Grinding the bottom of die or top of shell holder

Would something like this work ?

"Redding Competition Shellholder Set"
Click to expand...

Yes they will. I have a set, I do not use them but I have them just in case. I paid $5.00 for a #6 set.

I size/form cases for short and long chambers. I size cases for chambers that are .012” shorter than a go-gage length chamber, I size cases for chambers that are .002” longer than a field reject length chamber. I can size a case that is any length between the short chamber and the field reject length chamber; that is 28 different length cases when measured from the shoulder to the case head; all of that without grinding the top of the shell holder or bottom of the die.

As your link points out; the competition shell holder set cost $54.00.

As far as working; the competition shell holder set has a deck height that is on the plus side of .125”. Grinding the top of the shell holder reduces the deck height of the shell holder.

F. Guffey
 
F.Guffy,
I pay a LOT for my gauges, not the typical old style ignition gauges.
You can get shim stock that is probably more precise than the local parts store feeler gauges for a lot less money.
Lots of places sell it in specific batches, or mixed batches.
Common stock strips are about a foot long and an inch wide, although there are tons of types, narrower, wider, longer, shorter, ect.
Machinests often have to precisely shim, then bolt/clamp work pieces,
So there are dozens of types that are considered disposable, so they are cheaper than a good set of feeler gauges.

I managed to knock a set of Sterret gauges into a 3 phase box not long ago,
There went $100 turned into welded slag in about a second...
 
Last edited:
So there are dozens of types that are considered disposable, so they are cheaper than a good set of feeler gauges.
Click to expand...

I do not know what to say; just kidding. I left out the part about I am the fan of verifying. There was that time I upset everyone when I told them I took a picture of my gages; the picture weight 600 pounds. What is the difference between a $100.00 set of feeler gages and a $11.00 set? I have a shim cutting ball peen hammer I have also used it to cut gaskets.

Then there is ‘wrung’ and ‘wringing’.

F. Guffey
 
Jeephammer,

I agree on tolerance variation of cheap vs. good. For that reason, a good micrometer should be in every tool box and it should be used to confirm actual gauge and gauge stack thickness, where you have one. However, given that brass springs back a little coming out of the sizing die, and how much it springs will vary with the case size, you can still expect to have to undergo a little trial and error to arrive at the gauge thickness that provides the amount of shoulder setback you want to wind up with.

Even a brass shim isn't going to be deformed by sizing pressure. If it were, then shell holders would imprint case heads. For any kind of steel shim, mild or hardened and polished, there won't be a detectable performance difference except that a five thousandths brass shim may elastically deform, say, two tenths of a thousandth, where the steel ones only deform one tenth. I base that on the modulus of elasticity being about 16,000 psi for brass and about 28,000 for steels that shims might be made from. It would be about 27,000 psi for 1000 series mild steels (steel shim stock sheet roll) and 29,700 for 4000 series tool steels. It doesn't change with temper. Only the ultimate strength and yield and other limits do.
 
Much earlier in the string, it was pretty clearly asked if the chamber was short or just tight. Did that question ever get answered? It's all good and well to solve the wrong problem, as it adds experiential learning, but it doesn't solve the RIGHT problem.

Has the chamber in fact been determined to be short?

FIRST question: Is the headspace correct?

Long before you start grinding on tools, you should have both those questions answered.
 
Long before you start grinding on tools, you should have both those questions answered.
Click to expand...

I agree, there is nothing like knowing how much to grind. Then comes the confusing part, some grind the top of the shell holder and or bottom of the die to increase the presses ability to overcome the cases resistance to sizing.

I am the fan of measuring before and again after.

F. Guffey
 
The OP wanted to know if he could grind the bottom of a die. He did not ask for a bunch of opinions about his chamber. Yes, you can grind off the bottom of a die to change the size of your brass.
 
Sorry guys. It has been hectic at work, so couldn't check in till now.

Thanks for all the responses. Tight chamber is definitely a probability. I will look into that angle. Unfortunately it requires so doing. I am hand loading 7.62x45 Czech, an obselet cartridge. I can't just pick a box up at a local store.

-TL
 
That information puts a whole new vortex on the situation. The probability that this rifle w a s made out of saami specs, as your die was, is high. It should come as no surprise that a chamber might exceed a die's tolerance to the point that it is a problem.

The question that comes up over and over is what part of the fit is defective. Sending some fired brass and a chamber cast to rcbs may help you get a good set of dies.
 
The OP wanted to know if he could grind the bottom of a die. He did not ask for a bunch of opinions about his chamber. Yes, you can grind off the bottom of a die to change the size of your brass.
Click to expand...


Gunplummer: I'm sure that response is comforting to a man with a non-spec chamber.
Click to expand...

Thanks for all the responses. Tight chamber is definitely a probability. I will look into that angle. Unfortunately it requires so doing. I am hand loading 7.62x45 Czech, an obsolete cartridge. I can't just pick a box up at a local store.
Click to expand...
http://thegunwiki.com/Gunwiki/RefReloading762x45mm

Someone should ask the OP how his rifle got the chamber. I do not do well with guessing games. He claims he can not pock up a box of cases at a local store; it is possible to purchases cases and dies to form cases, then there is the hack saw, the man tool for trimming. I sent the wife to a hardware store for hack saws blades so she took the hack saw with her. She called me a short time later to tell me about the nice man at the hardware store; he wanted to trade her new hack saw with blade for her old, worn 100+ plus year old hack saw. The wife explained to the to him she left the house with the hack saw and she had to return to the house with it; unless he wanted to trade the saw for a Dewalt cut off saw, complete with blades. It was about that time the sales person ask her if her husband was a collector; she responded with no; “my husband is a musician, I am the collector”.

6.5x54 Carcanno cases can be formed to 7.62x45R, 220 Swift cases can be used if the rim is turned down and the extractor groove is cut deeper. Then there is the companion tool to the press; the feeler gage. It is possible in some areas the feeler gage is only available to advanced reloaders. In other areas the feeler gage is not something a reloader would be caught with on Main Street. With the feeler gage there is no such thing as a case that will not fit a short chamber.

The nice thing about forming cases is the need for understanding the incline plain.
http://www.bing.com/search?q=inclin...13&sp=2&cvid=c08f744986004983b47e0660a5daf934

F. Guffey
 
Brian,

There is no SAAMI spec for this cartridge. The CIP drawing is as close as we'll get. This means they expect you to use the old-fashioned method of trying to measure to the shoulder and case body or the shoulder and neck intersections (L1 and L2 on the drawing). The chamber dimensions are minimums, so if you fire and neck size a case several times until it has no more play in the chamber, you can measure if it exceeds those numbers. Another approach is to use the primer insertion method with a fired case that has been decapped without resizing. Not the most precise approach, but serviceable. You can also calculate the equivalent diameter for a SAAMI style shoulder datum and measure that. It looks like a 0.375" datum would work and in the chamber it would be 1.4687" forward of the breech end of a minimum chamber (of the primer, if you use that method).

Note that the case must be fired to fit the chamber because the Europeans, not having a common datum for the shoulder of the case and chamber, as SAAMI does, don't always keep the angles of the case and chamber shoulders exactly the same. In the 7.62×45 the chamber shoulder has a 50.2294° included angle and the case has a 49.7275° included angle, forcing contact to be made first near the neck. I suppose the thinking is that it would be harder to chamber if the case shoulder body were sized too long, but I don't see how that would happen.

If you make your own datum finder with a reamed 0.375" hole, you can measure this all easily. If you use a caliper case comparator, you'll get a low reading due to the small radius at the mouth of the hole in its adapter. So you could calibrate for that by zeroing the comparator on caliper anvil and then measuring a good quality 30-06 GO gauge with it. The result will be a little short, but if you multiply it by 1.41 (the ratio of the sines of the shoulder half angles) that's the error you can expect measuring your cartridge's headspace with that same adapter. This assumes a uniform radius on the adapter, which you probably won't have exactly, but the method is going to get you within a thousandth or so, just the same.

That head is the size of a 220 Russian, but the 220 Russian is too short (39 mm) to get a case out of.
 
It should come as no surprise that a chamber might exceed a die's tolerance to the point that it is a problem.
Click to expand...

And then, again, a case forming reolader should have the necessary skills to size cases for short chambers. I size cases for short chambers; I can size a case that is minimum length/full length sized. I can size a case that is go-gage length. I can size a case to any length between minimum length/full lengths sized to go-gage length. And then there is going beyond go-gage length. I can size a case to any length from go-gage length to infinity.

The infinity length sized case does warrant a caution. I do not want my bullets flying down the barrel with out guidance/support so I will say; I can size a case from .017” shorter than a go-gage length chamber to a practical .002” longer than a field reject length chamber with a common, ordinary everyday RCBS shell holder and a full length sizing die.

There was this shooter that walked into a smith’s shop in N. Texas with a rifle that had the bolt locked up. Long story; he purchased a box of 308 W ammo for a rifle with a 25x06 chamber. I will add the rifle did not belong to him.

F. Guffey
 
Last edited:
Thanks gentlemen for your inputs. Food for the thought indeed.

I am forming the brass from 6.5 carcano. It is a obsolete milsurp round. I am afraid saami has little bearings. I mostly ignore all that and focus on making ammunition to fit one rifle.

A tight, rather than short, chamber is a probability. Couldn't get a factory cartridge to try, so went the other route. I chucked one of my formed brass, upon which the bolt could barely close, to my drill. Span and sanded down its body diameter so that it actually wriggled in the chamber. No change to the bolt closing. Short chamber it is. Or the die is too long.

I couldn't screw down the die any further, as the shell holder started contacting the bottom of the die. I don't like the feeler gauge business myself, so I looked somewhere else before grinding. The formed brass has thick metal under its shoulder. Perhaps it sprang back. I annealed the area thoroughly before forming, and I formed the brass several times till resistance had noticeably reduced. It helped. It chambered and I still had a hair line between the die bottom and shell holder top. I don't need to grind anything after all.

I even shot some of the rounds I made. It was fun.

Thanks again for your help.

-TL
 
I don't like the feeler gauge business myself,
Click to expand...

The case whips the press or the press whips the case. I do not deny my self anything and the luxury of not liking something or somebody is a luxury I can not afford. That brings us to the gap between the top of the shell holder and bottom of the die. The gap should not be there. In the perfect world there would not be a gap; but when there is a gap I measure the gap with a feeler gage to measure the gap. The gap is caused by the failure of the case being shoved in to the die. In the perfect world when sizing cases for the perfect go-gage length chamber I can adjust the die off the shell holder .004” when sizing 30/06 cases that fit the chamber with no case travel.

And then; there is adjusting the die down to beyond contact with the shell holder. When I make that type of adjustment I get cases that are minimum length/full length sized cases.

Back to the gap; if I had a gap between the top of the shell holder and bottom of the die with the proverbial additions ¼ turn after contact (about .0178”) I would shove a feeler gage between the deck of the shell holder and bottom of the case head to increases the presses ability to overcome the cases ability to resist sizing.

Placing a feeler gage between the deck of the shell holder and bottom of the case head increases the dies ability to reduce the length of the case from the shoulder to the case head. Why would someone want to do that? This method and or technique is only for those that have the ability to determine the length of the case from the shoulder to the case head. This method is only for those that have the discipline to measure before and again after.

I do not know what dies you are using, I do not know what press you are using, I do not know what lube you are using. I do not have a King Kong press. For the heavy work I have arbor presses that are not designed for reloading but I have adapter kits; problem, getting the cases out of the dies or barrel after sizing.

F. Guffey
 
I am afraid SAAMI has little bearings.
Click to expand...

My opinion; even of you had specifications it would still be necessary to determine the length of the chamber from the shoulder to the case head. If you are not cutting the chamber SAAMI specifications only tell you what the chamber should be or what it could be.

I use the length of the case from the shoulder to the case head to off set the length of the chamber. And then; there is this other part we will never get around to talking about, my computer could run out of ink before there is an opportunity.

F. Guffey
 
My opinion; even of you had specifications it would still be necessary to determine the length of the chamber from the shoulder to the case head. If you are not cutting the chamber SAAMI specifications only tell you what the chamber should be or what it could be.
Click to expand...

The die I modified was for a round that has no SAAMI spec. The chamber of the rifle "is what it is" so it was useless for me to worry about measuring the length of the shoulder to case head, I just knew the die as it was didn't make that distance short enough for the case to chamber and after I faced a few thousands off, it would.
 
The die I modified was for a round that has no SAAMI spec.
Click to expand...

I can only guess you assumed I knew you modified a die. I have never found it necessary out side of case forming. I doubt we will ever get around to discussing that, I am afraid the weak could pass out and the strong would get dizzy.

F. Guffey
 
I can only guess you assumed I knew you modified a die. I have never found it necessary out side of case forming.
Click to expand...

It was the same one I was talking about in post #25, one minute after your post #24 and 32 min before your next one #27.

It remains the only die I have had to modify for it to work as originally intended. Or I never needed to until I needed to.
 
Last edited:
You must log in or register to reply here.
Back
Top