A while back I made a thread addressing many problems with my new MP7 and one of them was the accuracy. I've got everything else in check, and what remains is the obnoxious spread that riddles my gun. That's why I wanted to make a new thread focusing on only that.
When I got the gun, I thought the inaccuracy was caused by lubing the gun too generously. I bought this thing called EVO II from Maple Leaf. It replaced the original outer and inner barrels as well as the hop-up and the plastic pressing nub with a brass one.
The problem is still present. My BBs curve left and right, some fall short, some fly into the moon. Today I tested the accuracy at 180 ft. I know 150 ft is already very good for this gun, but I wanted to observe the trajectory a bit farther. The temperature was a little over 0 celcius. I understand that it's nowhere near optimal. A few different aspects of the problem:
Hop up adjustment
Before the EVO II, the best setting was 10 clicks CW. I'd have to use .25 or lighter to get a reasonable horizontal flight path. Only the BBs would almost fall to the ground after 100-ish feet (.28 earlier than that). A click higher flung the pellets almost straight up.
The problem remains largely the same except that now it's the 7th click and BBs still glide in an upward angle and then go down somewhere near 175 ft. 6th click means they hit the ground at 100 ft.
I don't know if this is the bucking's fault. After all both of the ones I've used enable this. The BBs seem to like left a lot better.
Still a bit problematic. The symptom that leads me to believe all this has something to do with the new parts breaking in. I strongly believe I had the exact same problem before the new hop up set.
The gun seems to double feed. The problem seems to be in recession, though. Right after having installed the EVO II set, I was getting double feeds all the time. Today about once per mag as far as I know.
Sometimes, after shooting either on full or semi, a BB would drop out of the tilted gun.
I believe the weather had something to do with the poor performance. Decreased range and muzzle velocity and all that. Still I know there is something wrong.
The new outer barrel can be twisted a little CW from its normal position. This is caused by a bit too deep grooves made by the manufacturer and does not twist the inner barrel.
I'm basing my consistency expectations loosely on my AEG which is JG AK Beta with a muzzle velocity of about 420 fps, everything stock.
The grouping at ~175 ft is mostly about 10x10 feet. I believe my AEG does somewhere near 4x4 at the same distance.
I was using non-lubricated gas.
.28g and .25g bio BBs from G&G
.20g bio BBs from GoldenBall
I'm sure I forgot information here and there, but I'll be adding it over time. Same goes for future testing of the performance.
Any thoughts and suggestions are welcome! Thank you in advance!
Edited by name.temp, 26 February 2014 - 11:30 AM.