If you have been involved in reloading
for more than about ten minutes, you are no doubt familiar with Dillon
Precision Products, Inc. and their incredibly popular line of
progressive reloading presses. I'm the proud owner of a Dillon
RL 550B Reloader fully decked out with all the available
accessories to feed my very hungry Glock 22 (40 S&W). My 550B is as
pictured at right, except I have the aluminum roller handle instead of
the plastic roller handle shown in the image.
The 550B produces consistent and accurate
ammunition for all but the most demanding applications, and its quick
change tool head design makes for rapid changes between calibers.
However, the quick change tool head presents a problem when extreme
precision levels are required. The trade-off for caliber change speed is
that the tool head to frame rail (and locator pin to locator pin hole)
tolerances are loose enough that there is "play" side-to-side,
fore-and-aft, and in the vertical axis. It is my theory that this
"play" may be partly/largely responsible for the variances in
OAL/seating depth, bullet alignment, and some other consistency
anomalies I have observed when trying to load test ammunition.
In order to test this theory, I had to
devise a way of eliminating all tool head movement. I've
done this, and I think you will find the solution intriguing. Read on...