Headspace Comparitor & Bumping

[dkhunt14]

FGuffey, cases do have headspace. You need to get off your rant and stop steering people wrong. You can bump shoulders, maybe if you didn't learn how, somebody can show you. Companies like Lyman, Redding, RCBS and many others refer to it in their manuals. If a case is to long to the shoulder, it will not fit the gun, just like a headspace Guage. If it is too short it stretches and can ruin brass by head separation. This is why we bump shoulders and measure cases. Just because you don't call it headspace, doesn't make it right. The companies and people have been referring to this for many years. Matt

 

[ireload2]

I have no problem whatsoever with the Hornady tool. I set it using a gunsmith headspace gauge and it works great.
This tool will detect changes in the shoulder location of formed cases due to slight differences in speed of sizing, the amount of lube used, length of dwell at the top of the ram stroke and number of times a forming stroke is repeated.
I have also made the same measurement with a large optical comparator at 20X. It is pretty awesome when the case reflection is 4 feet tall and the digital read out has 4 decimal places.

Hornady/Sinclair does not have a head space gage that measures head space because the case does not have head space. And then from the beginning the Hornady/Sinclair tool has and has an inherent problem and the reloader has a problem. Both problems involve 'the datum'. Hornady datums have a radius, in the real world the datum does not have a radius. A radius on a datum turns the tool into a comparator. Problem: Forget using the Hornady tool for anything other than a comparator and it does not do well when comparing other measurements made with other tools. A reloader with shop skills and or a smith should be able to make tools to verify a gage, if a smith/reloader can make a tool to verify a tool they should be able to make the tool; that is what I once believed but now? Not so much.

Wilson makes a case gage; Wilson's case gage datum has a radius. Reloaders tried to sell other reloaders on the ideal the Wilson case gage was a drop-in gage for two reasons; they did not know how it was designed or they there trying to sell other rleoaders a different tool.

A real head space gage can be used to check the Horandy comparator. After verifying the tool the user can use the error for adjustment. I am the fan of measuring before, during and after. I am also the fan of being able to measure the length of the chamber from the shoulder to the bolt face; if a reloader/smith could measure the length of the chamber from the shoulder to the bolt face there would be no use for a tool that has error built into it.

I know, many reloaders purchase bushing from hardware stores for nickels and dimes; the bushings work if the reloader knows how to make them work.

F. Guffey

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[dminn1]

Find the "Bump" distance (as determined by your comparitor) that just allows your bolt (without FP spring) to just fall on it's own......."Bump" an extra 0.002" for non-comp. shooting and use that as your default setting. Note- keep in mind that brass -even from the same lot, fired the same number of times-with the same exact load will work harden at different rates. To overcome this, measure each piece with the comparator and using die shims adjust the degree of bump accordingly on those that are out of the target bump dimension/ or start annealing your brass. Setting the brass back the "proper" amount each time is a lot easier on the brass than only setting it back at hard bolt closure ...hence the reason I have standardized on FL sizing dies only, and my Neck sizers are a distant memory.

How is setting the brass back on every firing easier on the brass compared to setting it back only when bolt closure becomes difficult. Its my understanding that each time you move the brass you are hardening it and thus reducing its life. I have moved back and forth between neck sizing only and full length sizing every firing and am always interested in hearing others experiences and what they have found to be the pros and cons of each method.

 

[dkhunt14]

Because moving it only .002 is so small it really isn't working the brass on the shoulder that much. The neck is getting moved the same amount after firing unless you are sizing it smaller with a smaller die or bushing. Most guys that bump anneal somewhere along the way. Annealing returns them to almost new condition. If brass gets tight in a gun it doesn't shoot as good at 1000 yards. This is especially true if one is snug and one is real tight. When you bump none are tight because you have clearance. Also if you are shooting BR or for accuracy, the gun cycles better without upsetting it. Matt

 

[fguffey]

Just because you don't call it headspace, doesn't make it right. The companies and people have been referring to this for many years.

A very prolific poster called SAAMI, he told them I said the case does not have head space and he informed them I said SAAMI did not use the symbol for head space on the case drawings. Sure enough they informed him the case did not have head space and they told him a lot of reloaders are confused about that. It had to set him back after he told him his pedigree like they were suppose to take him serious and then rewrite SAAMI's cartridge specifications and drawings. He was never been civil to me before and has not been civil since; it is not like a lost anything like a friend or something.

And then long before that and long before the Internet there was another situation that lead to confusion. I suggested all of the angry responders thing about it; we all know that never works. Anyhow, in the mid '50s instructions came with new presses. I have instructions for presses made in the mid '50s, and early 60s. One set covers two different presses and then there are separate instructions for each. One set is for 'bump' presses and the other set is for non 'bump' presses. Again, I have Rock Chucker presses, my Rock Chucker presses are not cam over presses because the Rock Chucker is not a bump press.

So I say there is something about sizing a case a reloader does not understand. Reloaders believe they are able to move the shoulder back with the die and do not understand the only way I can move the shoulder back is without case body support.

F. Guffey

 

[ireload2]

You just want to play with the semantics. People move shoulders back every day of the year. Get used to it.

A very prolific poster called SAAMI, he told them I said the case does not have head space and he informed them I said SAAMI did not use the symbol for head space on the case drawings. Sure enough they informed him the case did not have head space and they told him a lot of reloaders are confused about that. It had to set him back after he told him his pedigree like they were suppose to take him serious and then rewrite SAAMI's cartridge specifications and drawings. He was never been civil to me before and has not been civil since; it is not like a lost anything like a friend or something.

And then long before that and long before the Internet there was another situation that lead to confusion. I suggested all of the angry responders thing about it; we all know that never works. Anyhow, in the mid '50s instructions came with new presses. I have instructions for presses made in the mid '50s, and early 60s. One set covers two different presses and then there are separate instructions for each. One set is for 'bump' presses and the other set is for non 'bump' presses. Again, I have Rock Chucker presses, my Rock Chucker presses are not cam over presses because the Rock Chucker is not a bump press.

So I say there is something about sizing a case a reloader does not understand. Reloaders believe they are able to move the shoulder back with the die and do not understand the only way I can move the shoulder back is without case body support.

F. Guffey

 

[LHSmith]

To collaborate what Matt posted, this is from the book "Extreme Rifle Accuracy" by Mike Ratigan, notable short range Benchrest Competitor- "After finding a full length die of the correct size, use it from the start when making new brass for a barrel. You should not wait until the cases get tight before getting out the full length die. If the cases are allowed to work harden at the larger size, they (the cases) will not want to go back to the smaller size and will need to be replaced. In order to get the most life out of your brass you need to be proactive about the full length sizing process"
Remember the number one tenet to accuracy - Eliminate as many variables as possible in the process by doing everything exactly the same.

 

[LHSmith]

So I say there is something about sizing a case a reloader does not understand. Reloaders believe they are able to move the shoulder back with the die and do not understand the only way I can move the shoulder back is without case body support.

F. Guffey

This is also from the book "Extreme Rifle Accuracy" by Mike Ratigan- SuperShoot Champion, and member of multiple teams that have won Worlds Benchrest Championships. For those who don't know Benchresters roll their own ammo, so I believe Mike knows the ins and outs of reloading to the n'th degree: "You cannot push the shoulder back on the case without supporting the shoulder diameter. If you push the shoulder back without supporting the diameter, the case will get bigger at the front. When you push back the shoulder the brass gets thicker just at and below the shoulder-body junction.

 

[RonAKA]

"If the cases are allowed to work harden at the larger size, they (the cases) will not want to go back to the smaller size and will need to be replaced. In order to get the most life out of your brass you need to be proactive about the full length sizing process"

Annealing at the proper temperature takes care of that problem.

 

[RonAKA]

This is also from the book "Extreme Rifle Accuracy" by Mike Ratigan- SuperShoot Champion, and member of multiple teams that have won Worlds Benchrest Championships. For those who don't know Benchresters roll their own ammo, so I believe Mike knows the ins and outs of reloading to the n'th degree: "You cannot push the shoulder back on the case without supporting the shoulder diameter. If you push the shoulder back without supporting the diameter, the case will get bigger at the front. When you push back the shoulder the brass gets thicker just at and below the shoulder-body junction.

I wonder how the Forster Bushing/Bump die works then? I find fired and even neck resized and bumped cartridges fit easily in and out of the die (with the neck bushing removed) by hand. I in fact have used the die as a measuring gauge to determine how much I have bumped the shoulder.

Perhaps it depends on how much you try to bump the shoulder. One should not be bumping more than 1 or 2 thou at the most. If you try to bump 5 thou or so, then perhaps something has to give...

 

[dkhunt14]

I wonder how the Forster Bushing/Bump die works then? I find fired and even neck resized and bumped cartridges fit easily in and out of the die (with the neck bushing removed) by hand. I in fact have used the die as a measuring gauge to determine how much I have bumped the shoulder.

Perhaps it depends on how much you try to bump the shoulder. One should not be bumping more than 1 or 2 thou at the most. If you try to bump 5 thou or so, then perhaps something has to give...

I bet if you measure the shoulder before and after sizing, it sizes the shoulder a little. I agree the body has to be supported to bump the shoulder or the case will bulge or collapse. If you ever formed cases, you will see that. Matt

 

[John Russell]

I bet if you measure the shoulder before and after sizing, it sizes the shoulder a little. I agree the body has to be supported to bump the shoulder or the case will bulge or collapse. If you ever formed cases, you will see that. Matt

I have Forster Bump dies in several calibres. The die only touches the shoulder (and neck if a bushing is in place).
There is no contact with the body.
The body does not buckle, bulge, expand, or collapse.

 

[dmoran]

I have Forster Bump dies in several calibres. The die only touches the shoulder (and neck if a bushing is in place).
There is no contact with the body.
The body does not buckle, bulge, expand, or collapse.

Say you bump .002", where does the brass go?
(Not doubting you, just know it has to go some where and wondering where that is)
Donovan

 

[John Russell]

Say you bump .002", where does the brass go?
(Not doubting you, just know it has to go some where and wondering where that is)
Donovan

When a fired case goes into a FL die, the case first gets longer as the body is compressed, then when the shoulder hits the die's shoulder cone, case shoulder flows up the die's shoulder cone.. it adds to the neck.
It does not get compressed back into the body. It is why cases grow and need to be trimmed.

When the lubed shoulder contacts the Bump die, and then keeps on going, the brass flows up the shoulder cone, but without the case growing in length first.
Forster has been making these since 2009, and no one complains about them. They work great, and do what they are supposed to do.

If you take a 222 case, lube the shoulder, and run it into a 221 neck sizer (which does not touch or support the body), the shoulder will be pushed back, and the neck will get real long, but the body will not buckle.

fguffey is not knowledgeable on this stuff. He makes it up as he goes.

 

[dedogs]

Paul Becigneul (Pbike257 on this forum) makes a shoulder set back die for BR cases that will put the shoulder where-ever you want it. You can put a 1" long neck on a 30-06 case if you so desire. dedogs

 

[dmoran]

When the lubed shoulder contacts the Bump die, and then keeps on going, the brass flows up the shoulder cone, but without the case growing in length first.
Forster has been making these since 2009, and no one complains about them. They work great, and do what they are supposed to do.

They must be very unique dies !.!.!
To me, if there is no body support, any amount bumped would flow down and have to show up in the body to base. And if the body does have support, it would flow up in show in the neck. Just can't grasp how they can keep the flow contained with-in the shoulder when the shoulder is being bump sized, and didn't think that was possible.

On another note to this, some time back another member stated that he had JLC make his bump dies. I called JLC and inquired if there bump dies supported the body, and they said they've never made a bump die that didn't support the body as well.

Guess I'll remain confused on this one. Thanks for the reply.
Donovan

PS....
fguffey has knowledge, that is realitive nostalgic, but is beyond my own realm of nostalgia.
I'm into modern advancement myself... lol

 

[RonAKA]

I have Forster Bump dies in several calibres. The die only touches the shoulder (and neck if a bushing is in place).
There is no contact with the body.
The body does not buckle, bulge, expand, or collapse.

I only have one Forster Bushing/Bump die for my 6BR, but my experience is the same. Where does the 0.001" to 0.002" go? Probably back where it came from. It has not traveled very far! The other interesting thing is that overall case length over 5 firings with no annealing, has not changed a bit. I have not trimmed them. So the brass certainly is not showing up as a long case.

 

[CColt350]

I know this being my first post (been lurking for years) it may sound suspect. But in reference to a bump die with no body support; think path of least resistance. I'm not saying it can't crush/collapse the case, just that with a lubed shoulder any angle less than 90 or pretty much all shoulders would be less resistant than the column of brass below. Also the amount of movement is quite small. Make it 10X that and we might see the body moving/collapsing per case forming comment above.
Though I would think supporting the case would have less chance for inducing some sort of runout. JMHO. Cheers
Chris

 

[LHSmith]

When a fired case goes into a FL die, the case first gets longer as the body is compressed, then when the shoulder hits the die's shoulder cone, case shoulder flows up the die's shoulder cone.. it adds to the neck.
It does not get compressed back into the body. It is why cases grow and need to be trimmed.

When the lubed shoulder contacts the Bump die, and then keeps on going, the brass flows up the shoulder cone, but without the case growing in length first.
Forster has been making these since 2009, and no one complains about them. They work great, and do what they are supposed to do.

If you take a 222 case, lube the shoulder, and run it into a 221 neck sizer (which does not touch or support the body), the shoulder will be pushed back, and the neck will get real long, but the body will not buckle.

fguffey is not knowledgeable on this stuff. He makes it up as he goes.

OK, my gut instincts tell me that the shoulder/ neck junction will bulge without any body support. Since I got rid of all my neck sizers, I took a PPC case and using a Sinclair 30A bump gauge insert and pushing it against the bottom of a die as a stop in a press and was able to (with some finesse) set the shoulder back 0.0015". The diameter at this transition increased by 0.0003" and there was a definite bulge at the junction when holding a straight edge along the case body when held up to a light. For Benchrest requirements this would be unacceptable. Apparently bump only dies work OK under less stringent demands.

 

[jimbires]

this surprises me . I've always thought of sizing brass the same as squeezing a water balloon . when you push , or squeeze somewhere , it bulges out somewhere else , if not supported .