For our muzzleloaders, the Primary Arms 1x MicroPrisms scopes with the ACSS Cyclops reticle have been our favorite for the last few years. In 2026, Primary Arms came out with the ACSS Gemini 9mm reticle in the 1x SLx MicroPrism scope, a reticle that is looking to dethrone the ACSS Cyclops as our favorite 1x muzzleloader scope.
August 1, 2026
I have a lot of experience with the ACSS Cyclops reticle over the past few years and I am in the early stages of testing the newer ACSS Gemini 9mm reticle. I am in a waiting game with BPI Outdoors in getting a replacement Endura muzzleloader for the recalled Paramount I sent in weeks ago. Whenever my Endura shows up, I plan to mount the SLx with the ACSS Gemini 9mm reticle on it. As you can see in the following imagery, the Gemini 9mm is even finer and gives me additional potential holdover points.
The following photos showing targets and reticles were taken with my cell phone held behind the scopes on the range at 300 yards. I have zoomed in so that you can see the reticle and target better for this article. These reticles are very small and crisp, but you do need good eyesight to see them as well as any targets at ranges past around 200 yards.
Primary Arms 1x SLx MicroPrism with ACSS Cyclops Reticle on a 300 Yard Target
Primary Arms 1x SLx MicroPrism with ACSS Gemini 9mm Reticle on a 300 Yard Target
The top photo shows the ACSS Gemini 9mm aiming points aimed to the right and above an 11x17" target at 300 yards and the lower photo shows the ACSS Gemini 9mm chevron placed on the 11x17" target. The chevron is a little thinner on the ACSS Gemini 9mm reticle compared to the ACSS Cyclops reticle. The ACSS Gemini 9mm also has 2 additional holdover aiming dots. I'm really liking the size of this chevron to be able to see targets at a distance and not have the chevron covering up the whole target.
Primary Arms 1x SLx MicroPrism with ACSS Gemini 9mm Reticle Aiming Points for Our CVA Muzzleloaders
I was unable to find sizing specifications for the ACSS Gemini 9mm reticle, so I produced these measurements based on the size of the reticle when I viewed it on the range at 100 yards. My sizing is close, but I'm sure not perfect. With this reticle not available in the Strelok app, I did my best to calculate this sizing. I will update these charts as I start working with my new Endura, whenever I get it from BPI Outdoors.
Primary Arms SLx with ACSS Cyclops Reticle - 100 Yard Aim on a Deer-Sized Target
Primary Arms SLx with ACSS Cyclops Reticle - 200 Yard Aim on a Deer-Sized Target
Primary Arms SLx with ACSS Cyclops Reticle - 300 Yard Aim on a Deer-Sized Target
Primary Arms 1x microprism scope holdovers on a mule deer from Strelok Pro for 100, 200 and 300 yards with my CVA Paramount muzzleloader shooting 285 Gr Powerbelt ELR bullets.
The additional aiming points on the SLx 1x MicroPrism scope with ACSS Gemini 9mm reticle might be more beneficial to muzzleloaders like the CVA MR-X that have a max Blackhorn 209 powder charge of 77 grains by weight. Muzzleloaders that are shooting slower will have these additional aiming points falling in ranges that you would be able to see a deer-sized target with your naked eye. Hmm... I need my Endura so I can start testing the ACSS Gemini 9mm on the range. The additional aiming points might be for ranges too far for me to see a deer-sized target and effectively hit it. Come on BPI, I need my Endura so I can get to work testing this optic.
One thing to note on the SLx 1x MicroPrism with the ACSS Gemini 9mm reticle is that it currently only comes with an H1/T1 mount that is really high. I recommend getting a low-mount for it for use with a muzzleloader.
Ultimately, I would love for Primary Arms to place a target turret with a zero-stop on the 1x SLx MicroPrism scopes. Please, Primary Arms, Please!!!
See more info on why these scopes are our top choice for our muzzleloaders in this article: Best 1x Muzzleloader Scopes.
Primary Arms 1x SLx MicroPrism with H1/T1 Footprint
The H1/T1 footprint version on the left only comes with this really high mount. The standard SLx footprint is on the right and is shown mounted in its lowest position. This version comes with the supplied hardware to mount it at a couple of different heights and positions.
Here is what the H1/T1 footprint looks like on the SLx.
I purchased the Crimson Trace Low Red Dot mount, which has a footprint that matches the H1/T1 on the SLx. This footprint is a little confusing. It appears that this is a common red dot sight footprint, but I don't see it labeled as H1 or T1.