Generous Die space or Tight chamber?

S

Stats Shooter

New member
I have a rifle in which fired brass measures 2.2705" from Case head to Datum line. I bought the Redding competition shell holder set for it to easily control setback of the shoulder. However, when using the most shallow shell holder, I am moving the datum line/shoulder back only 0.001 to 2.2695. The bolt closure on this is a bit stiff but not "Tight" by my standards... What I mean is you can't just drop the bolt handle like you can with virgin Brass.

However, a standard RCBS shell holder only bumps the Datum line back .0025"...The bolt closes almost as easily with the cartridge shoulder setback .0025 as it does with new brass.

So is this just a loosley(deeply) reamed die? I'm just asking because my other RCBS dies/shell holders will push the datum back anywhere from .006-.008 in my other calibers/cartridges.

Next question, how stiff of bolt closure do y'all like to allow? For competitive shooting. For hunting I want minimal resistance but as long as the case chambers and extracts I don't think a heavy bolt is a big deal right?
 
It may be a die cut with a fresh reamer.
Or, it may be that you have a tight chamber (have a few myself - sometimes nice, sometimes a pain in the butt).

-

I don't like resistance to bolt closure, for any load or purpose.

It's one of those things that I reserve as a hint that something's wrong; or, looking at it another way, an indication that something has changed and I need to find out what and why.


The only exception I can think of would be the 437 gr bore-rider load for my .444 Marlin Handi-Rifle. That bullet has almost 0.650" of engagement with the rifling when chambered, and action closure is a bit stiff. Extraction is impossible without mechanical assistance -- a dowel or cleaning rod. (It's best to just plan on firing, once that load is in the chamber.)
But... when loading that rifle, I'm staring straight into the chamber and right down the barrel. So it's difficult to miss something like a ring of brass from a case mouth, or a bullet jacket stuck in the throat.
 
However, when using the most shallow shell holder, I am moving the datum line/shoulder back only 0.001
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However, a standard RCBS shell holder only bumps the Datum line back .0025"...The bolt closes almost as easily with the cartridge shoulder setback .0025 as it does with new brass.
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I'm confused a bit and don't want to come off snarky but are you really concerned about .0005 ? I ask because most of us that aren't happy with a tight bolt with a .001 bump just bump it back another .001 for a total of .002 . You seem to be saying your extra .0005 ( five ten thousandths ) is a deal breaker ? WOW and I thought I got a little OCD at times . I think you've taken it to another level :eek::D

And when I say I got anal about sizing cases I mean like shimming up cases inside the shell holder with feeler gauges when sizing to get every case the exact same size .
k441.jpg


So if you want to go all bat poop crazy you can use the .002 comp shell holder and shim the case up .001 using a feeler gauge and you should be right where you want to be ;)
 
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im confused a bit and don't want to come off snarky but are you really concerned about .0005 ? I ask because most of us that aren't happy with a tight bolt with a .001 bump just bump it back another .001 for a total of .002 . You seem to be saying your extra .0005 ( five ten thousandths ) is a deal breaker ? WOW and I thought I got a little OCD at times . I think you've taken it to another level
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No Boss, not a deal breaker. Just thought it a bit strange that a standard shell holder with a full stroke all the way until the shell holder hits the die firmly only moved the shoulder back 2 and 1/2 thousandths. Usually you hear about a FL die moving a lot more brass than that.

My other question was in reference to how much Y'all want to be able To feel the case being chambered.
 
My other question was in reference to how much Y'all want to be able To feel the case being chambered.
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I believe there are a few ways guys think of that . Some say you size the case so the bolt closes with no resistance . This is to allow the cartridge to freely expand evenly . While others feel slightly compressing the case in the chamber centers everything up so when the bullet leaves the case it's in perfect alinement with the bore axis . The isuue the other guys claim is that's only possible if the rifle has been trued completely all they down to the bolt face and you only neck size .

IMO if you are FL sizing and bumping the shoulder back . I'd have the bolt close freely-ish . I how ever feel you are going to test both ways out to find what's best regardless . I like that :)
 
Myself if I was shooting match off bipods/rest on the ground, I won't want any
resistance on that bolt other than smooth close.
 
IMO if you are FL sizing and bumping the shoulder back . I'd have the bolt close freely-ish . I how ever feel you are going to test both ways out to find what's best regardless . I like that
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I will probably test both. I'll load probably 20 rounds of each and shoot to see how I like the function of each and how each one shoots.

To be honest though, I am leaning towards the "little or No" resistance scenario and moving it back 0.0025. The extra 0.0005 won't matter I dont think as far as case life, especially since I am annealing on every single firing ( on an annealing machine I built myself :) ).

But, as Metal God indicated, I just Have to know how both would fire and function so more testing!

Sometime I wish I wasn't so anal about this stuff...in the end sometimes I find out that something is a waste of time and doesn't matter, but if I don't check, it will eat at me forever. It makes me good at my job at work when running simulations, and helps me turn out better ammo and build better guns, but it makes me a pain in my own butt sometimes.
 
I bought a set of the Competition Shell Holders too, as I was also having a difficult time bumping the shoulder back a tad for my bolt gun.

When I got them I slapped in the +.002 and ran a case. It was still too tight. +004, still too tight,, all the way to +.010, nope. What that??????

Then, like the intelligent adult that I am, I resorted to READING the darn instructions.

It seems I was supposed to start with the +.010 and go the other way. What the, that seemed counter intuitive, but it worked.

Sometimes I am such a dope. Acceptance is part of the drill.
 
Mississippi,
Do yourself a favor and try chambering a fired case before sizing it.
If it chambers easily but is difficult to chamber after sizing it indicates that there is a problem that is induced during the sizing process.

Improper lube of the inside of the neck can pull the shoulder forward.
The lack of a properly expanded neck or insufficient chamfer can push the shoulder out when seating the bullet.
The sizing die might be too large in diameter for your chamber which can make the cartridge drag when chambering.

If your cartridge won't chamber easily after being fired then you may have a load that is producing more pressure than your gun can use safely.

Since you didn't specify the cartridge or load we can only give you general things to diagnose your problem. I would start by chambering a fired, unsized, case and then keep chambering it after each step in the loading process that involves a die.
Example:
Chamber the fired case - goes in easy, good; chambers hard, bad.
Size case and chamber it - goes in easy, good; has drag, bad.
Seat the bullet and chamber - goes in easy, good; chambers hard, bad.
When you get a bad result it shows you where the problem starts. Fix that problem and continue the process.
 
I bought a set of the Competition Shell Holders too, as I was also having a difficult time bumping the shoulder back a tad for my bolt gun.

When I got them I slapped in the +.002 and ran a case. It was still too tight. +004, still too tight,, all the way to +.010, nope. What that??????

Then, like the intelligent adult that I am, I resorted to READING the darn instructions.

It seems I was supposed to start with the +.010 and go the other way. What the, that seemed counter intuitive, but it worked.

Sometimes I am such a dope. Acceptance is part of the drill.
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I followed the instructions, The .002 shell holder moves the Datum line back .001. The other ones, .004-.010 do not touch the shoulder or Datum line at all. A standard shell holder moves it back about .0025.



Mississippi,
Do yourself a favor and try chambering a fired case before sizing it.
If it chambers easily but is difficult to chamber after sizing it indicates that there is a problem that is induced during the sizing process.

Improper lube of the inside of the neck can pull the shoulder forward.
The lack of a properly expanded neck or insufficient chamfer can push the shoulder out when seating the bullet.
The sizing die might be too large in diameter for your chamber which can make the cartridge drag when chambering.

If your cartridge won't chamber easily after being fired then you may have a load that is producing more pressure than your gun can use safely.

Since you didn't specify the cartridge or load we can only give you general things to diagnose your problem. I would start by chambering a fired, unsized, case and then keep chambering it after each step in the loading process that involves a die.
Example:
Chamber the fired case - goes in easy, good; chambers hard, bad.
Size case and chamber it - goes in easy, good; has drag, bad.
Seat the bullet and chamber - goes in easy, good; chambers hard, bad.
When you get a bad result it shows you where the problem starts. Fix that problem and continue the process
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It isn't a pressure issue, or my method of sizing...The question is about how far to set back the shoulder. If I set it back .0025 - .003 using a standard shell holder and FL die with a full stroke, it slips in easily. If I bump it back using the +.002 shell holder .001, it chambers a bit more stiff.

So I just wanted to know, how much bolt resistance these folks think is acceptable. But so far, it sounds like NO resistance is best. Which means a .0025 bump. I suppose I could try and get somewhere in between but I hate having to make too many adjustments. A spacer is an idea, but Im not sure it is worth it to save 0.0005" .....but then again
 
Mississippi said:
Just thought it a bit strange that a standard shell holder with a full stroke all the way until the shell holder hits the die firmly only moved the shoulder back 2 and 1/2 thousandths.
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Nope. That's about right for a minimum chamber gun. A minimum chamber in the .308 Winchester, for example, is 1.6300" from breechface to shoulder datum diameter. Brand new brass is about 1.628" in most brands, though I've seen some foreign military brass that was the maximum 1.630". Anyway, the general thinking is that -0.002" is the right amount for reliable chambering, even in semi-auto's. Some benchrest types prefer -0.001", claiming better centering and alignment.
 
Nope. That's about right for a minimum chamber gun. A minimum chamber in the .308 Winchester, for example, is 1.6300" from breechface to shoulder datum diameter. Brand new brass is about 1.628" in most brands, though I've seen some foreign military brass that was the maximum 1.630". Anyway, the general thinking is that -0.002" is the right amount for reliable chambering, even in semi-auto's. Some benchrest types prefer -0.001", claiming better centering and alignment.
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So you don't think .0025 is too much? I wouldn't think so but I'm no expert, just ask my wife lol
 
Mississippi,
I wasn't degrading you, your equipment or your process. I was simply sating what you need to do to find out where the tight chambering came from. I have run into the same problems over the years and in my case the neck sizing plug was the cause for me. Others have had the same symptoms that were caused by pushing the shoulder out when they seated bullets.
No offense meant but without checking at each step we are all just guessing what is causing your symptoms.
 
Mississippi,
I wasn't degrading you, your equipment or your process. I was simply sating what you need to do to find out where the tight chambering came from. I have run into the same problems over the years and in my case the neck sizing plug was the cause for me. Others have had the same symptoms that were caused by pushing the shoulder out when they seated bullets.
No offense meant but without checking at each step we are all just guessing what is causing your symptoms.
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No offense taken, Im not a snowflake and don't need a safe space :D. I gave minimal info just because all I was wanting to know was: Do you guys accept a heavy bolt to prolong brass life, OR, do you size it until it slips in easy.

You hear all the time about "bumping" shoulders back and the like, but it seems setting it back only .001 would lead to a stiff bolt....at least in this case
 
No, 0.0025" is actually pretty good for case life. There are guys who do 0.001" to 0.002" for match shooting and 0.002"-0.003" for general purpose rock throwing. The main trick, if you will, is that once you drive a case into a die far enough that its shoulder is being set back at all, it is already narrowed by the die. That's most of the issue. If you look at the SAAMI drawings you see they actually allow for a bit of interference fit at the shoulder because the bolt can squeeze the case and there is still enough extra room in the chamber width so the brass can upset laterally enough to allow the bolt to close, so it still operates. The SAAMI 6.5 Creedmore chamber has a minimum of 1.541" headspace from the breechface to the shoulder, but the cartridge has a maximum of 1.5438", so 2.8 thousandths of interference fit is allowed, provided the case body is at maximum diameter tolerance or less. The benchresters don't seem to favor that sort of death grip on the case, but you can experiment to see if it works for you.

The Redding Competition Shell holders have the range they do because you'll run into some guns with long chambers at times, especially if they are well-used and bolt lugs have been hammered into a little bit of lug setback over time. My first M1 Garand bought directly from the Army when the DCM was still in place, had enough extra headspace that the brass came out of it 0.007" oversized. But at long as I pushed the brass back to 0.004-0.005 over minimum., it functioned just fine. When I rebarreled it, of course I put a tight chamber in, so that even new brass only stretched a couple of thousandths. That's good for brass life because it reduces the chance of getting a head separation.
 
Mississippi No offense taken, Im not a snowflake and don't need a safe space . I gave minimal info just because all I was wanting to know was: Do you guys accept a heavy bolt to prolong brass life, OR, do you size it until it slips in easy.

You hear all the time about "bumping" shoulders back and the like, but it seems setting it back only .001 would lead to a stiff bolt....at least in this case
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OK, let me share MY take on the matter of setting shoulders back.
First a little background; I am a hunter. I don't want cases that chamber hard or are hard to eject. I require a certain level of accuracy which is likely about half that of the long range competition guys. I rarely shoot beyond 200 yards so I have no need to push velocity at the expense of my rifles.

That said, I have been only partially neck sizing my reloads for 40 years. I have never had to push the shoulder back on my reloads in that time. I have never had to full length resize a case because it was hard to chamber. I don't load maximum listed loads - if I cant find a load that is accurate below the maximum level then I change components and try again.

Now, that has been my experience in my four hunting rifles. If you are trying to squeeze every last foot per second out of a cartridge and exceeding maximum listed loads to do so you will likely run into problems with sticky brass that grows too long for your chamber. I have no problem believing that can happen. I would expect it to happen! What causes the brass to grow longer or fatter than the chamber it is fired in is the pressure being high enough to expand the chamber more than the brass will rebound from. Since even hard brass will rebound (the harder the more likely it is to rebound or simply split) it makes sense that keeping pressures below the point of over-expanding the chamber is safer for the gun and the shooter.

Your load does not appear to be near the maximum. You didn't mention that it was hard to extract so I assume it came out of your gun easily. It should then go back into the same chamber just as easily if not easier after it cools.
After reloading it is tight in the chamber that it came out of without a problem. That points to a change in the size of the brass during reloading.
NOTE: if it wasn't sticky coming out what is causing it to be sticky now?

That is my take on this. Others may have different ideas due, at least in part, to their loading methods and their personal experience. I fully accept that. You have to decide what the real issue is with your ammo in your gun. Only then can you remedy the problem and not waste time and money on hiding the symptoms.
 
OK, let me share MY take on the matter of setting shoulders back.
First a little background; I am a hunter. I don't want cases that chamber hard or are hard to eject. I require a certain level of accuracy which is likely about half that of the long range competition guys. I rarely shoot beyond 200 yards so I have no need to push velocity at the expense of my rifles.

That said, I have been only partially neck sizing my reloads for 40 years. I have never had to push the shoulder back on my reloads in that time. I have never had to full length resize a case because it was hard to chamber. I don't load maximum listed loads - if I cant find a load that is accurate below the maximum level then I change components and try again.
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This load is within 3k psi of max or about 50-75 fps below max. It is a competition 1k Yard load.

My plinking around loads are like you described, neck sizing is all that is needed. But in some of my guns I try and wring all I can out of it, like my national match AR for service rifle matches and this .300wm for 1k Yard precision rifle matchs.

Shoulder setback is necessary. But I'm trying to get all the accuracy and velocity I can. I am fully aware that brass life is shorter in this instance, but careless reloading, setting the shoulder back too far, and not annealing will shorten it even more.
 
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