PDI hop up adjustment screws

Just got done testing out the rifle this morning. After two hours of adjusting, dissembling, reassembling, changing buckings, nubbings, etc. etc. still no luck.

It started off with me just tweaking the screws to adjust the hop up correctly. Then wild shots all over the place. So I checked the bucking, then decided to switch it. I literally put everything together perfectly. Everything aligned, so I thought I was ready to go. The bbs decided not to feed this time, so I took it apart again. A new problem came up when the magazine catch decided to fling a few of its pieces around. The outer barrel assembly and mag catch got stuck to the stock. After a few minutes of fiddling with that, I got that apart. So I went to work on the hop up chamber. Then the outer (largest) o ring on the hop up chamber decided to snap. So I got a new one, and final one from my repair kit. I put the inner barrel and hop up back into the outer barrel. When I slid the cylinder in, the rug on my carpet decided to stick to the hop up chamber, and got jammed up pretty good. A few minutes to get the carpet out, and I was on my way again. Went outside, took some shots, and still jamming up. So I decided to call it a day, after around 2 hours of my time, 300 rounds, and three dissembles and reassembles of the rifle.

I guess not everyday is a good day

Edit: I just could not quit on the rifle just yet. So I did some more tweaking, and now my magazine catch broke. I had a spare so I dropped that one in. Then the screw in the magazine catch stripped so now I have a wobbly magazine catch, that can barely hold in the magazine. Not to mention, after TWO more hours of fiddling with the rifle, I still have not solved the problem. It seems the rifle wants to fling some plastic left now, rather than to the right. :-/

Edit Edit:

Ok, two more hours of tweaking, and still sparatic shots all over the place.

Here is what I know is not the problem

1. Nubbin: I changed it four times
2. Bucking: Changed it four times as well, and its aligned correctly, no doubt there
3. BB weight: Changed it many times
4. Barrel vibration: I added a few more spacers

What might be the problem
1. Spring: This might sound odd, but after taking some shots, I noticed the consistency was not there. This is the stock spring that came with my rifle over two years ago. Maybe its worn down. Not to mention, the consistency of a clone rifle spring is probably very very bad. This could result in the sparatic shots. Each bb is propelled by a different amount of fps, resulting in inconsistent shots.
2. The hop up adjustment screws: I was pretty sure I fixed this, so I doubt this is still the problem. They are in there tight.

What to you guys think? I am leaning towards the spring. Its inconsistent fps output could cause the bbs to go all over the place.

Example:
shot 1: 387 fps
shot 2: 367 fps
shot 3: 378 fps

I do not own a chrono so these are just examples. Any thoughts on this?

Keep in mind I have adjusted the hop up in every way possible and have done this for over 30 some hours. Maybe more. Its driving me crazy. :'(

Haha, I decided to take the next few days off after this crazyness It will give me some time to get an order together for some stuff I need, including some more bbs, and a new spring.

By cylinder nozzle, I am guessing that is another term for cylinder head? If so, its a laylax cylinder head that looks like its in pretty good shape to me. But I can check it out again later when I dissemble it all again.

The spring is very very old, and that is what I am thinking is the problem. It just seems to be putting out sparatic fps ranges, so that could be causing the major inconsistency.

As for the nub. I tried using the pdi nub, and when the sparatic shots occurred, I immediately thought the nub was the problem. Switched over to the scs, same thing happened. Switched back to the pdi nubbin for now. So the nub is not the problem.

Thanks for the input. At this point, its got to be the spring. Nothing else makes any sense. Heck, I even switched out the hop up arms for my spares and same thing happened.

Ill keep you posted in the upcoming weeks. It should take around 8 days for my order to come from airsoftgi, and I have not even placed it yet.

That will give me some down time. Otherwise, I see myself throwing the rifle into a lake or something

Actually he uses the scs nubbin in the pdi chamber. He just meant that even if you use a great nubbing such as the pdi nub, or scs nub, best bucking, perfectly aligned, etc. etc. you will still have consistency problems when you are having various fps outputs.

http://shredderscs.proboards.com/index.cgi?board=pdi&action=display&thread=46

He got it to work by using some glue like substance. Scroll down the page.

Edit: Here is a conversation about a problem that is the same as mine:

"I've done that b4 except that i make it 4 pieces 2 for rear & 2 for front, mayb it will work. The strange thing is after i adjusted the hop up screws, the hop effect is very minimal for few shots lets say....5-6 shots & then suddenly the bbs went straight up like over hop even though i didn't adjust it. It is very weird since then as if the hop up doesn't sits properly. I think of it like a self adjust. I thought mayb the 2 screws is too loose causing it to adjust itself or the hop up lever spring that push the levers down is weak or inconsistant bbs weight. Go me puzzle at that time till now."

Click to expand...

Snake, ive met the same problem. the screws tend to loose as you fire, dont ask me why, but they do. In my case i was geting more hop on one side (left) the more shooting ive done.

Click to expand...

Solution: Lockite or any glue for screws will do. it worked wonders for me. The adjusting is not as smooth as it was, but it stoped geting more hop after few shots.

i hope this helps you.

Click to expand...

They were having the same problem. So far, going with the teflon tape, it seems to work somewhat. Can't really say how well since I do not have consistent fps output. But if the spring ends up not being the problem, perhaps I just need to work on the screws some more.

On another note, the stuff on that forum is very interesting. They talk about how that little silver piece on the pdi hop up chamber comes loose which could cause turning of the hop up chamber, despite if the two small screws (not the hop up ones) are in place. Everytime I take apart my rifle, that piece is loose and sometimes not even attached. I just put some tape on the barrel next to it, to keep it from moving around. Also, how the hop up arms are a little flimsy and how there is too much room for the arms to move around. Looks like a few mods in the future are in order, and I will see how it goes.

Edit Edit :

I have everything dissembled now, and am going to spend the next few days cleaning my rifle and its parts. I know vindi had a guide somewhere on how to clean your inner barrel, but I do not have access to some of the stuff he used. Woogie, what do you use to clean your barrel? I saw some stuff online, but I just do not trust some of the stuff they are doing.

Update!

Just got the zero trigger in last night. Put everything together and all the bits and pieces are aligned perfectly. One thing that is a little flimsy is the magazine catch which is connected to the hop up chamber. The screw stripped so I can only put it in so far. It makes the chamber alittle loose and flimsy, but hopefully that wont affect things too much.

Going to go test out the rifle soon. Update to come.

Update

Not good news :-/

1. The shots were consistently shooting left. Major curves after around 75-100 feet. Some were slight curves, but for the most part, the bbs just took off to the left.
2. Misfeeds: something wrong with the bucking or something. It was perfectly aligned. Only misfed around 5 times, then it stopped.
3. All of a sudden sparatic shots, up, down, left, right. All over the place. I had no clue where the next shot would go
4. The spring guide stopper decided to fall out in the process of me pulling the bolt back. I had to take off the barrel, and readjust the the trigger box, as cylinder unit could not go back in (fell out because the spring guide stopper got too loose.

I stopped after that. Just too tired to deal with it. At this point I have learned some new things.

1. Its not the spring that is causing the sparatic shots. The new spring has caused no changes in performance.
2. I have not cleaned the barrel yet. While this could be the problem, I doubt it at the moment. Reason being the shots had been consistent to the left, until the very end. Maybe I am wrong. Still got to get a barrel cleaning kit. So we will see if that helps.
3. It could be the nubbin. I am using the pdi nubbin. It seems the inconsistency could be coming from the nubb. I will try out a guarder nub to use along with my guarder bucking.

So I have to try out a few more things yet. Kind of disappointed. What puzzles me is the fact that the shots now go to the left instead of the right. Thats the kicker.... ???

Sorry for the double post, I want to let you guys know that I have an update

Ok, so I decided to put in some new things and take out some others.

What I took out:
1. pdi nubbin
2. guarder bucking: was ripped at the end; most likely was a part of the problem
3. High Hop up arms

What I put in:
1. Prommy nubbin: Way softer than the PDI nubbin. Since I am only shooting around 450 I should be good.
2. Prommy bucking (soft) (replaced the ripped guarder one)
3. Regular Hop up arms

I am hoping to see some major improvements.

Again, apologies for the double post. Just giving you guys a good ol' update. Wish me luck