kansasvet.....if your cases are lengthening that much YOU'RE DOING IT WRONG!!!!
And you're headed for casehead separation.
Period.
Yes this will cause the base of your necks to thicken too because you're pushing .006 to .010 of SHOULDER BRASS up into the neck where it doesn't belong. Look at a cutaway view, a sectioned case, to see that shoulder brass is thicker by design. Now, when you "push the shoulder back" you're actually driving the entire case up thru the die making the case longer each time you fire it. The mechanism is this, you jam the case forward ("push the shoulder back") and when you fire the case it's pushed forward in the chamber and STAYS THERE. This is the key. Cases DO NOT slide around in the chamber unless you grease them (stupid) or there is a design flaw in the case configuration (WSSM). So you end up with that .006-.010 of airspace BEHIND THE CARTRIDGE, between the boltface and the base of the case. With mild loads this gap basically remains through the firing cycle, in many cases the only thing that happens is that the primer "pops up"........ or it stretches partway leaving you with a cocked casehead and a popped up primer. These fired cases will rock around like Weebles if you stand them on their bases on the table. With stout-to-hot loads the brass case stretches back until it stops against the boltface, AGAIN it's left crookedy but in most cases the primer is hammered back into the hole, reseated, flattened back out. Do this a few times and the head of the case blows off. It can't help it, it's been destroyed by over-sizing.
All this because you're sizing too much. OVER-sizing is the single biggest safety problem amongst casual reloaders IMO.
Somehow, somewhere this complete MYTH got started that it was better to bring the sizing die into contact with the shellholder.
This is a mistake!
So here's the Facts Of Life regarding factory chambers and dies.....and the fit thereof. First of all let me preface this by saying that factory chamber-to-die fit is much better today than it's ever been because industry tolerance standards have tightened up tremendously. But their are still necessary manufacturing tolerances.
#1-Rifle Chambers; rifle chambers vary in length, in diameter, in eccentricity and in taper. Generally speaking modern rifle chambers stay within .002 of LENGTH across the boards. I'll say "plus/minus a thou" which is about half what it was up to 20-30yrs ago. Generally speaking I'll opine that modern factory chambers are within .004 or so in width, breadth and taper and lined up with the bore to within ten thou......not bad for 15 bucks....
#2-Reloading Dies; reloading dies are held to slightly better tolerances but still TOLERANCES..... the necessary evil of tolerance means that you get a BIG rifle chamber and a SMALL die and it's impossible to get an effective resizing effect. YOUR RELOADS WILL BE CROOKED AND OVER-WORKED!!! And if you bury the steenking die to the steenking shellholder you'll be maximizing crookedyness....And you can't do anything about it except back the die off to minimize the damage. Conversely, given a SMALL tolerance chamber and a die on the LARGE end of the tolerance stack and you'll be hard-pressed to get any sizing effect at all. And when THIS happens rednecks jump up and down and vilify the manufacturers. They badmouth the gun and the die, they send them back to their respective mfgrs and they spout gibberish all over the innertube. So the mfgrs retaliate by making things TIGHTER, making reloading dies SMALLER and chambers BIGGER.
It's a vicious circle.
So.... when you're stuck with factory setups just prepare for the worst, count yourself lucky if you have such a match-up that you can safely reload your cases 5 times before the shiny, granular ring of "incipient casehead separation" rears it's ugly head.
I could go ON and ON and ON...... all of this is why custom chambers and custom dies exist. To promote linearity and fit in the interest of better case life and better accuracy.
But take it as fact, brass does not "Flow" or move around during firing, brass DOES NOT somehow magically migrate into the neck area UNLESS YOU PUT IT THERE by the resizing process.
Too Tight necks, necks that will not accept a bullet after firing are indicative of some sort of PROBLEM.
Let's find the PROBLEM not go off on a "fix" junket. Fixing necks by just willy nilly reaming them to relieve pressure is kinda like siping your bald tires to get some traction back.....
colcolt
Fired cases are 1.689-1.690". They all refuse the bullet. I don't have any fired cases to measure neck diameter. They've all been sized and reloaded.
We need some numbers for comparison. You asked you question on the one shooting board in the world where you CAN get an answer, but you need to give the information. You NEED to do some comparisons and find the tolerance bind. You're dealing with a 65,000psi metal-cased grenade 8" from your eyeball.....
Or keep the bone in your teeth and forge ahead
just remember, "you better be tough!" You decide to just fire those things instead of pulling some to check, it's on your head. Or your face, to be more precise.
and WEAR THOSE FRIGGIN' SAFETY GLASSES GUYS!!!!!!!
God Only Give Ya Two Eyes
al-SAFETYGEEK-inwa
