I have purchased my first airgun Commando .22 cal

. I purchased from bangalore for Rs 3K. I also tried SISCO, DAWS and G.I.-35. All the three are very heavy 1~1.5 Kilos more than Commando. The trigger is rock hard and i am pulling to the right everytime when i tried to shoot.Cocking action is more or less the same on all models but the trigger is light but firm in the Commando. When you pull the trigger it moves without releasing the sear after 1-1.5cm travel further pressing down releases the sear. There is not much dieseling in the rifle. Infact there is not much oil and grease in the spring. I got Gsmith spring and washer is not available there.I was expecting some considerable loss of power after 100th shot but till now the power is good. I do not plan to put G-smith spring as of now. The breech seal was teared a bit during the purchase. The shop owner gave a new breech seal. Initially the sights are totally out of tune and I dont have any idea how to tune that. By trial and error the sights are somewhat better. I replaced the breech seal with a new one but unfortunately the groove is much deeper 6-6.5 mm which makes the new seal shallow and the air is escaping. It has moderate power can break ordinary bottles approx 25 meters (1st floor to the ground) but failed to break beer bottles. Previously it can make clean holes in the engine oil bottle but after the breech leak it cannot exit the can from the distance to 9 meters. I need to make some shims to compensate the height and planning to replace with O-ring. After successfully zero'ed the sight suddenly a new problem cropped up. After loading when I lock the gun the sear disengages automatically

. This is dangerous ,sometimes its holding up but many times its not. I need to fix this issue but not sure how to open the trigger assembly. Another problem is the master shot pellets are very tight. I need to press down very hard. When i measured with vernier caliper the bore size is approx 5.28mm from the breech end and 5.19mm from the muzzle end (Choked Barrel?). The pellet dia is approx 5.52mm. I really need to squeeze down to fit.
My hunt for better local Airgun is on. I would be getting AK Agni in the coming months. Another one could be Canon or IHP.
Good points:
1. Light weight compared to the other gun of the lot
2. Trigger is light and it has pre-determined pull
3. Accuracy is decent
4. Stock is decent, Balance is good
Bad points:
1. Unfortunately sear is not holding up when barrel is locked.
2. Front and rear sights are of poor quality
3. Trigger mechanism is within the tube. Not sure how to dismantle.
4. Pellet fitting is very tight and need to apply much force
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Trigger Assembly. Need help on dismantling
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