Gen 9 Priming Issues

Wouldn’t mind hearing from other Gen 9 owners about any issues they have with priming their M4s.

With the one I recently acquired I can fill the mag, fill the feed tube up to the keeper but when I fire it takes about 10 dry fires before I shoot gels. Filling up my old Gen 8 the same way I only had to dry fire two or three times. Gels feed fine after it’s primed, so I’m ruling out mag motor issues?

Any other owners found the same issue? :thinking:

Gen9 mags have a double reduction gear so feed is slower than other mags.

Okay… but it would still be at least one gel per cycle, yeah? Why the f#*k would JM change their mag gearing away from the Gen 8 setup if it worked? :exploding_head:

What I can’t work out is why with the feed tube full and only the t piece to fill I have to cycle it nearly a dozen times. The t piece only holds four or five gels. :thinking:

Might run my Gen 8 mag in it and see what it does. Is it possible to transplant the internals of a Gen 8 mag into a Gen 9?

Yep, you’re bang on the knocker there, Rattler. That double gearing also explains the difference in the capacity between the two generations. :+1:

Gen 8 mag filled the same way primes in two trigger pulls. Well, f#*k me if that ain’t dumb. :face_with_symbols_over_mouth:

Yep , the other thing to check is if the gear is slipping on the shaft

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Gear’s solid… but check this out…

Gen 9 on the left… much smaller. I was about to order spare Gen 9 mags, but I think I’ll opt for the Gen 8s.

Thanks for that info, Rattler. At the very least it’s made me open up my mags and give 'em a good clean out. :rofl:

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While they are apart oil the motor bushings both ends :+1:

Awesome… something to do… :rofl::rofl:

Just when I thought I had this sussed, a new hitch…

Because the Gen 9 mag motor feeds slower, half way into a Gen 8 mag and the t piece and barrel are full of gels and it jams.

Looks like I’m buying those shortarse Gen 9 mags after all. :roll_eyes:

I doubt that’s the mags fault

That’s what I figured… but the mag’s in, the t piece is lined up perfectly, everything looks okay… but a dozen gels in it jams… if I pop the mag I get showered with heaps of gels in the t piece and barrel. :man_shrugging:

Well I think you’ve found out you have an issue that was causing the original problem.
What size is the barrel and what size and type are the gels.
Give me all the specs for this blaster , speed , spring and mods from stock ?


It’s a Gen 9 M4, fitted with a 7.5mm alloy inner barrel 34cm long, aftermarket t piece from M4A1, 1.25 unequal spring, green o ring, 11.1v lipo… stock 18:1 nylon gearing and all original nozzle, cylinder head and piston… nothing wild about that setup.

It will empty a Gen 9 mag issue free with any gel (AKAs, ArmourTech greens, WI reds, milkies… all good).

With the Gen 8 mags all the gels will work for about 10 cycles before blocking up. Gels seem to fill the t piece and push up into the barrel. When it’s jammed if I point the muzzle downward, several gels roll out the barrel ( good name for a wartime ditty :joy:).

Makes no sense to me… I would have thought that if a Gen 8 mag feeds a Gen 8 t piece and barrel setup there’s no reason for it to be incompatible with a Gen 9.

Would it be worth throwing in the old plastic barrel and t piece and running a Gen 8 mag through it? T piece issue is about all I can think of at this point. :man_shrugging:

Sounds like your gels are too small, try some that will grow to 7.4 to 7.5mm.

Do didn’t mention the FPS your getting?

I thought of that too… :thinking: but if it were the gel size wouldn’t that be a consistent problem with both mags?

All the gels I put through it were freshly developed, btw.

Well not necessarily , the gen8 is feeding faster and if the gels are small it could feed two or more gels into the barrel then they hit each other when fired and cause jams, especially with the harder gels

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I haven’t put it through a chrono, not sure of fps…but I’d be guessing around 240 - 250… it’s noticeably less hard hitting than my Gen 8 that clocked 290 FPS on a chrono.

Barrel swaps are a piece of piss with these, so I’m going to swap back to the original to test and rule out possible aftermarket t piece issues… that’d be one potential cause ticked off.

If it starts to look like the issue you last posted, there’s nothing I can do about the mag speed issues, is there?

I’ve never seen a mag that feed too fast so I would be looking elsewhere.
The reason I asked about the FPS was to see how good you seals are because with hard gels blasters with weak seals jam easily and don’t have the power to clear the barrel and tbh with a 1.25mm unequal spring I would expect at least 300fps or more