Very tight cases

S

ShootistPRS

New member
I have a year old 257 Roberts in a Browning A-bolt. I was able to get some used brass to reload (I'm very picky because I don't want the +P brass).
The problem I am having is that after cleaning, prepping and sizing the brass it won't chamber without excessive force. The problem appears to be that the cases were fired in a chamber that was larger diameter and my full length die is not returning it to a small enough size. I have the die set so the ram over-centers on it (which I rarely do) but it takes a lot of pressure to get the bolt to close.
I checked the case fit with dye at the pressure ring and at the shoulder case junctions and there is a bit of interference at both places with more on the pressure ring (just above the solid portion of the base of the cartridge) I am wondering if firing these tight fitting cartridges in my gun will make them a better fit over time.
What are the opinions here?

I should add that the reason I don't want the +P brass is that it holds about 10% less powder due to the heavier case. Since there are many 55000 psi cartridges that use the standard 7x57 brass as a base and most of my load data is for the standard cases It just seems like an accident waiting to happen. I have culled out all of the +P brass as it has shown signs of being used with the standard powder loads with tool marks in the head and loose primer pockets. I am going to stick with the standard brass as long as I can get it or the 7x57 brass and form my own 257 with it.
 
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Opinion: You should look for new brass, you were sold scrap.

Trying to fireform brass smaller does not sound feasible, but give it a try. What have you got to lose?

I don't understand aversion to +P brass, as long as it is kept separate.

I also think there is more nonsense circulated about the underloaded .257 than about any other cartridge.
 
You are not going to fire form casings smaller.

I'm using PVRI ( headstamp PPU) 7X57 Mauser casings necked down.

Using H414, RL17 for up to 90gr bullets.
Hybrid100V is your friend for 100-115 gr bullets.
For 120gr. I'm using RL26.
 
JIM,
The +P brass has to have a separate load because the standard published loads are 3 to 5 grains too high. Having both brass in use is more than I need to deal with.
As far as under loaded ammo goes I haven't found problems with that. I get 3300+ fps from a soft load of 47.5 grains of H414 with the maximum charge listed at 50 grains. So far my velocities are close to 25'06 velocities even with my 22 inch barrel.
 
Will the fired cases chamber before they are sized? If so, that means the sizing die is elongating the cases and the shoulder needs to be set back some to chamber. This is somewhat of a common situation that I have encountered with over a half dozen dies with various calibers. My solution, that some think will ruin the die, is to grind off some of tphe die mouth, thereby allowing the sizer to contact and set back the shoulder some. But even if the fired cases will not chamber, the same solution is required.
 
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Condor,
the cases have never been fired in my gun and they will not chamber in the as fired state.

Std7mag,
I am using 87 grain bullets and H414. It is a very fast combination. Now if I can find a load that will shoot small groups I will be happy. So far the smallest groups have been in the 1.5" range which is half the size that I got with factory ammo - two different brands.
 
Well hounddawg, if I screw the die down on my Rock Chucker press I won't be able to overcam the press. You have given me an idea though; I can mill a thousandth or two off the top of my shell holder and that will let the case go in the dies more. I don't know what that will do to affect the filling of my headspace but its worth a try to get the case to fit the chamber. The other choice I have is to face the bottom of the die but I know what that will do - give me exactly as much free space as I remove from the die. I think that milling the shell holder will do the same thing. I am going to do a little more measuring to see if the rim itself is causing problems. I have five cases to play with and a bunch that fit just fine. I remembered that I had four cases that would not fit into the shellholder; there isn't enough relief above the rim. Maybe it's an exaggerated form of the same problem.
When I find a cure I'll bring it back here; maybe it'll help someone else in the future. I already found that RCBS doesn't make a small base die for it. i should check with other die makers I suppose.
 
7/8 14 thread dies move .07 per revolution so a half turn would need .035 taken off the die for a half turn. BTW in the video I linked the press the guy is using looks like a rock chucker. Just reading the comments section many of the comments say it cured the same issue


but good luck whatever method you try
 
Have you actually fired any of these? Myself, I wouldn't fool with them. Less expensive the replace the case's than body part's. Just not worth the effort!
 
FWIW, the "+P" designation on the case is indicative of the original load only. As far as I know all the brass is the same and the "+P" in the headstamp means nothing for handloads...
 
Some would think life is not fair because there is something about life that does not deal equally with everyone. I have presses that will not overcome the cases ability to resist sizing. I think it is nice press and die manufacturers put threads on presses and dies.

Life is easier for me because I have learned to deal with things I can do nothing about. I can increases the ability of my press to overcome the cases ability to resist sizing with loose shell holders. I have shell holders that fit and I have shell holders that fit like a hand me down shirt, the cases fir the shell holder only in places it touches. I can raise the case head off the deck of the shell holder .012" with a feeler gage, that method/technique beats grinding the top of the shell holder or bottom of the die and when I wonder about a small base die:rolleyes:

And there is nothing that beats the reloaders ability to measure a case from the datum/shoulder to the case head and the diameter of the case anywhere between the end of the neck to the case head.

If the primer pocket is loose the loose primer pocket is the results of the problem. There is a big chance the case head has increased in diameter, if the case head has increased in diameter the case head has shortened between the cup above the web to the case head and the flash hole has also increased in diameter. And then there is the other problem; If the case head crushed and increased in diameter the case has also started to separate between the case head and case body.

I have 257 Roberts cases that have been formed from 30/06 cases. I have 7mm57 cases that have been formed from 30/06 cases:eek: I have purchased thousands of 30/06 cases for 1 cent each, that was a good day; I purchased 1,400 30/06 cases for $14.00.

6.5mm50 Japanese chambers; I have a 6.5mm 257 Roberts chamber reamer, same thing, I want for nothing when it comes to cases.

F. Guffey
 
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FWIW, the "+P" designation on the case is indicative of the original load only. As far as I know all the brass is the same and the "+P" in the headstamp means nothing for handloads...
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In every OTHER case that I know of this is true. It is NOT true of the 257 Roberts +P brass. Winchester made the brass thicker when they made +P loads available. The internal volume requires a 10% drop in powder charge from the standard loads. This is verified in the Speer #13 manual that shows maximum loads below the starting loads in other manuals. The Sierra edition V, 6th printing says to reduce all loads 10% if using +P brass. Any 257 case marked +P uses thicker brass and has a large reduction in the internal volume of the case. The lack of knowledge about the modified brass has made the situation even worse. With the proper powder in a standard case I can get very high velocities without exceeding the 50000 psi limits of the standard brass which is limited by SAAMI to 45000 psi. There is nothing inherently weak about the cases and there was no need to limit the cartridge to 45000 psi in the first place. Winchester decided it was necessary to make the cases heavier to bring the pressures up to the level of modern arms. This set in motion a dangerous situation because folks started using the +P brass with the original loadings and without realizing it sent their guns into dangerous pressure levels. Anyone looking at their brass would notice the bolt markings on the brass and the heavy bolt lift - as I did after my first load workup. After that I did the checking to find out what I could about the +P brass and I have since segregated it all out of my standard brass. At some point I will have to use the +P brass brass because it is the only brass being made for the 257 Roberts now. I would rather form new brass from 7x57 brass than use the +P brass. The Speer manual is the only manual I have that specifically lists loads for the +P brass and due to the lower volume the powders they use are different than what can be used in the standard cases.
 
F. Guffey,
My problem is not one of a case that is too long for my chamber - that I have measured and the length is fine. The problem is the diameter of the case is too large to chamber. I would rather not shorten the distance between the base and shoulder to get the reduction in diameter. That is why I have not used shims, ground the top of the shell holder or faced the bottom of the die. They all do the same thing - decrease the distance from the base of the case to the shoulder. Yes it would also narrow the case diameter but at the cost of increasing the free play in the chamber.
You made 257 Roberts cases from 3006 brass?
You have my attention.
Can you share how you did this? What dies you used and whether you had to turn the necks? Can you describe the process from start to finish for me?
 
My problem is not one of a case that is too long for my chamber - that I have measured and the length is fine.
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I am one of the few that does not have case head space, I am talking about the length of the case from the datum to the case head and then there is another length that is measured from the datum/shoulder to the end of the neck,

If you can get the case into the die with the shoulder of the case contacting the shoulder of the die you are doing all you can do. Not me: If the case has more resistance to sizing than the press, die and shell holder can overcome part of the case will protrude from the die meaning the die does not make it to the shell holder when the ram is raided. I have no problem measuring case head protrusion from the die by removing the die with the case before lowering the ram and or measuring the gap between the top of the shell holder to the bottom of the die.

And If I thought there was a problem with the shoulder of the die stopping the case from being sized I would have no problem cutting the top of the die off below the shoulder. That would allow me to use the cut off die for anything that used the 7mm57 case as a parent.

I am a case former, I have forming dies, there are times I am required to run a case through as many as 3 forming dies before finishing the case with a minimum length/full length sizing die.

Chamber case: That is another topic that always ends the same way with one exemption.

F. Guffey
 
ground the top of the shell holder
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That would allow you to increase the length of the case (or prevent shortening the case) from the shoulder to the case head' or you could purchase Redding competition dies in sets of 5.

F. Guffey
 
I'm missing something here. How can you run a case like he's mentioned into a good FL die for that cartridge and not change the case back to factory spec's? If the die is adjusted right.
 
A standard full length sizing die will never return a case to minimum SAAMI specs. The dies are typically slightly over that size to begin with and the brass tends to spring back a bit. There is also the fact that the base of the shell is sitting in the shell holder and never touches the die. If a case is fired in a chamber that has excessive diameter then the brass stretches to the new diameter (even after rebounding a bit). It can be large enough that a small base die is necessary to get it back to minimum specs. With a minimum chamber and a maximum case diameter there can be an interference resulting in a "no fit" situation.

I am working with cases previously fired in another gun - not mine.
 
Well I learned something new today, never heard of +P in a rifle case.

OP: You did say you had markings that the shoulder was interfering as well as the diameter.

All the useful or if you even should be messing with this, technically it is in the die instructions to where they have a bit of cam over. Its bad in some ways as it is hard on brass, probably safe as many do not have the gauges, but it also will ensure the shoulder is pushed back as much as it can be.

That may not solve your problem but it is one way to see what happens.

The next of course is the shell holder shaving, I would try over cam first, then the shell holder next.
 
I'm missing something here. How can you run a case like he's mentioned into a good FL die for that cartridge and not change the case back to factory spec's? If the die is adjusted right.
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No you are not; reloaders assume the case is sized when they raise the ram, I do not assume, if the shell holder does not make it to the bottom of the die the case is not full length sized/returned to minimum length.

I have gone to the trouble of removing the die from the press without lowering the ram meaning I did not disturb the case in the die. If the case is sized when the ram is up the case head protrusion from the die is .125" because that is the deck height of the shell holder.

My dies and shell holders are designed to full length size a case with a shell holder that has a deck height of .125". If the case is sticking out anywhere the case did not get returned to minimum length. Again, I am the fan of standards and transfers, if I want to check the die and shell holder I place g go-gage into the die with a shell holder, the gap for a 30/06 die and shell holder with a go-gage installed should be .005" between the die and shell holder because .005" is the difference in length between a go-gage length chamber and a minimum length/full length sizing die from the shoulder to the deck of the shell holder.

F. Guffey
 
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