[souponherhed]

I've just upgraded my L96 with the following:
PDI Hop Chamber
PDI 6.05x495mm Barrel
Laylax Zero Trigger
Laylax 3 Element Piston
Laylax Spring Guide
Laylax Piston Head (accuracy cup thingy)
Laylax Teflon Cylinder
Laylax Cylinder Head
Laylax 170sp Spring

It's shooting quite hot now though - 590 on .2s, so I need to lose 90 FPS.
590 on .2s = 417 on .4s, both make a horrible rattle noise as I shoot. What could it be? Or is it simply the high velocity?
It used to do it with .2s when I was shooting 500 FPS, but not with .4s (travelling at 360 FPS).

Another problem I'm having is the cylinder scraping on the inside of the outer barrel as I push the bolt forwards. I've lubricated it, but it's not made a difference. The outer barrel is a PDI Fluted one if that helps.

I also, had problem with a Prommy hard rubber. The lip (where BBs enter, that stops it going all the way over the barrel) is really tough and BBs get jammed on it, making it extremely hard to push the bolt forwards, and when I do, the BBs are completely ruined, and now the hop rubber's in pretty bad shape. Any idea on this? It was definitely on right.

And finally, apart from getting a new spring, what's the best way to lower FPS? If cutting the spring, I know one coil at a time, but do I have to sand it down or smooth it off? And which way round does it go, cut end in the piston, or cut end on the spring guide?

Sorry for rambling a bit, but I kinda need this rifle shooting perfectly for two weeks time as I have a weekender and want some nice hits .

Thanks a lot,
Liam

 

[~Ranger~]

All I can help with is the scraping part. That sounds like your missing your front plastic ring that goes inside the reciever that keeps your cylinder in place without wobble or grinding. Take off your outer barrel and look inside the front of the reciever. Should be a white ring.

 

[woogie]

Yup ranger nailed it on the scrapping. If you are missing that little ring, try and find one of those old plastic film canisters. You can cut the bottom off, and cut down the side. With a little fitting you can get the canister to fit and you have a nice little sleeve

For the spring, yes go very slow as one wrong cut and you are out a spring. And yes you should file and sand the end down. This will make sure that it doesn't grab on to anything on the inside of the cylinder, and none of the scrapings get into your bucking or barrel.

As for the rattling it could just be the tension of the spring releasing. Springs of that high of an FPS rating are already under tension when you close the cylinder up. And when the sear lets go of the piston all that energy in the spring is released and snapped forward very quick. When the spring hits the end of the space, it will still have momentum, and will thrash around inside of the cylinder. And that is probably what you are hearing after you fire the shot.

It is really nothing to worry about, but just watch the stress on the cylinder head. You may end up finding that the cylinder head will start to pull out of the cylinder itself. So I would look at the cylinder after every game just to make sure that there are no signs of wear or anything like that.

 

[souponherhed]

The ring's definitely there, unless it's managed to fall out since I put the barrel in. Magic? . Could it be that I had to cut the thread end of the inner barrel slightly for it to actually fit in the receiver?

I'll do the spring when I get some spare time to sit and shoot all day . Does it make a difference which end I cut? The end in the piston or the end at the spring guide? I was thinking spring guide as it's cheaper to replace if it gets damaged.

That's good, I thought it was something to do with the barrel. Then adding more spacers made no difference and it worried me. Will cutting the spring down to 500 FPS stop/reduce the rattling? And if it doesn't, how can I quieten it? It's rather loud.

Thanks

 

[~Ranger~]

I would take out your cylinder then and inspect where its scratched up at. You dont wanna ruin the cylinder bro.. They aint cheap.

 

[souponherhed]

It's scratched along the bottom only, from the cylinder head until the gap where the sears catch the piston.
I've noticed the plastic ring is very slightly wider diameter than the bolt housing, meaning there's an extremely small lip between the two.
It only scrapes when the barrel's in though, not when I remove the outer barrel.
I can't see any scratches inside the barrel or the bolt housing though.

Do you know how you remove the plastic ring? I'd like to have a look at it for the sake of it

Thanks.

 

[~Ranger~]

When you pull off your outer barrel you should be able to just reach in and pull it out. Should have your cylinder out though. Is the thread area of your outer barrel rough or sharp sticking up?

 

[souponherhed]

Okay, it was stuck, pushed it out from the other end using an Allen key.
Yeah I've taken the cylinder out, wanted to test it without the barrel in to try find where it's scraping.
And nope, the barrel is smooth on the inside, only thing I can think is that I had to shorten it by a couple mm or so. It was too long to screw into the receiver, and as the thread wasn't the whole way along, I cut it after the thread stopped. Then filed the rough edges, inside and out, to remove any bits sticking out, but it's all smooth now.

 

[woogie]

What about that small set screw that holds the outer barrel to the receiver? If you over tighten this it will poke through and scrape the cylinder

 

[souponherhed]

I thought it could be that, or the screw that holds the receiver onto the stock, but it's not. There aren't any holes in the outer barrel for it to poke through.

 

[woogie]

Hmmmmm..... what about any burrs or anything like that on the inside of the barrel? Take a cotton swab and run it inside the barrel, as well as the receiver. If you see any of the cotton fibers stuck on the inside of either part, then you will have to sand those down and make it smooth.

I know a few of the rifles I have had, did have some really nasty ridges and stuff on the inside of the receiver. After some time on the lathe you can get it nice and sanded down and smooth.

 

[souponherhed]

I did check for burrs before I put the cylinder in, tried what you suggested and weren't any cotton fibres stuck.
I'll make the barrel smoother with a file anyway though, think that may be causing it.

It's not like a really thin scratch on the cylinder though, it's a 3mm wide part that's wearing down.


EDIT: There's a small gap between the plastic ring and the barrel, can you think of anything I can fit in this gap to fill it, as I think that may be causing the problem.

 

[woogie]

It could just be the sear that is riding on the cylinder itself as well. Or one of the screws that is holding the trigger mech on is a little to long.

 

[souponherhed]

Screws that are holding the trigger mech on aren't too long checked that. I've checked all screws.

Would it be okay to use the gun with the scraping?
I know it'll wear the Teflon down on the cylinder, but I can't seem to stop it..

 

[acer34p3r]

I have the same issue, but with the stock cylinder. For me it was the 2 trigger screws, but it only stopped the scraping half of the time. Is your cylinder riding the top of the receiver, as in super flush to it? That's how it is with mine, and some lube sorta fixed it.

If this is the trigger sears riding on the cylinder than I guess I now know why my bolt won't catch sometimes now.... Grr.

I'd be very interested in possible solutions to this as well, because I've had this problem for a couple months now.

 

[souponherhed]

Mine's definitely scratching on the barrel. Can't see how it could scratch on the sears as there's a huge gap in the bottom of the cylinder where they are and there's no other places they can possibly go (apart from when you're removing the cylinder).

Mine only scrapes when the barrels on, so it's definitely that. Gonna try fill the gap between the barrel and the plastic ring that should stop it scraping..