Forming Ackley Improved Cases?

Taroman · January 18, 2010, 08:30 PM

For my .257 Ackley, in the past I fired factory .257 Roberts loads to make the cases. With the price of factory loads gone through the roof, I'm considering just stuffing the Ackley loads in new cases and firing away.

Does anyone see a problem with this?

SL1 · January 18, 2010, 08:45 PM

because I don't have any. But, I do fire-form .30 Herretts, so I have a little experience in blowing-out case shoulders.

I would think that firing REGULAR .257 Roberts loads in the new cases would be more consistent with the practice of shooting factory loads in the Improved chamber. Then use the Improved loads in the formed cases for the second firing. I don't know if the Improved loads would even fit in the unfired cases; I guess it depends on the powder and the pressure the load is intended to develop. Some manuals load AI cases to much higher pressures than the factory loads the regular rounds.

I know from firing my Herrett cases that a full-pressure load can keep the case neck the same length by stretching the shoulder metal, whereas firing a mid-range load tends to shorten case necks by pulling metal back into the shoulder as it expands. But, I don't know what Ackley chambers do with factory ammo, so I only offer that as an observation that you may want to factor into your own knowedge of the Ackley.

SL1

GeauxTide · January 18, 2010, 09:01 PM

Yes, be sure to load a middle load for the standard 257 to fireform. I'd buy a box of 87gr for this purpose.

plainsman456 · January 18, 2010, 11:33 PM

When forming mine I use the middle load in the reloading book.Your choice of book.They have always formed the first time and will suprise you on targets.Have Fun with it.

Taroman · January 19, 2010, 12:14 AM

Thanks, That's sort of what I figured to do: A mid-range AI load. Funny the last group of factory loads I fired the pressures were so low that a few of the shoulders didn't form completely and the undistorted primers even backed out a bit, which I understand is a sign of low pressure.

B78-22250 · January 19, 2010, 10:38 AM

Try loading middle of the road loads as suggested but seat your bullets out long and into the rifeling. This will keep the case against the bolt face and give a little bit higher pressure. Your brass will be perfectly formed to fit your chamber. After that load the AI loads. Also I think I would make sure that I have a smoothe chamber you don't want the brass to grip the chamber walls while fire forming. I form brass for a 280AI this way and never have any problems. I also suggest you stay away from any nickle plated brass It's not worth the problem. hope this helps and have a great day.

brickeyee · January 19, 2010, 12:02 PM

Either the bullet needs to be touching the rifling, or the case should be a jamb fit in the chamber.

The 'go gauge' (minimum chamber length) is the AI 'no go gauge.

If the barrel was not set back it likely has excess headspace.

You can still form the brass to match, but it is not a real AI chamber.

January 18, 2010, 08:30 PM	#1
Taroman Senior Member Join Date: January 15, 2010 Posts: 166	Forming Ackley Improved Cases? For my .257 Ackley, in the past I fired factory .257 Roberts loads to make the cases. With the price of factory loads gone through the roof, I'm considering just stuffing the Ackley loads in new cases and firing away. Does anyone see a problem with this? __________________ -jwk- Si vis pacem, para bellum

January 18, 2010, 08:45 PM	#2
SL1 Senior Member Join Date: November 8, 2007 Posts: 2,001	I'm not an expert on Ackley's because I don't have any. But, I do fire-form .30 Herretts, so I have a little experience in blowing-out case shoulders. I would think that firing REGULAR .257 Roberts loads in the new cases would be more consistent with the practice of shooting factory loads in the Improved chamber. Then use the Improved loads in the formed cases for the second firing. I don't know if the Improved loads would even fit in the unfired cases; I guess it depends on the powder and the pressure the load is intended to develop. Some manuals load AI cases to much higher pressures than the factory loads the regular rounds. I know from firing my Herrett cases that a full-pressure load can keep the case neck the same length by stretching the shoulder metal, whereas firing a mid-range load tends to shorten case necks by pulling metal back into the shoulder as it expands. But, I don't know what Ackley chambers do with factory ammo, so I only offer that as an observation that you may want to factor into your own knowedge of the Ackley. SL1

January 19, 2010, 12:14 AM	#5
Taroman Senior Member Join Date: January 15, 2010 Posts: 166	Thanks, That's sort of what I figured to do: A mid-range AI load. Funny the last group of factory loads I fired the pressures were so low that a few of the shoulders didn't form completely and the undistorted primers even backed out a bit, which I understand is a sign of low pressure. __________________ -jwk- Si vis pacem, para bellum

January 19, 2010, 10:38 AM	#6
B78-22250 Member Join Date: May 24, 2009 Location: Eden NC Posts: 56	AI forming Try loading middle of the road loads as suggested but seat your bullets out long and into the rifeling. This will keep the case against the bolt face and give a little bit higher pressure. Your brass will be perfectly formed to fit your chamber. After that load the AI loads. Also I think I would make sure that I have a smoothe chamber you don't want the brass to grip the chamber walls while fire forming. I form brass for a 280AI this way and never have any problems. I also suggest you stay away from any nickle plated brass It's not worth the problem. hope this helps and have a great day.

January 18, 2010, 09:01 PM	#3
GeauxTide Senior Member Join Date: April 20, 2009 Location: Helena, AL Posts: 4,424	Yes, be sure to load a middle load for the standard 257 to fireform. I'd buy a box of 87gr for this purpose.

January 18, 2010, 11:33 PM	#4
plainsman456 Senior Member Join Date: December 31, 2008 Posts: 260	When forming mine I use the middle load in the reloading book.Your choice of book.They have always formed the first time and will suprise you on targets.Have Fun with it.

January 19, 2010, 12:02 PM	#7
brickeyee Senior Member Join Date: December 29, 2004 Posts: 3,351	Either the bullet needs to be touching the rifling, or the case should be a jamb fit in the chamber. The 'go gauge' (minimum chamber length) is the AI 'no go gauge. If the barrel was not set back it likely has excess headspace. You can still form the brass to match, but it is not a real AI chamber.