Bumping the Shoulder

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Who bumps their shoulders when reloading? Is there a change in pressure compared to full length resizing? Did you have an increase in accuracy?

Thanks for any input!
 
Shoulders only get bumped back when full length sizing. I will bump shoulders back only when firing the same ammo through several different guns because of differing chamber tolerances. If I have dedicated brass for one rifle, after the first firing the brass is fire formed and I only worry about bumping back the shoulders if extraction gets sticky or chambering becomes an issue. The exception is I double check my cartridge headspace via a Hornady cartridge headspace gauge after trimming the brass after enough firings to stretch it.
 
Chambers and dies vary in headspace length and diameter, adjusting your full length dies for minimum shoulder bump extends case life. Meaning adjusting the die for a custom fit of the case in your chamber.

Below I use Redding competition shell holders for getting the correct shoulder bump. I also full length resize with Forster full length benchrest dies because they produce the most concentric ammunition.

Redding Tech Line & Tips (FAQs)
Create A “Custom Die” With A Simple Shellholder Change!
http://redding-reloading.com/tech-line-a-tips-faqs/144-create-a-custom-die-with-a-simple-shellholder-change
 
I bump my brass... I find it more consistent and easier on the brass life. Allows to me custom the fit to my chamber.

It is all about fitting the brass to the chamber and application. Dimensions vary in dies and chamber so use the combo of dies that fit what you are trying to achieve.

Saying FL sizer really doesn't mean what you are hoping it will....

Jerry
 
I will use a Lee neck sizer to neck size for enough firings to feel resistance when closing the bolt on an empty case. I'll then measure the shoulder and set my FL die for a .002" bump. I use a Forster press and dies. Once the die is set I leave it as is. One FL die per gun, even if they're the same caliber.
 
For the most part I use FL dies and Redding competition shellholders. I use the .010 until there is a bit too much effort closing the bolt; then go through the series until just the right feel on the shoulder is achieved. A side benefit is that the same dies can be used on muliple rifles without resetting. I write the shellholder number on the die box or ammo box. Custom chambers inevitably end up the standard shellholder and the average factory rifle at .006".
 
I run whidden comp dies. They come standard with bump gauges and I bump shoulders .004 for my long range hunting rigs like the 28 nosler. And .002 for my target guns. I find .004 for hunting works well for reliability. And .002 works well for the bench in a controlled environment. I find that bumping is the most accurate for me, but you have to run high end dies. If your bumping with cheap dies you'll find concentricity to be poor.
 
I've bumped .303 cases with a Lee FL die, but without the expander ball in which case the mouth is too tight to accept the bullet. I have well used brass so I'm going to find out how long they'll last with FL sizing.
 
Thanks for all of the responses. I usually full length sized, as per instructions from the die maker. After my next shoot at the range, which will be in the very near future, I will try just bumping the shoulder. Yes, I do now have a new head space gauge. Reloading is alot of fun and there is always something new a person learns. Thanks again!
 
Dogleg said:
For the most part I use FL dies and Redding competition shellholders. I use the .010 until there is a bit too much effort closing the bolt; then go through the series until just the right feel on the shoulder is achieved. A side benefit is that the same dies can be used on muliple rifles without resetting. I write the shellholder number on the die box or ammo box. Custom chambers inevitably end up the standard shellholder and the average factory rifle at .006".
Click to expand...

What Dogleg said, I have found the same. As you change the shell holders you will find that as you go down in #'s the shoulder will move forward until you hit the right shell holder that sets the shoulder back.
With most cartridges that I work with, the .008 shell holder will push the shoulder forward about .002", as you reduce the size of the brass it has to go somewhere.

I think the Redding shell holder as the greatest thing since the invention of dirt, and for those that do't use them I suggest you get a set. You won't be sorry.

David
 
It's probably the best money I ever spent on equipment. I'm like most people, and thought the competition shellholdere were something that would only be of interest to target shooters and incurable equipment junkies. Instead it turns led out to be a simple, common sense way to actually do what many only thought they were achieving. There is so much flex in a press that adjusting headspace by screwing dies in and out is a joke.
 
Where to buy? Which to buy?Redding Competition shell holder set(s)

bigedp51 said:
Chambers and dies vary in headspace length and diameter, adjusting your full length dies for minimum shoulder bump extends case life. Meaning adjusting the die for a custom fit of the case in your chamber.

Below I use Redding competition shell holders for getting the correct shoulder bump. I also full length resize with Forster full length benchrest dies because they produce the most concentric ammunition.

Redding Tech Line & Tips (FAQs)
Create A “Custom Die” With A Simple Shellholder Change!
http://redding-reloading.com/tech-line-a-tips-faqs/144-create-a-custom-die-with-a-simple-shellholder-change
Click to expand...

I would like to try this for my 308 and 6.5 Creedmoor rifles. Where can I buy Redding Competition shell holder set. Do I just need #1 or do I need #1 and #2 sets.

Thanks!
 
Dogleg said:
It's probably the best money I ever spent on equipment. I'm like most people, and thought the competition shellholdere were something that would only be of interest to target shooters and incurable equipment junkies. Instead it turns led out to be a simple, common sense way to actually do what many only thought they were achieving. There is so much flex in a press that adjusting headspace by screwing dies in and out is a joke.
Click to expand...

so true and screwing dies in and out can also cause issues with the final indexing of the die. I switched to the Lee Breech lock inserts years ago and they have proven very reliable to get the dies in the same place each time I use them. They also make adjustment of the die much better as the die indexes more consistently.

Lee now makes a lock ring/insert combo which I think is a great idea. Make it even easier and faster to tweak die adjustment.

The Redding comp SH is a great idea and I can offer them BUT if your press has alot of slop and/or the die is not setting up the same way each time you use it, then you have the same variable..... just put into another part.

YMMV.

Jerry
 
I'm still using the RCBS Rockchucker press I bought in 1973 and the reason I went to the Redding competition shell holders is the slop/wear in the press.
Meaning when the shell holder makes hard contact with the die and you have cam over any "slop" in the press is removed and the press is no longer in the equation.
I also use Lee die lock rings with their rubber o-rings on all my dies. This allows the die to float and self center in the presses threads and not be locked down off center.

Bottom line between the competition shell holders and Forster full length dies with the high mounted floating expanders, I'm making very concentric ammo.
 
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