Bumping Shoulders Issue

[boomtube]

"Any ideas what I did wrong?
"

Yeah. It's highly likely you are changing your die by massive amounts as you do "little steps."

The full range of headspace tolerance of most bottle neck cartridges is about 7 thou. A 1/8th turn of a die is very close to 9 thou, being about 28% more than the total allowed range of headspace tolerance. Even half that. 1/16 turn, changes the shoulder almost 4.5 thou.

If you want to see adjustments in the 1-2 thou range you gonna have to make 1/64th turns, which gvies a bit more than 1 thou sholder change. All that means you gonna have to learn what "small die changes" really amounts to.

And, you likely gonna have to learn a different lever cadence than you normally use if you want any kind of consistancy at all. Push the lever fully down and HOLD it down for a full second, maybe two. And lube each case as nearly identical as you can too. Both things really do make a difference.

[Mikecr]

It's possible that your FL die isn't right for your bumping. FL sizing, neck sizing, body sizing & bumping are different animals, and not every die can hit em all right for every chamber. This leads to many inquiries here...
Forget SAAMI. As BB implied, Think YOUR chamber. Feel your case chamber.
Also as mentioned, lube consistency is vital for bumping.

Your results should have been more predictable though. So if I were you, I'd try it as an independent operation. Pick up a Redding body die(they're cheap), and RCBS case lube, and see if things go better.

I'm sure it isn't the answer you're looking for. You might not want to bump seperately from FL sizing.
But you can, & very well.
Hell, I do everything seperately.

[gunpower]

The only way that I have found, is that you have to turn the shell holder down- 2- 10 thou, that way you can push the case farther up into the sizing die. I just did one today for the 243, a fired case would fit the chamber, but when sized , it would not fit the chamber without forcing the bolt closed! I tried different settings with the die but no luck. I smoked the cases to see what was wrong and found that the case necks were not being bumped back enough. I phoned a friend who has done this many times. Turning the shell holder down ,will be a lot more help than trying to adjust your die!

[johnnyk]

I use the same method as described by BuffaloBob. There's no mistaking (in my mind) going from that slight crush feel to no crush feel on the case when the rifles bolt closes on it. JohnnyK.

[jimbires]

I use these .
http://www.redding-reloading.com/onl...ellholder-sets
when you use these you bottom the die against the shell holder as you do for full length resizing . it takes the guess work out of it . then just as the other guys have said , I keep changing the shell holder until I get that very light crush feel when I chamber a round . Jim

[flashhole]

This is what I do. It's very simple.

[J E Custom]

Originally Posted by statjunk

Hello All,

On the advice of many here I decided to give bumping a try as opposed to simply neck sizing. To say that my first attempt did not go well is an understatement. I'm hoping that by describing what occurred that someone can offer me advice.

Here goes. I first took the fire formed brass and I measured it using the RCBS precision mic. The measures varied somewhat but I settled on .002 larger than Sammi. I chose to bump the shoulder .002 so that would essentially mean that I need to bump the shoulder into Saami spec. Zero on the gauge.

I then put the brass in the press and sent the ram to the top. Then I started to thread the FL sizer die down onto the cartridge until it stopped. At this point the die is sticking out of the press like 1/2 - 5/8". This is from a normal position where I would FL size when business as usual. I lowered the ram and dialed the die down a half turn. Lubed the case and sent it up into the die. It met very little resistance pulled it out and miced it. The measure didn't change. Turned the die down a little more, send in the brass, mic again. No change. Did this a couple more times. Nothing. Sent another fire formed brass into the die and it came out .004 under saami spec. Dialed the die out a bit and tried it again. Nothing.

I went through several pieces of brass trying this before giving up and deciding to write a post here. I had a buddy with me and he was as confused as I was.

Any ideas what I did wrong?

Back up inf0: remington brass, Lee dies, Lyman press

Thanks

Tom

I'm Not sure that you did anything wrong you may have a set of dies that won't let you bump
the shoulder. (Some dies are adjusted by seating the die against the shell holder).

I switched to dies that don't seat against the shell holder so I could fully adjust to what case
size I wanted. I like the new dimension dies from Hornady because you can adjust down to
a small base setting (Normally .003 to .004 smaller than SAAMI Spec.)

There have been a lot of good suggestions and I would add that I always anneal before I
bump the shoulder to minimize spring back.

Also I remove the expander ball during the setup and just keep turning the die down untill
I get the desired size(One case) and then try a new case to check if it needs tweaking then
replace the expander ball/plug and proceed.

As BB said I never bump the shoulder unless it is nessary and always anneal befor I start.

Hope this helps.

J E CUSTOM