[Srosh]

Ok so I just recently fully upgraded a jg bar 10. Upgrades are as follow.



Action Army Zero Trigger
Action Army m150 spring
Action Army Blue Piston
Action Army Spring Guide
Action Army Hop Up
Laylax 555m 6.03 TB Barrel
Nine Ball Hop Up Bucking
Stock cylinder and cylinder head

Also have done some DIY teflon mods as well

So my problem first started off with curving bb's to the left. I checked the hop up bucking everything looked fine so I checked my nub looked alright as well so its just not making much sense to me the barrel is brand new and as straight as an arrow so no bending I clean the barrel and bucking as well. Should also state I'm using .32g elite force bio bb's the bb's go left, right (very rarely but slightly sometimes kinda normal for the range I was shooting at (200ft), but not this is where im dumb founded is sometimes when I'm shooting it the bb's will just go straight into the grass 50ft or so and then sometimes the bb's will majorly over hop without me adjusting the hop up. The hop arm is in the exact same place and has not moved at all since where I put it. I did notice that when I pull the bolt back it feels a little rough like metal on metal contact and when I push it back in it hits the top of the hop up which I've heard is normal till it wears in? But that doesn't explain the hard bolt pull backwards... I've checked my hop up literally at least 10 times literally and ive reset the bucking and everything everything you can possibly think of I've more than likely done to try and figure out the issue. I did notice when pushing the bolt back in the cylinder was slightly wobbly and if I pushed it in a certain way would make the left curving issue stop? Seemed to me like the cylinder spacer was moving forward when I pushed the bolt forward causing the wobble so I think that left curve problem is fixed. But I'm still getting random flyers up and downwards... Any help would be greatly appreciated

 

[Mixem]

This might be a compression issue. Have you chrono'd your rifle? If so, is your fps consistent? A wide fps range means that air is escaping somewhere inside your rifle and this leads to your shots randomly going everywhere.

Also, your cylinder should not be hitting the metal hop-up chamber. It should go in cleanly, hit the bb stoppers (the two plastic caps inside the hop-up), and then straight into the bucking. Try backing off a urn (or two) of the outer barrel where it is attached to the receiver. Also, check to ensure that you have not overtightened the two allen screws on the bottom of your stock. Doing so may have cause the barrel/receiver combo to bend slightly at their attachment point.

On a related-note, pretty much every screw on the Bar 10 is longer than they need to be. Make sure that when you tighten them, they are not protruding on the other side. This is important for that one tiny screw that holds the outer barrel and receiver together. Overtighten and it protrudes into the cylinder chamber where is can scrape your cylinder as it passes by. This could be the source of that metal sound that you are hearing.

As you can see, the tolerances of the Bar 10 are not the best. They are easy to work around but it does require some attention (as opposed to the "tighten-everything-up-and-we're-good-to-go" approach).

 

[Srosh]

Thank you for you reply Mixem, I did get it chronoed yesterday and it was all over the place at my field we chrono with .3's heres a list of shots off the chrono 335, 233, 175, 305, As you can see it was all over the place... which is a compression issue most likely so I did a teflon mod around the cylinder head and it seems to be shooting so much better than what it was. I do still get the very occasional small flyer but its very minor compared to what was going on I might need to put more teflon tape around the head still I only did one or two wraps. This week ill go get it re chronoed and see what happens this time cause I should be at least 400 if not over 400 with .3's I'd think right? EDIT: I have found a compression leak in the hop up as well even with the action army hop up?

 

[Mixem]

Another common spot for compression leaks is the o-ring on the action army blue piston. It may not be create the necessary seal (on the cylinder wall) when it propelled forward. Take a look at that area as well.

I have a similar build to you except I use a Maple Leaf bucking and an AA 6.03 430mm inner barrel. With the AA m150, I was shooting ~565 fps w/ .20 bbs. I cut off 1.5 coils which got me down to ~545 fps so I could use on my preferred field.

I will dig out my .30 bbs and chrono my gun for comparison.

Edit ---
Keep in mind that I cut 1.5 coils off my AA m150 spring to reduce power so your numbers may be slightly different than mine. I shot 10 times with Bioshot .30 bbs. Here are my results:

420.5
422.6
420.5
422.6
422.6
421.5
421.5
423.1
423.7
422.6

 

[Srosh]

Someone suggested to me at the field was to take my stock cylinder O ring and put it on my blue piston instead of the blue piston O ring since its a little bigger I guess? The air leak in the hop up is pretty bad if I hold my thumb over my barrel and fire you can just hear the air leak out of the hop up chamber its not a all at once thing it takes 3 or 4 second but all the air does end up leaking out eventually so I'll try to put some teflon around where the air leak stopper meets the bucking and see what happens I'll try to the other O ring as well.

 

[Srosh]

Ok so I've added more teflon to my cylinder head and as well as changing my action army O ring with the stock O ring off the original piston and its made a huge difference and now no longer shoots all crazy like it was so that most certainly was the issue hopefully it chrono's in at a decent fps this time and is consistent. I appreciate the help Mixem and thanks for the personal chrono test and info!