Air Pellet Rifle Gun B3 4.5mm Caliber 650-600 FPS Wood Spring Barrel Gun New

Air Pellet Rifle Gun B3 4.5mm Caliber 650-600 FPS Wood Spring Barrel Gun New Sold by: isaazon on March 24, 2025 for $69.99My reviews are always 100% personal opinion on items I purchase for my own use, I do not receive items nor anything for my reviews ever!TLDR: Great air rifle for the money, lots of wood and steel with modern silicone breech and piston seals. Easy to modify with a Gas Ram into a Storm B3 Omni.This is the current model of the B3-3. I am a fan of these “industry” underlever Chinese air rifles and have older versions with all metal sights and metal trigger guard in .177 and .22. One is so old it even uses the old leather piston seal. This air rifle is the modern version using silicone breech and piston seals, plastic front sight, rear sight, and trigger guard. Older and newer used plastic receiver end caps. Older models had a sling. Older models did not have a rubber butt pad. You can find replacement seals in another venue, you can also search for wf600 for parts. AFAIK, these are manufactured by Shanghai Gong Zi Machinery Manufacturing Co. Ltd. (Shanghai Air Gun Factory) and Imported by Isaazon. At the time of writing this review (March 2025), isaazon website was nonresponsive.Out of the box this pellet gun shot Hawki 7gr lead diabolo round nose pellets at 650fps for 6.57fpe (8.9 joule). Measured on M2 chronograph.I currently have over 20 air rifles and pistols including multi-pump, PCP, gas piston and springers, break barrel and underlevers products from Air Venturi, Beeman, Air Arms, Diana, Benjamin, Crosman, Hatsan, Gamo, Umarex in .177, .22 and .25 and have noted a few truths. If the rifle is inaccurate, more energy is useless. Most pellets are inaccurate at higher velocities, especially supersonic where air temperature dominates for the actual speed of sound. Supersonic bodies do well if they have an ogive nose and a boat tail. Look at a pellet, two cones stuck together at their points (Diabolo). This shape is not conducive to supersonic flight. The exception for pellets are slugs. Some slugs can be used in magnums but are best in PCP. Keep in mind most advertised velocities are based on the lightest weight alloy pellets they could find and some could be an outright lie while others routinely exceed the advertised. This rifle meets the statement in the sellers description (650fps).The combination of wood, steel and plastic on this air rifle makes it look attractive. It’s not particularly lightweight nor heavy. The trigger is a beast and not in a good way but it works. It has a positive safety as well as an anti-bear trap safety. At this price point I have no qualms whatsoever traipsing around in the woods, mud and rain with this pellet gun while my heirlooms stay safely in the cabinet. And I cannot say the manufacturing is any better or any worse than any other made in china air rifle, and comparable to those made in Spain and Turkey. IMHO for a measly seventy smackaroos OOB, it’s a great air rifle. I may swap metal sights and trigger guards from an older B3-3 parts queen, and maybe even the sling. But the plastic parts won‘t rust. So maybe not.The other wonderful attribute of this inexpensive chunk of mostly steel and wood is that it is amazingly adaptable/modifiable. I have modified this to take a modified gas RAM. The modification on the gas ram is so that I can pressurize it to whatever pressure I want, thereby allowing adjustment of fps and fpe within a wide range. Obviously the other benefit of this is that I can re-pressurize the gas piston when it eventually leaks as they all do. I call this the Storm B3 Omni mod. LOLThe gas ram I used is Model: Air spring YQL254*108*18*8*750N. It has overall length of 254mm, a stroke length of 108mm, a body diameter of 18mm, external piston rod diameter of 8mm and 750 newtons of force = 168.607 pounds force. I drilled the back of the body with a 7mm drill bit and tapped it with an 8x1mm tap and epoxied in an 8mm foster quick connector (8mm Fill Nipple Male Quick Disconnect Valve with One Way Foster Stainless Steel for Paintball Airsoft PCP Diving Mountaineering):https://www.amazon.com/dp/B0CQX5JWLG?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_1&th=1And then I pressurize the ram to 1000, 1500, 2000, and 2500psi using a PCP compressor:https://www.amazon.com/gp/customer-reviews/R334T165ZSH225/ref=cm_cr_dp_d_rvw_ttl?ie=UTF8&ASIN=B0D7C8D35G1000psi yielded 528fps, 1500=568, 2000=628, 2500 psi got me back the original spring velocity of 650fps all runs using the same pellet of course, the previously mentioned Hawki 7gr round nose lead diabolo. At 3000psi there was very little noticeable increase (670fps, 12std dev) making 2500psi a good stopping point given this air spring and this piston chamber. I am unsure of the original pressure that spring piston came with so although I have had no problems, it could vent/rupture violently. Meaning, don’t do this mod. I point out this modification as a product improvement suggestion for Isaazon/ Shanghai Gong Zi Machinery Manufacturing Co. Ltd. Or some other entrepreneur.To do this conversion I needed to make two modifications to the rifle and modify one extra part. The receiver spring guide pin through hole needed bored out to 5/16” and the rifle stock at the rear of the receiver needed to be notched out. That’s it. I used a 1 1/8” half-moon router bit to notch out the stock.The additional part is a 5/8” shaft collar, stainless steel, 1/2” thick who’s ID was 1.125” which fit snugly inside this rifles rear receiver tube. The four I purchased for less than 10 bucks used 5/16”-18tpi set screws. I made two modifications to one of these shaft collars. First modification is to drill a second set screw hole opposite of the first using a letter “F” or 17/64 drill bit and then tapping it for 5/16”-18tpi and using the set screw from a second collar. This gives the collar two set screws on either side. The second modification was to drill the 5/8” shaft hole partially (not all the way through – leaving 1/8” undrilled) with a 3/4” drill bit. I used a drill press and vise grips for drilling both holes. This modified shaft collar serves as the end stop in the receiver for the modified gas ram.The rest is straight forward, disassemble barrel/receiver assembly from the stock (three Philips screws) and remove rear plastic receiver cover, use a press (warning – use a press or suitable spring compressor as the spring has a LOT of preload) to slightly compress the spring guide so the retaining pin slides out, remove the spring, plastic spring guide, drill the pin hole to accept the set screws as stops, insert modified gas ram and modified shaft collar, screw in set screws so they also catch the receiver tube, notch out wood stock to rear of receiver to accommodate pressurizing, reassemble stock to receiver and barrel assembly, pressurize the gas ram using a PCP compressor (a hand PCP pump would do) and shoot. Easy peasy pie.Hope this helps…