03The rubber that touches the BB

Buckings

The bucking is the only part of the rifle that touches the BB, and it has to match the chamber above. These are the same rubbers the SRS uses — the two platforms share this part, which is why the SR hop bucking is sold as an SRS and TAC-41 item.

The Kraken buckings are the VSR/GBB side: Gen 2 concave is the current one, Gen 1 is still stocked for builds set up around it. Concave means the contact patch wraps the BB rather than pressing on a single line, which is what keeps a heavy BB stable at range.

Silverback flat hop, by hardness

The AEG-side rubbers, sold by durometer: 50, 60, 70 and 80. Softer (lower number) grips more for the same adjustment but deforms sooner under a heavy spring; harder holds up to hot setups and heavy BBs but needs more pressure to bite. At 2.8 J with 0.40 g, start in the 60–70 range.

05Air system

Pistons

The piston is half of the noise your opponent hears. It is not only how much energy it moves, it is how it stops at the end of the stroke.

Stalker Scorpion for the TAC-41

This is the most adjustable part on the page. Piston mass is settable from about 65 to 148 grams, it carries two adjustable airbrakes — an airbrake traps a cushion of air ahead of the piston so it decelerates instead of hammering the cylinder head — and it comes with a spring guide. Silverback’s own claim for it is quieter running and more consistent joules shot to shot.

The one that gets overlooked: it supports an optional short-stroke setup. Shortening the stroke gives you a shorter bolt pull and a faster reload at the cost of some volume — worth it on a rifle you work quickly, and the reason to buy this over a fixed piston.

The factory pistons, in the open

The plain TAC-41 piston is 52 g: 6000-series aluminium body, steel piston end, silent 70° NBR head. The Variable Mass version plays the same mass game as the Scorpion but with a fixed set of parts — four aluminium and four steel counterweights, PTFE grease and the tools in the box. Both are shown here rather than hidden.

07Energy

Springs, joules and the legal limit

These are 13 mm outer diameter springs, the size shared by the TAC-41, SRS, SSG and VSR — which is why the same range serves all of them. Rapax are hand-made in Europe and their pitch is not only power but running quieter.

To play in Spain: 2.8 J

The one most people buy, and it ships with a spacer — no two builds are sealed identically, and the spacer is how you land just under the limit instead of over it.

The Rapax scale, by power

We quote the colour grades rather than exact joule figures on purpose: real energy depends on your cylinder, air seal, barrel and BB weight. Two rifles on the same spring do not chrono the same — and on the TAC-41 the Scorpion piston’s mass setting moves that number too.

Silverback, rated in newtons

Silverback labels by spring force in newtons rather than joules: 90 N, 100 N, 120 N, 150 N, plus the M130 and M150. More newtons means more energy but also a harder bolt pull, more piston slam and more mechanical noise. There is a point where a stronger spring costs you more in stealth than it gains you in range.

09The foundation

Chassis

This is the decision that shapes the rest of the build, because the chassis determines which handguards, rails and stocks fit. There are two families and they are not interchangeable.

The ARCA rail on the A chassis is the one feature worth calling out: it lets you slide the rifle fore and aft on a tripod or a compatible bipod and clamp anywhere, rather than being stuck with one fixed mounting point. If you shoot from a hide or off a tripod, that is the version to want.

The L / P polymer chassis kit is a complete set built around the TAC-41 action assembly. Lighter to carry all day, and the one to pick if you move a lot. There is also a plain polymer stock replacement here if all you need is a spare rear end.

11Mounting

Handguard and rails

TAC-41 A Handguard

A full replacement forend for the aluminium chassis: full-length Picatinny on top, 8.5 M-LOK slots each side, 4.5 on each 45° lower face and 4.5 underneath, CNC 6000-series aluminium hard-anodised black, 310 g. The detail that matters in practice: the outer barrel can be removed without taking the handguard off, so changing barrel length is not a full strip.

Front top M-LOK rails for the P chassis

Long (4 nylon lugs) or short (2 lugs), both bolting into the side M-LOK slots of the polymer body. They carry a rubber pad pushed by a set screw to fine-tune vertical alignment and kill the free-float flex — which is the honest admission that a rail hung off a polymer forend can move. Silverback’s own advice, and ours: if you use a bipod, put it on the tripod mount, not on this rail.

13Bolt handle

Bolt knobs

The bolt knob is pure ergonomics, and on a bolt-action that is not a small thing: it is the part you work between every single shot, usually with a glove on, usually without taking your eye off the scope.

By weight: the Light knob is the minimum at 20 g, the Vauban is 21 g in fibreglass-reinforced nylon with a steel nut, the Bakelite is 23 g and the original shape, and the Carbon and Grip knobs are the heavy end at 38 g. The Grip one is the interesting one — NBR80 O-rings for grip, and threaded on both sides so you can extend or shorten the bolt handle to suit your reach. On a conventional-layout rifle like the TAC-41 that reach adjustment matters more than it does on a bullpup.

15Trigger group

Trigger

Last on the page on purpose. A trigger will not add a metre of range, but it is what stops you pulling the shot off target at the moment of release.

The TAC-41 Match Trigger is CNC 6000-series aluminium, hard anodised, 20 g, riding on two 10×4 bearings with a steel axle. Bearings rather than plain bushings is what gives it a break with no grit in it. Two things adjust: trigger height and trigger angle — so you can set the blade where your finger naturally falls rather than reaching for it, which is the whole point on a rifle you shoot from awkward positions.