Miniature BSA Switch Barrel Martini .17 HMR, .22 WRM Barreled Action

Miniature BSA Switch Barrel Martini .17 HMR, .22 WRM Barreled Action

Posted by Morris Melani on 1st Jun 2018

This rifle exhibits the culmination of features that were initiated when I designed and created four barrels for a takedown BSA Model 6 action, for my friend Denny Daigger. This project developed into one of the most perfect Martini’s I have ever seen and became the proofing project for production of sophisticated barrel contours using CNC mill. Additional features evolved as another miniature Martini project was being created and this and my barreled action project were developed in parallel.

Although the action was a Model 12, a BSA model that has thick side walls, I liked the contour of the takedown Model 6 that I had worked on earlier. The non-takedown Model 6 has thin side walls but the takedown Model 6 has narrow bolsters at the front of the action. These bolsters were necessary to accommodate the cross screw used in the takedown system but for a custom rifle these become panels for engraving enhancements that would not be possible with a full flat surface. By milling and surface grinding the Model 12 became a Model 6 takedown contour.

The takedown screw hole was welded up and the screw that retains the trigger group was replaced with a much sleeker spring retained takedown pin.

Additional modifications to the action included reduction of the action's original 7/16" through bolt hole to 1/4", making a new 1/4" through bolt. The rear of the action was scalloped and a small top tang was added to the rear of the action.

The cleaning rod hole at the rear of the action was opened up slightly using an EDM electrode that also had a small inverted 'V' at its top. This 'V' provides index guidance as the sight base is inserted into the hole.

A #29 1/2 and a #30 1/2 vintage Lyman windage adjustable peep sights were the foundation for the rear sights. I removed the bases of each sight and using D-2 steel I created bases that have a spud that inserts into the modified action cleaning rod hole. A vertical thumb screw secures the indexed sight into place. The new bases were heat treated to ensure a lifetime of use.

This is a switch barrel action with two barrels chambered for .17 HMR and .22 WMR. Because both cartridges are rimfires and share the same head dimensions no modification of the breach block or extractor was necessary.

A new lever was profiled on the CNC mill. This lever has an elegant cylinder at its end its curve will make for an eye-pleasing stock pistol grip.

The final action modification was milling a small and narrow notch in the receiver face. The barrel takedown system has a longitudinal bolt and its tip slides into this notch to properly index and lock each barrel into place.

The barrels have identical profiles that are full length ovates with petite integral ¼ ribs. The rib can be used to accommodate detachable scope mounts or for a fixed rear sight.

The small front ramp is longitudinally dovetailed to accept Recknagel front blades available from NECG.

Integral sling swivel stud that accommodates the Recknagel small sling loops, again available from NECG.

The integral fore end lug is located 4” forward of the receiver face and has a slight draft on the sides to facilitate forearm stocking.

The takedown system I designed is solidly dovetailed to the bottom of the barrel. The locking bolt moves longitudinally within the housing under spring tension and slips into the notch at the front of the action. The actuation button is visible on the bottom of the action in the forearm and is designed to lock into the open position when moved rearward and then snap into the locked position once the barrel has been indexed. This petite button is ideal for checkering.

This has become one of the most unique rifle projects I have ever created and is worthy of only the finest stocking, engraving and case work.