There are many quality Arbor presses on the market. But the K&M offers features that will be appreciated by anyone seeking ultimate reloading precision and control over bullet seating. This unit employs a unique toggle-link that provides ultra-smooth movement of the ram during bullet-seating. In addition, the bottom of the ram features a Bellville Washer stack, a spring that compresses during the seating stroke. This provides extra feedback during the seating process, and the spring compression can be monitored with an optional strain gauge that fits in the top. When you add the gauge to the unit you get a visual read-out of bullet seating effort. We've found empirically that when bullet seating force varies significantly from round to round, your ES jumps and accuracy falters. Using the K&M Arbor with the optional gauge lets you monitor seating force and thereby load more accurate ammo. It really works, and I'm completely sold on K&M's technology--at least for cases with light to moderate neck tension.
How does the K&M compare with other Arbors? Most Arbors use a screw thread or a rack and pinion. The K&M toggle link works differently and gives more leverage near the bottom of the seating stroke where you encounter more pressure (usually). The tip of the ram (that contacts the top of the Wilson die) holds a stack of Bellville Washers that are calibrated to give a specific amount of compression for each thousandth of travel. The strain gauge is a dial gauge with a floating tip. It seats in the top of the arbor. As the Bellville stack compresses, the dial gauge measures the amount of compression. This in turn, corresponds to the seating force in the case neck. With a little practice, you can seat very smoothly and consistently when monitoring the gauge. More importantly, you can really see if specific cases deliver more or less resistance to seating. And if you strike a doughnut, you'll see the needle spike.
Is the K&M press perfect? Well, not quite. To adjust the ram height, you have to loosen four Allen-head bolts. A simple quick-release handle (as found on the Sinclair and Harrell's arbor presses) would be better. But once you've set the height for your dies, that's really not much of an inconvenience. The other thing I noticed is that the K&M, with its spring-loaded ram, could use more leverage when seating cases with a lot of neck tension. I noted that when seating bullets into fresh Lapua brass taken right out of the box, I really had to mash down on the handle to get bullets to seat. For this reason I now slightly expand the necks of Lapua brass for the initial load, or I use the Forster seater in an RCBS turret press.
Order directly from Ken at:
Carbide Neck-turners, Arbor Press, Case Prep Tools
5430 Salmon Run Road
Dover, PA 17315
Phone: (717) 292-3175
Or, Precision Reloading carries all the popular K&M products at good prices.
Technical/Customer Service: 605-996-9984
124 S. Main St.
Mitchell, SD 57301