Another Headspace Headache

[Miseryguts]

Hi been trying to bump back the shoulder on some donated 223 brass a couple of thou to bring them into line with my rifle's headspace, but my Lee breech lock press does not seem to be up to it, nor does the Lee FL sizing die. So my question is....... what is the most reasonable way of doing this???

M

[Webby]

A better definition of not up to it may be required! Lee press should be man enough. Are you saying that winding the die in further makes no difference? Are you measuring to the shoulder and finding that it is not reducing or are you trying the case in the rifle?

 

[TJC]

Are you saying your FL die won’t FL size or bump the shoulder ? 

Brass not fire formed in your chamber should be FL sized. It may or may not fit if not. 

[Miseryguts]

Sorry should have been more specific! Webby, TJC, winding the die in makes no difference - shoulder as measured in headspace gauge  does not change, and the rounds will not chamber in my rifle with the pin removed and after F/L resizing. I have a lot of brass which has been resized in this die that all checks out ok on the headspace gauge and fits the rifle. Some time ago I measured the headspace on the rifle and that came out at 1461 ON MY COMPARATOR. Brass sized at 1458 on my comparator chambers with no tightness, at 1459 slight resistance, at 1460 fairly tight, at 1461 very tight, at 1462 not chambering. I have brass at 1462 -1463 and fancied bumping it back to fit but ran into this problem, and ended up with a stuck case as winding the die in made the force required to operate the press more and more until the case separated.

Ho Hum

M

[Catch-22]

Just a thought, but if you're not bumping the shoulder back at all despite screwing the die down further into your press, it may be due to three reasons;

1. The brass is oversize down at the case head, so all the force you're using is actually trying to size the body back to spec - so you're never really reaching the shoulder at all. Have you measured the base of these donated cases against cases that fire/fit your rifle?

2. Are the donated cases too long? Sometimes the mouth of very long cases essentially hit the top of the inside of the die, so regardless of how deeply you screw the die in, the case is too long to size the shoulder. 

3. Related to point 1, you may have a die that is too tight to allow the case (if slightly oversized) to go all the way up into the die for proper sizing. This can be an issue with some dies apparently. Remember reading something about it on Accurate shooter.com

Hope you find a simple (and cheap) solution.

[Miseryguts]

Hi Catch-22, you may have something there, on checking the diameter of the cases just above the shell holder, I find that most of my brass is 0.3735 to 0.374,whilst the brass I have a problem with is 0.374 to 0.375 compared to the SAAMI spec of 0.3759. All the brass is trimmed to an OAL of 1.755 to 1.759 so I do not think that is the problem. It is always the last 3-5 mm of the case that needs the extra force and sticks in the die.

Have just ordered another die, so hopefully that will sort it

M

[hughes.s]

If you have used the die and the press (if you have used another press then there might be a problem with the press) to size other cases to your satisfaction then it can only be the brass that is the problem. Is the  brass to hard? , if I use a Lee fl die set to top of the ram they come out well short approx 1.448 ish (on my comparator) I find useing lee lube requires less pressure on the ram handle and also sizes .001/.002 more than Imperial Wax ie 1.455(wax) 1.454/3(lube)

[VarmLR]

Just a thought but are you applying enough lube to the cases?  I only ask because very occasionally, I used to find (when I started reloading) than if the cases stuck even a little bit, they stretch as the ram was lowered and the cases would then not chamber.  I would find it very unlikely that the die was at fault as they're manufactured to very tight tolerances.

[Miseryguts]

Headache over! had to strip the die as had a case stuck, and found the fault - decap/throat mandrel was too low down, and when I lowered the die the mandrel was pushing the case base out jamming it into the die and causing it to stick and not bump the shoulder. Ran the cases through again without the mandrel, and bumped the shoulders back sweet as a nut!!

Thanks to all for their suggestions

M