Shoulder bump question

[msinc]

You have to care what the diameter is otherwise if the shoulder angle is off you will have an error - I guarantee....
I have asked you many times if you know what ASME Y14.5 is. Apparently you don't and you don't want to know because it would interfere with your riddling.
ASME Y14.5 is the US national standard for dimensioning and tolerancing of drawings, including datum and datum structure definitions. It the document that controls the conventions for the SAAMI and other industry's engineering drawings. This standard is pretty much adhered to by all significant industry in the US including the automotive, aerospace, medical components and semiconductor.

I fully understand what you are saying and I will absolutely be the first to say you are 110% correct...but.........................for what we are doing, I agree with Guffey that as long as we have a diameter on the comparator that is set with a gauge cases sized to that dimension will go in the rifle and be safe to shoot because that point {where ever it happens to be on the shoulder} will not allow the case to move forward when the striker hits the primer. Don't get me wrong, I want the shoulder angle to be correct and I want the best possible brass case to chamber fit that will give me the best accuracy and case life like everyone else. I have yet to run up on a chambering reamer or a resize die of any kind that did not put the correct shoulder angle in the rifle/case.

The subject of headspace is a tough one...I really believe most people do understand what it is and the importance, but they have trouble when it comes time to convey their thoughts on the whole process of measuring it. We are concerned with 4 dimensions...chamber minimum and maximum and shoulder to datum min/max. The part that is hard is that both chamber and case sizes only matter when they are put together. If a chamber never sees a round who cares how deep the chamber is??? If ammo is going to sit in the box what difference does the length make??? Guys are always talking about "no, that's chamber headspace" or "I am only concerned with the case shoulder to head length". They both interact to make the gun safe or dangerous.

Edit: I have several Ackley Improved rifles that are my personal hunting rifles. When I reload for them I made my own comparators to go in the dial calipers because no one makes them for Ackley's. I turned the size of the hole to the dimension of the neck and shoulder junction. I did it by running the same chambering reamer into the comparator I was making so it has the exact same dimension as the chambers I am loading for. I understand the need for the exact hole size especially with an Ackley. I want to know exactly what my headspace is if at all possible, otherwise I may not be making the correct adjustments.

 

[fguffey]

Edit: I have several Ackley Improved rifles that are my personal hunting rifles. When I reload for them I made my own comparators to go in the dial calipers because no one makes them for Ackley's.

A reloader could make his own but there is a problem, I would have to convince them it can be done. And then there is the coir, they are the ones that always say they are 'SOOOO confused.

F. Guffey

 

[hunter243sgk]

Why does anyone have to make one for there ackleys? I use the hornady and with a 243 the size is .400 with my 243ai I just dropped down a size or two.(cant remember but it is a .330 or a .350). I am sure I will be told that its wrong to do it like that but I haven't blown anything up yet

 

[OffPaper]

OK, I've learned a lot about shoulder bumping on this forum. A lot of great info and I now understand how to use a Hornady headspace gauge, comparator set, and OAL gauge to measure fired and reformed cases. I have also learned several methods by which you can bump case shoulders - shims, FL die adjustment, bump dies and others. I've learned but haven't done yet. There is one question that nags me and I can't seem to find the answer. It may seem obvious but I need it answered to tie everything together in my mind please. When using a FL die to shoulder bump you still FL resize the case, right?? You aren't just using the die to adjust the shoulder only? Yes, I can be a little dense but I'm moving from reloading by the book just to reload for shooting to reloading for precision. Thanx for your responses.

 

[jimbires]

OK, I've learned a lot about shoulder bumping on this forum. A lot of great info and I now understand how to use a Hornady headspace gauge, comparator set, and OAL gauge to measure fired and reformed cases. I have also learned several methods by which you can bump case shoulders - shim, FL die, and others. I've learned but haven't done yet. There is one question that nags me and I can't seem to find the answer. It may seem obvious but I need it answered to tie everything together in my mind please. When using a FL die to shoulder bump you still FL resize the case, right?? You aren't just using the die to adjust the shoulder only? Yes, I can be a little dense but I'm moving from reloading by the book just to reload for shooting to reloading for precision. Thanx for your responses.

when setting a full length die up to bump the shoulder , lets say .002" , I call this partial full length sizing . the reason being is the die could size the case more by screwing it in until it makes firm contact with the standard shell holder . by removing shims .

or if using the redding competition shell holder set ; lets say you get your .002" shoulder bump by using the shell holder that is a + .008 " . so the full length die is set to partially full length resize your brass . you can switch the shell holder to a standard shell holder and potentially get .010" bump , I'd call this full length resized . or use of any of the other shell holders in the set will change the amount of shoulder bump accordingly , I'd call this partial full length resized .

 

[Richard Coody]

Gents
I ensure the press cams over slightly no need for shims in my reload room

and how much are you bumping your shoulder? difference between fired and sized brass.

 

[JFrank]

and how much are you bumping your shoulder? difference between fired and sized brass.

Just enough to chamber, I use a Forster benchrest neck sizing die, if you feel the need for OCD look into bump back bushing dies. As I mentioned to another I stay away from constant FL sizing due to over working my brass to a point I had several come apart on the range using RL15 . Not fun...

 

[OffPaper]

Great info. Thanx for sharing your knowledge.

 

[Bart B.]

when setting a full length die up to bump the shoulder , lets say .002" , I call this partial full length sizing .

Some years ago at a Shot Show, I asked four reloading die company reps about case sizing terminology. All agreed to the following for rimless bottleneck cases sized with a full length sizing die:

Full length sizing is when all fired case outside dimensions from pressure ring forward are reduced any amount. Doesn't have to be the smallest possible nor back to within SAAMI specs. Shell holders in the press don't have to touch the die. Full length sizing die headspace (shoulder reference diameter to touching shellholder bottom) is typically .005" less than chamber GO gauges so cases sized with the shellholder against dies bottom will have a few thousandths less headspace than chambers with GO gauge headspace.

Partial full length sizing happens when the die is set to size part of the case neck. This reduces case body diameters a little and usually moves case shoulders forward a few thousandths. Bolts usually bind up and require more force to close into battery as case headspace is typically about .001" greater than chamber headspace.

Neck sizing:

Neck sizing is mostly done with neck sizing die and only fired case neck diameters are reduced. Some neck sizing dies also set shoulders back if so adjusted.

 

[fguffey]

when setting a full length die up to bump the shoulder , lets say .002" , I call this partial full length sizing

I do not bump the shoulder back because it is impossible to bump the shoulder back, and; the only press that bumps is the cam over press.

When sizing I size my cases to minimum length/full length size. When sizing to a length longer than minimum length I back the die off. I am the only reloader that have cases that have resistance to sizing. When sizing a case I adjust the die in the press to assure the press has the ability to overcome the cases ability to resist sizing.

And how does a reloader do that? For me it is a matter of the press winning or the case winning. If I adjust the die to the shell holder with a 1/4 additional turn the die contacts the shell holder when the case is sized to minimum length. If the case has more resistance to sizing than the press can overcome there will be a gap between the bottom of the die and top of the shell holder.

Many years ago I adjusted the die off the shell holder with a feeler gage. There were times I used a .001" thick feeler gage, other times I used a .003" thick feeler gage. I have one chamber that requires me to adjust the die off the shell holder .014" because the chamber is .016" longer than a minimum length/full length sized; that would be the same as being .011" longer than a go-gage length chamber from the datum to the bolt face.

F. Guffey

 

[chop house]

You have to care what the diameter is otherwise if the shoulder angle is off you will have an error - I guarantee....

yep

and also both round and concentric, might add

 

[ireload2]

We are well aware of your inability to learn how shoulders are moved.
Perhaps you should stick with case designs that have NO shoulders.

I do not bump the shoulder back because it is impossible to bump the shoulder back, and; the only press that bumps is the cam over press.

When sizing I size my cases to minimum length/full length size. When sizing to a length longer than minimum length I back the die off. I am the only reloader that have cases that have resistance to sizing. When sizing a case I adjust the die in the press to assure the press has the ability to overcome the cases ability to resist sizing.

And how does a reloader do that? For me it is a matter of the press winning or the case winning. If I adjust the die to the shell holder with a 1/4 additional turn the die contacts the shell holder when the case is sized to minimum length. If the case has more resistance to sizing than the press can overcome there will be a gap between the bottom of the die and top of the shell holder.

Many years ago I adjusted the die off the shell holder with a feeler gage. There were times I used a .001" thick feeler gage, other times I used a .003" thick feeler gage. I have one chamber that requires me to adjust the die off the shell holder .014" because the chamber is .016" longer than a minimum length/full length sized; that would be the same as being .011" longer than a go-gage length chamber from the datum to the bolt face.

F. Guffey

 

[Bart B.]

Here's a belted case 3/4ths the way towards becoming a 300 Win Mag one.

Where does its shoulder start forming by the next die before it's at position C (SAAMI spec from case head) when the case is ready to be trimmed to length?

Position A B C D or E ?

 

[M-61]

I do not bump the shoulder back because it is impossible to bump the shoulder back, and; the only press that bumps is the cam over press.

fguffey: Just read your sentence carefully. "it is impossible to bump the shoulder back......." That should end it HOWEVER you then add "the only press that bumps is the cam over press."
So where are you? Impossible to bump BUT with a cam over you can. You have a choice to make here.

 

[dmoran]

Regardless of fguffey's refusal to reply to proof, and regardless of how he tries to mislead the forum, here again is just one example that shoulders do move:

Not only did the shoulder move in position a 0.100", as clearly seen by the case marks, it also moved in shoulder angle <> from 30-degrees to 40-degrees.

@fguffey often states: "I am the only one".... and I suggest to let him be just that !.!
Donovan

 

[dmoran]

fguffey's shoulders don't move....​

 

[fguffey]

Where does its shoulder start forming

A, B, C nor D is a standard. I am a case former, I form cases from cylinder brass. That means nothing to anyone on this forum but I start by determining the distance from the datum/shoulder to the case head in thousandths. A reloader that starts forming that case in the finish chamber is going to form some ugly cases because of dents and creases.

I start with short forming dies, again my favorite forming dies are short forming dies because of utility.

F. Guffey

 

[Milo 2.0]

A, B, C nor D is a standard. I am a case former, I form cases from cylinder brass. That means nothing to anyone on this forum but I start by determining the distance from the datum/shoulder to the case head in thousandths. A reloader that starts forming that case in the finish chamber is going to form some ugly cases because of dents and creases.

I start with short forming dies, again my favorite forming dies are short forming dies because of utility.

F. Guffey

Do you ever put reloading seminars on? You have a whole forum here who would like to learn.

 

[ttfreestyle]

Do you ever put reloading seminars on? You have a whole forum here who would like to learn.

Or a book we can buy , but then you wouldn’t be THE ONLY ONE that knows.

 

[tmwinds]

Regardless of fguffey's refusal to reply to proof, and regardless of how he tries to mislead the forum, here again is just one example that shoulders do move:

Not only did the shoulder move in position a 0.100", as clearly seen by the case marks, it also moved in shoulder angle <> from 30-degrees to 40-degrees.

@fguffey often states: "I am the only one".... and I suggest to let him be just that !.!
Donovan

Think about it. Did you really move the shoulder. I would be more inclined to say a new shoulder was formed. If the shoulder was moved, what replaced it and where did it come from? I'm starting to understand fguffey. Should I seek help?