A rec.guns reader wrote:
My questions focus on the merits/demerits of full-length vs neck- only. I've read that neck-only works the brass less, presumably resulting in longer case life. if that's so, why would anyone full-length resize? also, i read that you should neck-only resize only after firing the brass in your particular rifle, and that you should never use that brass in another rifle unless full-length resized. what gives? wouldn't simply firing the brass expand it to the other rifle's chamber, even if neck-only resized???Which will work best in a given rifle can be determined only by trying each for comparison. I have found that there is so little difference that buying a neck-sizer is a waste of money and my neck-sizer only dies have languished for several years. In addition, some rifles have the characteristic of allowing brass to stretch/swell an amount upon each firing which can eventually prevent chambering. This USUALLY happens in rifles with "sprin- gy" actions; those like the Lee Enfield that have rear locking lugs. Neck sizers will not correct this condition. Cartridge pressure also plays an important role and holding the pressures down in the Lee Enfield, etc. will go a long way towards minimiz- ing stretch.
The answer that I have found to work well across-the-board is controlled (partial) sizing using a full length resizing die.
Fitting your lot of cases to a given rifle will pay off in case life increase. To do that I use a little known, but not origi- nal, technique:
Using a light charge of powder, seat a heavy (long) bullet into the case just enough so that it will not fall out during normal handling. Single load. The intention here is to cause the bullet to be jammed into the origin of the rifling by the bolt. A tight case neck will aid in holding the case base back against the bolt face during this operation. When the round is fired the case will not be pushed forward by the firing pin but rather the shoulder will be blown forward thereby forming the case to the chamber, resulting in zero headspace.
Then, using a match or candle, smoke the case neck and shoulder of one fired case. Back off your sizing die several turns and size the fired case. Turn the die down in steps until you have sized the case (as indicated by the removed carbon) 90 - 95% of the neck length. Be sure that you stop short of the point where the die touches the case shoulder. Once the proper amount of sizing is determined, lock the die at that position in the press.
The above should be done using the MINIMUM recommended charge for any given powder. This technique has been used many years and it works. DO NOT use maximum charges with this method as pressures can become excessive. I use reject cast bullets to do the form- ing.
The above has an additional advantage in that with 90 - 95% resizing, the case base (pressure ring) is reduced back to normal diameter, a feature that the neck-only sizer does not offer. This is particularly important to those that do relative pressure testing according to the Ken Waters' method.
I have had only one rifle that required slightly touching the shoulder with the sizing die after each firing. It was Model 94 Winchester.
I have been an active shooter for a lot of years and have not ever had a case head separation. Maintaining a zero headspace clearance condition is the reason. My old Lee-Enfield No. 1, Mark 3* has about .020" extra headspace when measured by conven- tional methods but has effective headspace clearance of zero because of the above practice. I have been shooting it since 1957 without the first problem. All my rifles are set up this way.
A Tip:
When using some lots of once fired military brass, a somewhat similar technique can be used. Many military rifles have over length chambers and brass fired in them will not chamber in sporting rifles because the case has been stretched. Take advantage of the situation when preparing the brass for reloading. Back off your die as mentioned above, then, in steps size the empty brass case until it will just chamber.
Note that this has the advantage of changing the method of head- spacing to the shoulder, even on rimmed cases such as the .30-30 and .303 British.
Another tip:
Some once fired military brass is so stretched that it is dangerous to reload under any conditions. I once had a lot of about 1000 .308 cases that were so stretched (about 30% of them). Use a bent paper clip to examine the inside of the case immediately forward of the base. If incipient head separation is present you will be able to feel the stretched (thinned down) ring because it is very abrupt. DO NOT use brass that has this condition. In my case the supplier was willing to replace my lot.
For semi-auto and lever action rifles, partial resizing after firing works only some of the time. The problem is, depending upon that particular rifle's design characteristics and idio- cyncracies, cases may stretch enough after a number of firings that they will no longer chamber reliably. If this is the in- stance with your rifle, lube a case that hesitates to chamber reliably and tweak your sizer die down about 1/16th of a turn (or less) at a time then run the case into the die. Attempt to chamber between each 1/16th turn and resizing. When the case chambers with just the slightest resistance (or ideally, with zero headspace clearance) lock the sizing die. It is doubtful that you will ever have to change that die setting again (using the same press, of course).
I have used the above for my T/C Contenders, which have no camming action to close them, with 100% success. NOTE: In the case of the M1 (or other semi-autos), do not allow the action to slam shut when using the above case adjusting method or the slamming of the action may accomplish that which the die should do. Standard full length resizing is ok but this method will increase case life quite a bit and, more important, practically eliminate case failure due to head separation.
God Bless!
Norm