Headspace gauge/ case head separation

I have had some issues with my 223 case head separation. I split one in half yesterday with the case stuck in the chamber on my first shot on a mob of goats. Luckily the case fell out of the chamber easy enough.
After reading why it's happening (thanks to a previous thread and real knowledgeable fellas on here) I am over working the brass. I have decided I need a headspace comparator gauge so I can accurately bump the shoulder back.
Has anyone used this before from TradeMe?
https://www.trademe.co.nz/4923839449
Are headspace gauges much the muchness? I'm not looking for extreme precision.
Can I bump the shoulder back the 2-4thou with a Lee full length sizing die or do you need a bushings die?

Is this a new problem for the rifle you are using? Are you using new brass with your re-loads or how many cycles have they done? There are a number of reasons why this may happen.Take your time and think through any differences that you may have made.

Yes that will work fine and yes you can set up your lee to bump 2-3 thou back.

Are you running hot loads?

Another way to gauge head space https://www.amazon.com/Lyman-7832323.../dp/B001RI7A66
Gun works have them, Steel ones 75 bucks

It's a new howa rifle. The brass has 3-4 firings on it and is at book max with 26grn of 2206h for my 223 with a 55grn pill.

Not sure but I have come across hand loaded loaded rounds for howa, that had to have the shoulder bumped to fit a Savage chamber so presume Howa's headspace might be slightly longer. What brass are you using?

Mostly federal and ADI

I would not buy a headspace comparing device if only loading for one rifle - once you find where the measurement is for setting up the die to resize the cases just enough to fit your rifle's chamber you don't need to adjust it.

If you have a couple of cases that are fired out of this rifle, set the die up long in the press and mark the neck and shoulder of one of the cases with permanent marker. Run the case through, and see how far down the neck the die runs. Wind it down until the witness marks are just close to the neck and try the case in the rifle - if it fits lock everything up and reload the cases as per and if they get stiff to chamber wind the die down 1/6 of a turn and try them. There's a picture around here that someone posted which tells you roughly how many thou of an inch down each fraction of a turn on the standard die thread gives you...

A headspace gauge and a case comparator gauge are different things. I don’t mean to point out the obvious if you know this, but just checking.
The headspace gauge will check safe headspace in your rifle, which most people don’t bother with in a new rifle as it should not be out of spec. But by all means check it if you feel like it.

A case comparator gauge measures cases to compare the difference between fires/unfired, sized/unsized etc, so you can size your cases appropriately. Case comparators are strictly only for comparing one case to another, not for comparing chamber headspace to SAAMI specs.

You can reduce the amount your are sizing your cases without the need for comparators anyway. Simply wind your dies out and make a minimal sizing pass, and try the brass in the chamber. Repeat until the case will chamber, and you can feel the slightest amount of resistance on the bolt handle where the case shoulder is meeting the chamber shoulder (or whatever datum
Point the case is meeting on). Once your dies are adjusted thus, size the rest of your cases and periodically check the occasional piece in the chamber.

As an aside, I never use the terminology ‘bumping shoulders forward’ because you can’t move case shoulders forward with dies. Shoulders might move forward upon firing and May move back when sized. I describe the process as above; ‘reducing the amount of full length sizing’ as this is less confusing to beginners. But hey that’s just me.

I'll have a search to see if I can find the diagram on how many thou each fraction of a turn does.

Golly folks make life hard for themselves. Look up partial length resizing. Basically when setting up your full length resizing die,instead of screwing it in the extra turn to ensure its hard down on case holder,you back it off half a turn.resize case,try for easy chambering in rifle.if it fits easily ,load up a few and make sure they going to work for you.

Quote:

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Originally Posted by Micky Duck

Golly folks make life hard for themselves. Look up partial length resizing. Basically when setting up your full length resizing die,instead of screwing it in the extra turn to ensure its hard down on case holder,you back it off half a turn.resize case,try for easy chambering in rifle.if it fits easily ,load up a few and make sure they going to work for you.

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Hahahah, your right on that one mate.
I'll stop thinking into it so much and start with that one.

A standard die is threaded 7/8 - 14". One turn of the die moves it by 1/14" I.e. 71/1000" To move it by 2/1000" (which is what all of the internet sources advocate) you would have to turn it by 2 x 1/71 of a turn. That is impossible to set and more impossible with the slop in the die and press. So, you need a set of shims to go between the die and the shell holder to set the case to fit the chamber in your rifle, so that the case will fit in the way that -BW- has described. The easiest shims are cut from beer can which is 0.004" thick. Cut as many as you need to set the resizing of the case to fit the chamber of your rifle. You may need to reduce the number of shims as the cases work harden and develop more spring back.

Quote:

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Originally Posted by -BW-

A headspace gauge and a case comparator gauge are different things. I don’t mean to point out the obvious if you know this, but just checking.
The headspace gauge will check safe headspace in your rifle, which most people don’t bother with in a new rifle as it should not be out of spec. But by all means check it if you feel like it.

A case comparator gauge measures cases to compare the difference between fires/unfired, sized/unsized etc, so you can size your cases appropriately. Case comparators are strictly only for comparing one case to another, not for comparing chamber headspace to SAAMI specs.

You can reduce the amount your are sizing your cases without the need for comparators anyway. Simply wind your dies out and make a minimal sizing pass, and try the brass in the chamber. Repeat until the case will chamber, and you can feel the slightest amount of resistance on the bolt handle where the case shoulder is meeting the chamber shoulder (or whatever datum
Point the case is meeting on). Once your dies are adjusted thus, size the rest of your cases and periodically check the occasional piece in the chamber.

As an aside, I never use the terminology ‘bumping shoulders forward’ because you can’t move case shoulders forward with dies. Shoulders might move forward upon firing and May move back when sized. I describe the process as above; ‘reducing the amount of full length sizing’ as this is less confusing to beginners. But hey that’s just me.

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Ha - I have found one case where the resizing die did move the case's shoulder forwards, but I would say it was not right or normal. We came to the conclusion that the chamber for some random reason was too wide at the shoulder, which meant the case was basically being fire formed to some un-named feral kitten case. The fatter shoulder going through the die body contacted the die wall prior to the right part of the die, and it rolled the shoulder forwards and kind of weirded out the cases' shoulder - neck area. Rather than a nice angled taper on a normal case, it looked like it had been molested by a Weatherby magnum and the injuries hadn't yet healed. Without the die hard down and the press rammed up into it like it stole it the cases were troublesome on chambering to say the least...

Factory ammo fixed the problem. Well, lazy fixed it. I put this forward purely as a point of 'never say never' as there will sooner or later be a situation that pops up that doesn't obey the rules...

Greetings all,
I struggled with setting headspace on my brass for decades. For years I neck sized brass, which brought its own set of problems, and meddled with setting the die of the shell holder with a feeler gauge. Nothing, I repeat nothing is half as convenient or accurate as using the Hornady headspace comparator together with the Redding Competition shell holder set to achieve consistent headspace on my sized brass.
Regards Grandpamac.

Quote:

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Originally Posted by grandpamac

Greetings all,
I struggled with setting headspace on my brass for decades. For years I neck sized brass, which brought its own set of problems, and meddled with setting the die of the shell holder with a feeler gauge. Nothing, I repeat nothing is half as convenient or accurate as using the Hornady headspace comparator together with the Redding Competition shell holder set to achieve consistent headspace on my sized brass.
Regards Grandpamac.

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Yep redding comp shell holders are absolutely fantastic
The other way to do it is find a tight ish bit of fired brass and take the decapping rod out of your die.
Start sizing with the 10.000 holder and work down 2.000 at a time till you have bolt closing tension you require.
Alot of my cases of diferenf chambers sit at 6.000 which means if I didn't use them I would have between 6.000 to 7.000 head space which for me fixed case head separation I was having problems with.
For those of you who just undo their die a fraction at a time it has been proven to be quite an inaccurate way to gain exact replication of head space.
A redding podcast explained why it is so!

Sent from my SM-A556E using Tapatalk

It's a funny old thing, years back we were taught to never wind the die in hard and lock it solid as that way it can float and not push the case of too one side with an affect on the neck runout. If only we knew how bad it was for headspace!!! :D

This is how I do it now.
IMO for hunters anything from 0.002" to 0.005" would be fine as you tend to lose cases in the field.
The tape is a good trick.
To measure bump u can get away with a pistol case.
I just use a short length of brass with a hole drilled down the centre to give u a "tube" of brass. It's about 20mm in diameter. I have two. One for 223 and another 30.06. The hole in the brass sits about halfway down the shoulder. Just sit over the nech/shoulder and use dial caliper to measure.

Having said that I'm sure the Hornady comparator would be better and more consistant. I don't neck size any more.

https://youtu.be/htvk1UYOXm8?si=UlPxVmkwpUJeWBT5

Quote:

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Originally Posted by No.3

It's a funny old thing, years back we were taught to never wind the die in hard and lock it solid as that way it can float and not push the case of too one side with an affect on the neck runout. If only we knew how bad it was for headspace!!! :D

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Greetings @No.3 and all,
There were a lot of things touted as fact that many find hilarious these days. Regrettably many can not let go old beliefs that were debunked decades back. We each develop our craft of handloading in different ways and at different speeds. It is well over 50 years since I timidly put my first handload together. A .303 with a 180 grain Norma projectile and 34 grains of AR2201 powder. Decades later I am loading 150 grain Hornady projectiles in my .303 in neck sized cases with a light 34 grain load of AR2206H for around 2,100 fps. Some things change but others not so much.
GPM.

Quote:

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Originally Posted by Porter83

I'll have a search to see if I can find the diagram on how many thou each fraction of a turn does.

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80 thou per full turn on my dies.

No one has mentioned yet that new brass can take 2 or 3 firings before it stretches out enough that the shoulder contacts the chamber and causes tight bolt closing. So you think you ve got good clearance and done enough sizing but you need to rethink a few months later .

Has anyone else found this or just me ?

Ive actually noticed that but thought everyone would know that...

The distance from the cartridge base to a defined reference point on the shoulder is called the cartridge headspace dimension, to distinguish it from the chamber headspace dimension, which is fixed when the chamber is reamed out, as long as the bolt lugs dont wear down. This is shown on the SAAMI drawings which you can find by google.


Attachment 260384

For 223 the specified headspace dimension, shown on the drawing below with a triangle snd an asterix, are actually at the corners at front and back of the shoulder. But SAAMI also helpfully specify a length in the middle of the shoulder at a diameter of 0.330” where it is easy to measure. Ive indicated the length at 0.330 with fine red arrows. The required cartridge headspace length is 1.4666” down to 1.4596” @0.330”. Hornady helpfully make a set of gauges which includes one with 0.330” internal diameter.

This is the setup you need:

Attachment 260386

This is a Federal factory loaded round and the length is 1.4555” or maybe 4 thou shorter than SAAMI spec. However, the gauge seems to have a small chamfer on the inside to enable smooth seating and twiddling without scratching the brass, so perhaps it under measures the length at 0.330. As noted in an earlier post, the gauge is for comparing cartridges rather than getting an absolute length to compare with your chamber.

Ideally, you will see each case shortened in this dimension by around 0.003” when its sized.

I'd suggest the OP search YT for Eric Cortina's item on setting FL dies.

Basically, you first dismantle the bolt and remove the striker assembly so the bolt will fall closed on its own if there is nothing in the chamber. Start with the die set long ( ie, no sizing other that neck) and slowly wind it down in say 1/16 turns until you reach a point where the bolt will -just- fall closed with the case in there. This will be minimum shoulder clearance and should eliminate the case separations.

Using this technique in my main target gun, the resultant shoulder bump was 1.5 thou measured with a gauge made from a case fired in that chamber.