NEW M4a1 gen 8 - Only Firing Downwards!

Hi All,

So took delivery of my brand new Jin Ming Gen 8 M4a1 today. It’s all together GELS ready but disappointed to find it only seems to fire the balls out (kind of ) consistently when I am pointing the muzzle at the floor! Otherwise, it only shoots a ball out every 5 or 6 fires… A completely NOOB issue I am sure but if I could get some guidance I’d be very grateful!

Hi and welcome…

Sounds like small balls to me?

What gels are you using? Not those crap blue gels that come with it?

Chuck them and get some red packet milkies or something decent.

Being a Gen 8, it is likely in desperate need of a real spring and a decent seal…


Thanks for the advice, yeah, stock gel balls can the box. May I ask you for the best way forward in terms of optimal upgrades and a cost effective place to buy the milkies? Thanks in advance!

Could be an air seal issue as well.
The advice you have is valid. It may seems like a waste but the gels that come with a blaster unless branded (there’s always a first) is best used in air fresheners, bath gels or binned.
Get to know the inner diameter of the barrel of your blaster and the diameter of the gels you intend to use. The gels should be slightly wider and reasonably consistent in size.

Have you found gels larger than the barrel id to be beneficial ?


Not if you prefer to see gels just falling out the barrel.

Oh testy :rofl:
May I suggest you try using a mosfet with active brake or an active braking module.
This would solve a few issues your having because there would never be a gel in the breach when not firing.

  1. Gels falling out of the barrel
  2. Harder gels smashing in you tight barrels

Plus you will get a few bonuses…
Better trigger response
More speed
Better accuracy


Decide on an inner barrel ID and type

I like the 7.3ID stainless ones. I have some nice FB 7.2ID alu ones but the SS are the tits for many reasons.

Gel size is a function of your barrel ID

Upgrades for your adventure, knowing I have no clue what’s in your blaster

  1. Oring
  2. Piston head with bearing - if needed
  3. Cylinder head (or glue it to the stock cylinder - airseal)
  4. Nozzle with oring - absolutely has to be the right one
  5. Metal gearing and new piston ladder (usually whole piston)
  6. Barrel
  7. If you want ROF a motor or 3s I’d you are running 2s
  8. Hopup. I like the rizers
  9. MOSFET of some kind. An active brake will serve you well in a gen8
  10. Spring retainer with bearing
  11. Spring. Resist larger than 1.3 until you decide how you want to play
  12. A vision in your head of play style and performance

Now some of this may already have been done. You won’t know until you look into it

Some of it you don’t have to do, other bits you really want to get some skill before you do.

There is tons of chatter about current gels and which ones are decent available from the search on this board



Thanks for the info everyone. Its a stock blaster with no upgrades so a completely blank canvas. Knowing my noon status is there a kit I can buy that will cover the initial bases? Thanks in advance.