recurring 6.5x55 sizing problem

[brad]

had this problem a while ago and thought i was on top of it but not so
ok 6.5x55 swede highland brass FLS shoots perfectly but when i go to neck size the cases are tight to chamber ?
have candled a case and its bearing on the middle of the shoulder ?

have tried
lyman neck die and lee collet neck die
differant brass
re-FLS fire then neck size again

[Simpson]

Brass length is ok? ie not too long?

[Knackers]

How tight, is tight to chamber? have you fired one? how did it exstract?

[brad]

just checked that lengths vary a little but under max

last half of bolt is uncumfortable tight to lower but possible
fire and extraction is ok

[stinkitup]

What rifle? is it a mauser or tikka, model 70 ?

[chris.tyne]

Is the action a front locking/rear locking,at the end of the day if everything is in spec and you have contact at the datum point the shoulder is going to have to be hit.





Regards Chris.

[trevort]

sounds like my 300wsm, tight chamber. Cant neck size must FL size or it wont work. If thats the go and you really want to neck sizze you have some choices. A body die, does the FL job without touching the neck, a bushing FL die which sizes the body as per normal but uses bushings on the neck or maybe have a smith put a reamer in. Third one probably extreme!

[chris.tyne]

Trevor.T,He has said that the case is contacting at the datum point................so a neck die wont do anything,rechamber wont do anything,sounds like a hot load in a front locking action,warmish(is that a word)load in a front locker or just a combination of work hardened brass springing back to much when sized or all of the above.......................thats providing that it is the shoulder causing the problem which it sounds like going of the descriptionand brad gave and not the body or base.



Regards Chris

[284win]

Have you measured the shoulder length yet??

[brad]

Have you measured the shoulder length yet??

how do i measure the shoulder length and how do i know what it should be ?

Trevor.T,He has said that the case is contacting at the datum point................so a neck die wont do anything,rechamber wont do anything,sounds like a hot load in a front locking action,warmish(is that a word)load in a front locker or just a combination of work hardened brass springing back to much when sized or all of the above.......................thats providing that it is the shoulder causing the problem which it sounds like going of the descriptionand brad gave and not the body or base.



Regards Chris

all loads have been below listed maximum and showed no presure signs
43-46gn AR2209 120gn pill
problem started on first reload of once fired factory brass
i checked back over my notes and the cses were also tight to extract right for the really light loads but the tightness barely increased with load increaes
(i know tight extraction is a too late preasure sign but ihave reloaded many thousands of rounds and as the problem did not occur with factory or FLS brass i was confidant it was a sizing issue not a preasure problem)

[chris.tyne]

Brad you need a way of measuring things and a vernier is a good start,you need to measure from the base of a deprimed case to the datum point or somewhere between the shoulder radius and the base of the neck.You can use a pistol case if you have one or anything that is square and true on both ends that contacts at or near this point,here is a pic of what I use

now once you have a way of measuring this distance,measure it and write it down,now back the lock ring of a smidge on your FL die and size the case and measure it again,you keep doing this..size the case .screw the die down a smidge.size the case until the distance becomes less...........bingo and I will bet that it went more than a few thou.Hopefully you have a couple more cases that are tight and screw the die up a little and size again all the while watching the measurement,it is trial and error but once you are moving the shoulder 1thou try and chamber the case,if all good the bolt will close with a slight feel and alls sweet......lock the die up and away you go.
Now there is another way to do this and I have used it before and that is with bolt feel,now if you have to do it this way atleast strip the bolt so that you are not letting the firing pin spring influence your results and you basically close the bolt on a tight case,remove case and size it,try again,still tight,screw the die down a smidge,try it again,this will work but I like useing a measurement that is known and then it allows greater precision.
Ok now we have a case that is FL sized with the shoulder bumped back 1thou from a tight case and the cases are still tight ,we will deal with that if/when we get to it


Regards Chris

[brad]

thanks chris, very informative
i fixed the cases initially using the second method, but without the measurment but turning the die 1/8th turns
i thought i had the problem licked untik i fired them, then only neck sized and the problem returns ?
i can assume that in the future i will have to bump the shoulder all the time
i am just curious as to why this needs doing ?
i have always neck sized for all my other rifles thinking that that case matched that chamber and only required neck sizing

[MISSED]

Trevor.T,He has said that the case is contacting at the datum point................so a neck die wont do anything,rechamber wont do anything,sounds like a hot load in a front locking action,warmish(is that a word)load in a front locker or just a combination of work hardened brass springing back to much when sized or all of the above.......................thats providing that it is the shoulder causing the problem which it sounds like going of the descriptionand brad gave and not the body or base.



Regards Chris

Chris, its Trevort here. I know neck sizing wont fix the problem. I was trying to tell him how to size the body where the problem is and still control neck tension with a bushing.

Sorry I wasnt clear enough

[JasonF]

I am complete reloading novice, but wouldn't TrevorT's suggestion of a body die (redding part 75132) be the best bet for this situation?

[chris.tyne]

[/quote]

all loads have been below listed maximum and showed no presure signs
43-46gn AR2209 120gn pill
problem started on first reload of once fired factory brass
i checked back over my notes and the cses were also tight to extract right for the really light loads but the tightness barely increased with load increaes
(i know tight extraction is a too late preasure sign but ihave reloaded many thousands of rounds and as the problem did not occur with factory or FLS brass i was confidant it was a sizing issue not a preasure problem)[/quote]

Hmmmm I missed the extraction part in my first reply,
Hard to close the bolt is usually shoulder and hard to extract is usually the case head/base this is the same thing that happens to a lot of Remmo's that are set up as bench guns or chambered for high intensity cartridges with min spec chambers and they get the Remington bolt click as primary extraction begins as the base is oversize compared to the chamber.As Trevor T said earlier you could try a S/B body die as these are for body and shoulder setback.Also it can be that as you size them so that the full length die set the shoulder back your full length die will also squeeze down the area around the web and this actually made your cases longer.
If you have a case that hasn't been sized at all measure from the casehead to the shoulder not the mouth.Run the case into your die and measure it again.Chances are that it is now longer to the shoulder.
Also there is no definative measurements for the ones that we are discussing such as web dia,shoulder setback as they apply to your chamber and brass only,use them as a reference for any other measurements.Measure the distance from the heads to a circle on the shoulder on all of your sized cases, then measure them all after they have been sized, you will see that the amount that the shoulders of various cases have been set back are not all the same, even with the same die setting. There are several possible reasons. Differences in the amount of case lube will change the amount of bump, as will differences in the degree to which cases are work hardened and/or annealed. Once you have established the amount of variance of bump that a given lot of cases has, you may decide to adjust your die so that the one that was bumped the least, at a given setting, gives you the bolt feel that you are looking for but sometimes depending on how often that particular case has been fired it may not size the same as the others.........its all fun isnt it.

PS I hope this makes sense,gets lost in the translation sometimes



Regards Chris.