I seem to be plagued with ball breaks with my fastback, I originally had the e-blade and most parts on a standard 03vert cocker body and it work very good. I could play all day(2-3cases) and never break a single ball. First of all it was chopping and just breaking paint in the barrel. I have played with the adjustments in the e-blade related to the eye and now it no longer chops but I am still getting barrel breaks about every 10-20 shots. Its not the paint or barrel, I'm using a pipe with a matched back section(worked fine on my other cocker) and I've tried a variety of high end paint. If it matters I'm using a Jackal valve with the main pressure set around 200psi with a velocity of around 260fps.

I'm thinking the problem is the small outlet hole in the bolt, it would concentrate most of the pressure right in the center of the ball which is the weakest point. I was going to open the face up a little more to see if it helps but I want to find out if anyone else was having a problem like this.


Any idea's is greatly appreciated, if I can't fix this problem soon I'll have to sell it off.

Thanks

I don't think it has to do with the smaller outlet hole. The smaller outlet hole is actually better because the gas doesn't have to waste energy to expand and fill a massive gaping output hole.

I might have had some similar problems this weekend (granted thought, I WAS shooting footballs and dimplers). Take a look at the bolt and where it lies in the body when it is fully forward. It kinda seems to me that the bolt might be too short. I haven't compared it to my other cockers, but I will tonight. Might be because the bolt doesn't shove the ball far enough into the barrel before unleashing the blast of air. So maybe a little bit of bobble forcing the ball into the barrel causing the problem. Anyways, I'll take a look tonight and compare.

Scratch my theory above. Even though visually (my perception anyways) the fastback bolt tip sits further back in the bolt bore, it actually feeds a paintball further into the barrel compared to a compulsive edge bolt and the stock bolt. This is because the fastback bolt tip has a small exhaust hole. The bolts with larger exhaust holes let the paintball sit further back into the bolt since it "cups" it more. In my eyeball measurements, the fastback bolt left 0.250" of the paintball sticking out the back of the barrel compared to 0.310" when using the compulsive edge bolt. Same paintball, same barrel.

I used Doc's generation 1 at the first MSTS here in Anchorage for both the 3 man and 5 man events and suffered no breaks (till late Sunday) whatsoever in his gun. Now the only breaks I got with it was when I let one of my teammates used it on Sunday and he failed to check the battery on it. But in this case it doesn't sound like a battery failure because of where it's breaking.

Don't give up on it just yet. Let's see what the old mighty one has to say about this problem.

just a guess, i dont have a fastback yet though, but wouldn't an eye help the break problem? or is the problem farther down the chain in the cycle of the gun?

He said he had already eliminated the eye as a cause of his problems. Plus a ball break in the barrel would not be an eye problem. The eye is designed to eliminate chopping. If you turn the eye off or if your eye breaks, you can still shoot but your chances of chopping are alot greater. I've experienced both so far this year with my GX-4 E-Blade, so I kind of know in this case it's not the eye.

Hey guys I was having the same problem with breakage around the bolt and barrel area, at first i thought it was the paint and or barrel, but i tried diffrent combinations of both and i still get the same outcome... ball brakeage. This is my theory, i believe that the small opening concentrated too much force to a section of a paintball causing it to break. What i ended up doing was... i modified my existing delrin Worrblade bolt to fit the fastback...... and BAM! no more ball breaks. So far 3 cases with the modified worrblade bolt and no breaks. I talked to Doc about the small opening and he said that a larger face opening on other bolts yeilded lower fps, and the fastback bolt would yeild higher fps. Well i tested my modded Worrblade bolt to the fastback bolt and low and behold the modded worrblade bolt yeilded higher fps with the same opeating pressures (nothing changed, just swapped out the bolt)

Modded Worr bolt<----->Fastback Bolt
275 250
277 248
278 253
275 251
275 249

These were my findings (All I did was switch the bolt out)
So atleast in my case, I figure the fastback bolt is the culprit. Oh yeah I tried putting back the Fastback bolt after the 3 cases of flawless non-breakage.... guess what..... breaks started happening again.

Next i modified my AKA lightning bolt to fit the fastback... Lets see how that works.

Jason

How did you modify the bolt, (cuts drilling, ect.)

I bascally chopped the bolt tapped the rear for a detent system and got a impulse pull pin and modded that to fit.

I'm still not 100% convinced it's the small exhaust hole on the bolt tip.

J.Directo, if you have the means, can you enlarge the fastback bolt exhaust hole to see if that fixes things? I'd do it, but I don't have access to a drill press.

-yochi.

I'm gonna give it a try later, i just wanna make sure the Modded Worr bolt works perfectly, i'm gonna give it a couple more cases..... but so far so good.


Jason

Thanks guys for all the input, I've seen other open faced bolts cause similar problems to this thats why I suspected it. I'm going to open the face a little in the lathe when I get a minute and hopefully it makes a difference.

thanks again.

"I'm thinking the problem is the small outlet hole in the bolt, it would concentrate most of the pressure right in the center of the ball which is the weakest point."

Actually, the seam is the weakest point on a paintball. It's really a moot point though since a sphere is naturally a very strong object. I'm sure you've all seen paintballs bounce off trees, pavement, and other players.

One thing you can do is to check the bounce rating of your paint (not sure how? Go here).

If you're using a Pipe/Freak type system, try going up a bore size. Just because a few balls fit a back well doesn't mean they all will. Remember, paintballs are far from perfect and paint sizes can vary drastically even from the same case. They can even change through out the day from changes in temp. and humidity.

Try checking the joint between the body and barrel. Check for burs or bumps. Also check the bolt face for any burs or irregularities. Also check the bore size of the breach where the paintballs travel through before entering the barrel. If it's far too tight it may have to be honed to a larger size.

If none of that helps, well, blame it on the paintball fairies.

Now you're thinking, "Wait, you didn't mention the bolt opening!" You're right. That's because it's not the problem. If you're running at 200 psi there's no way a blast of air could break a ball unless it's extremely fragile paint. Even if it's 4-6 bounce paint it should handle 750 psi with out problems.

Here's an example for you're consideration. A stock VM-68 runs at around 700 psi and has a bolt opening of 17/64". Cockers and VMs both use the same basic Sheridan style valve design. Heck, even their cup seals are interchangeable. I can shoot most any kind of paint through a VM with out problems. If I do start to get barrel breaks I grab a larger bore barrel and the problem usually goes away.

I haven't gotten my Fast Back yet (soon! ) but the opening looks similar in size to what Palmer's uses in their Blazers, Typhoons, and Strokers. I currently own a Nasty Typhoon and two Strokers and have never had a barrel break problem with them and they run at 600-ish psi. I never had a problem with my Blazer either and it ran at 400 psi.

Barrel breaks are not related to the size of the opening in the bolt. And unless you're using very fragile paint, the operating pressure has little effect on barrel breaks as well.

Chris
http://www.vm68.com

J.Directo> are you the guy that I talked to at the last TOC that had the chrome fastback? Just wondering:)

Chris Mader> I hear what your saying but I'm not sure I to totally agree. I've seen bolts in other guns cause this exact problem, change it out with a different bolt and the problems gone. All I know is that my 03cocker with basically the same parts, same barrel system would shoot all day long and never break a ball. High end or cheap balls and not even the right bore match it didn't matter. If I was just play'n rec ball I could live with a few breaks here and there but thats not the case. With the money I've invested I expect more.

Yeah that was me at TOC with the chrome Fastie.

Jason

The face opening is NOT the problem. Put it this way- the PGP has no face opening at all, the air comes up from the valve through a tiny hole- a little bigger than 1/8"- and at about 800 psi. If hole size/pressure was a problem, the PGP would never be able to launch anything short of a solid nylon ball.

There's been two causes we've run across so far for breakage in the Fasties- not setting up the ram/cocking block correctly which doesn't let the bolt open fully (it's just as important in a Fastback as it is in a regular 'Cocker) and the ball detents.

I set up a Fastback for a player just before last weekend's MSTS, by taking all the parts off his Gen-X and swapping 'em over. The gun came with a Shocktek detent, which, when screwed into the Fastback body, didn't stick out far enough to reliably stop a ball. I swapped it out with a new stainless/delrin detent (which I'm now carrying in the store, I just haven't had time to post a pic) which worked perfectly.

Turns out, when I got to the tourney, the owner had swapped back to the Shocktek detent (he 'liked it' better) and was, naturally, complaining about chopping problems.

The size of the hole in the bolt is NOT the problem, but having too big a bolt hole, and/or having the bolt/block setup wrong, will. Too big a bolt hole allows the chambered ball to roll backwards, which can let the next ball in line fall just slightly into the breech, where the bolt slamming shut will "crack" it. (Same thing that was happening to the 'Mags prior to the L-10, and the primary cause of choppage in an Angel, a factor that no eye can solve.)

Doc.

Well.. I just finished opening up the face on the bolt basically made it look just like a DART eclipse cocker bolt. I didn't make any other changes on the gun, using the same hopper, barrel and balls. Guess what, no more ball breaks, shot 4+ hoppers and not one broken ball. I even seen about 10fps more velocity. Also tried some old crappy balls and not one broke.

I did originally had chopping problems as well but with a little extra ball detect time and adjusting the eye sensitivity down a little that problem totally stopped. I was not chopping or breaking balls in the breach what so ever, they where just breaking in the barrel while firing maybe 1 ball per second.


I can't explain why this is the case nor do I understand all the logic behind it but it seemed to correct the problem and thats about all I care about at this point.

Hey Chris, that's great I'm probally gonna open up the face on mine too. got any pics of the mod job? Pass me you email and i'll send you some of my Worr bolt mod, and AKA Lightming bolt mod. Email: jdirecto@rogers.com

Jason

How did you open up the face of the bolt? I'm looking into a fastback and that bolt hole is just too small for me. Anywho, if you could mail me the process by which you did this, I'd be really appreciative.

Email: Baind@mailbox.sc.edu

Thanks,
Devman

I just got my eblade eyes yesterday and installed them. To test them out I removed my main hammer spring. So all that would happen is the bolt moving back and forth feeding balls. No barrel either. I shot all the paint into a bag.

This test ran pretty well I must say. I broke 2 balls and I think I know why now. The exhaust hole has nothing to do with it since there was no blast of air. I found that some of my paint was so badly deformed that it would barely fit in the bolt bore if put in a certain way. So what I think happened was the ball drops down into the breach and the bolt tries to push it through the barrel bore and if the paint was too big or deformed, it would crush the ball and voila, you have a break.

The fastback bolt in the fastback body is a perfect fit. Almost zero slack against the bolt bore. I put the fastback bolt in my Excal and I noticed slack. So I would suspect that the fastback bolt bore might be smaller than usual and would be less forgiving on large or deformed paint.

Anyways, I guess I'll have to get my hands on some more consistent stuff...hard to find here (FPO field).

-yochi.

If i were you i would just shoot marbalizer cause not only is it the most accurate but it is increadabley thick in the shell
If that doesnt work i would say that you are acualy choping not just breaking.