Krieger Barrels Inc.

 

The Steel

There is nothing so important to the making of a good barrel as the steel that a barrel maker uses. Early on they realized they had to give the mill their own specifications for their steel, accept the higher cost, and then have each lot heat tested as it came in to assure compliance to their strict requirements. They started by having exhaustive metallurgical tests run on samples of both good and bad steel to determine, on a molecular level, what made good barrel steel. Having determined this, they met with representatives of the steel mill, the metallurgist, and the heat treater to discuss the results of their findings and to implement the changes that they needed. For over 30 years this process has never stopped, and Krieger Barrels continues to test and perfect the steel composition and heat treatment regime. They do not offer multiple grades of steel. All of their steel must meet the same standards. They do offer most of their barrels in a choice of either stainless steel or chrome moly. their stainless and chrome moly barrels are both held to the same standards from initial steel mill quality to final inspection of dimensions and finish.

Single-Point Cut-Rifling

Krieger Barrels rifle all of their barrels using the single-point cut-rifling process. Although their machines are state-of-the-art, the process itself is the oldest and slowest method of rifling a barrel. It’s also the most accurate. The cutter removes approximately .0001 inch, or 1 ten-thousandth of an inch, at each pass, thus taking several hundred passes to rifle a barrel. This method produces almost perfect concentricity between bore and groove, a very uniform twist rate, and induces no stress into the steel that later has to be relieved. Along the same lines, they do absolutely no straightening of their barrels as this would only put stress right back into the steel. their barrels are lapped after reaming to remove the tool marks, and then hand-lapped again after rifling. It has been said that if a barrel is cut-rifled correctly, it does not have to be finish lapped, and to some extent this is true. It should not have to be lapped to obtain uniformity of dimensions. This should come from the tooling and procedures used. But there is a slight improvement to the finish achieved by finish lapping, and the lay of the finish is now in the direction of the bullet travel so fouling is greatly reduced, and cleaning is made easier. It takes longer to finish lap, but they do it because it makes a better barrel. They are lapping to finishes under 16 micro-inch in the direction of the bullet travel. In contrast the government requires only a 32 micro-inch finish on its M-14 National Match barrels.