Re: What is needed to convert a Dillon from 223 - 308?
Caliber change kit: shellplate, locator pins, powder funnel.
If primer size is different, you also need a primer feed tube and primer punch with the correct primer diameter. Primer pickup tubes in large and small primer diameters are a basic need when both size primers are being encountered.
I simplify matters by mounting the dies in an additional separate tool head with powder die, and for the three most common calibers I load, I keep a separate powder measure assembly mounted, too.
I also keep an entire primer feed system for each diameter, and an additional primer punch slide, already set up with the correct punch.
Maintaining these small extras can reduce caliber changeover time to its absolute minimum, because basic initial setups and adjustments are already good to go.
When mounting the measure, the initial setup requires the powder die height to set up so the powder slide's end gets just flush with the measure body when the measure and press are syncronized at full stroke. If there's any 'forcing', the die is too low <span style="text-decoration: line-through">high</span>. If there's a significant bit of the slide protruding at full stroke, the powder die is too high <span style="text-decoration: line-through">low</span>, the measure is not operating at full stroke, and charge weight consistency can be degraded. Ideally, at full stroke, thumbing the end of the slide will induce a tiny but perceptible amount of additional movement before it hits the limit fof its possible travel.
The measure's 'fail-safe' rod should be adjusted a little too short, then allowed to 'click' at full stroke to get the length adjustment optimal.
I also keep powder measure slides of different gross capacities available.
When setting up the resizing and seating dies, once I get the adjustments right, I loosen the die lock ring, run the press up to full stroke with components inside the dies, and tighten the lock rings down while the press is fully extended. This can help with concentricity.
If the stroke includes a significant amount of force during 'camover', it becomes possible that dies are adjusted too low, and imposing forces on the press that are both unnecessary and injurious to the equipment.
The main vertical operating rod should be kept spotlessly clean and lightly lubed with common motor oil. If you can see black gunk, it's dirty and should be cleaned and relubricated without delay. A few drops, evenly distributed, is enough.
The shellplate is tightened until it binds, then loosened just enough to allow rotation without a bind. This reduces stacking tolerance to a minimal level. Excessive stacked tolerances can increase variances associated with the press's vertical stroke.
When replacing the primer punch/slide, loosen the primer feed tube base screws, run the primer punch all the way up, and tighten the primer feed tube base screws. This allows the primer punch to be properly centered and smooths out its operation.
When adjusting the powder measure, I will drop and collect ten charges, then compare their total weight to 10x the intentional charge weight.
This allows finer tuning of the powder measure without having to resort to superfine scales. If you allow time for filling/emptying at each end of the stroke, and maintain a consistent stroking rhythm, this total can fall to within .2gr of the proper 10x value (this translates to an accuracy of .02gr per avarage charge). It's a good way to to learn how to perfect the timing and rhythm, and the best way I know to deal with dropping better and more consistent cylindrical powder charges.
If I am measuring my charges, I will set up the measure to drop charges within a range where the lightest variations are equal to or slightly higher than desired weights, then pinch grains from the scale pan to correct the charge weight. No adding needed, and the excess gets dropped back into the top of the powder hopper.
When operating the press, always eyeball the powder level in the case for each case before advancing to the next station.
Also make a serious effort to keep the face of the primer punch clear of errant powder kernels, etc., as these can emboss a pattern in the face of the primer as it is seated.
If ringlike slivers of copper can be seen accumulating, the case neck is shaving the bullet while seating it.
Chamfering/belling the case necks can resolve this, but it can also be an early warning indication that case necks are getting sgnificantly work hardened, causing neck tension issues.
If you're using a neck sizer ball, careful additional partial strokes, bumping the end of the case mouth of the already resized case with the ball can impart a small amount of case mouth belling.
Be careful, sometimes the decapping stem length adjustemnt can be such that the right length for belling can also influence powder measure consistency if the measure gets even partially stroked. The optimal length for the decapper stem when at full stroke, it gently bottoms out on the inside of the case base. This works best when flash holes have been consistently reamed.
Greg
