Crosman Optimus .177 rifle: Part 2
by B.B. Pelletier
Photos and test by Earl “Mac” McDonald
Crosman’s Optimus offers a lot of power for a low price.
Today is the day we find out if the Crosman Optimus delivers all the power it’s advertised to. We learned from the comments on Part 1 that several readers are watching this report because of all the potential value the Optimus has to offer.
Before I get to the velocities, though, there are a couple things for all of us to remember. When Mac took the rifle from the box, it was dripping with oil. Although it made sounds like the piston seal was dry, it also smoked a lot when shot, so he didn’t oil the piston seal.
The cocking effort is remarkably smooth. The piston squeak comes at the end of the cocking stroke.
Mac was very disappointed by the trigger. It has no defined stop, so you just have to keep on pulling it until the gun fires. That seems to be the experience of all who own this airgun, so be aware of it.
Okay, with all of that behind us, let’s take a look at the performance. Mac says the rifle is very stable and smooth when it fires.
The first pellet Mac tested was the RWS Superdome, which in .177 caliber weighs 8.3 grains. They averaged 930 f.p.s., with a spread from 919 to 944 f.p.s. At the average velocity, they generate 15.94 foot-pounds, or almost 16 foot-pounds. That’s a lot of power for a rifle in this price range. The Superdomes were the most powerful pellets Mac tested.
The next pellet he tried was the 10.2-grain JSB Exact dome. It averaged 807 f.p.s., with a spread from 795 to 815 f.p.s. The average muzzle energy was 14.75 foot-pounds. Heavier pellets usually deliver less power in spring-piston guns, so this is no surprise.
Next, Mac tried the 8.4-grain JSB Exact dome that should have been more powerful than the 10.2 pellets. It averaged 877 f.p.s., and the spread went from 867 to 889 f.p.s. That’s a muzzle energy of 14.35 foot-pounds, which seems to defy the rule mentioned above, however Mac says these pellets fit the breech of the rifle very loosely; so there could have been some air blowby. All other pellets tested fit the breech tightly.
Crosman Premier 7.9-grain pellets averaged 923 f.p.s., with a spread from 913 to 929 f.p.s. That’s just a 16 foot-second spread and the tightest of the whole test. At the average velocity, the Premier lites produced 14.95 foot-pounds of energy.
Mac also tried the heavy 10.5-grain Crosman Premiers. They averaged 759 f.p.s. and went from a low of 743 to a high of 770 f.p.s. That works out to an average of 13.43 foot-pounds of energy at the muzzle.
The last pellet Mac tested was the RWS HyperMAX. At 5.2 grains, these non-lead pellets are among the fastest pellets in the world. He got one velocity of 1138 f.p.s., but the firing characteristics of the gun were so harsh with this pellet that he didn’t complete the sequence. He was trying to see if the rifle could meet its published velocity of 1200 f.p.s., which it didn’t quite do. However, please remember that the piston seal was dry and also Mac didn’t use Crosman SSP pellets, which are the fastest on the market. At just 4 grains, they fly! Still, I’d say the rifle is within specs.
Next, we’ll test accuracy. At this point, the Optimus is stacking up to be an interesting air rifle. The appearance is okay for the price, and the powerplant seems very stable. I hope it can shoot!