Bumped Shoulders too much

[D.Camilleri]

I have been reloading for over 40 years, so I guess I am on the downhill slide of CRS. I had my sizing die set up (so I thought) to bump my shoulder back .0015 on my 338 RUM. I prepped and resized all of my once fired remington brass that I used to break in my new barrel last year. I loaded some shells with my pet load of 99 grs of RL33 and a 300 gr Berger OTM and headed to the range. I haven't shot the rifle since I had it Ceracoated last month. It shot like crap! I went back to the shop and double checked everything I had done. First I used a case comparator and found out that my shoulders were bumped back almost .010! They now measured the same as new Nosler brass, and the reason I haven't used the Nosler brass is because they are short to start with, so fire forming is necessary. So no I have a dilema, waste components to fire form all of this brass, or just start over with other brass. I hate to have to fire form so many rounds when I am trying to conserve my barrel life. Any thoughts?

Also, I grabbed my RCBS resizing die and ran a casing through it and it was perfect with a cam over. The redding die is also camming over, but is bumping the shoulder too much. I know I could buy a shell holder set and fine tune the die, but now I think I will just stay with the RCBS die. I obviously forgot what I was doing.

Also, I have some brand new Bertram brass and I have seated some bullets and found the brass didn't hold them even after resizing. The bullet pulls partially back out when retracting the casing. I have a VLD redding micrometer seating die.

 

[eklarsen]

I wish I knew what CRS is but I am sure I will find out...
In my opinion if you have to worry about burning out your barrel to the point of buying new brass and starting over you should just put that thing in the safe and call it a day. Shoot those bad boys to fireform and if you have to pony up for a new barrel in the future, well, that is just evidence of a well spent life

 

[velvetant]

CRS...cant remember sh@*

Pull all your bullets then neck up your cases,
then neck back down but just far enough to create a false shoulder.
Load and shoot

 

[Bullet bumper]

First off what kind of resizing die are you using ? You don't cam over if it's not required using a normal type die . If you use a lee collet die to neck size you can cam over .
Seems to me you need to forget I bumped .00xx and stick to resizing to fit the chamber . If the cases get tight resize until the bolt just closes nicely on the case and a few others and set the die at that point . If using a body die the ram should just run out of travel at that required setting not cam over .

 

[Gene]

Cam over means you are pushing the case in the die too far, causing shouder set back. You will not hurt the brass or your rifle by doing this, and brass will chamber smoothly. It creates excessive headspace. The only downside is that accuracy may suffer. As others have said, raise the die about one full turn, then lower it about 1/8th inch at a time until the shoulder sets back just enuf to chamber with the slightest resistance.

 

[Mikecr]

I used a case comparator and found out that my shoulders were bumped back almost .010!

IMO, a lesson to take from this is always verify what you're doing -while doing so (instead of finding out a harder way).

Every chamber, brass, case holder, press, and die are different,, even the lube type and amount vary results, so there is no rule of thumb that credibly applies for proper bumping. You creep into it, and verify it is correct, for every single case. Just get used to this, and it's no big deal.
Same with powder charging, primer seating, bullet seating, neck turning, etc..

 

[Edd]

Also, I grabbed my RCBS resizing die and ran a casing through it and it was perfect with a cam over. The redding die is also camming over, but is bumping the shoulder too much. I know I could buy a shell holder set and fine tune the die, but now I think I will just stay with the RCBS die. I obviously forgot what I was doing.

I use standard shell holders and place a shim on top of them to set the height I need for cam over.

 

[BountyHunter]

CRS...cant remember sh@*

Then there is the advanced stage called CRAFT = "Can't Remember a Fxxxing Thing"

 

[eklarsen]

Then there is the advanced stage called CRAFT = "Can't Remember a Fxxxing Thing"

That's right, I knew both of those but couldnt remember

 

[J E Custom]

I have been reloading for over 40 years, so I guess I am on the downhill slide of CRS. I had my sizing die set up (so I thought) to bump my shoulder back .0015 on my 338 RUM. I prepped and resized all of my once fired remington brass that I used to break in my new barrel last year. I loaded some shells with my pet load of 99 grs of RL33 and a 300 gr Berger OTM and headed to the range. I haven't shot the rifle since I had it Ceracoated last month. It shot like crap! I went back to the shop and double checked everything I had done. First I used a case comparator and found out that my shoulders were bumped back almost .010! They now measured the same as new Nosler brass, and the reason I haven't used the Nosler brass is because they are short to start with, so fire forming is necessary. So no I have a dilema, waste components to fire form all of this brass, or just start over with other brass. I hate to have to fire form so many rounds when I am trying to conserve my barrel life. Any thoughts?

Also, I grabbed my RCBS resizing die and ran a casing through it and it was perfect with a cam over. The redding die is also camming over, but is bumping the shoulder too much. I know I could buy a shell holder set and fine tune the die, but now I think I will just stay with the RCBS die. I obviously forgot what I was doing.

Also, I have some brand new Bertram brass and I have seated some bullets and found the brass didn't hold them even after resizing. The bullet pulls partially back out when retracting the casing. I have a VLD redding micrometer seating die.

Many of the new die sets don't require braking/caming the press over, because they are designed to go past minimum sizing. also some shell holders are different heights and can cause this problem.

My advice is to take a fired case and size it with the die backed off first, and remove the expander
button as to minimize over working the neck. Try it in the rifle and check the fit, Then slowly screw the die in checking the fit every time you increase the sizing until you feel a slight change.

All chambers are different so I size the brass to best fit the chamber and still allow chambering. I rarely have to actually bump the shoulder back on any cases unless it is a semi-automatic.

Bumping the shoulder only shortens case life and alters Head space. To much shoulder bumping can cause other problems and just recently a friend was showing signs of pressure with a known load that should not be a pressure load because the primer was moving back a few thousandths upon
firing and when the case came back and slammed the bolt face, it flattened the primer severely.

I have all the latest tools to compare cases but find that after over 50 years of loading I still find something different and have to go back to the basics to correct it. I have many different brands of dies and find that if most are set up correctly for the chamber to be fired that they are still good.

As mentioned by another poster, Once I have a set of dies set up correctly I try not to change anything. If I have several different rifles chambered in the same cartridge, I will simply slip a .001 or .002 shim under the case head to bump the shoulder and not alter the die for normal sizing.
After having the same problem I now include a shell holder in each die set to eliminate differences
in there height. (A .001 thousandths shim will rarely bump the shoulder .001 because of brass spring back, making it about perfect for my likes.

Being older, and having all of the malady's mentioned and a few more, I have to keep things simple to minimize problems and stay out of trouble.

Just the way I do it

J E CUSTOM

 

[bigedp51]

Chambers and dies vary in size, example I have a Lee full length .223 die that will bump the shoulder back .009 shorter than a GO gauge with the die making hard contact with the shell holder. This same die will also reduce the case diameter more than my small base dies.

I use Redding competition shell holders to set the amount of shoulder bump and still let the press cam over. Cam over eliminates any slop in the press when the die makes hard contact with the shell holder. This in turn gives you more constant shoulder bump and far less variations.

 

[D.Camilleri]

I am not quite sure how I got mixed up. My RCBS full length sizing die is set up perfect. I am not sure why I used the redding sizing die. I think I had the redding die set up to try and fix some bad cases that were the result of a poor chambering job two barrels back. I also have a neck sizing die that I can use. I don't know if I want to mess around with the short brass now as I have an additional 200 cases of bertram brass on the way. Maybe I will just sell the once fired brass to someone that needs it. I was thinking that having the shoulder bumped back too far was affecting my group size, but then I found the action screws weren't torqued proper and caused the group size to open up. Time for more testing.

 

[Bullet bumper]

I think we have two different concepts of what cam over is in this thread .

 

[Mikecr]

Cam-Over has different meanings. One is built in with eccentric linkage design, the other is method.

Designed cam-over varies with different press designs. You can see it with movement of the ram through handle travel. The free ram raises, slows, stops, and finally lowers a bit.
Analogy in this is a lifter riding a cam lobe, going just past 0-Mark. The ram is a push rod.
My presses do this, I've yet to need interference contacts to bump shoulders 1thou after spring back(for bolt guns), but there are plenty of different situations out there.
For one, I don't use FL sizing dies for anything. And I would not vary my neck sizing lengths to adjust shoulder bumps anyway.. I use body dies for bumping, and neck dies for neck sizing.

Then you have presses(some very powerful) with no built in cam-over. With enough leverage you can flex them enough to reach full handle travel, with great interference, like caused with die contacting shell holder. This does not actually provide any more leverage or difference to the sizing function. That extra effort is merely stressing the press.
If the reasoning for this is a sloppy press, I suggest a local dumpster could rid you of that problem, and don't ever stress your next press. If the die isn't right, and maybe the manufacturer recommends interference contact, don't. Work around it or fix it with a better plan.

The worst plan I've seen is the common -raise the ram, screw the die down to contact the shell holder, + 1/8 turn for cam-over, with no followup verification of results.
Probability of correct bumping here is nearly nothing..