Head spacing

[dellet]

I answered that question in detail in post #67


I answered that question in detail in the very next post or post #67 . Yes they do if you start with the # 10 comp shell holder . If you then switch to the #8 your case will go into the die .002 further , if you then switch to the #6 shell holder your case will go in the die an additional .002 for a total of .004 from where you started . If you go to the #4 the case goes another .002 deeper into the die . The guy in the video specifically says and starts with the #10 and the question was posed after saying "I watched the video" . When I answered the question it was assumed that part of the video was understood . I'm very confused as to what's going on here . You may be right , I very well may have missed something because to me it just seems a few of you are just doubling down on your beliefs to the point of saying things that really don't make sense . Like the comp shell holders don't work if you have a chamber that no other standardized commercial equipment will works for ? OK fine there is nothing in the world that will work for your chamber with out modification . Why would anyone think the comp shellholders are any different , they're not magic

However here is a video demonstrating what is different about the Redding competition shellholder compared to a standard Redding shell holder . He talks a little slow but covers the real difference in first few minutes

I guess this became a matter of splitting hairs.

The design of the shell competition shell holder is to place the datum line farther from the base than a regular or zero holder.

I shoot enough non or pre SAAMI cartridges and rifles that needing a shorter datum line is not uncommon at all with an off the shelf die. It might actually be more normal on my loading bench.

I completely understand both the advantages and limitations of the product, and have more than a couple sets on the shelf as well as some custom ground ones sized that would be considered negative numbers.

There was nothing untrue in my post, only people not willing to think that there might be some other types of challenges in a world they are not familiar with.

The competition shell holders are a great tool for many reasons, they also are worthless for others. One thing for certain, they do not solve every headspace issue one might encounter.

 

[Metal God]

The competition shell holders are a great tool for many reasons, they also are worthless for others. One thing for certain, they do not solve every headspace issue one might encounter.

I agree completely and thanks for the clarification . I have a much better understanding as to where you were coming from on this

 

[Texas10]

I answered that question in detail in post #67


I answered that question in detail in the very next post or post #67 . Yes they do if you start with the # 10 comp shell holder . If you then switch to the #8 your case will go into the die .002 further , if you then switch to the #6 shell holder your case will go in the die an additional .002 for a total of .004 from where you started . If you go to the #4 the case goes another .002 deeper into the die . The guy in the video specifically says and starts with the #10 and the question was posed after saying "I watched the video" . When I answered the question it was assumed that part of the video was understood . I'm very confused as to what's going on here . You may be right , I very well may have missed something because to me it just seems a few of you are just doubling down on your beliefs to the point of saying things that really don't make sense . Like the comp shell holders don't work if you have a chamber that no other standardized commercial equipment will works for ? OK fine there is nothing in the world that will work for your chamber with out modification . Why would anyone think the comp shellholders are any different , they're not magic

However here is a video demonstrating what is different about the Redding competition shellholder compared to a standard Redding shell holder . He talks a little slow but covers the real difference in first few minutes

I appreciate your generosity in replying, but in fact you didn't answer my question because you used a different term without clarification. I used the term "shell platform" to describe the surface the shell sits on. You used the term "deck height" without clarification, and to me this means the top surface of the shell holder that makes contact with the die, much like a car engine where deck height is the top of the cylinder where the head mates.

Grinding down this "deck height" would allow the shell to go further into the die, and receive more shoulder bump. And so would grinding down the die where it make contact with the shell holder, as I have had to do on a chamber I set up a bit on the short side. I ended up resetting that barrel to get more chamber length.

So if I am correctly interpreting the above discussion regarding competition shell holders and how they differ from standard shell holders, and to use my chosen terminology of "shell platform", the competition shell holders are ground so that the shell platform is deeper (further away) from the top surface of the shell holder, and this does the same thing as backing the sizing die out, but without actually having to readjust it. Is this correct?

To further clarify, competition shell holders DO NOT push the shell progressively further INTO the die, in order to bump back the shoulder of a case being used in a chamber set up on the short side of SAAMI spec. In other words, if the standard shell holder is already making firm contact with the die, no further adjustment or shortening of the cbtd (headspace) is possible. Correct?

Furthermore, shims that sit between the press ram and shell holder will do nothing to increase shoulder bump if the shell holder is already making firm contact with the die. Only by placing a feeler gage or shim under the head of the cartridge case being sized will the cartridge be moved deeper into the die and the shoulder be moved back more during sizing. Correct?

Two more questions. Does anyone make a set of such shims for placement under the head of the cartridge so I don't have to sacrifice my feeler gage set? And finally, wouldn't it be easier to just buy another die and dedicate it to the particular chamber?

I appreciate all the contributions to this discussion, and hope the OP will also, if he hasn't already run for the hills from being soaked in urine. Just kidding, of course. You guys are great.

 

[cw308]

You are correct , I'm sure others will know where to purchase the shims .

 

[cw308]

dellet
One thing I'm not getting , a chamber with shorter base to datum line . Let's say I buy a 308 and the base to datum is shorter , how would chamber your first round . Isn't the chamber too small . Not everyone is a reloader to get around the problem .

 

[Texas10]

dellet
One thing I'm not getting , a chamber with shorter base to datum line . Let's say I buy a 308 and the base to datum is shorter , how would chamber your first round . Isn't the chamber too small . Not everyone is a reloader to get around the problem .

Been there, done that. Some off the shelf ammo will fit, some won't. Seen it in brand new factory firearms too.
In my case I didn't have a go gage to install a new barrel, so I used a new (pulled down) cartridge as a headspace gage. Turns out I grabbed a short one and my die would not bump the shoulder back.

If i'd had a surface grinder I could've ground off some of the shell holder. As it was, I ground off some of the die, but in the end this just persisted the error so I went back and reset the barrel.

EDIT: I misunderstood your question. The answer is send it back to the factory, send it to a gunsmith, or if you have the tools set the barrel back using a go gage. If the chamber is too short you'll likely experience loading problems with some factory cartridges, possible excessive pressure with pierced or blown primers with many factory loads.

 

[cw308]

Texas
Could it be that the chamber was slightly wider and over expanding the case making them shorter ? Did you check your chamber length?

 

[dellet]

dellet
One thing I'm not getting , a chamber with shorter base to datum line . Let's say I buy a 308 and the base to datum is shorter , how would chamber your first round . Isn't the chamber too small . Not everyone is a reloader to get around the problem .

Most people who don’t reload who buy a rifle and then find they can’t chamber a round, take it back to the seller if it’s new, maybe a gunsmith or trusted friend if it’s used. A few select individuals probably hammer the action closed and fire away.

If you participated in forums 5-6 years ago after Sandy Hook, the number of people who joined up with their first post being, “I’m new to guns and just bought a 4000 improved whiz bang. I can’t find any ammo so I’m reloading for it.” The number of people who created truly dangerous rounds and did not kill themselves was simply amazing, as were the number of out of spec chambers that were discovered.

You also asked what I would do.
I either chamber an empty case, measured before and after to make sure the shoulder is not being crushed if it has one. Then I find the lands with the same piece of brass.

If it’s a rifle that I question the chamber and do not have a case, or it’s something like a 25-20 where there were more than one cartridge with that designation, I cast the chamber if there is any question.

This is something that the more time I spend on forums and read horror stories of crap that is on the market, the more I think everyone who buys a gun off the shelf should do.

A perfect choice is 300 Blackout. I know of at least half a dozen factory loads that are/were completely unsafe to shoot. The brass was in spec, the COL was in spec. Base to ogive and chambers were in spec. The problem was that if the datum line was at the low end, and the chamber was also. Certain bullets would hit the lands before the shoulder seated. Head spacing off the bullet.

How many SAAMI drawings can you name that will show Base to Ogive on the cartridge drawing?

You mentioned 308, but how about 30-06? It was available commercially for 20 years before SAAMI existed. I can tell you for a fact there are a few short chambered model 1895 Winchester’s out there.

When I started going to gun shows it was very common to see people with go/no-go gauges. I can’t remember the last time I saw someone pull one out.

I tend to shoot rifles that are often 100-150 years old. I have brass that is that is 100 years old and still use. People that pick up a rifle of the shelf, drop in a factory round and pull the trigger without checking things out first, are crazier than I am.

Kind of a drift, but headspacing question’s are as much about safety as they are about accuracy. You wouldn’t know it by looking at the threads tho.

 

[cw308]

dellet
That's why I asked if he knew the chamber length . I do use the go gauge .

 

[Uncle Ed]

I bought the Dicks Shims first and then tried the Redding competition shell holders and prefer the competition shell holders.

The Redding shell holders allow the die to make hard contact with the shell holders, the press to cam over and remove any flex or slop in the press. Meaning more constant and uniform shoulder location after sizing. That being said my Rockchucker press is over 46 years old and has wear and a new press or different type press may not flex as much.

 

[Metal God]

Well I think I’ve reached the end of my ability to help in this thread . It seems more and more posters want to talk about how the comp shell holders don’t work on there out of spec rifles . I believe it was the posters responsibility to point out they were speaking of out of spec rifles and thats why they believed the comp shell holders would not work for them . I don’t think it unreasonable to assume we were talking of properly spec’d chambers and to post accordingly.

To the OP Fng, if you have a rifle that is with in SAAMI spec . You very well could benefit by using the Redding competition shellholders . Although you will need to check you cases headspace while you size them . The comp shell holders help the confidence that you don’t need to check every one . Like checking charge weights , when sizing using the comp shell holders I generally check one case every 10 or so unless it’s a new to me case with unknown history . If so I’ll check much more often to the point of all if need be .

I hope what has been said in this thread was more help then confusion .

MG

 

[Texas10]

Texas
Could it be that the chamber was slightly wider and over expanding the case making them shorter ? Did you check your chamber length?

I'm afraid that I failed to clarify that when I reset the headspace (this was on a new X-Caliber 28 in, 22-250) , I used a go gage. One of the first steps I perform after setting a new barrel is to determine the max chamber length by loading and shooting the brass several times without FL sizing. This grows the brass until it will still chamber but with a stiff bolt drop. That is the max chamber dimension. I keep that cartridge case as a standard for that barrel and label it. Now I know the starting point for setting up the shoulder bump.

Once I have several cartridge cases that are at or close to max chamber size, I use those as tools to explore the bullet touching the lands dimension. I then keep that dummy cartridge/bullet combination as a standard and label it with date, chamber, CBTO, and bullet lot. I now have a reliable model of the chamber and CBTO with bullet seated at touching lands to work with to start load development.