bumping the shoulder?
- Thread starter Ernest II
- Start date
GrizleyHunter
New member
It all relates to a head space problem where the cartridge expands to much to fit in the chamber with some room to spare. the shoulder area on most brass is what stops the cartridge from moving forward enough for the bolt to close.
.
.
CatShooter
New member
Originally Posted By: Ernest IIWhen you guys talk about FL sizing and not bumping the shoulder back what does that mean? Ive reloaded a bit in years past but I was never a neck turner and all those things that the pros do for accuracy. I don know all this tech talk.
Thanks Daryl P.
It means setting the FL die so it does NOT touch the shoulder when the case is sized. "If" the case grows in body length enough so closing the bolt is hard, then the die is adjusted in teeny amounts until the die just touches the shoulder enough to move it a few thousandths - that is called "Bumping" as opposed to fully sizing the case.
This allows the case to fit the chamber without having the shoulder pushed back so far that the case stretched at the web when fired and eventually comes apart.
Cases should be sized the LEAST amount that will allow them t just be chambered with the least space around the case.
Thanks Daryl P.
It means setting the FL die so it does NOT touch the shoulder when the case is sized. "If" the case grows in body length enough so closing the bolt is hard, then the die is adjusted in teeny amounts until the die just touches the shoulder enough to move it a few thousandths - that is called "Bumping" as opposed to fully sizing the case.
This allows the case to fit the chamber without having the shoulder pushed back so far that the case stretched at the web when fired and eventually comes apart.
Cases should be sized the LEAST amount that will allow them t just be chambered with the least space around the case.
BuckeyeSpecial
New member
I just posted a response on this in the Help Reloader thread that may be helpful to you.
Forester neck sizing dies are very good in "bumping" shoulders back. They are the only standard neck sizing die that will bump shoulders back.
I had a 25/06 that loved hot loads of R#19 with 100's, I bumped the shoulder back 12x without full length sizing the brass. 243's that I have owned were particullarly fond of having their shoulders bumped back.
I had a 25/06 that loved hot loads of R#19 with 100's, I bumped the shoulder back 12x without full length sizing the brass. 243's that I have owned were particullarly fond of having their shoulders bumped back.
Last edited:
EJ Reichenbach
New member
I have found that bumping the shoulder back just a tad, on all of my cartridges works good except my 223 wssm, but that is mostly because the brass sucks and everyone expands differently because some of it is thicker than others so I have to bump the shoulder back .08 on all of them to make dang sure they all stay the same. I have some 22-250 brass that has had the shoulder bumped back a dozen times and still works great. You can acheive this with the hornady head space gauge and your regular dies.
1holeaddict
New member
I use the forster bushing bump die for several calibers and it works great. They set comes with 3 different bushings for adjusting neck tension.This die will bump the shoulders but on neck sizes instead of full length sizing. The only draw back is after a few firings they need a body die or full length die.