The Nesika Bay Action

By: Daniel Lilja

Recently Dave Brennan and I were discussing the number of new custom-made actions available, and he suggested that the readers of PRECISION SHOOTING might be interested in a regular column devoted to reviewing custom actions. He asked if I would undertake such a venture. Well, here is the first of what we hope will be a long lasting, informative, and interesting series.

To kick off this series, we will first take a look at the Nesika Bay action made in Washington state. I feel compelled to add where these actions are made, because my first reaction to the name was that it had a very Japanese ring to it. Not so. Proprietor Glen Harrison resides in the very scenic Puget Sound area, near a bay for which the actions were named. (Nesika has now relocated to Sturgis, South Dakota and Glen has started a new company; Defiance Machine in Columbia Falls, Montana)

Glen designed these actions with one purpose in mind: competitive benchrest shooting. Glen, an active and quite competitive benchrest shooter himself, decided that maybe he could improve on the state of the art. The fact that Glen had benchrest in mind does not mean, however, that these actions would be unsuitable for live varmint rifles. In fact, they would make an excellent foundation for a true varmint rifle. Bolt face head sizes are available for the .222 family, PPC line, and short .308 size cases.

The Nesika T action with a Nightforce 2.5-10x on top.
The Nesika T action with a Nightforce 2.5-10x on top.

I’m getting ahead of myself, though. Let’s discuss this action from the ground up. Glen decided that he wanted an extremely reliable and durable action, one that was both functionally well thought out and pleasing to the eye. From a material standpoint he chose a precipitation hardening stainless type steel, 15-5 Vacuum arc remelt PH. This steel (like its close cousin 17-4) offers a warp free, easily heat treatable, rust resistant, and exceptionally strong material, well suited for a rifle action. One of its drawbacks, however, is that it’s difficult to machine.

Unlike some actions made from precipitation hardening steel, the Nesika Bay is heat treated after machining. This results in a harder and stronger steel than if the action were left in its natural state. The Nesika Bay actions are hardened to Rockwell C-42.

Of interest, too, is that Glen has made a couple of actions from titanium instead of stainless steel. The only other difference between them is the price.

The bolt is made from one piece of heat treated 4340. It is hardened and drawn back to a hardness of Rockwell C-38. Now when I say one piece, I mean that the bolt handle is integral with the bolt body. In the accompanying photograph, a roughed out bolt is shown fresh off the
milling machine. This in my opinion is a very impressive bit of machining. According to Glen though, this type of machining is everyday work for the machine shops he contracts to do the machining work for him. But I’m getting ahead of myself again.

Glen designed the action completely on a 486 computer using AUTOCAD. This is THE program for computer aided design or CAD type work. It permits three dimensional views of parts and their interaction on the computer screen, long before the actual parts are made. One of the advantages to using CAD is a greatly reduced need for prototypes. This in turn reduces the time required to produce a product and helps ensure that the final design is the right one. Shop drawings for individual parts can be outputted to a plotter.

With an abundance of high-tech machine shops in his area, primarily because of the huge aircraft industry there, Glen decided to have the parts for his action farmed out rather than invest in hundreds of thousands of dollars in machine tools. Glen has 8 different shops that do work for him.

By choosing shops with a reputation for close tolerance work with difficult-to-machine materials, Nesika Bay has very close control on every aspect of machining. This attention to detail really shows on the finished product. In addition, all machine work in these shops is performed only under his watchful eye. In fact, ATF regulations require that he be in attendance while this work is being done, since he is the manufacturer. Glen does the final quality control work and assembly. Nesika Bay owns the designs and the tooling necessary to make these actions, as well.

There are two essential ingredients for producing a quality product. The first is a top flight design. The second is the quality put into its manufacture. Nesika Bay has both of these bases covered very well. There are a few things I would change, but we’ll cover that later.

The Nesika Bay action at first impression reminds me of an Arab mare: almost petite in size and very refined in appearance. Its overall length is 7.25″ and the width is 1.345″. Its weight is 34 ounces. This compares to an 8.50″ length for the Stolle Panda and 8.00″ for the Hall `M’. Both the Stolle and the Hall are 1.50″ wide. Because of its extensive use of aluminum, the Panda weighs less at 30.5 ounces while the `M’ comes in at 42.0 ounces. Fluting an `M’ bolt removes 2 ounces.

Production on the action begins with a drilled, reamed, and honed hole for the bolt. All other operations are referenced from this centerline. The lug ways are cut with state of the art, wire EDM machinery which leaves a very smooth, dimensionally accurate surface. Other operations on the exterior are performed with CNC milling machines and then cleaned up on a surface grinder. The final exterior finish is an attractive bead blasted finish.

As can be seen in the photos, the top of the action is composed of a series of facets that are 30 degrees from each other. If this sequence were followed completely around the action there would be 12 flats. In fact Glen has one rifle built up that has a barrel on it with 12 sides, matching the profile of the receiver. The top flat on the action is drilled and tapped with blind 6-48 holes and conventional .860″ spacing.

The bolt and loading port are available on either the right or left,or any combination. Personally, I like my bolt handles and politicians on the starboard side, and my loading ports on the more natural port side.

Nesika Bay bolts are fairly small in diameter at .590″. In comparison again, the Stolle is .700″ diameter and the Hall is .870″. I believe this smaller diameter bolt is one reason that the Nesika has the petite look to it. It is produced with 12 narrow flutes that can’t remove much weight
but do improve the looks and probably add to the overall smoothness noticed when operating the bolt.

A disadvantage associated with a small diameter bolt is the decreased camming power realized when opening the bolt and in cocking. Since the bolt handle becomes the cam follower riding on the opening cam of the action, its relative position to the bolt centerline is shorter with a small
diameter bolt. As a result it has less leverage. Again because of the small diameter, the cocking piece must follow its cam up a steeper angle. Because all bolts with 2 lugs rotate 90 degrees on opening, the cocking piece must return to its cocked position over a shorter area.

For example, with a .590″ diameter bolt the circumference of the bolt is 1.853″. If we divide that number by 4 to find out the distance over the 90 degree bolt lift, we find it is .463″. Compared to the .700″ diameter Stolle bolt the corresponding measurement would be .550″. And with the big Hall bolt, at .870″ diameter it would be .683″. If all three bolts have the same amount of striker fall, the Nesika Bay has to do its work over a shorter length, meaning it might have a bit stiffer bolt lift. Other factors enter into the equation though, such as striker spring tension, surface finishes, and hardness of the cocking cam and cocking piece. In all fairness to the Nesika, I can decock the striker and then recock it by hand with the bolt out of the action.

The bolt closing cam also is affected negatively with a smaller diameter. With this cam, the major diameter of the bolt lugs is the important dimension. With the Nesika Bay this diameter is .840″. Action makers have two places they can machine this cam surface, either on the bolt lugs
proper, or inside the action on the lug abutment. From a machining standpoint, it’s much easier to put this cam on the bolt lugs. In my judgment, it’s better to put it inside the action because it results in a stronger bolt and a cleaner appearance. Glen has chosen the more difficult inside method.

Like most custom actions, the Nesika’s bolt face is coned to aid in feeding. The angle is 120 degrees included. The extractor is the conventional sliding plate type. I mentioned earlier that the bolt was machined from one solid piece of steel. The actual bolt knob, however, is a separate aluminum sphere screwed onto the end of the handle. The bolt shroud is also aluminum with the 12 sided flat contour of the action neatly milled onto it. In the event of a case rupture, the gas is controlled through two .073″ diameter holes drilled into the bottom of a port side flute, behind the lugs.

While discussing the bolt, we’re going to take a look at two values related to bolt lug strength: bolt lug shear strength and bolt lug flex. Since this review is the first of more to come, I’m going to go into a brief definition of these two terms and how they are derived in an accompanying short article.

For the Nesika Bay action, firing a PPC size case at 65,000 PSI, the amount of bolt thrust generated is about 6990 pounds. The lug shear strength is 36,740 pounds. This is a respectable safety margin, and owners should have no fear of firing reasonably warm loads. The amount of bolt lug flex for these conditions is .0013″.

This action is designed for a Remington 700 type trigger, like all correctly designed custom actions. As with most actions of this genre, the trigger is held in place by a removable trigger carrier. This allows the action to be glued into a stock permanently but leaves the trigger
accessible and removable from the bottom with the trigger guard out of the way. The carrier is aluminum.

I do have a few minor criticisms of the Nesika Bay. I would make the bolt stop a bit wider to eliminate the chance of impressing a groove into the bolt lug when the lug is pulled hard against the stop. I have seen this happen with another action. (Incidentally, the bolt stop is made from titanium.)

I like the bolt handle, but I would either make it a little longer or possibly increase the diameter of the aluminum knob. In a stock that is wide through the action area, such as the McMillan, the handle will not protrude very much.

For some reason Glen chooses not to mark the bolts with the serial number of the action. I can see the potential for mixed up bolts if you are loading and cleaning with some buddies at a match who also have Nesika Bays. Or a gunsmith fitting up barrels to receivers in a batch, as I do, could mix up the bolts on his bench.

One other comment is the barrel thread pitch. I’ve installed barrels on many types of actions, most of which have had 16 TPI thread shanks. In fact I would almost consider 16 TPI as standard. The Nesika Bay, though, has 20 TPI. Not a big deal, but one worth mentioning.

I was impressed enough with the Nesika Bay that I bought one. While I haven’t shot it in many matches yet, it has performed well, including a ‘teen agg and an .090″ 100 yard group. My wife has owned a few Arab mares, and fortunately the similarity between the two ends in the eye of the beholder. Unlike the horse, my Nesika has a pleasant temperament, doesn’t kick, and is all fun to use.

Glen Harrison, the original principal of Nesika, is now making an even further refinement of the bolt action under the Defiance Machine brand. Their website is: http://defiancemachine.com/      406-756-2727