Grinding the bottom of die or top of shell holder

[F. Guffey]

IMO why risk irreversibly modifying an expensive $25 die when you can irreversibly modify a $7 shell holder?
That was answered in the first post when he described ripping the top off the shellholder.

If it won't chamber factory ammo, I'd stop worrying about making a die work
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When I ream a chamber I start with cases that are sized for short chambers. When finished I save the short chamber cases. It beats waking up in a new world everyday. Like you, I save a few rounds of new ammo for comparison.

Snyper, I tried to convince reloadrs they could measure the length of the chamber from the shoulder to the bolt face before they left for the range, and now? I am convinced they can’t. I was looking for gun parts at a local gun parts store when a proud owner of an exotic rifle asked to have the length of the chamber checked (head space). The owner/smith informed the proud owner he did not have a head space gage for the chamber; meaning he could not check the length of the chamber.

I said nothing; when the owner left I informed the smith I can check the length of any chamber from the shoulder to the bolt face three different ways without a head space gage. And then the owner asked; HOW? Well you know me; it took me about 2 seconds to recover from that one. He was convinced, and then I suggested he modify his go-gages to go to infinity gages. Anyhow; I did not have to convince him it could be done.

F. Guffey

Short dies; short dies are my favorite, same for forming dies. My favorite forming die is the 308 W forming die. If I only had one forming die it would be the 308 W forming die. If I only had 2 forming dies the other/second forming die would be the 243 W forming die because it is short.

 

[Nitescout]

Like Road Clam said it doesn`t take much to remove .005 to .010 from your shell holder...I use my good old Craftsman belt sander ...be careful not to lean on one side too much...I try to rotate a little while sanding it off...

You won`t need to grind it until the top bends.. It looks like you`d have to grind a sixteenth of an inch off to get it thin enough pull off the ears.

by altering shell holders, you still have un-altered dies to use on other standard rounds/chambers.

I usually have more than 1 .308 win in the vault, I`ve used the same die set on the mossburg NITE train, and the ruger SCOUT, bolt guns, as well as Rem 700 SP and my new Rem 700 AAC .308. Still one die set on all of them.

 

[JeepHammer]

Shell holders are NOT created equal, I've pulled brass through a sloppy holder that didnt fit the brass rim tightly,
I've pulled rifle brass through soft metal shell holders,
I've had to lap/grind shell holders for 'Deck' height (thick rims).

I've even widened the 'Mouth' on a smaller rim size holder to get a tight grip on the brass.
My shell holders are color coded for a reason, and they sit on the decapping rod of the resize die they fit with when not in use.

Since no one can see the issue, I'm wondering if its case swell at the base, which small base dies would fix (need a stout press!),
Or if its actually the datum point/headspace/shoulder issue that's keeping the brass from fitting the shoulder?

I've got a FN .308 in the shop right now with the same issue,
Loads fine with factory ammo,
Won't chamber reloads without cranking on the bolt like a gorilla.
Haven't got to it yet, but I suspect its going to take small base/true full length dies since FN doesn't screw up headspace very often.

The owner isn't going to like it, all he's got is an open 'C' press made of light cast aluminum, and that probably isn't going to live long with small base dies...

 

[F. Guffey]

Nitescout, and like I said I have never found it necessary to grind the bottom of a die and or the top of a shell holder. My favorite shell holder is the shell holder that is loose. My RCBS shell holders are so loose they afford me the luxury of raising the case head off of the deck of the holder .012". I know, that means nothing to a reloader but when I want cases for short chambers I use a feeler gage between the deck of the shell holder and case head. The nice thing about the feeler gage and a reloader that knows there knows what they are doing is the feeler gage comes in different thickness. Meaning I can size a case for a short chamber that is .017” shorter than a go-gage length chamber or I can size a case for any short chamber that is .001” shorter than a go gage length chamber. One more time, I am limited by the loose fit between the case head and shell holder. I do have shell holders that fit, meaning if I fire a case with a heavy load I can count on the case not fitting the tight fitting shell holders. OR! I could check the fit between the case and shell holder with a feeler gage, but there is a problem; they day is not long enough to explain that one.

Then there is that part about “how much stock removal is necessary”, a reloader with a feeler gage and loose fitting shell holders should be able to determine how much grinding is necessary to ‘custom grind their shell holders’.

F. Guffey

 

[jmorris]

I had the same problem one time, ground the shell plate as you did and it broke like yours. I turned the die in my lathe after that and it still works to this day.

 

[Clark]

Gunplummer
I have ground pounds of carbide and made a lot of braze tools. The carbide retains it's properties. There is something else going on there if your carbide dies crack after grinding.

I chambered a Mauser with a 0.469" straight fluted reamer for 45acp, because the 45acp brass springs back to 0.469" when it comes out of a Lee carbide 0.467" ring in the carbide die body.

To size the web of cases I had to pound them in and pound them out. All that hammer work is what cracked carbide rings.

 

[F. Guffey]

The owner isn't going to like it, all he's got is an open 'C' press made of light cast aluminum, and that probably isn't going to live long with small base dies...
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Back before the Internet in a book that has never been read but by a very few reloaders test were done on presses. Some presses were modified; the same company selling some of the presses that did not do so well during the test was the company that modified some their presses.

I have gages that could be used to test presses. I have never found it necessary to use them but; just in case. I have a ‘better gage’’ I have the companion tool to the press; the feeler gage. Back then as it is today the case can whip your press and stretch the press out of shape. When I want to know if my press won or the case won I use the companion tool to the press, the feeler gage. If the die is adjusted to the shell holder with the proverbial ¼ additional turn after contact there should be no gap between the top of the shell holder and bottom when full length sizing.

I have measured the gap between the top of the shell holder and bottom of the die on presses that are not suspect when it comes to strength. I have removed the die with the case before lowering the ram to measure case head protrusion; in the perfect world with a shell holder with deck height of .125” the case head protrusion would be .125”.

F. Guffey

 

[briandg]

Elkins, you are wrong. Assuming that this is a rimless case, that is supposed to headspace on the shoulder. Simple fact. Now, after grinding, it is probable that his shoulder to rim length of his full length resized rounds are TOO SHORT FOR HIS CHAMBER. This will result in stretched, malformed, ballooned or otherwise damaged brass that will be further damaged with every load cycle. Eventually that brass will inevitably fail. Rimmed, belted, anything but a shouldered round is probably going to be distorted beyond safe limits if the die is shortened beyond specs compatible with the chamber.

There is a reason for the go-no go standards for both chamber and brass. An oversized chamber and undersized ammo must still be compatible, or a dangerous situation develops.

Don't drag in the completely irrelevant issue of fireforming brass. When fire forming brass, that cartridge is stretched to fit the chamber only one time, and never again. That cartridge is sized to properly fit the chamber with every subsequent loading.I have read that even proper forming fails occasionally and brass is ruined after only a single stretching.

 

[condor bravo]

It seems that there are some assumptions here that the operator will automatically turn down the die to contact the shell holder after grinding some off the die and then perhaps set the shoulder back more than necessary. Can't we assume that the operator knows enough to only adjust the die setting to maintain proper setback as needed? It doesn't automatically follow that shell holder contact should be made after grinding off a portion of the die.

 

[Unclenick]

Braindg,

I'm not sure you are solving the same problem I am. If the chamber is truly short, as the OP says, that means it's shoulder is too close to the breech face of the bolt when the bolt is closed, and and it will start to pinch a headspace GO gauge before the bolt is fully closed. This means the chamber reamer was not run as far into the chamber as it should have been when the chamber was cut. So he then has a chamber that is too short on headspace and very slightly too narrow at the breech end. Therefore, putting the sizing die in a lathe and using a toolpost grinder to take the mouth of the die back the same number of thousandths as the chamber is short, plus one or two thousandths more to have some shoulder bump, merely makes the die a better match to his chamber, and appropriate to use with a standard shell holder. It's no different than having a wildcat that is a shortened version of a standard cartridge and making a shorter sizing die for it.

The only possible adverse effect will occur if the slight narrowing due to being short is narrower than his case heads. This is unlikely to occur, but not absolutely impossible.

There are, as Mr. Guffey explained, a number of ways to determine headspace. One I've used is to ream a fired case primer pocket in my Wilson trimmer with its primer pocket profile cutter, which makes it very easy for a primer to slip in with minimal pressure. I then intentionally seat a high primer in it and then set it into the chamber and gently close the bolt on it. When it is extracted, the primer now protrudes by the amount of the headspace clearance (the extra headspace). When doing this with a fired cartridge, the primer then protrudes by whatever amount of springback the case experienced during fireforming. The primer to shoulder distance then represents the true headspace of the chamber quite well. That reference allows you to use a comparator to determine if your die is unable to size fired cases far enough or not.

The remaining issue, though is diameter. If his chamber is narrow (worn reamer in need of proper resharpening by the reamer maker was used), then he may not have a headspace problem but fired cases that are not fat enough for a standard die to resize, so that pushing the shoulder back fattens the cases in the die. In that case his chamber needs a small base die.

Probably the easiest way to double-check which is the case is to paint a resized case with Magic Marker and try to chamber it. See if the color rubs off the sides (case too fat and needs a small base die) or marks at the shoulder (case made too long by a sizing die whose shoulder is too far forward; see second from left position below).

 

[F. Guffey]

When fire forming brass, that cartridge is stretched to fit the chamber only one time, and never again. That cartridge is sized to properly fit the chamber with every subsequent loading.I have read that even proper forming fails occasionally and brass is ruined after only a single stretching.

Braindg, There was a time when I believed a reloader could get a good grip on fire forming and stretch. Problem; reloadrs believe the firing pin drives the case forward until the shoulder of the case collides with the shoulder of the chamber. I understand that is one neat bundle and to most it makes sense and it does not take them long to type it. Problem; if any of that was true and the case did stretch? Well you only have my word for it but hope your cases do not stretch.

There is a difference between forming and fire forming. I am the fan of forming first then firing. I off set the length of the chamber with the length of the case to reduce all that case travel

Back to case stretch, I have cases that I have formed and then fired that shortened .045”. I do not have a word or term that can be used for the opposite of stretch.

F. Guffey

 

[Unclenick]

That definitely happens with cases fired at pressures too low to stick them to the chamber wall harder than the force needed to stretch the wall at the pressure ring. I once ran some 45 Auto brass through 50 cycles of target level reloading. It was splitting pretty badly at the end and half had been lost to The Range Gods by then, so I retired that lot, but the survivors had all shortened about half a thousandth every load cycle, so they were about 0.025" shorter at retirement than when new. Kind of like people, that way.

 

[Road_Clam]

Instead of fueling arguments, I just want to convey thanks to the experts as this thread is yet another fantastic reference for those of us still in an "amateur" reloading knowledge curve. Weather I agree with your views or not it's still all great reading.

 

[Gunplummer]

I don't know if all brass is knocked forward by the firing pin, but I agree that lighter loads are. I have seen a lot of empties with the primer protruding out of the case. Rimmed cases are notorious for that. Don't know why that is. Maybe because the true headspace is usually screwed up on rimmed case guns.

 

[HiBC]

If the chamber /bore is hard chromed,my suggestion will be far less practical.

If the chamber is reamed to accept a "Go" headspace gage,there should not be a need to alter the dies or shellholder.

For the price of dies and the time and trouble to make and keep track of short ammo,
Why not rent a reamer and headspace gages,and make the rifle right?

Its even possible to rent pull through reamers in some common military semi auto cartridges.The headspace function is built in.Ream till the bolt closes.

That's what I would do.

Another question.How much effort does it take to draw the case out of the sizer die and over the expander ball?

If things are a little dry ,dirty,or sticky,or if the die reduces the neck too much,if the neck thickness is too much,especially if you are necking down...

The shoulders might be annealed quite soft

If for whatever reason the shoulder is being pulled forward by the expander ball,you migh be chasing the wrong problem

 

[Gunplummer]

That seems like a good idea, but is not. Unless you have the exact same reamer, there will usually be trouble. Over the years I have made a few reamers, and this advice is hard won knowledge. Most companies that make headspace gages advise you not to mix brands because of the variation in tolerance. You have even more tolerance with a reamer.

 

[F. Guffey]

If for whatever reason the shoulder is being pulled forward by the expander ball, you might be chasing the wrong problem.

I do not have a list of reasons ‘it can not be done’. I have heard the story about pulling the neck sizer plug through the neck causes the case to increase in length from the shoulder to the case head. I have said pulling the sizer plug through the neck will shorten the neck. Then there is still that part about pulling the shoulder forward; how would a reloader go about measuring that?

I like those stories that start with; I have been doing some testing and here is what I have found.

F. Guffey

Many years ago a Lord/Duke owner of a small kingdom offered part of his dukedom to anyone that could make an object that solved a riddle. Much to his surprise he found himself sharing part of his dukedom with the common man.

Many years later I challenged a large group with the same riddle. I was told it could not be done; that came after a month of trying. Long story.

 

[JeepHammer]

Wish this would have been on a thread of its own...

F.Guffy,
I guess you could use a 'Feeler Gauge',
Personally, as a long time machinest, I know that the really small feeler gauges are built to flex, and just to gauge.
I use shim stock for pressure applications, not as flexible, but designed to take pressure without deforming. (Cheaper too when you buy a handful of strips at a time)

The shim stock *Should* deform less than a feeler gauge giving longer service before it does deform too much to hold your tolerances.
It comes in strips or sheets, and that thin you can cut it easily with a razor knife to fit your application.

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The idea of using a primer set shallow in a case for a one use chamber/headspace gauge is a good idea!
I drill chamber dummies for a slip rod (drill rod) and a nylon tipped set screw.
Same principal, about a 1/4" drill rod blank longways, set screw in the side with just enough pressure to keep the rod in place as the chamber is closed, then opened.
Caliper or mic does the rest.

Non-rotating bolt face, 'Plasti-Gauge' type filiment works too.
Rotating bolts smear the filiment.
One thing about a filiment, no caliper/mic needed to see if you are too tight or too shallow on the chamber.

 

[4runnerman]

Guffy- Yes the neck or shoulder or a combo of both can be pulled forward with the extraction of the expander ball. Will it happen, not always, but it does. Also, pulling the expander ball out can throw your neck off kilter too. It is a very simple test to do. Run your die threw 10 cases, now take expander ball off and run 5 of those cases back threw the die again. Take those cases, put them on a level table ond roll them across the table. Very good chance what you will see is a small wobbel in the cases you used the expander ball in and no wobble at all in the cases the expander ball was removed. There are to many if's that come to play such as, enough lube, annealing necks, how many times reloaded, ect.
Draw back is- with expander ball out, your neck tension will be .004 plus tighter.
Not a danger thing but real tight neck tension. When I load for a match I do the removal of the expander ball all the time. I how ever did send my die and 5 cases into Forester and had them hone the inside of my die to .002 tension. Bullet grab as you call it I think. Most of this depends on how anal you want to get with reloading. At 300 yards does it make a difference??? to hard to say, When I run out to 1400 yards, Yes I did notice my groups tighten up after I started doing it.

 

[F. Guffey]

F.Guffy,
I guess you could use a 'Feeler Gauge',
Personally, as a long time machinist, I know that the really small feeler gauges are built to flex, and just to gauge.
I use shim stock for pressure applications, not as flexible, but designed to take pressure without deforming. (Cheaper too when you buy a handful of strips at a time)

You guess I could use a feeler gage? I will assume you are referring to adding shims to the case head when checking the length of the chamber from the shoulder of the chamber to the bolt face and or determining clearance. I do not use shims or feeler gages. There are exceptions. I do have feeler gages that have the appearance a Tasmanian devil got hold of them. I was checking clearance on something that was moving and not gun related.

F. Guffey