Ackley improved cartridges are designed to headspace .004" shorter than the parents, so you can shoot 280 factory ammo, or use cornmeal and a papertowel plug if ya don't wanna waste bullets. here's how I turn 270 win cases into 6.5 Gibbs cases
resize to a crush fit in the 6.5 chamber
prime and charge with 11 gr of unique, put a finger over the case mouth and tap once on the bench to settle the powder
fill the case to the top of the case neck with corn meal, put a finger over the casemouth and tap once or so to settle the cornmeal to the bottom of the case neck
now tear a 1.5" wide strip off a paper towel and twist it into a skinny worm, stick it into the case neck, wad it in till full then pinch it off, use a small punch to pack the plug in tight.
keep muzzle pointed down, if you have a brake remove it, watch barrel heat (cause it'll get hot!) clean your barrel well when done, shoulders should come out just rounded on the edges, but will sharpen up nicely on the first full power firing.
RR
Ackley improved cartridges are designed to headspace .004" shorter than the parents, so you can shoot 280 factory ammo, or use cornmeal and a papertowel plug if ya don't wanna waste bullets. here's how I turn 270 win cases into 6.5 Gibbs cases
resize to a crush fit in the 6.5 chamber
prime and charge with 11 gr of unique, put a finger over the case mouth and tap once on the bench to settle the powder
fill the case to the top of the case neck with corn meal, put a finger over the casemouth and tap once or so to settle the cornmeal to the bottom of the case neck
now tear a 1.5" wide strip off a paper towel and twist it into a skinny worm, stick it into the case neck, wad it in till full then pinch it off, use a small punch to pack the plug in tight.
keep muzzle pointed down, if you have a brake remove it, watch barrel heat (cause it'll get hot!) clean your barrel well when done, shoulders should come out just rounded on the edges, but will sharpen up nicely on the first full power firing.
RR
So would you expect better results after the second full power firing? Essentially the first full power load would finish the job of the cornmeal and paper towel. Correct?
Might be easier to just shoot some core-loks, at least just for a little pointless range time...Could any accuracy, even remotely, be expected?
Location: S.W. Pa.-- Heart in North Central Pa. mountains-
Posts: 2,505
Quote:
Originally Posted by Cut'em Jack
So would you expect better results after the second full power firing? Essentially the first full power load would finish the job of the cornmeal and paper towel. Correct?
Might be easier to just shoot some core-loks, at least just for a little pointless range time...Could any accuracy, even remotely, be expected?
.........You may be surprised at the accuracy you get with a decent fire--forming load... Some people have found it to be nearly equal to the formed case loadings. Like RR stated, you can shoot factory ammo in a properly constructed AI chamber and may or may not get acceptable accuracy, just as a given gun may or may not like a particular load that could be extremely accurate in someone else's gun of the same cartridge, bullet weight, powder weight, primer, etc. ........
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I love Christmas lights. They remind me of the people who voted for Obama. They all hang together; half of them don't work, and the ones that do, aren't that bright.
For those who understand, no explanation is needed. For those who do
not understand, no explanation is possible.
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I just load up some cheap bullets with a stout (not max, but not min either) load of a cheap powder and go shoot...
__________________
I love Christmas lights. They remind me of the people who voted for Obama. They all hang together; half of them don't work, and the ones that do, aren't that bright.
For those who understand, no explanation is needed. For those who do
not understand, no explanation is possible.
A golf course is a willful and deliberate misuse of a perfectly good rifle range.
I haven't noticed a sifference in accuracy between the 1st and second firing, just sharpening the shoulders doesn't seem to effect it much.
Now the gibbs doesn't shoot very well fireforming, mostly due to the fact that in the gibbs chambering you not only sharpen the shoulder angle to 45° but you move it foreward over 1/8" all that caseforming doesn't help accuracy and if you load them up to acceptable velocity for any attempt at accurate shooting you'll split alot of shoulders. using cornmeal I'll lose 2 out of 100.
However rounds that only have a shoulder/body taper change shoot surprisingly well with fireform loads.
I hunted with fireform loads for my 7mm Allen Magnum, velocity was down but accuracy was outstanding.
couple pics of the process
case on the left is one of the 2% which the shoulder splits upon fireforming
the next case is the parent case 270 win
third is a 270 necked to a crush fit in the 6.5 Gibbs chamber (note the false shoulder or donut on the neck
4th case is a loaded 270
last is a 6.5 gibbs that has been fireformed and loaded ( note slightly rounded shoulders)
Now the finished product, the case on the right has been fired full power 1 time and loaded you can see the shoulders are now sharper more defined
RR
RR-
Great pix..so you are actually chambering the empty case to crush fit or is that the done with a resizer die? You ever have a problem with blown shoulders shooting factory rounds instead of the cornmeal process?
So essentially it would go through this order......(sans the blown shoulder)
Fire forming 280 AI brass
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