Re: New Brass for OCW testing or not.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: vman</div><div class="ubbcode-body">Regardless if and where possible remove all variables.
If at the end of the day the shooting is sub average something is either wrong with the rifle or the operator. </div></div>
Of course, that goes without saying, but the entire purpose of OCW is to find an exact pressure level, or more correctly a precise in-barrel bullet speed, via very small changes in powder weight, that/which puts your bullet exit at an optimum time when barrel harmonics shock waves have the least effect on the muzzle of the barrel. These exit times are the "nodes" often spoken of. I find two distinct nodes in most OCW work ups; one is two thirds the way up in the parameters, and the other is usually right there almost at what quickload has calculated as a maximum charge for my case capacity/COAL.
The best results sought in an OCW are still only basically roughing it in. Once you find that pressure level and exit time, then the load can be refined with small changes in seating depth; which are actually resulting in even smaller changes in pressure level and exit time than can be obtained with changes in propellant volume. If you are shooting very attractive groups with an OCW work up then you lucked into a COAL that is very close to the end result. If that's the case then you can prove it out with +/- COAL changes making the groups worse instead of better.
Heavy barrels will typically curtail the effects of what happens in an OCW work up, simply due to the lesser effects of barrel harmonics on the muzzle of the barrel; less occilation due to barrel stiffness. Heat issues aside, a skinny barrel can be made to shoot exceptionally well with an OCW work up.
The great thing about OCW is that by default it negates a lot of varibles that often worry a reloader. Since you are playing with the pressure and the in-barrel time to begin with you are finding a specific node, and thus in actuality a RANGE of consecutive powder weights, and thus a range of consecutive pressure levels where your bullet exits the barrel at the acceptable time. This usually translates into a broader span of pressure levels than most differences in brass can produce. Since differences in brass usually equate to available powder capacity, and thus pressure levels,and thus effects on in-barrel bullet speed, it stands to reason that a proper OCW work up will give you a powder charge that can be universally acceptable despite variences in case capacity.
Of course it also is proven that matched brass with same capacity is where things will tune the best, which is why anyone with any lick of sense wouldn't shoot mixed brass for "accuracy", but one of the varibles that I quit being annal about is weighing cases. I simply don't bother with that anymore. The +/- within the same lot of good brass is too small to have a large enough effect on how my rifles shoot after an OCW is found.
The answer to the OP is that new vs fireformed is not a large enough varible to affect the results in an OCW test. I would however use fireformed to tune the load via COAL after the powder weight is found. After the load is final tuned he will be pleasantly surprised to find that future virgin brass will shoot that load VERY well.
