270 AI, so he does not have the information you are asking for yet.
greenejc
Well-Known Member
Just read that your round will be a .270AI. You should get around 100fps increase with safe loads in it in a 24" barrel. Good luck. And the reason your 7mm Rem Mag stretches is that most all the rifle manufacturers headspace that round on the belt instead of the shoulder, and then they make the chamber too long. My 300WinMags are headspaced on the shoulder, which gives me about twice the brass life of the 7 mag.
randy86314
Well-Known Member
I chambered a rifle in 250 Savage AI in the nineties. I headspaced the barrel with factory brass. I have never heard that the brass should be a crush fit or that the necks will shorten. The shoulder should blow-out but shouldn't pull brass from the neck. In the pic of 338 Lapua AI, the hydraulic formed cases are much longer to the neck than the factory cases. Doesn't look right to me.
I've used about every method out there from COW, cheap lead bullets with pistol powder (Lyman Cast Bullet Manual), cheap jacketed bullets with pistol powder or fast rifle, hydro, full power loads, etc. Fire forming is all about creating enough "pressure", so there are many ways to achieve that. Some ways are cheaper and easier on barrels than others.
greenejc
Well-Known Member
Thanks. I didn't know that, but the chamber should still fit a factory round with a slight crush-fit. If it won't chamber a factory round with a slightly tight fit, he will need to have the barrel set back slightly so it will do so, so he can reliably use both the AI ammunition and the factory ammunition in it. I've thought about having both my .35 Whelens chambered for the AI version just for the case life improvement it confers. But I already get more than enough velocity out of the 225 grain and 250 grain loads I use in them and 30-06 brass is easily converted to .35 Whelen, so I haven't done it.
greenejc
Well-Known Member
I forgot about cast bullets. Lee makes a great .277 mold for gas checked bullets that would be great for that. He could use wheel weights for casting material and it would give him a neat close range varmint load for plinking while fireforming the brass.
What picture?
