King arms thompson help

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CivilWar63
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King arms thompson help

Post by CivilWar63 » Tue Aug 19, 2014 1:03 pm

I'm somewhat new to the hobby, and have a king arms thompson m1a1. I run .20 match grade crossman bb's. I've had it a few weeks and am starting to run into problems. The last 2 days it's begun to dry fire and have feeding/firing problems. The magazine will feed a couple rounds that fire just fine but then stops, dry fires, and then the rounds just dribble out. Only about 20 out of a 110 round mag fire correctly. The gun has no jam, the barrel had been cleaned, the magazine doesn't seem to be a problem because all 5 mags I have produce the and result. I'm beginning to think this is a hop up problem, but reset the hop up to 0 and I'm still having issues. Any help is appreciated.

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Re: King arms thompson help

Post by Touchette » Tue Aug 19, 2014 6:43 pm

Welcome to the forums.

I would suggest starting by getting better BB's, your best bet is to get to one of the airsoft retailers in MN or buy online. I'm partial to KSC Perfect .25g bb's, but everyone has their favorites and there is already a bunch of info on BB's available out there.

Good luck.
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CivilWar63
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Re: King arms thompson help

Post by CivilWar63 » Wed Aug 20, 2014 10:18 am

Touchette wrote:Welcome to the forums.

I would suggest starting by getting better BB's, your best bet is to get to one of the airsoft retailers in MN or buy online. I'm partial to KSC Perfect .25g bb's, but everyone has their favorites and there is already a bunch of info on BB's available out there.

Good luck.
Gun fired fine with the crossman's for a few weeks with no problems. I loaded up some airsoft elite .20's today and the problem persists. I've heard talk that it could be the air nozzle or tappet plate.

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Re: King arms thompson help

Post by neoM4tech » Wed Aug 20, 2014 5:22 pm

Start with the easy things. Inspect the bucking first. This can cause the feeding issues you describe, combined with the low quality bbs you are using, this is a very likely cause. If its not torn/worn then look at the end of the nozzle, see if it is bent or deformed. This happens when poor quality ammo jams in the gun or misfeeds and the nozzle doesn't hit the bb square on. If you need help there are lots of locals that can help. Depending where you are or if you are willing to travel I can give you some help. Message me if you want.

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Re: King arms thompson help

Post by CivilWar63 » Wed Aug 20, 2014 7:00 pm

neoM4tech wrote:Start with the easy things. Inspect the bucking first. This can cause the feeding issues you describe, combined with the low quality bbs you are using, this is a very likely cause. If its not torn/worn then look at the end of the nozzle, see if it is bent or deformed. This happens when poor quality ammo jams in the gun or misfeeds and the nozzle doesn't hit the bb square on. If you need help there are lots of locals that can help. Depending where you are or if you are willing to travel I can give you some help. Message me if you want.
Thanks, but niether shows any signs of wear. Anything else that could be causing this?

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Re: King arms thompson help

Post by neoM4tech » Thu Aug 21, 2014 9:24 pm

Next i would ensure the nozzle is moving with each shot. Look in the feeding tube of the hop up and watch the nozzle as you fire. If it isn't moving every time then you need to look at the tappet plate. To do this you will need to open the gearbox, so if you aren't comfortable opening the gearbox yourself then you need to find someone who is or take it to a shop. Personally i have not opened a v1 gearbox, but i have worked on just about everything else. They are all basically the same once you get the basics down.

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Re: King arms thompson help

Post by CivilWar63 » Sun Aug 24, 2014 11:38 am

neoM4tech wrote:Next i would ensure the nozzle is moving with each shot. Look in the feeding tube of the hop up and watch the nozzle as you fire. If it isn't moving every time then you need to look at the tappet plate. To do this you will need to open the gearbox, so if you aren't comfortable opening the gearbox yourself then you need to find someone who is or take it to a shop. Personally i have not opened a v1 gearbox, but i have worked on just about everything else. They are all basically the same once you get the basics down.
Yes, the nozzle is moving with each shot.

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Re: King arms thompson help

Post by CivilWar63 » Mon Aug 25, 2014 10:57 am

I put a magazine through her and she fired every time. Unfortunately, every round only went about 10 feet on a steep downward angle from the barrel. I started with the hop up turned all the way down and turned it all the way up eventually and it is still firing at a downward angle. My battery is fully charged.

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Re: King arms thompson help

Post by Tank » Tue Aug 26, 2014 9:05 am

It sounds like you have more than one problem here.
The BBs you are using are not very good, and could very easily explain the feed issues. The low velocity problem may be an entirely separate issue.

I think that your piston head is coming off of the piston.
You should NOT fire it anymore and have it serviced. If I'm correct, every time you pull the trigger you are causing more damage. The more damage, the more expensive the repair will be.
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Guges Mk3
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Re: King arms thompson help

Post by Guges Mk3 » Tue Aug 26, 2014 9:08 am

Also note....Crosman is not an OEM maker and neither is Airsoft Elite.

One batch of bbs from thee makers may be just fine and another batch could be junk...know your brands and keep trying main stream brands that are not rebrands...
I rather use a "nightmare" that shoots like a dream over something that looks like a "dream" but shoots like a nightmare.

Don't fear the gun...fear the one that's wielding it!

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Re: King arms thompson help

Post by CivilWar63 » Tue Aug 26, 2014 4:41 pm

Tank wrote:It sounds like you have more than one problem here.
The BBs you are using are not very good, and could very easily explain the feed issues. The low velocity problem may be an entirely separate issue.

I think that your piston head is coming off of the piston.
You should NOT fire it anymore and have it serviced. If I'm correct, every time you pull the trigger you are causing more damage. The more damage, the more expensive the repair will be.
Any shops you would recommend in the Coon Rapids area?

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Guges Mk3
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Re: King arms thompson help

Post by Guges Mk3 » Wed Aug 27, 2014 8:36 am

Opfor in Otsego and soon to be Elk River.
I rather use a "nightmare" that shoots like a dream over something that looks like a "dream" but shoots like a nightmare.

Don't fear the gun...fear the one that's wielding it!

CivilWar63
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Re: King arms thompson help

Post by CivilWar63 » Wed Oct 15, 2014 1:43 pm

Just stripped the gun again and found the air nozzle to not be looking so pretty... What quality air nozzles are there that will fit the king arms m1a1 and who is most likely to sell them?

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Guges Mk3
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Re: King arms thompson help

Post by Guges Mk3 » Thu Oct 16, 2014 7:24 am

KA nozzle get a KA replacement. OPFOR may have some....or paypal me 11.00 and I will mail you one.
I rather use a "nightmare" that shoots like a dream over something that looks like a "dream" but shoots like a nightmare.

Don't fear the gun...fear the one that's wielding it!

CivilWar63
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Re: King arms thompson help

Post by CivilWar63 » Fri Nov 07, 2014 6:47 am

Replaced the air nozzle, and got the gearbox back together EXCEPT the reversal latch. Can anyone post a picture of how a reversal latch and spring fits in a V6 gearbox?

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Guges Mk3
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Re: King arms thompson help

Post by Guges Mk3 » Fri Nov 07, 2014 9:13 am

Google > Image
I rather use a "nightmare" that shoots like a dream over something that looks like a "dream" but shoots like a nightmare.

Don't fear the gun...fear the one that's wielding it!

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Tank
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Re: King arms thompson help

Post by Tank » Tue Nov 11, 2014 7:20 pm

^^^^ That is a V2, not a V6.

But yeah google that shit. I'm sure someone somewhere has posted a pic.
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CivilWar63
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Re: King arms thompson help

Post by CivilWar63 » Thu Nov 13, 2014 9:09 am

I bought multiple airnozzles for the gun, a stock KA one, a 5KU one, and an element air one. The element air one is the only one that came with an o ring, I assume that this one would be the best to install but the o ring is too large to fit into the interior of the nozzle. I assume this is a manufacturers error, or am I simply installing the o ring wrong?

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