feet. They said it got cold after I left, the coldest in the last 30 years. So much for global warming. Each parking place in the Norma Mfg. facility parking lothas a hookup for car engine block and interior heaters. I stayed at a small hotel in Arvika, a town of about 25,000, 23 kilometers from the Norma plant. The people there were wonderful, so very friendly, the food was excellent and the beer may be the best in the world!
The Test Cartridges
The 6mm/52 SMc cartridge was specifically
designed for this test. It was designed to have the same internal
volume as the 6mm Remington, that cartridge being one of the most
efficient large capacity 6mm commercial cartridges available. We did
everything we could think of to make the test conditions the same
for both cartridges. The internal volume of the test cases, 6mm Rem
and 6/52, shown in figure 2, was equal within 1/4 grain of water,
which is less than normal manufacturing lot variability. However,
the 6mm/52 was about .4" shorter. We had Dave Kiff of Pacific Tool
and Gauge (a Precision Shooting advertiser) provide a chamber reamer
of each; type, both having the same neck, throat, leade and pilot
dimensions.
We obtained two stainless steel 6mm barrels from Border Barrels in England and had them shipped to the Norma facility, as it is now very difficult to ship gun parts in and out of the US. These barrels were as alike as possible in every respect. 1.25" diameter cylindrical, same 8.5" twist, same length, and same raw material lot, and manufactured in sequence. They were first chambered to '96 Swede Mauser actions and broken in together. After a 50 shot break-in with a lot of cleaning they were converted to pressure barrels by epoxying a 4" diameter sleeve over the chamber end, cutting off the threads then rechambering to the same 26.5" length. An "AN" type pressure tap hole was drilled into the center of the body of each case to match the Kistler high frequency pressure transducer as noted in figure 2.