25WSM
Well-Known Member
Yeah love those things and some guys have a back for getting into them. Me not so much.
Brass undersized by .020” :(
- Thread starter Mram10us
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I fired 39 and lost 8 total to faint lines. Luckily I only have 11 more. I might pull them to test the false shoulder method. Glad only 50 were wrong. The other 150 were unfired and measured normally. Definitely not a headspace problem with the rifle
I have two. I'll pm you later.
sheesh! I leave for a few hours and people are name calling and bantering.
6.5-300 BEE
Well-Known Member
Seven Pages ? It's all in Fred's book! This will solve OPs problem with no barrel wear.
Rimless and rebated cases are easy to fireform for Ackley chambers if the headspace is correctly set as described earlier in this chapter. You can fire factory ammunition for the parent caliber in the chamber with no ill effects. The result will be velocity slightly reduced as compared to firing the same load in a standard chamber. This loss of velocity is primarily as a result of energy being used to form the brass, secondarily because the larger volume of the improved chamber requires more powder to get the same velocity.
Rimmed or belted designs headspace on the rim or belt respectively so you can fire factory ammo and in most cases will produce good results most of the time — even though the shoulder is often blown forward. One exception would be using old fired brass: often it is too brittle and will split during fireforming. So using new unfired cases is recommended for fireforming.
If you happen to have a wildcat that requires a large amount of forming, firing factory ammo will sometimes cause an unacceptable loss of brass, resulting in split cases. This happens because the cases expand so quickly that if there is a flaw or weak spot in the brass it will pop like an overfilled balloon. One example of this would be the .219 Zipper Ackley Improved. If you experience this there are two possible solutions. Try annealing the neck and shoulder down the body to as much as half way along the body. Make sure you do not anneal the case head or the thick web area just above the head. Annealing the head will greatly reduce the case's ability to handle pressure. Once annealed, load the cases as normal and try fireforming a few. Initially don't load more cases than you are willing to pull bullets from.
First insert a spent primer (for safety) in an unformed case. Fill the case with Bullseye® pistol powder to the top of the neck (DANGER, never to be fired). Then pour this charge into the pan of your powder scale and weigh the charge. Divide that amount by 10, so that 1/10 of the total volume will become your starting load. Now take that 10 percent load for your case and put it in your normally primed case. It may take some testing to get a load that fully forms the case. Tear a single sheet of toilet paper in quarters, insert one quarter as a wad over the powder charge. Now fill the rest of the case with your inert filler (corn meal, or fine ground hot cereal, etc., dry of course). You will want to place a wad of some sort over the cereal so it does not spill. Bees wax, bullet lube, or toilet paper work, it must be light enough so that the wad can be blown down the barrel without doing any damage.
https://trends.revcontent.com/click...WAdwWAnu+uZzis1D9FzxLUQrA==&s2s=1&viewed=true
You are ready to fireform a case. Keep in mind that even without a bullet these loads could be deadly, so use all normal gun safety practices. Pointing in a safe direction fire the first load. If it is not fully formed, bump your 10 percent load by one-half grain at a time until you get a fully formed case. It is possible to generate dangerous pressures if you use too much powder in these inert filler loads, so be careful. The interesting thing about this method is that it will often form cases without any loss to ruptures when a factory load will cause ruptures.
L.R. Wallack wrote this method up for American Rifleman. After describing the method he said, "I then did 10 cases with this load with no splits and all formed nicely. Such success has been practically unheard of, as anyone who has formed cases for this wildcat well knows. I have no hesitation, therefore, in recommending the method."
Rimless and rebated cases are easy to fireform for Ackley chambers if the headspace is correctly set as described earlier in this chapter. You can fire factory ammunition for the parent caliber in the chamber with no ill effects. The result will be velocity slightly reduced as compared to firing the same load in a standard chamber. This loss of velocity is primarily as a result of energy being used to form the brass, secondarily because the larger volume of the improved chamber requires more powder to get the same velocity.
Rimmed or belted designs headspace on the rim or belt respectively so you can fire factory ammo and in most cases will produce good results most of the time — even though the shoulder is often blown forward. One exception would be using old fired brass: often it is too brittle and will split during fireforming. So using new unfired cases is recommended for fireforming.
If you happen to have a wildcat that requires a large amount of forming, firing factory ammo will sometimes cause an unacceptable loss of brass, resulting in split cases. This happens because the cases expand so quickly that if there is a flaw or weak spot in the brass it will pop like an overfilled balloon. One example of this would be the .219 Zipper Ackley Improved. If you experience this there are two possible solutions. Try annealing the neck and shoulder down the body to as much as half way along the body. Make sure you do not anneal the case head or the thick web area just above the head. Annealing the head will greatly reduce the case's ability to handle pressure. Once annealed, load the cases as normal and try fireforming a few. Initially don't load more cases than you are willing to pull bullets from.
First insert a spent primer (for safety) in an unformed case. Fill the case with Bullseye® pistol powder to the top of the neck (DANGER, never to be fired). Then pour this charge into the pan of your powder scale and weigh the charge. Divide that amount by 10, so that 1/10 of the total volume will become your starting load. Now take that 10 percent load for your case and put it in your normally primed case. It may take some testing to get a load that fully forms the case. Tear a single sheet of toilet paper in quarters, insert one quarter as a wad over the powder charge. Now fill the rest of the case with your inert filler (corn meal, or fine ground hot cereal, etc., dry of course). You will want to place a wad of some sort over the cereal so it does not spill. Bees wax, bullet lube, or toilet paper work, it must be light enough so that the wad can be blown down the barrel without doing any damage.
https://trends.revcontent.com/click...WAdwWAnu+uZzis1D9FzxLUQrA==&s2s=1&viewed=true
You are ready to fireform a case. Keep in mind that even without a bullet these loads could be deadly, so use all normal gun safety practices. Pointing in a safe direction fire the first load. If it is not fully formed, bump your 10 percent load by one-half grain at a time until you get a fully formed case. It is possible to generate dangerous pressures if you use too much powder in these inert filler loads, so be careful. The interesting thing about this method is that it will often form cases without any loss to ruptures when a factory load will cause ruptures.
L.R. Wallack wrote this method up for American Rifleman. After describing the method he said, "I then did 10 cases with this load with no splits and all formed nicely. Such success has been practically unheard of, as anyone who has formed cases for this wildcat well knows. I have no hesitation, therefore, in recommending the method."
This is my last post on this. IF you can't figure out that bolt head thrust is a vector measurement, it wouldn't be thrust otherwise, meaning it is directional as well as being pressure then there is no way to further explain it to you. The greater the distance the cartridge head travels before it impacts the bolt face the more torque or stress you apply to the lugs and the bolt face, same as the play in the lugs, threads etc explained in this article. I know it is somewhat complicated for the average shooter but it does make clear that slop, free play, tolerances etc clearly have an effect..
P.S. No where in here have I, or anyone else that I have seen made fun of, belittled or called you names. It isn't our fault you are wrong and don't want to admit it, or at least quit defending an indefensible position. I would greatly appreciate it if you would extend the same respect and courtesy to the rest of us that we have extended to you.
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25WSM
Well-Known Member
That's why I asked about mushrooms.
Shep
Shep
Done a bunch of fireforming that way. My shop always smelled like burnt cream of wheat. Thanks for the reply
It seems to me, you have a case at 65k psi with an inch behind it. The pressure would reduce based on The extra capacity, thus, less bolt thrust??
Ive always hated anything to do with bolt thrust....
25WSM
Well-Known Member
I let engineers figure that stuff out. They are smarter than me and the actions are over built to stop us from killing ourself. The brass is the weak link. If they made indestructible cases we would blow up actions. Had a guy bring me his short action 700. Bolt would not open. Had to remove barrel. I was worried about fixing it so I sent it to Remington with the brass still in the bolt face. They told me that he exceeded 125000 psi with that load. Said action was fine just needed a new extractor. Unbelievable. Was a 6br and he had to put the wrong powder in it. You just can't put too much varget in one to hurt. He swears it was varget.
Shep
Shep
bigedp51
Well-Known Member
- Joined
- Dec 10, 2010
- Messages
- 1,022
There is nothing in your link that states the longer the headspace the greater the bolt thrust.
Your link simply talks about bolt lug stress analysis and nothing about the amount of headspace and bolt thrust.
So again there is no one in this or any other forum that can prove that longer headspace increases bolt thrust.
25WSM
Well-Known Member
Dean needs to change his name to focke-wulf 190. Then they can go at it.
Shep
Shep
J E Custom
Well-Known Member
Depending on the time it takes to move back the pressure of the detonation will determine the amount of pressure. the momentum is very minor because of the case weight. The smaller the head space, the less impact pressure from the charge. The bolt loading will mostly depend on the load pressure and be applied during firing. The brass case will yield early in the burn process so it is important to minimize any movement as previously discussed.
J E CUSTOM
J E Custom
Well-Known Member
Sometimes the ring at the case web is from a slightly larger chamber. Normally if the ring is not as shinny as the rest of the case it is a sign of case stretch.
J E CUSTOM
25WSM
Well-Known Member
That ring you get at the .200 line on almost every factory chamber.
Shep
Shep
