sure enough, shoulder moves forward.....

A

alinwa

oft dis'd member
It's often been postulated that when setting up the resizing die if you set the die just high enough to not touch the shoulder, f'rinstance the guys who want to "neck size only" using a FL die, that the shoulder actually bulges FORWARD until you get down far enough to reset it.

Yesterday I took the time to start 10 thou high and go down, down down a thou at a time until the shoulder moved.......

Sure enough, as I got down to within about four thousandths the shoulder started to move forward (measuring with a 'gizzie' or barrel stub tool) and bulged almost two thou before contacting the die and moving back on the large case I was using. I also tried the case in the rifle's chamber thruout the process and the case tightened up to refusal two steps before I could measure it..... in other words the shoulder started oozing forward before I could see it on a caliper.

This particular case was a large one spec'd with ten thou/inch taper and 35* shoulder.

al
 
Yup, the first time I ever heard of "partial resizing" was in a Speer Manual maybe 25 years ago or more. Being willing to try anything once I did, and found that by the time the case necks were sized enough to hold a bullet there was NO WAY to chamber the case. Can't remember what the case was, but came to the conclusion right then that it was one of the dumbest ideas I'd ever heard of. I've read it published elsewhere, and wonder what sorts of cases, chambers, pressures, &c. were involved. Alternatively what was being smoked or imbibed by the author(s).

I've found that cases sized in a properly adjusted FL die in a properly cut chamber will produce accuracy as good or better than those sized in a NS die, AND all the cases will chamber easily and without resorting to a cheater bar on the bolt handle.
 
Yep, did that one several years ago...best way to get a handle on what is taking place.

With old style ,smaller angle, shoulders, it is sometimes best to FL to zero bump, compared to a one time fired case with a warm load, so that the case doesn't take a run at the chamber shoulder when the primer goes off. With some body diameter reduction, the bolt closes fine.
 
What I found

When I realized all my cases needed to be re-sized smaller than any of the Full length dies I have, I, out of desporation took my 308 Small Base die and ran it over my FL resized 30 BR cases. I found the area just below the shoulder and the web area were both too big, causing erratic bumps and a clicking bolt. Reizing with the small base die pushes everything forward so that I had to bump the shoulder back.

Something else I found was that the OAL of the cases was too long then to allow the bolt to close, requiring trimming the necks back. My question now is WHY HAVEN'T DIE MAKERS FIGURED THIS OUT BEFORE NOW? It would be real easy to make every full length die to mininum size in the beginning. Those folks who throw away cases simply because they get tight could save themselves a lot of money and time by using the cases they put so much time into, for a lot longer. I bought just over 500 used 30 BR cases last Summer CHEAP and re-habbed them over the winter. I only had 5 or 6 culls due to loose primer pockets from the cases having been fired with too hot a load. It was obvious when the case wouldn't fit into the shell holder on the press. I have enough good cases now to last me out :)
 
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Pete,
That is why I have started with sized cases and ordered reamers that produce the desired clearance...much cheaper than a custom die.
Boyd
 
Pete,

Interesting post. Again our experience matches. As you know I shoot more wild cat caliburs than most. Getting the right die set up is often and issue with these strange cases I use. The procedure I am now using that seems to work quite good when I have good fitting dies is:

Mechanical case form,
Fire form and check dimensions. Trim and tune up as needed.
Fire form and check dimensions, Usually the dimension on the cases are true after three shots.
Anneal and full length and small base form if needed.

Depending on how good my chambers and dies are I usually shoot five to seven time and then clean in the shaker, anneal, full length size, small base size if needed and trim AOL if needed. With this process the cases usually last 40 or 50 cycles. Case failure usually starts to show up as a hairline burn crack around the base of the case about 1/3 of the height up to the shoulder. If you keep the cases clean and pay attention you will see a hairline crack before there is a failure. I all ways start out with 50 rounds of cases in a box and I keep them together till they are done. As you know I also keep quite detailed cycle and measurement records on all of my cases. Over the years this history has shown me a lot about what works and what does not.

Usually I only neck size except after annealing. I am thinking with the right die the FL sizing may be better. Problem is I hate the mess with the bullet lub and I have found it to be necessary. Any suggestions.
 
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Yes,

Especially after annealing when the are more soft. Using a shoulder bump die without very good lubrication will often cause the shoulder bulge. This is also a problem anytime I am forming wild cat cases that require the shoulder be moved back. The Red Rooster Laboratories CFL -56 Case Forming Lubricant is the best I have found. I got a small jar from Graf and Sons years ago and still have 60% of it left. A little goes a very long ways.

Usually if you get a case bulge you can work it out if your are careful about the process. Sometimes it takes three die steps to fix it. Oversized first, then FL die and then a small base or undersized die. All done with lubrication.

What has caused your bulges?

Octopus
 
L. E. Hanson said:
High pressure loads.

I find that I must regularly bump back the shoulders on my 6PPC and 22PPC-.100 short cases in order to allow them to chamber easily. In my case (no pun intended) it is the case shoulders that tend to prevent easy cartridge chambering.

LE Hanson
Click to expand...

Yes, but don't assume that's always the "case". In my early days I carried that same assumption to a head separation by doggedly pushing the shoulder back trying to fix some tough cases. Experience since, with too many barrels to count, showed me that expansion in the case web area is just as likely.

The competition shooter will need the tools to correct both issues but when head expansion is determined new cases should be in the near future. Unless you're winning every match with the current load, some consideration should also be given to reducing the powder charge. Difficult champering in a benchrest match is the same as using a single shot in a rapid fire event - you can't get your shots off in the allotted time. Certainly, you can shoot five shots and more in seven minutes with the most difficult cases but the truth is you get seven minutes to choose which 15 second period you're gonna actually "do it" in.
 
W/resp to the understanding of die makers(especially custom), or to factory gun designers, or to reloaders who seperate their sizing actions, there is in no way a 'discovery' here..

FL sizing is not for improving accuracy.
It's not even a shortcut.
It's merely an inevitable requirement accepted, to run extreme pressure loads, with poorly designed cases, and ugly high clearances.
 
mikecr said:
W/resp to the understanding of die makers(especially custom), or to factory gun designers, or to reloaders who seperate their sizing actions, there is in no way a 'discovery' here..

FL sizing is not for improving accuracy.
It's not even a shortcut.
It's merely an inevitable requirement accepted, to run extreme pressure loads, with poorly designed cases, and ugly high clearances.
Click to expand...

huhh?
 
It's common, and predictable.
I could demonstrate the opposite with a well designed case, tight clearances, & rational loads. This, using Wilson NS & Redding body die.

If the purpose of this is to highlight a FL sizing struggle to partial neck sizing, then I can follow that.
FL dies are not a good choice for partial neck sizing.
But then, there is also nothing good in sizing the full length of necks.

I can think of nothing good about FL sizing, other than you gotta do what ya gotta do.
But technically, anyone could choose to avoid that position.
 
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mikecr,
If I may, let me disagree, hopefully without being disagreeable. While there are many cases where the die brass and chamber are not well matched, it is not always the case. I hardly think that one would describe cases such as the ppcs and BRs as being poorly designed, and the chambers that they are typically shot in are usually quite carefully dimensioned. Also, the custom dies that are used for these calibers hardly move the brass at all. Accuracy is a composite of multiple factors. As you are undoubtedly aware, in both short range and long range benchrest, there is often some advantage to be had by shooting as rapidly as possible, so that all of the shots are fired in as close to the same wind as possible. Additionally, it is always desirable that a rifle not rock excessively in its sand bags as the bolt is cycled during reloading. Tight cases favor neither. As to high pressures, the reason that they are used, is that they work. Competition is like a race, in that certain things are knowingly sacrificed so that a more important goal may be reached. On the other hand, I have a friend that almost never FL sizes his .223 cases, that are shot in a bolt action varmint rifle. He gets the performance that he needs at low enough pressure, so that neck sizing, with a Lee Collet Die, works just fine. As I mentioned in my earlier post, several of my friends and I have avoided problems with chamber and die dimensions by designing reamers around well used, FL sized cases. The results have been excellent.
Boyd
 
I agree with you completely Boyd.
And everything you just said supports my contentions.

You CHOOSE to run extreme pressures -for accuracy.
You CHOOSE to oversize cases -for ease of bolt turn.
And you CHOOSE to FL size -because it's the only way you can run with the first two choices.

If it happened that running moderate pressures produced better groups, which may have been in the past, then IMO competitors would choose FL sizing far less.
They would instead focus on very precise ammo that is sized more conservatively. It's just my opinion. I can bump shoulders without squishing case bodies like a tube of toothpaste. I can size necks every which way but loose without affecting ANYTHING else. I can do both at the same time. I NEVER FL SIZE.

I guess all I'm sayin is that these are choices in the end, and that any price to pay for them -is nothing new.
 
I'm sure I've mentioned this several times before because it fits and I think it's mildly funny. My friend and I entered a fishing tournament that had a 12 inch minimum. We only caught one fish that was just under 12 inches. My friend, not wanting to be "skunked", stepped on it and made it legal length for weigh in. Of course, we weren't the first to weigh and quietly slipped away when the first guy came in at something close to a ton. Most anything will get longer if you squeeze it down in the middle.

Pretty sure, not completely, that I can agree with mikecr's comments within the envelope he drew. There are no tolerances or case designs that will prevent tight cases given enough pressure to cross the line. Said line is dictated by factors beyond my understanding and said understanding was deemed unnecessary a long time ago.
 
I have been reading this thread with interest. I have an older 700 BDL Remington Varminter in 22-250. When I try to full length resize my cases, it seems the further down I screw the die the tighter the shells seem to fit the chamber? I'm not a novice here, I have changed full length dies 3 times trying to fix this problem, currently using Redding Type S bushing die. I have many bolt action rifles and have no problem setting up a die to match the chamber. I seem to have to screw my die down really far and can feel a lot of push when I size a case to get the cases to chamber half decent, but the last time at the range I had splitting above case head, real bummer so I know that means shoulder pushed back too far. Should I get a custom die made for this gun?
Dave T
 
Ok guys I'm going to try and explain what I found using a GIZZY to measure my shoulder bump, after they were fired I put the case in the gizzy and got a wierd reading. So I neck sized one, remeasured and now its right. You may want to make sure your neck is not giving you a false reading before you try bumping the shoulder or you will end up with case seppuration.

Joe Salt
 
Maybe it's old age accompanied by lack of attention, but the only time I ever found that FL sizing shortened case life was in a Ruger 77V in .22-250 about 40 years ago. That rifle had a chamber that was so oversized that if cases were FL sized the heads would fall off after three or four firings with mild loads, 50-53 gr bullets at 3500-3600 fps. It also produced better accuracy with new or FL sized cases, but to ensure any sort of case life cases had to be neck sized. My live varmint rifles, all of which have custom barrels except one, don't seem to care whether or not cases are FL sized with the shoulders bumped 0.001-2" or neck sized. However, if the cases are FL sized I KNOW that when I'm out shooting prairie dogs all cases will chamber. Nothing is quite as much fun as having to trudge back to the truck to collect the cleaning rod to (hopefully) remove the stuck round from the chamber. My loads for these rifles tend to be on the warm side.

The one live varmint rifle that still has a factory barrel on it is a CZ 527 in .222 Rem. Even firing loads that are some warmer than what the manuals show for the .222 pressures appear moderate (primers well rounded on the edges and one finger bolt lift), cases that are neck sized do not produce accuracy equal to new or FL sized cases. When these cases are FL sized in an RCBS Partner press only slightly more effort is required than if the cases are neck sized, so it doesn't seem that the chamber is much too large (fired cases haven't been measured because of my laziness and lack of ability to measure cases with a sufficient level of accuracy except for length and head diameter). I imagine that with the pressures I'm running in this little rifle cases could be neck sized many many times before they'd need FL sizing, BUT the accuracy wouldn't be there unless I changed the barrel. Being cheap I won't change the barrel until or unless it shows a need.

I'm not sure that my observations prove anything, but if loads at moderate pressures worked as well as those at higher pressures I'm sure that the winning Benchrest shooters would be firing 3100-3150 fps loads in their 6 PPC's. If lower velocity loads showed less wind deflection and were accurate then I'm sure we'd all be using lower velocity/pressure loads.
 
DaveT said:
I have been reading this thread with interest. I have an older 700 BDL Remington Varminter in 22-250. When I try to full length resize my cases, it seems the further down I screw the die the tighter the shells seem to fit the chamber? I'm not a novice here, I have changed full length dies 3 times trying to fix this problem, currently using Redding Type S bushing die. I have many bolt action rifles and have no problem setting up a die to match the chamber. I seem to have to screw my die down really far and can feel a lot of push when I size a case to get the cases to chamber half decent, but the last time at the range I had splitting above case head, real bummer so I know that means shoulder pushed back too far. Should I get a custom die made for this gun?
Dave T
Click to expand...

If I understand your problem (splitting above the case head) correctly the cases are splitting longitudinally (head toward shoulder) rather than circumferentially, I doubt that a custom die would do much more than cost money that might be better spent on a new barrel. In either case the chamber sounds like it's too large, and although a custom die may help a new barrel with a tighter chamber would be a better and more economical solution.

Factory chambers are cut fast and can be out of round, too large in diameter, or both together. Not much that can be done without rechambering, and that is sort of a waste of time and money on a factory barrel IMHO.
 
NO NO I said, I had a couple that seperated at the head, circumferently (if there is such a word) not longitudinally.
 
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