Not enough hop

[Hallam87]

Hi All,

I have an asg mk13 sniper rifle and am having issues regarding the hop up. It's not getting enough hop at all and if I go too far the BB just gets stuck. It's got a unicorn 6.03 inner barrel, 4uad friction pro bucking, the original har concave nub that fits under the hop arm. Presuming the hop up chamber is just a standard vsr 10 as it's fully vsr compatible.

Thanks in advance

All help will be greatly appreciated as it's doing my head in lol ?

 

[ButcherBill]

Have you checked that the nub is fitted correctly?

 

[Hallam87]

Have you checked that the nub is fitted correctly?

Yes buddy, it will only go in one way as it has 2 little arms that fit into a slot. Sort of like a t-piece

 

[Rogerborg]

Hmm. Two things occur:

1. The bucking has got fouled with something slippery - silicone, or grease. I've even had it happen when I silicone lubed a magazine and the BBs transferred lube to the bucking more than I'd expected.

2. Not enough puff to push the BBs past the bucking. Weak spring, or knackered air seal?

 

[Hallam87]

Hmm. Two things occur:

1. The bucking has got fouled with something slippery - silicone, or grease. I've even had it happen when I silicone lubed a magazine and the BBs transferred lube to the bucking more than I'd expected.

2. Not enough puff to push the BBs past the bucking. Weak spring, or knackered air seal?

I'll have it apart and check the bucking, what would be the best way to check the air seal? 

 

[Rogerborg]

what would be the best way to check the air seal? 

Depends how far you're stripping it down. If it's all the way to components, then start with piston and cylinder. Seal the end with your hand or whatever squishy surface you have handy, and push the piston sharply forwards - a perfect airseal will stop it dead.  If it's leaking around the piston ring(s), replace, grease, or stretch it/them.

Then add cylinder head and repeat, and then the nozzle and repeat - and test the seal with nozzle forwards, not pushed back against the cylinder head.  Finally, push the hop unit and barrel against the gearbox, finger on the end of the barrel, and check that you still have good seal, as shown here (actually, just start here and work backwards if you don't have a good seal).

What I don't recommend is doing this with the gearbox intact, using the gears and motor, as you're begging to strip the cylinder.

If you have a quick-change gearbox, you pull the spring and test with a long screwdriver or rod pushed in from the rear.

 

[Hallam87]

5 hours ago, Rogerborg said:



Depends how far you're stripping it down. If it's all the way to components, then start with piston and cylinder. Seal the end with your hand or whatever squishy surface you have handy, and push the piston sharply forwards - a perfect airseal will stop it dead.  If it's leaking around the piston ring(s), replace, grease, or stretch it/them.

Then add cylinder head and repeat, and then the nozzle and repeat - and test the seal with nozzle forwards, not pushed back against the cylinder head.  Finally, push the hop unit and barrel against the gearbox, finger on the end of the barrel, and check that you still have good seal, as shown here (actually, just start here and work backwards if you don't have a good seal).

Thanks buddy I guess I can follow this process apart from the gearbox as it's a spring sniper rifle

 

[Rogerborg]

Thanks buddy I guess I can follow this process apart from the gearbox as it's a spring sniper rifle

Oh, sorry, my mistake, I was thinking of the chap with the weird BB-stuck-in-hop issue.  Yes, it's much easier with a springer - just mash your finger in the end of the barrel to see if there's good seal there. You should be able to shoot it, remove your finger, and hear a pop.  If so, you're good.  If not, something is leaking, and it's a question of working backwards to find where.

Have you changed the stock spring?  Stock seems to be around 1.8J, but some snipers come super-weak out of the box to be safe in all markets.