Hakkotsu APM40A3 - BB's not loading.

[Sherbert85]

Won Hakkotsu "APM40A3" in prize raffle. NIB from Redwolf. Not my thing, but I've never had a BA before, so I thought what the heck, let's see what this is.

Loaded KA 0.25BBs into single magazine (not the supplied ammo from box) and test fired last night. Shot great, good distance, nice smooth bolt movement, no issues.

Loaded magazine this morning for more test firing / sighting in scope. Pulled bolt back, pushed forward, locked handle down, fired, no issues. Adjusted hop-up. Pulled bolt back, pushed forward, locked handle down, fired, no issues. Adjusted hop-up again to about "middle" position towards "more hop." Pulled bolt back, pushed forward, handle would not lock down into proper placement, resulting in ability to fire. Immediately identified this was a problem and did not force bolt.

Removed stock to assess barrel, trigger, and loading mechanisms. Removed trigger mechanism and inspected trigger and sear for breakage or wear, no obvious issues. Removed loading ramp from outer barrel assembly and found jammed BB in front of loading fin and under piston head area which was not loaded correctly and caused gap in bolt movement that prevented lowering of bolt handle.

Removed the bolt assembly from outer barrel, inspected for damage, noted very small shards of plastic stuck on grease from bolt near piston head and nozzle. Assumed that the loading mechanism had failed somehow, but did not see any obvious damage. Noted abrasion on front lower section of loading fin to explain plastic shareds, assumed to be from jammed bb forcing against it.

Reassembled gun, tested bolt movement while unloaded, dry fired, no issues. Turned the hop all the way off, suspecting that hop was interfering with loading or was on too far. Loaded magazine with 1 BB to test loading mechanism, pulled bolt back, BB did not chamber, jammed under piston head, same issue.

I am not familiar with these rifles, but this is obviously a failure of some sort, given it won't load again. It does not appear to be the firing mechanism or bolt, but the loading mechanism, which from what I've read is based or uses the TM L96 configuration. The magazine design is also "refined" from the TM L96 according to their manual and the engrish I can decipher.

What is the issue? Is this even worth my time? Should I continue diassembling the front barrel and hop-up? Pictures so far included.

I've noted that this Hakkotsu model is not well liked in reviews and regarded as medium to poor quality in both QC and performance. Wish I'd never fired it and just sold it, to be honest.

[Sherbert85]

Update: I got it firing again successfully for about 4 rounds before jamming again. This time there were 2 bbs jammed in the front, which leads me to believe it may be a double feeding or hop up issue

[Hectic]

yep, definately soumds like a hop up issue, but it could be in relation to too much hop, the allingnemt between the feed ramp and hop, or just the bbs. Not to familiar with the KA bb's i stick with bastards or madbulls exclusively, and even with alot of hop adjusted in a flat hop setup ony vsr 10 .43's never jam. My aegs and gbbr's as well, even with .36's (so a bunch of hop) no jamming. Only time i.had an issue was a promy smooth rubber in an lct akm, the slightly narrower part on the rubber (that mates up to the nozzel) was just too stiff or tight and it either would jam right away first shot or after2 or3 rounds. I would suggest tryin different bb's and or a different hop rubber, if it doesnt solve yer issue then it has to be something to do.with the alignment. I really liked the look of this gun but the feed ramp turned me off of it.
I assume it ways worsk if the hop is set low or off, just when you try to actually set it to lift tje bbs it jams?
good luck, keep us posted if u resolve the issue.

[Sherbert85]

Hectic,

I tore down the inner barrel and hop and found a rather poor quality rubber, complete with large seam down the middle. Feels very cheap, but this doesn't in itself seem to be the problem. I have a number of types of BBs to try out, but I've never had to align a spring rifle before. Got any tips?

And it still jams with hop full off, quite maddening. It's as if the BB never actually seats correctly from the ramp and winds up *under* the nozzle.

[Sherbert85]

I got it! It was a *multitude* of issues out of the box.

First, the loading ramp was poorly molded and required modification along the inner well at the first 35* bend. The loading plate/fin was hitting this point and forcefully scraping my BBs or jamming the bolt. With a little grinding down of that corner, it began feeding properly.

Also, the loading ramp did not seat correctly due to two notches on the upper rear plastic that are designed to sit under the screws holding the front barrel on. Those sections were sitting on *top* of those screws. I cut further back on those notches to ensure the screw heads were not pushing the ramp down and lo and behold this was interfering with how the ramp seats into the rear barrel portion. Once altered, the ramp's feed end (caught by the nozzle from the bolt) was in perfect position to be struck by the nozzle and it fed a whole mag perfectly.

THE 3 SCREWS ON THE LOADING RAMP NEEDED TO BE HAND TIGHTENED ONLY. Any more torque and it began misfeeding again. So apparently with this model it has to be *perfectly* lined up.

Mag... Next, the mag was too loose and resulting in bizarre loading behavior. I shimmed the magwell with electrical tape to reduce wobble, worked fine.

Lastly, the hop up. The hop rubber is absolute garbage. I observed that every shot was literally ripping it up. Replacing this resulted in smooth loading motion and perfect hop operation.

Also, the general quality of the parts is fairly poor. Three of the four screws on the stock/body stripped with a simple screw driver. These were replaced. It's a shame, but I wouldn't recommend this gun to anybody. I don't think it would stand up to any upgrading, better to get a decent base.

That said, it does shoot 380+ - 400 pretty consistently, as was advertised. But it took a lot of simple work to make it operational, and the internal parts as is are very low end and poorly made.

[TheRainbowWizard]

Joined forum just to ask you a few questions about this model. Please let us know if these issues seemed to be cleared up for good after your fix or if it broke again? Check your PM's please, and thanks!