sizing die/neck tension/pressure/accuracy/whipped

Point? I understand it is cool to mention Norma, Lepur and other expensive cases when reloading and comparing with cheaper cases. I do not do that. Again, when shooting the expensive cases you should have compared the outside diameter of the fired cases neck with the new, over the counter factor outside diameter of the necks.

And then there impressionable reloaders taking advise from a choir that recommends every new gadget like collet and bushing dies. There is a chance you have already gotten into that trap. From the big inning I have not added a lot if equipment that would elevate my status, my big concern is the fit between the outside of the case and inside of the chamber, I have insisted on having air between the chamber and case, I do not want a lot of air just a little and I insist the air be clean.

I have no ideal why reloaders insist the inside of the neck is tapered, if it was the bullet would increases in the amount of effort when seating. Again, there is nothing that works like the bullet being aligned with the neck of the case. I have two seating dies from RCBS, some reloaders insist the seating die comes with a bushing, my seating dies from RCBS come with guides. To make my money to further I purchased a die body and guides for different bullets.
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Again with the generalizations as to reloaders, speak for yourself Guffy assuming you are capable. Don't you dare lump people in with your quite old and tired sorry generalizations. Grow up at your old age and get a life. Try real hard to post something constructive beyond your usual drivel and actually an image once in awhile would be nice.

Ron
 
Well Folks, to those who have tried to enlighten me as to my reloading failures, thank you, I do appreciate your thoughtful consideration.To the other, Go Pound Sand!......OUT!
 
I happened on this thread and confess to confusion, not only by the usually confusing Mr. Gufffey, but by the topic in general. The folks here seem to believe that the bullet is held firmly by neck tension while the pressure of the burning powder pushes it forward into the leade. If that were true, neck tension would be an important part of loading consistency. But that is not the situation. The only real need for case neck tension is to retain the bullet in the case in normal handling of the ammunition prior to firing.

In firing, the gas pressure building from the rear first pushes gas around the bullet, and forward, pushing the case neck outward until the bullet is free of the case neck. At that point, the bullet is "floating" in gas, free of the case neck; only inertia keeps it from moving forward.* As pressure builds and that inertia vanishes, the bullet will begin to move forward into the leade, and will continue to do so until it moves down and out of the barrel.

The reloader needs to be concerned about one major condition, that there is sufficient room in the chamber neck to allow for that case neck expansion. This is critical; if the case neck is too thick, the chamber neck too small, or the bullet too large, the case neck cannot expand to release the bullet and pressure goes very high very quickly. That is not only dangerous in itself, but can result in blown cases and, worst, failure of the rifle. Normally, failure of the bullet to move under pressure will not cause failure of a well-made rifle, but it is not a condition the careful reloader wants to encounter.

So if one wishes to play in areas like bullet diameter or making cases out of those intended for other calibers, it would be a good idea to measure both the chamber neck and leade diameters; it might not be enough to simply measure the OD of the case neck.

Jim

*At that point, gas begins to move forward around the stationary bullet; it is this hot gas, moving at very high speed, that eats into the steel of the leade, causing throat erosion which will eventually move forward into and past the start of the rifling, allowing the bullet to yaw, damaging it and destroying accuracy.

JK
 
That's a great internal ballistics explanation but the OP is trying to figure out why he is shaving bullets during the seating step.
 
So if one wishes to play in areas like bullet diameter or making cases out of those intended for other calibers, it would be a good idea to measure both the chamber neck and leade diameters; it might not be enough to simply measure the OD of the case neck.
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Agree, if they have ever fired the case once in the rifle there is no excuse for not knowing the diameter of the neck in the chamber and there is no excuse for not knowing the clearance. Again and again and again all a reloders is required to do if fire a case and then before chambering another round place the bullet of the next round to be fired into the neck of the fired case.

And then the reloaders needs to understand the one thing they do not want to find is difficulty placing the neck into the case. BUT! If they do find difficulty placing the bullet into the neck of the fired case check for carbon buildup in front of the shoulder; meaning there is a possibility the neck is not expanding fast enough to seal the chamber at the neck.

And then there are those that prefer little bitty tight chambers, the neck of the case needs to expand, for that to happen it is necessary to have clearance between the chamber and case neck. Those that prefer little bitty tight chambers get into a bind when they create a chamber with no case to fit it. When that happens they are required to turn the necks to reduce the outside diameter. It seems to me if they had a plan when they choose the little bitty, tiny chamber they would have considered all of the options.

I find it more useful to increase the thickness of the brass in the neck than make it thinner.

F. Guffey
 
I was given 80 7mm Remington Mag cases by a very disciplined reloader. I looked at the cases and then informed my friend he had a problem; it was about this time he made it clear the cases were not his and he informed me a friend died and his wife gave him the cases. There is not reason to top there so I informed him we had to find the rifle and the new proud owner of the rifle.

Anyhow, I have never found cases with caked on carbon on the necks. If carbon was caked on the case necks carbon was caked in the chamber in the neck area. Anyhow, the search was going to require too much effort.

So I wondered about pressure caused by the delay in the bullet leaving the case; after all, there was no way the neck could expand.

F. Guffey
 
Thanks for looking! I am at a loss as to what to do with my reloading technique. I think that my reloads have way too much neck tension. When I seat my bullets, it takes considerable pressure and there is a definite pop when the bullet goes into the neck. I always have the little shavings, and I think it is causing inconsistent groups.
It is not my intention to develop BR quality loads but I want to be better than this. I like to F/L resize all my loads, and try to be consistent in my neck chamfering and I have tried graphite as well as lubing the neck, but the resistance when seating a bullet is obviously excessive. This problem seems to exist throughout the range of calibers I load, and regardless of which brand of the two different sizing dies I have.
Initially, I thought it was due to growing neck thickness, and am ready to purchase neck turning equipment, but I have started just reloading with new cases and it hasn't helped.The majority of my reloading is .243, 25-06, and .270. Any insight would be greatly appreciated!
speedgun is offline Report Post
Old January 2, 2017, 07:27 AM
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If you are shaving bullets then there is at least one of the following problems:
1. necks are not expanded enough
2. you are not chamfering the inside of case mouth enough
3. bullets are the wrong size
4. your die is off center

Since it is happening with all your loads in several calibers that would rule out # 3 and 4.
If you are using a die with a neck expander "ball" on the decapping rod you can measure the expansion ball with a mike to see it it is withing .001 to .003" larger than the bullet diameter. I doubt all the expander balls are undersized, so that leaves #2.
The inside chamfer should extend almost to the outside wall of the neck. You then deburr the outside of the case mouth slightly. That allows a flat base bullet to slide into the case without much friction. The bump you are describing sounds like the mouth of the case is too small or not tapered far enough to allow the bullet to slip into the case. It is instead catching on the wall of the neck and forcing it open. That is the "bump" you feel. Try chamfering the case mouth more and I believe it will solve your problem.
 
And then there is an outside chance the press is sprung out of alignment, I know of only one person that that made a tool for choking presses for alignment, even then there are a few presses that use the case to align the top and bottom of the press.

F. Guffey
 
Considering the amount of slop in the case holder there is no real precision alignment between the case and die until they are pushed together. The dies are internally concentric so that when you size the case neck and base are in alignment.
 
Considering the amount of slop in the case holder there is no real precision alignment between the case and die until they are pushed together.
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I am the fan of all that wiggle room and when my cases aligns and all the slack is removed the shell holder aligns with the die. That is what I call 'under a load'. Again, I have 3 Rock Chuckers, when not under a load my rock Chuckers do not align. The ram at the top kick forward and the bottom of the ram is kicked back. Again, when I have a case in the shell holder the case aligns everything.

F. Guffey
 
Thanks to all of your inputs, I seemed to have corrected my bullet seating issues. After watching an RCBS you tube video, I discovered that I was supposed to be deburring the outside of the case first and then chamfering the inside. I also replaced my rcbs chamfering tool on my my case prep station with a Lyman vld tool, and replaced my nylon brush with a phosphor bronze brush. Somewhere in this group of changes, my problem was solved. I reloaded both .243 and 25-06 cases today and all my bullets started easily and seated smoothly. Thanks again!
 
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