I love Fat Kings! All hail the Fat Kings!
Disclaimer: All observations made by a non-scientific, real world, enthusiast in an uncontrolled outdoor natural environment, exposed to random variables of Mother Nature. All observations made today from 10:30 to 11:30 EDT.
Weather: 55 degrees, wet but not raining yet. 79% humidity with light 2-3 mph wind with occasional gusts up to 10mph coming from my 11 o'clock. Elevation = 73ft. No motorcycle riding today but good day for pellet testing.
The pellets: All purchased from PA during sales events 20 tins per order. 3 separate orders of JSB Skinny Kings 25.39gr , JSB Fat Kings 1 33.95 gr., and JSB Fat Kings 2 33.95gr. I picked 40 Pellets randomly from each of three tins. All pellets previously lubed with Remington spray Dry Lube. No washing or sorting.
The Gun: FX Bobcat mk1 with ST barrel. July 2016 surgical procedures and enhancements made by Dr. E.R. to optimize performance to shoot Fat Kings (highly recommended, ER is a wizard). ER voodoo included, reg set @ 155 bar, "increased" hammer weight (unspecified), and ER tweaked hammer spring tension. ER barrel voodoo procedure ( unspecified), all tuned and tested with skinny and fat kings. Results = 44 shots per 250 bar fill or 4 mags on the reg. Chrony Beta. Reverification today, from 200 bar, 10 shots each, refilled to 200 bar for each of three pellets. Skinny Kings = 973fps, Fat King 1 = 881fps, and Fat King 2 = 888fps all averages, all with very tight ES and SD. Only other mod to gun is a Huggett LDC (works great tames 59 FPE for neighbor friendly). Optics = Athlon Argos BTR 6-24x50 Mil/Mil with APMR reticle, 1/10th Mil Turrets. Zero distance is 48 yards set to Fat King 1 against a dead tree with smooth surface easy to see impact holes. Remaining pellets compared using same zero. All adjustments for pellet POI made using turrets, no holdover.
The Range: max range set up is 110 yards. Range is a 35 yard wide 110 yards long "tunnel" cut into dense woods with good wind protection. Why is it an odd 110 yards you ask? Because I'm former military and I still think and shoot in metric. My furthest installed metal spinner target is 100 meters or 109.4ish yards. Shooting position = indoors seated @ my breakfast table with back door open. Gun resting on rickety red plastic MTM Predator shooting rest. Yeah yeah, poke fun at me for shooting from indoors but I'm no longer in military and I'm a house cat now!
The Shooter: Awake 2 hours. Slight hangover but well caffeinated. Hungry AF no breakfast at time of test.
Comparitive observations. At 48 yard zero, the Fat King 1 makes one slightly enlarged hole on dead tree using 3 shots. Using same zero, the Fat King 2 shares the same hole 3 shots with last shot slightly clover leafed up and left by a couple mm. At same zero, the Skinny Kings shoot slightly over Fat Kings' impact but horizontally centered. Three 1/10th Mil clicks down brings the next 3 shots exactly in line with Fat Kings. I expected this difference given Skinny Kings higher MV and lighter weight.
Moving out in distances allows some comparison of trajectory, BC, wind susceptibility, and long range accuracy. Today's target is at 98 yards and is the Birchwood Casey metal spinners. The three different sizes: 3 5/8", 2 1/4" and 1 5/8" circles.
https://www.birchwoodcasey.com/Targets/World-of-Targets/World-of-Targets®-Qualifier®-Spinner.aspx For today's purposes, only the two smaller spinners were used. Why did I choose 98 yards? Because yours truly thought I lasered 90 meters but came up 1/2 a meter short when I piled up some dead logs behind the target for a backstop. Lesson learned, measure twice or three times and place your target first BEFORE making a backstop.
. So 98 yards it is.
Prep and order of shooting. Order = Fat King 1, then Fat King 2, then Skinny Kings. All pellets previously lubed with REM Dry Lube spray. Barrel cleaned with pull through patches between each pellet followed by 5 shots seasoning of each type before test. Gun refilled to 250 bar between each pellet type. The 2 1/4 inch spinner used for sighters 10 shots each with elevation turret adjustments and the 1 5/8 inch spinner used for final 22 shots each or 2 mags once fully dialed in. No windage adjustments or holder used during test.
Fat King 1 required 3.1 Mils of elevation adjustment on the sighter spinner's 6 o'clock position just at bottom edge. Dumped the remaining 22 shots aiming dead center on the 1 5/8 inch target with 22 hits.
Fat King 2 required 3.3 Mils of elevation adjustment to hit sighted 6 o'clock. Remaining 22 shots on smaller spinner center resulted in 21 hits. The missed shot fell just right of target. My guess is wind gust. Remember no horizontal adjustment or hold off.
Skinny Kings required 2.9 Mils of elevation to hit sighter 6 o'clock lower edge. Remaining 22 shots resulted in 19 hits with one shot dropping short by a small margin and the other two hitting just right of target but close to center line. My guess here is a combo of wind, pellet variation, and shooting the Skinnies at a pretty high velocity.
Bottom line for me: I love this ER magnum tuned .25 Bobcat (many thanks Ernest). Although the Fat King 2 started at a slightly higher velocity, it hit just a tad lower at terminal end indicating a lower BC than Fat King 1. Skinny Kings still shoot ok at this high velocity of 973 but are certainly more susceptible to wind. My BC observation is visual only since I was not prepared to sacrifice my Chrony at distance with an errant shot
Chairgun settings Fat Kings 1 = 881fps, scope height 2.7inch, 48 yard zero and BC .054. 58.5 FPE at muzzle and 37.2 at target.
Chairgun settings Fat Kings 2 = 888fps , scope height 2.7, 48 yard zero and BC .046. 59 FPE at muzzle and 35 at target.
Forgot to mention visual comparison of MK1 vs MK2 both purchased in Jan 2017 from PA. Comparing side by side, MK1 appear slightly taller, skirt is slighter more flared, wider at bottom edge and if you turn it over, the concavity of the hollow base goes just a little deeper. It also requires slightly more force to close the lever when loading an MK1.