Some cases hard to chamber, most aren't- what's going on?

[Ledd Slinger]

Thanks for all the replies.

I understand the thinking behind the "run it through a full length sizer" argument but this does not answer the basic question- where/what is the difference?

If sizing now is producing cases that have the same OAL, same neck ID and OD, same shoulder bump, same body diameter, same rim thickness etc, than what will running them through a full length sizer do?

When run through the full length sizer, theoretically the cases will be sized correctly and fit better correct?

Where is the difference? What measurement will be different?

which part of the body are you measuring?
The key spot to measure is the body of the case just above the rim. Nothing except for a full length sizing die will get that portion of the body back into spec. If your bases are a little wider than they should be, they will chamber tight until run through a FL sizing die.

 

[bigedp51]

mattri

If the cartridge case does not have equal case wall thickness the case will expand more on the thin side of the case, and this may be where your cases are rubbing.

The advantage of full length resizing is the body of the case is reduced in diameter and the body of the case will not rub the chamber walls. Not only can a neck sized case rub your chamber walls the bulged side of the case can also cause the bullet to be misaligned with the axis of the bore.

Basics: Resizing - Case Dimension Changes
by Germán A. Salazar
http://riflemansjournal.blogspot.com/2010/06/basics-resizing-case-dimension-changes.html

Reloading: Indexing Cases
by Germán A. Salazar
http://riflemansjournal.blogspot.com/2010/11/reloading-indexing-cases.html

Reloading: Audette Case Checking Method
Checking Case Wall Concentricity
by Germán A. Salazar
http://riflemansjournal.blogspot.com/2009/07/reloading-audette-neco-case-checker.html

This expansion of the thin side of the case is greatly magnified when shooting thin commercial cases in larger diameter military chambers, AKA the warped banana shaped case.

 

[Albany Mountain]

Is this chambering issue with the bullets in the case or are the cases empty??

 

[Patch700]

Thanks for all the replies.

I understand the thinking behind the "run it through a full length sizer" argument but this does not answer the basic question- where/what is the difference?

If sizing now is producing cases that have the same OAL, same neck ID and OD, same shoulder bump, same body diameter, same rim thickness etc, than what will running them through a full length sizer do?

When run through the full length sizer, theoretically the cases will be sized correctly and fit better correct?

Where is the difference? What measurement will be different?

Mr. fguffey in his way has given the answer... A case that will chamber properly WILL be different dimensionally from one that will not chamber smoothly... The difference is the measurements between the two cases and that will be up to you to measure.

If you have a known case that will chamber nicely and know the key measurements for that case then you are halfway there... If the shoulder datum is the same between the good case and the problem case then obviously that is not the problem.

If you measure the diameter of the cases just below the shoulder body junction and they are the same then obviously that is not the problem.

If you measure the base of the cases .200" up from the groove and those measurements are the same then that is not the problem.

Keep in mind you are dealing with .001 to .0005" being the difference between a case that will chamber nicely and one that wont with respect to these three measuring points.

These 3 points should be measured in conjunction with the obvious such as oal and neck diameter etc.

It is a series of deductions

Good luck.

 

[bigedp51]

If you measure the diameter of the cases just below the shoulder body junction and they are the same then obviously that is not the problem.

If you measure the base of the cases .200" up from the groove and those measurements are the same then that is not the problem.

Keep in mind you are dealing with .001 to .0005" being the difference between a case that will chamber nicely and one that wont with respect to these three measuring points.

These 3 points should be measured in conjunction with the obvious such as oal and neck diameter etc.

It is a series of deductions

Good luck.

And all this was covered in the links I posted previously and they even have pictures. :
If posters would read more than Mr. fguffeys postings we wouldn't have redundant postings.

Basics: Resizing - Case Dimension Changes
Resizing - Case Dimension Changes
by: Germán A. Salazar

Key Dimensions
The four key dimensions that must be resized properly in order to ensure proper chambering and extraction are:

Base to cone
Base diameter
Shoulder diameter
Case length

http://riflemansjournal.blogspot.com/2010/06/basics-resizing-case-dimension-changes.html

"Those who fail to read history are doomed to repeat it"

 

[Ledd Slinger]

bigedp51, why are you posting that link ^^^ again? ;D

 

[bigedp51]

bigedp51, why are you posting that link ^^^ again? ;D

Because sometimes you have to be redundant to stop redundancies. :

People should read all the postings and not repeat what has already been posted.

Signed
Attila the Hun

 

[CatShooter]

When run through the full length sizer, theoretically the cases will be sized correctly and fit better correct?

Where is the difference? What measurement will be different?

No... when run through a FL sizer or Body die, the case will be smaller and shorter (in headspace) than the chamber... so you are starting all over again, along with the case stretch that comes with it.

 

[noload]

[

If sizing now is producing cases that have the same OAL, same neck ID and OD, same shoulder bump, same body diameter, same rim thickness etc, than what will running them through a full length sizer do?

When run through the full length sizer, theoretically the cases will be sized correctly and fit better correct? ]

Its obvious the cases are not sized the same or they would not act differently. Look for dimension differences, or scratches on a shinny case, most case problems will be caused from a large base diameter or the shoulder not bumped enough.

 

['Freak]

You say you’ve looked ‘bout everywhere else except I don’t recall any mention of having checked for the banana thing or concentricity at a couple different points along the case body and on the neck. If the shoulder isn’t crowded then could be there’s a wobble about the middle of the few doing the rubbing.

 

[fguffey]

5) The seated bullet and cartridge runout of loaded rounds. The accuracy of any firearm is determined -- and limited -- by the quality of the ammunition shot in it. The effect of imperfections in ammunition is cumulative; each flaw adds to the influence of all others. Precision shooters spend much time and effort "uniforming" cartridge cases, using advanced techniques to eliminate variation. Yet until recently, one of the most important of these variations has not been susceptible to detection by any device readily available to marksmen.

And all this was covered in the links I posted previously and they even have pictures. :
If posters would read more than Mr. fguffeys postings we wouldn't have redundant postings.

http://www.neconos.com/details.htm

Redundant: Neco does not agree with the Violin and or punch bowl fitting of a case, something like a peanut with hull or a hand me down short, it fits only were it touches.

Then there is bump, it is always .002", there is nothing about .002" that can be described as a peanut with hull in a punch bowl or the closing of a violin case.

It is impossible for reloaders to accept the case has resistance to sizing, some cases have more resistance to sizing than others. When sizing the press must have the ability to overcome the cases ability to resist sizing.

Some times the case wins, other times the press wins. The reloader is advised to purchase another tool, the best tool I have for cases with resistance to sizing is case lube. I have cases that can not be sized with the best of lube and the best of dies. When comparing the fired cases with new factory unfired cases I know before I start sizing the cases is a waste of time and hard on the equipment.

F. Guffey

 

[/VH]

mattri,

Have you tried re-indexing either a case that chambers or one that doesn't to see if that affects the outcome? If it does, I'd expect that maybe your chamber is not concentric.

 

[mattri]

Have checked the "banana" effect by re-indexing cases as mentioned, no effect.

 

[/VH]

Well then; have you been having sex in the middle of the day?

.............Oh I just remembered...........that's supposed to make it rain! Please forgive me.

I don't know what is causing your issue but I expect it must be some degree of 'nannerism'. I will say that I prefer FL sizing and don't run into the issues that I did when I was neck sizing and I still get very good life from my brass, especially with custom FL dies.

I hope you get it figured out and let us know what is causing it.

 

['Freak]

‘Re-indexed’ would show if ‘banana’ were due to error about the chamber. Spinning the brass on a concentricity gauge could tell you a good bit more.

 

[halfmoanut]

It is in the chemistry of the brass, I have a tool that measures the shoulder bump with a .0001 and you can see the difference. I put the longest together and the shortest together and keep checking after each firing after about 5-6 firings they seem to even themselves out, in other words they settle into a stretch or not so much stretch pattern I can also see it by trimming every firing, and some seem to not settle. If you work day in and day out with a measuring tool of .0001 you will become accurate, if not you can easily be off by .0005 and that is enough to feel the difference with your stripped bolt. Keep em segregated,shoot em segregated and you will know which ones shoot best in your chamber but it takes time along with everything else when achieving precision accuracy.

 

[mattri]

Good news and bad:

The full length sizing die "fixed" the problem, cases chamber uniformly now. Shoulder bump is consistent, accuracy is the same.

Never found a measurable difference in cases.

 

[Concha]

If you measure the diameter of the cases just below the shoulder body junction and they are the same then obviously that is not the problem.

I am betting on this being the issue. A full length sizing will always fix this problem.

Big ed. The thing is, you are often correct. You information has helped many new reloaders. But you often use a know it all attitude and get touchy if others do not acknowledge your time and efforts to be the final word on a topic. After a while people believe you are just regurgitating the same old stuff someone else taught you. That's why you use someone else's GIF's and regularly link to someone else's writings. I like you best when you take the time to be a part of the discussion. Don't be a Jim Baker from Savage Shooters.

 

[LHSmith]

Good news and bad:

The full length sizing die "fixed" the problem, cases chamber uniformly now. Shoulder bump is consistent, accuracy is the same.

Never found a measurable difference in cases.

Exactly.....very difficult for the average reloader to ACCURATELY measure to one thousandths with average reloading tools. Measuring accurately below 0.001"is a learned skill even with top end instruments.

 

[bigedp51]

If you measure the diameter of the cases just below the shoulder body junction and they are the same then obviously that is not the problem.

I am betting on this being the issue. A full length sizing will always fix this problem.

Big ed. The thing is, you are often correct. You information has helped many new reloaders. But you often use a know it all attitude and get touchy if others do not acknowledge your time and efforts to be the final word on a topic. After a while people believe you are just regurgitating the same old stuff someone else taught you. That's why you use someone else's GIF's and regularly link to someone else's writings. I like you best when you take the time to be a part of the discussion. Don't be a Jim Baker from Savage Shooters.

Concha

I see by your bio that you are from Texas so I have a joke for you..............

How do you bury a six foot Texan?

You beat the crap out of him and put him in a match box.

Signed
Attila the Hun.

P.S. A picture is worth a thousand words, and when I link to more experienced shooters it is to prove it isn't just "MY" opinion. Now grow up and if you do not like my postings then don't read them.

If you can't trust the late Jim Hull of Sierra bullets and Kevin Thomas of Team Lapua USA and a picture "borrowed" from another website. Then no information will ever make you happy. :