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Joined: Sep 2008
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Hello All, I recently got a custom 6.5x55 Ackley built and have been fireforming brass and doing load development with some interesting results. With standard(not fireformed) brass it shoots 140VLDs with 48.0gr 7828 to .25moa every time. When I reload the fireformed brass however, I haven't even come close to that level of accuracy. I have tried 50-53grs 7828 in .5gr increment and the best it will shoot is .75moa. The point of impact also shifts 3" high and to the 1" right. According to quickload the velocity of the Ackley loads should equal the standard loads with 50.5gr 7828. Does anyone have any thoughts or ideas? I don't care for the idea of always having to buy fresh 6.5x55 brass! Thanks
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Joined: Jan 2003
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Campfire Outfitter
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Campfire Outfitter
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Same dies? Try the fire-formed brass with the standard load (48g)?
W
"I would build one again, if it were not for my 350RM (grin)."
MtnHtr
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Joined: Oct 2008
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Campfire Tracker
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Campfire Tracker
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Wild ass guess but your forming load is hitting an accuracy node. I would try two experiments load down to the same velocity with the formed brass and do a ladder type test to see if you hit the accuracy node again at a higher velocity.
Could be other causes but I would start there. I have shot a 6.5x57 AI or AAR and it was easy to load for. Never have shot the swede version.
"When you disarm the people, you commence to offend them and show that you distrust them either through cowardice or lack of confidence, and both of these opinions generate hatred." Niccolo Machiavelli
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Joined: Nov 2004
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Campfire Tracker
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Campfire Tracker
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Try seating depth and Vit N160
Last edited by nathanial; 10/26/12.
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Joined: Oct 2009
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Campfire Ranger
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Campfire Ranger
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Try the fire-formed brass with the standard load (48g)?
YUPIf accuracy is still degraded (although it's slight in this case), then it's a reloading issue. First thing I'd want to know is how is the resizing being done? (neck only, full size, bumping shoulder, yada, yada, yada). Next up would be runout.
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Resizing is an RCBS full-length after fireforming. Seating depth for standard and Ackley is to the same COL-- 3.125, right at the lands. I actually have tried the same 48gr load in the fireformed and it was the worst of the bunch, then I ladder tested 50-53gr in .5gr increments.... to no avail. The chronograph reads the 50.5gr fireformed loads are equivalent velocity to the standard brass with 48gr. I think I might try a different powder(perhaps slower burning). I guess my thinking was if a bullet exits the barrel with the same velocity it should be as accurate and have the same point of impact.
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Joined: Oct 2009
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Campfire Ranger
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Campfire Ranger
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What method do you use when establishing contact with the rifleing?
As to resizing, here's what Mule Deer has said in the past:
"..screwing the die down so it contacts the shell-holder, then backing it off half a turn. Resize a FIRED case that isn't cracked, then try it in your rifle's chamber. Chances are it won't fit, or will chamber hard. Screw the die in SLIGHTLY, then size the case again, and see if it fits the chamber. Keep repeating this as necessary, until the case will chamber with a very slight amount of resistance."
////////////////////
It works.
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I measured the length to the rifling with the hornady lock n load gauge. It was verified by the smith when he cut the chamber. I have always set die depth just so the shell holder touches and then the handle barely "snaps" down at the bottom. I'll have to give the method you suggested a try a try next time. I guess I just assumed the rifle would be more accurate shooting the ackley brass and not as finicky.
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Joined: Oct 2009
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Campfire Ranger
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I measured the length to the rifling with the hornady lock n load gauge. That'll work! Leaving that brass conformed to YOUR chamber (rather than a die) can make a big difference. Might want to consider a neck-sizing only die. There's several available, I'm partial to the collet-styles from Lee.
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Thanks for the info..... I was thinking about getting one anyways, I hear it saves brass life.
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Campfire Regular
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Have you checked the run-out on your loaded brass. Neck sizing can definitely help. I personally like Redding dies, you might look at the type-s bushing dies.
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Campfire Regular
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Campfire Regular
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I would try jumping the bullets .030-.050" and maybe trying H4831sc.
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I measured the length to the rifling with the hornady lock n load gauge. It was verified by the smith when he cut the chamber. I have always set die depth just so the shell holder touches and then the handle barely "snaps" down at the bottom. I'll have to give the method you suggested a try a try next time. I guess I just assumed the rifle would be more accurate shooting the ackley brass and not as finicky. Sounds to me like you are setting your shoulders back too far. Set up your dies for partial full length resizing, skip the neck sizing die.
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fire forming loads are often more accurate than the finished product. It has something to do with the expansion of the original brass to the chamber your fire forming too.
Wac em and stack em
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Campfire Kahuna
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Campfire Kahuna
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fire forming loads are often more accurate than the finished product. It has something to do with the expansion of the original brass to the chamber your fire forming too. I had not heard this. Interesting. Is this often or always the case? I had heard that velocity was less when firing standard loads in an improved chamber...
_______________________________________________________ An 8 dollar driveway boy living in a T-111 shack
LOL
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Hello All, I recently got a custom 6.5x55 Ackley built and have been fireforming brass and doing load development with some interesting results. With standard(not fireformed) brass it shoots 140VLDs with 48.0gr 7828 to .25moa every time. When I reload the fireformed brass however, I haven't even come close to that level of accuracy. That will teach you not to mess with a perfect thing.
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Joined: Nov 2007
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Campfire Ranger
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Campfire Ranger
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Try the Lee Collet Neck Sizer Die for the standard swede; they work w/ AI'd versions. I guarantee you'll get better case life and I bet you get your accuracy back, too...
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Campfire Outfitter
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fire forming loads are often more accurate than the finished product. It has something to do with the expansion of the original brass to the chamber your fire forming too. Not in my experience. Similar accuracy? Yes. More accuracy? No.
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