Airsoft Canada - View Single Post - King Arms M4A1 Velocity Drop/Feeding Problems

mc_tammer · December 30th, 2013, 22:18

Hey, all! I'm hoping somebody here can help me diagnose this problem. There are multiple stages so I'll list them one by one.

1) The gun doesn't fire a BB every time. For every 10 times I pull the trigger, maybe 4 or 5 BBs are fired. The motor turns and the piston cycles but no BB comes out. It happens regardless of whether the gun is set to Semi or Full Auto. I thought it might be a magazine feeding problem but the same thing happens regardless of whether I'm using the stock HiCap mag or spring-fed 75-round MidCap PTS EMags.

2) I can't hit a target 20 feet away. I set up an 8.5x11 sheet of paper with a half-inch circular point of aim in the middle and I can't hit it! When the gun DOES fire, the BBs begin to arc down almost immediately and impact the target stand and never the target itself. I should note that the hop-up is set to max.

3)The muzzle velocity is way low for my spring. The gun supposedly came with a 450FPS-rated spring but the last time I brought it to a gun doc for some wiring work, he chrono'd the gun afterwards and it was only shooting at around 290FPS. We figured it was maybe just the winter cold affecting the gun when I drove with it in my car trunk, or that the gun came with a lower-rated spring than I'd originally thought. However, when I tested it today, the gun had been in my house for weeks untouched so it can't be the cold, and I don't think the gun would have come with a spring so weak that it can barely propel a BB out the barrel.

Anyone have an idea as to what's wrong? I'd really appreciate any thoughts you may have regarding this.

December 30th, 2013, 22:18	#1
mc_tammer Trader rating Join Date: Jan 2010 Location: T-dot	King Arms M4A1 Velocity Drop/Feeding Problems Hey, all! I'm hoping somebody here can help me diagnose this problem. There are multiple stages so I'll list them one by one. 1) The gun doesn't fire a BB every time. For every 10 times I pull the trigger, maybe 4 or 5 BBs are fired. The motor turns and the piston cycles but no BB comes out. It happens regardless of whether the gun is set to Semi or Full Auto. I thought it might be a magazine feeding problem but the same thing happens regardless of whether I'm using the stock HiCap mag or spring-fed 75-round MidCap PTS EMags. 2) I can't hit a target 20 feet away. I set up an 8.5x11 sheet of paper with a half-inch circular point of aim in the middle and I can't hit it! When the gun DOES fire, the BBs begin to arc down almost immediately and impact the target stand and never the target itself. I should note that the hop-up is set to max. 3)The muzzle velocity is way low for my spring. The gun supposedly came with a 450FPS-rated spring but the last time I brought it to a gun doc for some wiring work, he chrono'd the gun afterwards and it was only shooting at around 290FPS. We figured it was maybe just the winter cold affecting the gun when I drove with it in my car trunk, or that the gun came with a lower-rated spring than I'd originally thought. However, when I tested it today, the gun had been in my house for weeks untouched so it can't be the cold, and I don't think the gun would have come with a spring so weak that it can barely propel a BB out the barrel. Anyone have an idea as to what's wrong? I'd really appreciate any thoughts you may have regarding this.