It is a heavy rifle. They didn’t cut corners with this one, its made solid and from steel.The only plastic used is in the seals/o-rings; only a few parts aren’t made of machined steel .
A good bit of the weight comes from the main units. Breech is large, mostly solid, steel rectangle and the air tube is an unusually thick tube of steel (kind of over kill on the gas tube, it’s way thicker than needed,).
Very solid rifle, but no light weight and not a repeater (and no readily available conversions).
Here is an older post, shortened up a bit, from another forum:
MUST DOWN LOAD: It’s a long download, so save it to a file (or to your start up screen). It’s going to be your best friend if you decide to go inside the rifle.http://www.klickcue.com/air_rifle/b50_51/technical_details_for_adjusting_the_bam_b50_51.pdf
Probably bought as a “Combo-Special” with the scope. The Chinese made 3-9 and one piece mount is serviceable. May not be the best choice for a recoiling springer, but it holds zero, adjusts consistently, and is sharp and clear (but a little dim compared to higher $ glass).
At least to today’s airgunners. That odd shaped brass thing at the rear is how you cock it; works like a bolt handle: turn it sideways to unlock, pull it straight to the rear.
WHAT TO EXPECT AS ISSUED:
The blue on this example is the best of the cheap PCP’s . In fact, the polish and blue is better than several guns costing 2 or 3X as much.
It is fast. Perhaps too fast. Won’t quite get the advertized 1000fps with standard weight .22 pellets, but it’s decently close. Not going to get a long shot count as issued, but are going to see numbers (in .22) in the 960-980fps range with 14-14.3gr. pellets ( a bit over 30 foot pounds) and 865-875 with 18 – 21gr. pellets (call that 34 foot pounds).
Test gun in .22, but reports of the .177 put a stock gun getting a little bit MORE than 1000fps with heavier weight (10gr.) pellets (call it 20-23 foot pounds).
Can be adjusted to deliver a bit more energy or considerably less.
Trigger is adjustable by way of the supplied adjustment screws for a decent pull.
It’s loud. There is a “brake” on the end of the barrel, but it’s mostly cosmetic.
It’s a bit stiffer to cock than the others. It runs on a rather short stiff spring and a short striker travel compared to some other PCP’s, so the cocking effort is a little harder. Not excessively so, just noticeably.
Stocks are variable. Some are quite nice, some are butt-ugly (mostly knot holes or dark patching of a blemish). They fit a standard sized person quite well.
First shot strings:
14.3 gr. CP’s:
Rather than give the shot string, will just sum it up:
Average vel.: 957fps/ 29 foot pounds
Sweet spot shot count (925-955-925fps)= 22shots
Sweet spot fill: 170BAR- 115BAR
This is not bad for this power level, but while I’d prefer less power for my uses, believe it could easily be adjusted to get to 32-33 foot pounds. .
Something in the 22-25 foot pound range would have the most use for me, and if the sweet spot happened at a lower pressure, would make pump-filling a bit easier.
Added an extension to the issue “brake”.
Took off the barreled receiver and adjusted the striker length. By screwing that part in, increased the travel of the striker, increased the force of the hit to the valve stem, and boosted power.
Getting the barreled breech off just requires removing the brake, the barrel band, removing the scope, and loosening 4 screws. I decreased the length until nearly flush with the striker.
It’s a whole lot easier to take the barreled receiver off, then the end cap, remove screw #26 (from that download at the start of this post), hold the sear lever up, and slide the spring/guide/striker out from the back to do your adjustment.
14.3 gr. CP’s
Average Vel: 992fps / 31.2 foot pounds
Sweet spot shot count: 962-992-962 = 13 shots
Sweet spot fill: 185BAR – 125BAR
That wasn’t a direction I wanted to do, so took the barreled receiver and the end plug out, and cut the issue mainspring by one coil, making a new “dead end”.
With the striker nose adjustment in a middle range, got the following:
Average vel: 848fps/14.3gr./ 22.8foot pounds
Sweet spot: shot count (823-853-823): 28shots
Sweet spot fill: 135BAR – 95BAR
Not unexpected, by reducing the force of the spring tension to the striker, reduced the sweet spot fill pressure.
Adjusted “up” from there by taking it down again, and screwing IN the striker tip, which makes the striker have a longer travel 9higher vel) before it smacks the valve.
Average Vel.: 865 / 14.3 / 23.7 foot pounds
Sweet spot shot count ( 835-865-835) = 28 shots
Sweet spot fill pressure: 145BAR – 100BAR
Really, it was simple, I just missed it. Taking the gun apart, checking this, checking that, driving myself with those occasional (about 1 out of 7) “fliers” that randomly landed well out of a tight group.
Short and simple: the barrel is kind of free floated, the barrel band doesn’t grip the barrel tightly, the barrel is free to slide in and out, and even vibrate a bit side to side.
The brake slides onto the muzzle. DO NOT SLIDE IT INTO CONTACT WITH THE BARREL BAND!. As soon as I moved the brake forward to leave a little gap between it and the barrel band, my odd fliers stopped.
Wife is home, and she has a bad attitude about me shooting though her Kitchen and out the back door, so am back to 20yard tests. But with the brake slid forward, the groups are odd-flier-free.
Adjusted the scope after the first target. It really could use a little more “left”, decided to just leave it along for the last 5 targets. All shot on one fill, pushing things a little bit with the last target (28 sweet spot shots…but I shot 30 shots).