Chamber and Saami- shoulder bump problem?

[ucsfl05]

Hey everybody,
Thanks again for all your help.
I was able to get to the range and zero, get some fired brass.
In order to set up my FL die- I'm following these instructions:
(Stripped bolt, plunger out, bolt close). The issue is that the bolt drops freely with my fired brass??!
How do I set the bump if its already falling on its own?


Thanks again

 

[nn8734]

Bolt gun? If so, Just bump it back .002 relative to the casehead to shoulder measurement of your fired brass.

Also virgin brass sometimes isnt 100% fire-formed until after the second firing

 

[918v]

Hey everybody,
Thanks again for all your help.
I was able to get to the range and zero, get some fired brass.
In order to set up my FL die- I'm following these instructions:
(Stripped bolt, plunger out, bolt close). The issue is that the bolt drops freely with my fired brass??!
How do I set the bump if its already falling on its own?


Thanks again

You take your longest fired case and set the bump to that dimension.

 

[ucsfl05]

Guys, there is a lot of hate happening on this thread. Please, please be nice to each other. I doubt these things would be said if we were hanging out together around a fire or at the bar. Thank you to those who have been patient with me and have given me advice.

 

[Im2bent]

 

[nn8734]

Guys, there is a lot of hate happening on this thread. Please, please be nice to each other. I doubt these things would be said if we were hanging out together around a fire or at the bar. Thank you to those who have been patient with me and have given me advice.

My apologies. Normally i dont get into it with folks (at least not outside the Pit) and didnt mean to derail your thread.

Ill delete my unsavory posts. Perhaps @Baron23 can do likewise but its up to him

 

[ucsfl05]

My apologies. Normally i dont get into it with folks (at least not outside the Pit) and didnt mean to derail your thread.

Ill delete my unsavory posts. Perhaps @Baron23 can do likewise but its up to him

No need to apologize! You were standing up for me. Some people are less courteous and automatically assume that I'm ignorant or cant read and post useless comments that don't promote any camaraderie or help those who are somewhat new to the sport feel welcome.
@Baron23, you probably need to change your signature line because you, sir, seem to be full of resentment.

 

[Baron23]

Perhaps @Baron23 can do likewise but its up to him

Also done. Tempest in a tea pot, is all.

@Baron23, you probably need to change your signature line because you, sir, seem to be full of resentment.

You don't know me well enough to make this statement

Cheers

 

[ucsfl05]

Also done. Tempest in a tea pot, is all.


You don't know me well enough to make this statement

Cheers

It is true that I don't know you. Im simply observing that your behavior/attitude seems incongruous with your motto based on your comments and word choices.

 

[spife7980]

Damn it, I missed all the drama.

The issue is that the bolt drops freely with my fired brass??!

If all of your fired brass lets the bolt fall freely then its not fully formed. Run a piece of brass up into the die until the shoulders do move, then back it back out just a hair so that the base and neck get sized smaller but the shoulders dont move back any.

Just make sure that its actually falling freely.

 

[ucsfl05]

It was juicy. Thank you @spife7980 - this is exactly the information I needed. You have been extremely patient with me and helpful. I really appreciate you!

 

[Average guy]

Damn it, I missed all the drama.


If all of your fired brass lets the bolt fall freely then its not fully formed. Run a piece of brass up into the die until the shoulders do move, then back it back out just a hair so that the base and neck get sized smaller but the shoulders dont move back any.

Just make sure that its actually falling freely.

Sage like advice sir

 

[Taylorbok]

Does anyone know if this is a shouldered pre fit or barrel nut?
I'm, assuming its a barrel nut. My take on what is happening here is you have the headspace set at a slight crush on the factory brass. Which is already under saami spec and now you fire it and its even shorter. Then you set up the sizing die and as it sizes the body the brass needs to go somewhere and it actually pushed the shoulder forward, past what your chamber can accept.

 

[ucsfl05]

Does anyone know if this is a shouldered pre fit or barrel nut?
I'm, assuming its a barrel nut. My take on what is happening here is you have the headspace set at a slight crush on the factory brass. Which is already under saami spec and now you fire it and its even shorter. Then you set up the sizing die and as it sizes the body the brass needs to go somewhere and it actually pushed the shoulder forward, past what your chamber can accept.

It is a shouldered pre-fit. Proof barrel, impact 737R action
this is a good thought as well....thank you

 

[Taylorbok]

It is a shouldered pre-fit. Proof barrel, impact 737R action
this is a good thought as well....thank you

Either the die is bad or chamber is short.
measure with your comparator. (.375 hole) the base to shoulder on a new piece of brass, a fired piece and a resized piece.

 

[ucsfl05]

So, gents!
I finally figured out what the issue was. After playing with the shoulder bump and having some cases that still did not chamber despite plenty of bump, I realized that the dimension that was out of spec was the base of the case. It's not being sized by the die and anything over .471 doesn't let the bolt close.

I ordered a Whidden die and am waiting for the SAC modular sizing die to become available.

 

[r.tenorio671]

So, gents!
I finally figured out what the issue was. After playing with the shoulder bump and having some cases that still did not chamber despite plenty of bump, I realized that the dimension that was out of spec was the base of the case. It's not being sized by the die and anything over .471 doesn't let the bolt close.

I ordered a Whidden die and am waiting for the SAC modular sizing die to become available.

....this is why I prefer the Sheridan Slotted gauges, it allows you to see where a casings issue lies, i.e., the base reduction, the shoulder bump and trim length....all in a single glance. The gauges are cut with a SAAMI chamber reamer (at MIN spec) so it ensures cases that fit in it will fit a properly cut SAAMI chamber. I would imagine if there is enough demand, I suspect Sheridan could add 6GT gauges since it is a SAAMI spec cartridge.

...sample of my 6ARC gauge that was used to validate my conversion of 6.5 Grendel cases for my initial sizing die setup before committing components to loading, YMMV.

 

[ucsfl05]

....this is why I prefer the Sheridan Slotted gauges, it allows you to see where a casings issue lies, i.e., the base reduction, the shoulder bump and trim length....all in a single glance. The gauges are cut with a SAAMI chamber reamer (at MIN spec) so it ensures cases that fit in it will fit a properly cut SAAMI chamber. I would imagine if there is enough demand, I suspect Sheridan could add 6GT gauges since it is a SAAMI spec cartridge.

...sample of my 6ARC gauge that was used to validate my conversion of 6.5 Grendel cases for my initial sizing die setup before committing components to loading, YMMV.

Damn, those are cool. Can’t wait for them to make a 6gt!

 

[spife7980]

Damn, those are cool. Can’t wait for them to make a 6gt!

You don’t need that shit. Just use calipers and you’ll save yourself all this trouble.
Had you measured the base like was asked in post 7 you would have solved it long ago.

 

[Feniks Technologies]

....this is why I prefer the Sheridan Slotted gauges, it allows you to see where a casings issue lies, i.e., the base reduction, the shoulder bump and trim length....all in a single glance. The gauges are cut with a SAAMI chamber reamer (at MIN spec) so it ensures cases that fit in it will fit a properly cut SAAMI chamber. I would imagine if there is enough demand, I suspect Sheridan could add 6GT gauges since it is a SAAMI spec cartridge.

...sample of my 6ARC gauge that was used to validate my conversion of 6.5 Grendel cases for my initial sizing die setup before committing components to loading, YMMV.

Would likely do nothing at all to identify potential sticky cases due to sizing issues. Most of the time, the brass fits in the chamber fine.

They are cool for sure and really good visual tools.

But not really gonna help the OP’s situation except in the most extreme situation. Which is typically obvious and had he taken advice thar was giving immediately in the thread, he would have known immediately.

 

[smoothy8500]

Damn, those are cool. Can’t wait for them to make a 6gt!

Sheridan gauge is like using a cutaway pistol to see why reloads jam...

 

[r.tenorio671]

Would likely do nothing at all to identify potential sticky cases due to sizing issues. Most of the time, the brass fits in the chamber fine.

They are cool for sure and really good visual tools.

But not really gonna help the OP’s situation except in the most extreme situation. Which is typically obvious and had he taken advice thar was giving immediately in the thread, he would have known immediately.

...I don't disagree with this.

Assuming the OP had the proper tools (calipers. comparators and inserts) to measure his fired cases and the experience/knowledge to apply his findings to adjust his reloading process, he could have done so. My suggestion was based on the tool the OP used in the attempt to debug the issue. The benefit of the Sheridan tool is to create a loaded cartridge that WILL FIT in a SAAMI spec chamber so it CAN be fed/chambered and fired. That fired casing can then be measured to extract updated data to adjust one's load procedures. If the loaded cartridge can't be chambered, it can't be fired to blow the casing out to conform to the chambers dimensions so relevant data measurements can be obtained for subsequent reloading.

 

[Baron23]

Had you measured the base like was asked in post 7 you would have solved it long ago.

had he taken advice thar was giving immediately in the thread, he would have known immediately.

Too funny!

Well, except when I point it out...then I'm just being mean! haha

Glad the OP solved his problem and life is good again .

Cheers

 

[Mike Casselton]

Yes, a comparator. The issue with the plunk gauge is that you don’t know if it’s the shoulder or the base jamming you up.

Measure the base diameter, the shoulder diameter, the neck diameter with calipers and then the shoulder datum with calipers&comparator for both fired and sized brass. You answer is in the numbers.

I don’t have a 6gt to share my numbers with that. But it’s relative to your chamber that you need to worry about the fitment of.
View attachment 7834980

I see the problem, your shoulders are crooked and the base isn't level.

 

[Mike Casselton]

Sorry, you don't seem teachable . Wasted enough time on you . Don't let facts cloud your math .

I know you're no longer here to defend yourself, but to say there is one way, and one way only to do a job is asinine.

You say that using gauges is the only safe way. Bullshit.
Go buy 100 gauges and correctly measure them. You'll get 30-40 different numbers.
Which one is correct?

If you doubt the truth of the above fact, ask any gunsmith that's worth a shit and he/she will tell you how many they've had to buy to get a correct set.

There's 100 ways to skin the neighbor's cat. To say or think otherwise makes you the unteachable one.

Don't let your idea of facts cloud your ability to recognize actual facts.

 

[Mike Casselton]

Expensive tools are great as long as they work as advertised. Uh, and the individual knows how to use them.

With a caliper, a sharpie or scented candle and a deprimed 40 S&W case, I can get the exact information needed to ensure my brass fits properly in my chamber.

Smoke or sharpie the brass and use the pistol brass as a shoulder bump gauge. It works but takes more effort to do correctly.
The smoke/sharpie gives you a visual indication of what is being sized.

It might take a little more time and a bit more care, but the information ends up the same.

Write the before and after sizing numbers down on paper and as pointed out above, the problem will reveal itself.

What a lot of people overlook during die setup is the balloon effect that happens when your die setting gets very close to being correct.

To simplify it, just before you get correct shoulder bump, the body and web area is squeezed inward and upward.
Because the shoulder isn't touching the die it causes the body to actually balloon forward more than inward, thus giving the impression that your die needs to go much further down.

With the die set correctly, the web and body squeeze inward instead of upward. The shoulder is prevented from going forward and you get good brass as long as the die body can size the web area to the correct dimension.

Sorry for the broken way this is written, I'm at a basketball tournament and am trying to write this during time outs.

 

[nksmfamjp]

OP, you have heard a lot here. Does it make sense or are there more questions?

IME, you have to look at what is new and unchecked. I like the idea of prefits, but I think you need a GO gauge to really know where your chamber length is at.

Also, you may need a chamber cast to know the exact base dimension.

Last, it seems like you narrowed this to oversized case base on fired loads. Depending where that is at, the die may or may not fix it for you. Try a Redding or Forster die. If those are not ok, it needs to go back to the barrel maker. The chamber is possibly too tight. There are no dies that actually size the base. That is because it is too hard. The actual case base will crack a die cut to size the base. Now if you are talking about expansion at the 0.200” line, the die should size the case to SAAMI or just below.

I find a micrometer aligned with the edge of the measuring surface just above the extractor groove will measure the 0.200” line expansion well enough. Starting with fired, what does each die produce as a sized dimension?

Also, Wilson makes several gages. I’m guessing yours is not for fired brass.

 

[918v]

OP, you have heard a lot here. Does it make sense or are there more questions?

IME, you have to look at what is new and unchecked. I like the idea of prefits, but I think you need a GO gauge to really know where your chamber length is at.

Also, you may need a chamber cast to know the exact base dimension.

Last, it seems like you narrowed this to oversized case base on fired loads. Depending where that is at, the die may or may not fix it for you. Try a Redding or Forster die. If those are not ok, it needs to go back to the barrel maker. The chamber is possibly too tight. There are no dies that actually size the base. That is because it is too hard. The actual case base will crack a die cut to size the base. Now if you are talking about expansion at the 0.200” line, the die should size the case to SAAMI or just below.

I find a micrometer aligned with the edge of the measuring surface just above the extractor groove will measure the 0.200” line expansion well enough. Starting with fired, what does each die produce as a sized dimension?

Also, Wilson makes several gages. I’m guessing yours is not for fired brass.

Bullshit.

Dies are machined to whatever spec. That spec sizes the base of the case to under what it needs to be due to spring back. I have multiple small base dies that size the base below the original factory diameter of certain brass and that brass yields to the die.

 

[nksmfamjp]

Bullshit.

Dies are machined to whatever spec. That spec sizes the base of the case to under what it needs to be due to spring back. I have multiple small base dies that size the base below the original factory diameter of certain brass and that brass yields to the die.

If you make a sizing die too small at the base, it will crack. Call any die maker.

 

[918v]

If you make a sizing die too small at the base, it will crack. Call any die maker.

That’s not what you said. What you said was:
“There are no dies that actually size the base. That is because it is too hard. The actual case base will crack a die cut to size the base.”

and that is not true.

I have a number of small base dies that size all the way down to the base and can further reduce the original base diameter. The trick is not to size down too much all at once.

The OP needs to go below .471” and that is not an issue at all with the right die.

 

[918v]

So, gents!
I finally figured out what the issue was. After playing with the shoulder bump and having some cases that still did not chamber despite plenty of bump, I realized that the dimension that was out of spec was the base of the case. It's not being sized by the die and anything over .471 doesn't let the bolt close.

I ordered a Whidden die and am waiting for the SAC modular sizing die to become available.

What is your fired case diameter?

 

[ucsfl05]

an update- I got a SAC die and it fixed everything. The hornady die was not sizing the base of the case and this was the issue.
I cannot thank you all enough for helping me trouble shoot the issue.