The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Guns, Politics, Gunsmithing & Reloading Reloading Please help, fireforming problem.Go | New | Find | Notify | Tools | Reply | |
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I went to the range the other day. I shot 60 rounds of previously loaded rounds that were loaded medium to maximum. Maximum being loads that were loaded 1.5 grains lowere than those where pressure signs were apparent. I then fireformed 20 cases the way I always do. It is a 338-06 AI rifle on a 1909 Argentine action. When building this rifle, I personally cut back the bearing surfaces in the front ring to clean up any setback, squared the bolt lugs, and lapped the lugs and bearing surfaces for 100 % contact before reheat-treating. In allof my load development and fireforming, I have never had a single primer back out. I always fireform with 14 grains bullseye and cornmeal using Winchester 30-06 bulk brass that I bought from the same lot so all the cases I'm using are, presumably, dimensionally the same. As I was fire-forming, I noticed that 7 out of 20 cases had primeres that backed out slightly. This has never happened before. When I say slightly, I am talking about .006-.009. I am wondering if I am experiencing set-back in my action. I feel like a newbie even tough I have handloaded for years and have fire-formed mabye a thousand rounds of brass in my life. I have fired approximately 2500 rounds of ammo through this rifle with normal pressure signs appearing when maximum working loads are found. I don't hot-dog in handloading. I always avoid high preassures for my shooting and hunting loads. Please, someone tell me what might be causing this to happen. Thanks, ------------------ | ||
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one of us |
I'm surprised you see that much primer backing out with 14 gr. of Bullseye. That's a fairly stout load. It may be setback, but in 99% of the cases this is a sign that your pressure is low. The sequence goes like this. The firing pin moves the case ahead to the datum point, and starts ignition, at the same time. Pressure rises, the primer backs out against the bolt face, and the bullet starts moving. Now, if the pressure continues to rise, AND HOLDS THIS PRESSURE LONG ENOUGH, the case will stretch until the head hits the bolt face. Upon which you extract the case, and you have a fireformed case. I have played with this a little, and with fast burning powders, brass doesn't usually stretch to fill the chamber, even at 55,000 PSI, or thereabouts. The cure to your problem, then, is to headspace off the bullet when fireforming. Seat firmly into the lands, and the problem SHOULD go away. Or, fireform with a slower powder, but then you are stretching the case at the head, which is not recommended. Unless it is setback. HTH, Dutch. | |||
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I wanted to see if nickel plated brass could be fireformed so found a single case and loaded it along with some of my plinking loads, ie full powder charge and a 250 gr. bullet. It was the best looking fireform I've ever gotten. By the way, that 14 grs. of bullseye (with no bullet of course) doesn't even sharpen up the shoulder. Thanks for your input, -Catter ------------------ [This message has been edited by Wildcatter (edited 01-16-2002).] | |||
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one of us |
I once had some problems fireforming 8mm-06 A.I. cases. I normally use a 10% reduced load with the cheapest bullet I can find that approximates what I shoot normally. I was having all sorts of problems fireforming Win 30-06 brass to 8mm-06 A.I. Shoulders wern't forming out, (some I had to do 3 times) misfires and cases failing to seal resulting in blow back etc. I was using 52grs IMR 4064 behind a Sierra 175gr bullet. This should have generated more than enough pressure to do the job. After some study on the subject I came to the conclusion that I had run the die all the way down, setting the shoulder back, thereby eliminating any chance to "headspace". Since then when I "neck up", I place a .090" shim under the die lock nut. This allows me to neck up, without setting the shoulder back to the A.I. dimension. I haven't had any problems since. Perhaps this is the cause of your problem? ------------------ [This message has been edited by wildcat junkie (edited 01-16-2002).] [This message has been edited by wildcat junkie (edited 01-17-2002).] | |||
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Wildcatter To fireform cases I would suggest first neck your new 06 cases up to 338. If your die does not have a tapered expander plug get one.You could go up to 8mm first then to 338 if you have an 8mm die.Buy some cheap 338 cal bullets. Load a medium charge of powder and seat the bullet far enough out that you feel the bullet engage the rifling when you close the bolt the last 10 degrees or so.Practice with these loads. They will fireform perfect. With the method you are using you are NOT blowing the shoulders out completely and I suspect they will have excessive headspace and you will likely end up with premature case separation. | |||
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jerrys, Let me know if you'd like some load data. What weight bullets are you interested in? -Catter ------------------ | |||
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| <jerrys> |
Wildcatter, Thanks, I'm leaving on a trip this weekend. If you get time, please mail me at jerrys@spacestar.net, early march. I will be glad to load some and share results. Thanks agian, Jerry | ||
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That is not an uncommon occurance...The problem is you need to up the dose of Bulleye as you are creating headspace because the load is sharp enough to fire form fully....I usually up the load one grain at a time until the primers quite comming out and the shoulders are crisp and sharp..... I have seen this happen a lot with people that use Unique and other pistol powders..Bullseye is the only dynamite for fireforming cases IMO. ------------------ | |||
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| <sure-shot> |
I'm with Ray's answer- bump up your charge in .5gr increments until your shoulders start looking sharp. I use bullseye also but have read IMR 700x works well too. sure-shot | ||
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| <gamecock> |
Wildcatter: Like you, I had been loading for many years when I experienced the pooched primer on my .338-06 AI. Seems that the primer moved case forward, THEN the case expanded, griping the chamaber wall prior to full length case expansion. Snowman's solution worked for me. A moderate load, cheapest bullet, seated so that It barely engages the lands. No more problem. Good luck! | ||
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Ray, I agree, but unless you create a shoulder to headspace on, or use a bullet to headspace on, upping the charge WILL result in stretching the case just in front of the head. Seems to me that if you go to the expense and effort of wildcatting and fireforming, a bulk bullet is not a signficant additional expense. JMO, Dutch. | |||
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Wildcatter: AGAIN- Smoke the neck on the brass before you neck up and make sure you are not setting the neck back. If you are even touching the neck, shim you die locknut .090" or so. The Ackley Improved shoulder is set back .040" from the standard shoulder. If you have bumped the shoulder, with no 40 degree shoulder to headspace on you will have problems. The A.I. shoulder was set back so that "standard" rounds could be used in the A.I. chamber in a pinch. The problems I experienced happened even though I had "seated the bullet long" If you have Nosler's #4 manual compare the shoulder dimensions on the "standard" 30-06 and the 30-06 A.I. ------------------ | |||
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Does anyone who forms cases for a 338-06 AI have any insight on cheap bulk bullets in this caliber for fireforming? I tried one case with the bullet touching the lands and it worked very well. It was a nickle-plated case and it expanded perfectly,...and none of the nickle came off as I expected it would. Thank you to all who posted, -Catter ------------------ | |||
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quote: ------------------ | |||
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| <gamecock> |
Just dug up an old copy of an article on the .338-06AI, by Ken Waters (from God only knows where). In it he states that, "...I tried loading previously fired '06 cases (after first expanding case necks) with moderate charges of a medium-fast burning powder such as IMR-3031, then seating a bullet out so as to contact the rifling origin, thereby holding the cartridge back against the bolt face...I quickly abandoned the procedure however, after one comlete case separation and several near-separations ahd occurred! Apparently, the RCBS Improved chamber of my rifle has a somewhat longer headspace dimension than standard .30-06 cases." Any insight on this? I was at the bench getting ready to load when I picked this damned article up. And just when I was beginning to feel secure about this procedure...crap! Maybe the Bullseye route is the better road to take, but I've been concerned about throat erosion; not because of anything intellectual on my part, but due to a worrysome imagination. Just had another thought: When reforming with B'eye, even holding the rifle vertical, could the force of the firing pin move the case forward enough before firing to cause the overall case length to be shorter? Man, these dreary, wet Saturdays are a sure prescription for cabin fever. [This message has been edited by glenn (edited 01-20-2002).] | ||
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| <Paladin> |
I do not use a filler of any kind, do use Bullseye (usually a slightly smaller charge), plug the case MOUTH with a disc of thin wax, and ALWAYS point the rifle vertically. Works. My other approach in radical wildcats is to load a reasonable full-power load with a scrap bullet and fire vertically. Works, but "vertical" necessarily must be a few degrees off of 90 degrees: what goes up must come down.... | ||
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| one of us |
One last time: The Ackley improved versions have the shoulder set back .040" for a reason. That is so that a "standard" cartridge WILL STILL HEADSPACE in the A.I. chamber, thus allowing the safe use of the standard cartridge and ease of fireforming! If you don't run your Ackley Improved Die down far enough to set the shoulder back during the first laoding (before fireforming) all of these problems will go away. (unless your chamber was not cut properly to begin with) A little case lube also does wonders to illiminate stetching the case ahead of the web! ------------------ [This message has been edited by wildcat junkie (edited 01-20-2002).] | |||
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"The sequence goes like this. The firing pin moves the case ahead to the datum point, and starts ignition, at the same time. Pressure rises, the primer backs out against the bolt face, and the bullet starts moving." Dutch is on the money. The cause is in the case design. I get the same thing when I fire form for 30-06 AI. The lack of body taper reduces bolt thrust & allows the case to "grip" the chamber walls more than it would in a standard 30-06 or 338-06 chamber. ------------------ [This message has been edited by Bear Claw (edited 01-20-2002).] | |||
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