Thread: Full length sizing and head space

Maybe just a greenhorn question, I do not have a case comparator gauge yet and i have some 6.5 creedmoor fire formed cases and a full length die, how do I know weather my headspace is ok after sizing. Do I just set the die following manufacturers instructions and check how the bolt closes on the resized case or Am I best to wait till I can measure with a gauge?

Greetings,
You can follow the manufacturers instructions but this is likely to set the shoulder back more than needed. Only one of my rifles needs the die down hard on the shell holder. I have found that the Hornady comparator is great. You can then set your full length die by trial an error to get your shoulder bump right using the comparator to set your die.
Regards Grandpamac.

If you set it up per manufacturers instructions your ammo will be sized back to close to minimum SAMMI specs, this lets it chamber in any 6.5 creedmoor rifle and headspace will be fine.

The best way to do things though is to set it up so you're only sizing the brass just enough so the bolt closes easily. To do this take the ejector out of the bolt (if it has one) and then run sized brass through until the bolt drops freely, make sure you're sliding the brass under the extractor so it doesn't interfere.

With the brass I'd start with the die 1.5-2 turns high then adjust from there. Just remember that your adjusting the die about 9 thousands of an inch for every 1/8th of a turn, and ideally you want to bump the shoulder back 2-3 thousands so go easy on the adjustment when you get close.

My first loads I tried bumping shoulder 2 thou but had problems, brass showing bolt swipe, ejector marks. now will just size to bottom of neck and only bump shoulder if things get to tight

now will just size to bottom of neck and only bump shoulder if things get to tight

Exactly
No need to overthink things
KISS.

Originally Posted by Hunterdave

My first loads I tried bumping shoulder 2 thou but had problems, brass showing bolt swipe, ejector marks. now will just size to bottom of neck and only bump shoulder if things get to tight

Which is perfectly fine as long as you're checking it fits every time before you load it up

Originally Posted by charliehorse

Which is perfectly fine as long as you're checking it fits every time before you load it up

Alternatively get a case without primer and powder and size it, fit a projectile and see if it chambers. If it chambers well mark your die with a black marker as a reference point.

Greetings again @Scotts.
I looked up the difference between the SAAMI maximum chamber and minimum case fror headspace an it amounted to 0.365 mm (0.014"). For the Creedmoor I would expect the tolerances to be closer as it has been touted as an accuracy cartridge. The only way to know how much slop there is between a fully sized case and your chamber is to measure it, otherwise you are just guessing. The Hornady headspace comparator is a reasonably inexspecive way of making this comparison assuming you already have a set of calipers which no handloader should be without. You can then measure the length of both cases and see just how much slop there is and make some decisions on what, if anything, you need to do about it. I have been handloading for over 50 years and only got a comparitor early this year. It has been a revelation. I sat down and measured new, fired and FL sized cased for most of my rifles. For some I have splashed out on the Redding competition shellholder sets but for others I have set the die back from the shoulder using the comparitor which allows me to check that I have got things right. I used to use a combination of neck sizing and adjusting the die by trial and error. These worked up to a point but the risk is cartridges too tight to chamber in the field or case head separations as early as ths third firing if you don't get it right. Get the comparitor, do your measurements and go from there. Happy to answer any specific questions.
Regards Grandpamac.

@grandpamac, I full length sized and decapped last night, I just set my rcbs sizing die a just over a quarter turn down after the ram had touched the die, I chambered a few cases while working through the brass to make sure they fit. I hope to have purchased a comparator by the next time I load this brass and make the measurements you have commented and be able to set my dies much more accurately.

Hi All,
This is exactly what i came here for.

I made the mistake of loading up a bunch of rounds before checking if they chambered well.
80% of the rounds chamber but most of them I would consider too tight to use while hunting as closing the bolt is a little bit of an effort.
What I was hoping to do was use these rounds when sighting in my new scope.
Once I have these three times fired cases resized using the headspace compare I have bought. Will I be able to remove the projectile powder and primer of the other tight rounds, and resize them with the correctly set die. ?

Cheers

Also I’m using Hornady dies in a lee press and firing a 7mm wsm with Winchester brass.

you COULD ,if they will chamber....use them up as they are.....you will rezero rifle more than once...you will take longish shot with time to switch round thats chambered.....
or pull them and start again....pull projectile,put powder aside.....take the guts out of FLS die and resize the case to where you want it.... CHECK IT in chamber...replace powder,replace projectile...check it again... then do same for rest of rounds.

but if they will chamber...yeah rezero rifle using them etc..much less mucking around.

I agree, I COULD, use them as they are but i much prefer having a round that chambers nice and smooth, what i was essentially getting at is, is it possible / still accurate to resize a case to 2 thou shoulder bump after it has already been full length resized?

Also can a primer that hasnt been fired be reused after it has been pushed out with a resizing die ? would be great if I could as they are expensive these days.

why would you push it out??? remove stem and proceed..and no you cant grow the case easily.... but you can shrink it.
if you dont measure it..the 2 thou is irrelevant..if it chambers use it.

Originally Posted by BenTheBuilder

I agree, I COULD, use them as they are but i much prefer having a round that chambers nice and smooth, what i was essentially getting at is, is it possible / still accurate to resize a case to 2 thou shoulder bump after it has already been full length resized?

Also can a primer that hasnt been fired be reused after it has been pushed out with a resizing die ? would be great if I could as they are expensive these days.

Yes, primers can be reused after removal from a primed case. I'm shooting some loads today that I primex with once removed primers.