[bluedust]

I took my VSR to a skirmish today and I had trouble right from the start. It started to jam every few shots while I was trying to set the hop, and eventually it jammed every shot. The only time this happened previously was when I tried 0.40 bbs and it jammed so often that I decided to go with .36, and these never jammed over the, roughly, 500 shots in the back garden. At this moment it jams all the time on 0.36 and 0.4 and sometimes with 0.25 and 0.20; I am confident enough to state that the jams increase in frequency the higher the BB weight.

About my rifle:
TM VSR 10 G-Spec
AA Hopup, MapleLeaf A.bot 60 degree
MapleLeaf concave nub
AA 430 SS 6.03 barrel
ASPro III 90 trigger and Piston set
Laylax PSS10 150 Spring
ASPro SS cylinder
ASPro cylinder head

Before the jamming I was shooting consistently 485 fps on 0.20s

Now its shooting between 430-470 fps (It jams less often on 0.20)
I have carefully taken the hop apart expecting damage; I have photos:

1) The bucking is shredded in the entry point; I noticed this previously, so it is not as a result of activities today; however it seems worse than previously observed.

Closer look of bucking: nozzle side:

Alternative look at bucking: patch side

2) The nub was still in place, but it is clearly damaged. I don't know how it got this slice mark and I am 100% sure it was not there before. When I had issues after the initial install I checked if the nub was seated correctly and it was fine. Update: The only thing I can think off that can cause this is the nub catching on the side of the opening that is should go through; I must have installed it incorrectly when checking if it was seated properly. I am wondering if it is still good to use; what do you guys think?

Here is what I did to try and resolve this before posting:
1) Loosened the bb stopper: no effect
2) Tried lighter bbs: slight improvement
3) Slower careful bolt actions: no effect
4) Use different hop settings from 0% up: no effect

My thoughts:
a) I possible could have damaged something when clearing the jam; i was in a rush because I didn't have much time to tune the hop before game time and I noticed I made too mistakes 1) double loaded a few times when tuning the hop 2) while clearing the jam I went too far once and may have damaged the bucking, and I once forgot to pull the bolt back and the rod obviously bb could not come out. I know I have made mistakes today, but this does not explain my previous jams with 0.40 bbs. I was using the cleaning rod you get with a TM VSR.
b) I am using the ASPro nozzle which has a black O ring on it; could this be shredding the inside of my bucking?
3) The screw that is meant to fasten the upper and the outer barrel is not working well; even after it is screwed in the barrel still rotates a fraction either side. This is because the hole in the outer barrel has gotten bigger horizontally (any tips to fix this will be appreciated). I am wondering if this slight rotation could cause any issues
4) I am thinking the bucking and the nub is the issue, so I am thinking of using the AA nub with stock VSR bucking; however I thought it would be wise to wait on some wise counsel before I cause any more damage :bow:

Thanks in advanced.

FYI Due to my bad VSR fortune I had to play with my gas DMR, and although I had fun I just wanted to snipe with my quiet VSR. The blow back action is so loud that I only get one shot until the element of surprise is blown due to noise. Even with all my problems I am still determined to switch to role of sniper (let's see how long that lasts :shrug: )

 

[Reliku]

Hi, I got your PM :hehe:

The only thing I can think off that can cause this is the nub catching on the side of the opening that is should go through; I must have installed it incorrectly when checking if it was seated properly. I am wondering if it is still good to use; what do you guys think?

Yep, that is probably what happend, you're not the first and you won't be the last to do this... It may still be usable, try it and see if it works. Be prepared to buy a replacement though as it'll probably give curving issues.

The bucking is shredded in the entry point; I noticed this previously, so it is not as a result of activities today; however it seems worse than previously observed.

This is some kind of damage I see a lot with the new autobot buckings and it is the obvious source of your problem... it's pretty insane. Do you have any other buckings to use?

I'd recommend trying an old ML monster bucking (diamond is my recommendation). They're designed differently and they don't get torn to shreds as easily (no leakstopper ring and different rubber). I've been using them with ASP cylinder heads for a long time now and they haven't eaten a single bucking of mine yet.... *knocks on wood*

Either way, the ASP head is not the problem. If anything, the tapered head with the O-ring treats buckings very well whereas the stock head can really rip them to pieces.

The screw that is meant to fasten the upper and the outer barrel is not working well; even after it is screwed in the barrel still rotates a fraction either side. This is because the hole in the outer barrel has gotten bigger horizontally (any tips to fix this will be appreciated). I am wondering if this slight rotation could cause any issues

Curving and some inconsistency if it's really bad, but the outer barrel is also screwed into the stock so generally it's no big deal (it isn't on mine). It won't kill your bucking like this, so it won't cause jams.

 

[bluedust]

I am wondering if this type of damage can happen to the nub if the arm is raised too high so the nub leaves the hop, and then catches the aperture on the next adjustment down; I say this because I remember trying to decrease the hop, and I took it too far (I am blaming my tools for this mistake).

Anyway I looked at buyers review for the ML nub and it said this

"If you install Maple leaf bucking Then You must install this Nub with it, some people-have bad feedback to this nub Because They Did not know how to install it, there is an easy way to do so:
-put very little (normal glue ) in the top of the Nub and Then attach it with pressure arm in 330 degree (qui is mean 4 o'clock).
-Just wait a Few minutes till drying glue and you got the magical touch.
* DO NOT install this Nub in 90 degree or will put to much pressure on your bucking and Then jamming of shooting your gun or kill your FPS *."

What do you make of this; does the angle really matter that much and should super glue be used?

I always wanted a monster diamond bucking, but they were out of stock. I have found where I can get them, so I will ordering them soon.

 

[Reliku]

Doesn't happen, generally speaking, I wouldn't consider that a source of the problem :tup:

 

[kazuchan]

My bucking worn like you LOL, i have same cylinder head like you. I know what you feel bro ( I feel it 3 times haha ). I'm Ordering Action stainless steel cylinder head for hope it can fix "eating" problem.
I think you nub not sitting correctly and got that cut.

My nub is working good ( Maple leaf nub )

 

[Reliku]

My bucking worn like you LOL, i have same cylinder head like you. I know what you feel bro ( I feel it 3 times haha ). I'm Ordering Action stainless steel cylinder head for hope it can fix "eating" problem.
I think you nub not sitting correctly and got that cut.

My nub is working good ( Maple leaf nub )

Have you tried any of the old buckings yet?

I think the leakstopper ring on the new ones pushes the bucking lips inward which causes added friction. Along with the weaker rubber this would explain this type of wear :hehe:

 

[kazuchan]

hmm, Maybe I will try with stock JG bucking xD. But will after off game in this weekend.

 

[threshold]

Bluedust and kazuchan how long have you been using your autobot/decepticon buckings and which degree? I have autobot 70 degree through wich I shot around 300 bb's and would be nice to know for reference how much have you used yours.

 

[kazuchan]

Bluedust and kazuchan how long have you been using your autobot/decepticon buckings and which degree? I have autobot 70 degree through wich I shot around 300 bb's and would be nice to know for reference how much have you used yours.

I owned 60* auto, deception, 70* autobot

60* auto bot: up to 1000 rounds, can't 100% airseal more.
60* deceptions: Just upto 400, and I switched to 70* for "hope" it can longer. pretty much worn but still hold fine.

70* auto bot: around 300 rounds, worn less than OP, but I guess the "death" is coming >

 

[Plazmaburn]

I have that problem with mine, (different bucking and nub combo however.) I cut a small section off of my nub in order to fit the window in the unit better. I have also noticed that I need to trim my nubs for them to work 100% with the AA chamber. Also note, I have 1 of every revision of the chamber so far. (I think there were only 2 revisions so far. I do not need more then 3 chambers...)

This is something that I have needed to do with every single unit.

I have some decepticons on the way as well as a ML nub.

The amount I remove is .030in / .762mm.

 

[Reliku]

That's a flat nub though, the ML concave nub fits really well in my experience :yup:

 

[Plazmaburn]

Are you 100% sure about that fit? I thought the same thing too. Also I did state that it was a different nub... or did you miss that? (Kinda hard seeing as it is in the first line...)

I installed a few ML nubs in some other rifles with mixed results. Some are awesome, some not so. So I am looking into them. I have 10 nubs in-route with about 20 buckings. Should give a decent sample size.

 

[manbehindtherifle]

Have you tried any of the old buckings yet?

I think the leakstopper ring on the new ones pushes the bucking lips inward which causes added friction. Along with the weaker rubber this would explain this type of wear :hehe:

Ya I can attest to this the autobot 60 I have in my hi capa is torn around the entrance and is highly used (doesn't affect performance in any way). For me this was a combination of the anti blow by ring and a slight misalignment of my uac aluminum loafing nozzle!

Sent from my iPhone using Tapatalk

 

[whalesmash]

I'm currently running an 80 deg autobot in a mancraft MCM700x, no issues or wear in the cylinder head seal just yet, but this is only after ~100 rounds. I've also got the same in a 70 degree autobot in a WA2000 (also mancraft). No wear just yet either. When I checked my 338MSR though, I noticed that the lips were pretty tattered on the nineball bucking (15k rounds). It doesn't seem to be affecting my performance at all, though there is definitely noticeable damage. As a side note though, I'm not running either of my autobots with concave nubs, and I'm seeing the exact same performance as when I did use their specific nub. The WA2000 in particular has a pretty proprietary arm with a built in nub that I don't want to modify if I can avoid it.

 

[Homie]

Hey Bluedust,

I had a similar issue and made a post about it here. It turns out my cylinder head nozzle was too wide. I took it to a machine shop and had the leading edge tapered by a millimeter or so. That corrected the issue.

 

[Reliku]

Are you 100% sure about that fit? I thought the same thing too. Also I did state that it was a different nub... or did you miss that? (Kinda hard seeing as it is in the first line...)

I installed a few ML nubs in some other rifles with mixed results. Some are awesome, some not so. So I am looking into them. I have 10 nubs in-route with about 20 buckings. Should give a decent sample size.

Yeah, I'm pretty sure, I've had a fair amount of them by now :hehe:

And yes, I saw that you're using the different nub, I just mean that you shouldn't have to use it. The ML ones have worked really well for me. I try to stay away from flat nubs and the like because they're just not designed for the ML but I have seen some decent performance from them as well. I just prefer the ML ones.

Eager to hear how that batch of yours does :tup:

For me this was a combination of the anti blow by ring and a slight misalignment of my uac aluminum loafing nozzle!

Lol, alu nozzle. Yeah that'll damage them :hehe:

 

[bluedust]

Bluedust and kazuchan how long have you been using your autobot/decepticon buckings and which degree? I have autobot 70 degree through wich I shot around 300 bb's and would be nice to know for reference how much have you used yours.

60 degrees for the autobot and around 500 shots

 

[Coolstan]

Hi Bluedust,

I also had a same issue with the 70 degree ML bucking after 100 rounds. I contacted ML and they told me I am using too soft of bucking for the 170 m/s. However, this bucking issue really bother for a long time, not to mentioned the number of buckings used as well as accuracy issue.

I visited ML today to purchase 80 degree bucking, and they asked to see the worn bucking. I showed it to them (the ML boss and staffs). Well...they started tell me stories, how they initially designed the buckings to be a tight fit to assure 100% air seal as well as the function of the ring. I told them I already fixed the issue (I just wanted to get the bucking and out of there).

They asked if I use aftermarket loading nozzle. Ha... I told them I use ML cylinder kit, which is the ML loading nozzle. I told them I have turned down the loading nozzle O.D. to reduce the rubbing, as the loading nozzle O.D. was slightly too large.

Cut the story short, ML staff gave me a 75 degree replacement for the damaged 70 degree bucking. But ML boss believed all their products comply with each other.

I showed them your damaged bucking picture, and reply was... "silence". i shook ML boss's hand and walked out.

Try checking on the loading nozzle O.D. If it is a little too big, turn it down a little. It solved the bucking tearing problem for me. I still favor the ML bucking.

 

[kazuchan]

Look like I will stick with old version for keep it survive more longer xD...

 

[bluedust]

I received my replacement bucking and nub in the post today; I have a ML diamond monster 60 degree bucking now with a ML concave nub. While installing the nub I removed the BB stoppers to get a clear sight of the nub pushing into the bucking. I noticed it is quite easy to install wrong by having the nub clip the edge of the aperture, but in the end I visually inspected a concave hump while looking through the inner barrel when the hop was set to around 70%.

I am able to shoot BBs without jams from 0.20 through to 0.36, but the gun still jams on 0.4s; I even tried reducing the tension on the BB stoppers. I am really wondering if there is something wrong with these 0.4s; there are from BB King. There are two parts to this issue:

1) Sometimes it fails to feed: when pushing the bolt forward the bb has not been aligned properly, so the nozzle is unable to push the bb forward and therefore is half in and half out.
2) When the bb is fed it gets jammed in after firing.

What could be the problem?
Could it be the mag spring or BB stopper is preventing proper loading properly?
Could it be the gun is not powerful enough to push the BB past the bucking? It is currently shooting 470 fps on 0.20s