In theory the Trilase can be used with any scope that it can be fitted to. At the moment this only includes one inch 25.4mm scopes provided there is enough clearance with the rifles magazine. One inch scopes are still in production today. There are not really any first focal plane scopes that are in one inch and side focus is perhaps the reason for the increase to 30mm, to allow room for the mechanism inside the tube. The one inch scopes do have the advantage of being more compact and lighter in weight. The 30mm scopes and larger are said to have the advantage of transmitting in more light than the one inch equivalent but this is not necessarily true.

The Trilase has some fairly strict requirements for scopes. The scope must be 25.4mm, it should really only have a fine duplex or MOA reticle.

Wide depth of field scopes also tend to work well with the Trilase. The side focus parallax adjustment feature tends to shorten the depth of field of the scope.

The less moving parts of the scope the greater the accuracy potential. The Trilase solves a lot of problems with targeting using rifle scopes; from parallax to trajectory compensation. So it can be used well with a sort of ‘hands off’ shooting approach for trajectory estimation and avoiding parallax error. This works well with a fairly low features rifle scope. A fixed parallax rifle scope can actually work very well with the Trilase providing the factory setting can be altered. The scope parallax can be reset from the factory setting in some models. This is done by loosening the front ring accessing an inner threaded ring holding the objective lens, adjusting this to a more suitable setting like 35 meters for air rifles. This is done by just sharp focusing the scope to 35m readjusting the objective lens threaded ring. Or better still by using the Trilase to see that the laser pattern in unmoving at a target at say 35m together with changing eye position. The scope is then parallax free at this range, this really improves a scope for air rifle usage.

Beamtek recommends the 4-12×40 AO second focal plain scope with duplex reticle, for use with the Trilase. These scopes are still produced in quantity by various manufactures such as Bushnell and Hawke to name a couple but there are many more. A 50mm lens lets in more light than a 40mm lens so provides better low light perfomance. Only side focus and fixed focus scopes can be used currently with the Trilase at 50mm.

Part of the reason Beamtek recommends front parallax adjustable scopes is simply ease of use. You do not necessarily need a ‘short depth of field’ side focus scope for use with the Trilase and an air rifle. This is because the Trilase can be used effectively to eliminate any parallax error. This is the same function of the short depth of field, side focus feature of scopes. So you can ‘sort of’ replace the short depth of field side focus feature with the Trilase and achieve a similar thing. This is done by using a front objective parallax adjustment scope with the Trilase. Any cost savings this makes, could be put into buying a better scope with improved optical clarity. Front objective parallax scopes are usually wider depth of field and probably have better potential for optical clarity than the side focus equivalents. The main reason side focus scopes tend to be better optically is because they are more expensive to produce, so tend to use better quality lenses. There are of course exceptions to this such as the Delta Optical scopes that use the front AO format and high quality glass. There are probably many more examples of high quality front AO scopes with good quality lenses. It is certainly the case in old models of scopes that were produced with good quality glass and AO parallax adjustment. Perhaps a fixed parallax scope that can be altered in the parallax free distance by removing the front ring and altering the lens position is one of the best ways to use a Trilase especially if it is in 50mm.

A recommended scope for the Trilase is the 4-12×40 AO Duplex. Although this scope is good scope type it can often suffer zero-shift in parallax adjustment. It has unfortunately been found that there is always a bit of zero-shift when adjusting the parallax setting of any rifle scope. Some people call this ‘mushy internals’ but it is really due to the fact that any moving part between the barrel and the LOS line of sight is a common source of accuracy alignment error. The better the scope is produced, the less the movement there is, but there is always some. Just like the argument that an under-lever is more accurate than a break barrel. It is the same with scopes, but perhaps the problem in scopes is more severe. Every adjustment of a scope is a source of unwanted movement. That is; elevation, windage, zoom magnification, parallax focus and the first focal plane feature all represent additional sources of movement when adjusted. Fortunately the zoom feature of the scope rarely affects zero and these effects are much more pronounced in cheaply made scopes. Through experimentation the cost of a scope is a common indication of build quality explaining why it is common to pay as much for a scope as an air rifle. This could not be more true than when the air rifle shooting becomes competitive.

Some shooters have learned through practice ‘to mess with the scope adjustments as little as possible’. Beamtek recommends using the Trilase with the scope parallax set to say 35 yards or the visual sweet point of the scope, using it just like a fixed parallax scope. Perhaps only using the zoom feature of the scope. So lowering the magnification to view closer targets and increasing it to view targets further away, this also inadvertently seems to bring the scope into focus without altering the parallax setting.

The Trilase can also be used effectively with side focus scopes, taking advantage of the fine adjustment available in these scopes.

The Trilase can be used as a reference for readjustment of the scope zero. When scope zero wander has occurred, the centre of the laser aim-point pattern should always be the LOS, so the scope can be re-calibrated to align with Trilase.

The Bushnell Banner 4-12×40 AO Multi-X is available and is good scope choice for use with the Trilase.

One scope that is interesting to use with the Trilase is a 6-24×40 AO duplex match scope. These are really long so could be used with multi shot PCPs that have protruding magazines, as the Trilase would be mounted closer to the mussel end. The main problem with these match scopes, is the difficulty in finding really good reliable examples in duplex and one inch. Scopes of this type are made by Delta Optical. Which includes high end Japanese optics, a lightweight example is the 4-16×42 AO Duplex which has not been yet been tested by Beamtek.

A modern equivalent second focal plane, side focus scope, with a fine etched reticle with a 50mm front objective, is the Bushnell Engage 6-18×50 with MOA reticule. This excellent scope has been tested by Beamtek and is recommended as one of the best quality scopes suitable for use with the Trilase.

The Trilase device is designed to be fixed laser aim-point, that is fixed beams. The lasers are adjusted, left at zero, so do not represent a movement point. Many people particularly FT shooters like to adjust the scope between shots. This is because they use scopes with a very low depth of field, ie focus sensitive, so that they can take full advantage of the range-finding feature of the side parallax at the same time as eliminating parallax error. Of course they require a top quality scope to do this effectively and these scopes are high cost. These scopes are almost always 30mm plus. The Trilase might work very well with these scope types but unfortunately a 30mm version is not yet available.

HFT often use 25.4mm scopes. The Trilase might be useful in HFT, if it were permitted. As it could greatly speed up the time it takes to make the shots as well as eliminating parallax error without adjusting the scope. The method of shooting used in HFT is very similar to the method recommended for use with Trilase. The only real difference is using the Trilase triple laser pattern for range finding rather than the bracketing method. Some of these HFT scopes are quite similar to the classic 4-12×40 AO and could be used with the Trilase. The Valiant Themys 4-12×40 AO at two hundred pounds is a fully adjustable example.

The Trilase might even be some use to the FT circuit in the future if it were in a 30mm version and permitted. It could be used to eliminate zero wander risk, by checking the scope reticle at the maximum ordinate for alignment with the laser pattern. Also, lasers could be used to check that parallax is set ‘error free’ and adjusted at the correct range. This could be done using Trilase the reverse way it is intended for; adjusting the side parallax or AO parallax setting, using the Trilase laser aim-point pattern as a fixed reference, to confirm that there is no parallax error movement at that range. Such that, the laser aim-point pattern is un-moving, compared to the scope reticle even when not looking through the centre of the optic, this would confirm the range setting of the scope is right. This is an even more precise way of using the parallax adjustment to determine range, compared with just checking that the sight picture is crisp.

In summary currently there are only some specific scope models that can be used well with the Trilase. When a 30mm Trilase version becomes available this scope selection will broaden. If a modern scope is required for the Trilase. A scope like the side parallax 6-18×50 MOA reticule Bushnell Engage is very suitable. Currently the 4-12×40 AO Duplex, wide depth of field, 25.4mm is the common scope choice for the Trilase.