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View Full Version : Classic chopping or barrel breaking like crazy



Railgun
04-29-2007, 11:47 PM
I've got a problem with my Classic. Near as I can tell it's got a PMI stainless barrel. The nubbin what rusted almost away when I got it so I made a new one of roughly the same shape. After the first time out when it chopped occasionally I looked at how the balls fall into the barrel and slightly modified my nubbin. But despite what appeared to be successful tests in the shop it only shot about 8 balls in my first game when it chopped or barrel broke and it was downhill from there.

Is there a guide or other info on how to fix this barrel breaking or chopping issue? Or can someone offer some suggestions?

My Classic is running a level 7 bolt and when it shoot well it's running at around 285 to 290 fps. And for the most part I'm doing OK with my cockers so I don't think it's a case of short stroking the trigger. Especially since when it blew the first ball apart during the game it was only during a point where I was shooting about 2bps. The replacement nubbin is made from 1/32 spring steel music wire from the local hobby shop. The nubbin was made using round nosed pliers so the part sticking into the barrel is nicely rounded and very smooth.

I should add that my 'mag has a fair amount of blowback up the feedneck but it seems to mostly come out the hole. To ensure this I relieved the feedneck angle adapter so the blowback vent hole is clear. I don't get any sort of popcorn effect in the ball stack if that helps.

olinar
04-30-2007, 12:15 AM
first ogg you should give the valve a good cleaning and make sure your trigger rod measuers 2.125" and your on/off pin measures .750" . you should probably replace the nubbin for a newer plastic one and see what goes on from there. your mag should be shootin perfectly!

Tao
04-30-2007, 12:27 AM
My experience with wire nubbins: if you touch them they start breaking your paint. your wire might be to stiff. I would just get the plastic ones from AGD, they work the best.

Railgun
04-30-2007, 02:14 AM
Thanks guys.

The valve is clean, no problem there. This plastic nubbin is interesting since it's the first I've heard of it in my readings. I'll likely order a couple.

In the meantime I've got some teflon tubing coming that I can push on over the wire to provide a more slippery and more rounded surface to the nubbins. I may also try making them from a lighter guage wire or going with two side by side very light wires with the teflon tubing pushed on over the wire.

Tao, that comment about touching them is an interesting one. From that I tend to think that there's something that the balls feel is very abrasive on the wire. So it's cutting the balls enough that they pop when the air hits them....

Tao
04-30-2007, 03:38 AM
Thanks guys.

The valve is clean, no problem there. This plastic nubbin is interesting since it's the first I've heard of it in my readings. I'll likely order a couple.

In the meantime I've got some teflon tubing coming that I can push on over the wire to provide a more slippery and more rounded surface to the nubbins. I may also try making them from a lighter guage wire or going with two side by side very light wires with the teflon tubing pushed on over the wire.

Tao, that comment about touching them is an interesting one. From that I tend to think that there's something that the balls feel is very abrasive on the wire. So it's cutting the balls enough that they pop when the air hits them....

What I meant was that wire nubbins are not onoly stiffer than plastic nubings they apply the force on the paintball in a smaller area thus increasing the chance to chop. I found that handling them alone can be enough to bend them slightly forward and that alone is enough to make the difference.

Smoothice
04-30-2007, 01:58 PM
Doubt this is your problem but it happened to me.

One of my twistlock barrels would untwist itself. A ball would only partially feed because the barrel and body were not alighned and then my level 7 bolt would chop it.

Easily fixed if this is the problem.

Railgun
05-01-2007, 08:24 PM
OK Tao. I've been wondering if the wire was cutting into the balls as well.

I'll look into ordering some of those plastic detents but in the meantime I'm going to make up a dual wire jobby that's made from a lighter guage and slide some small gauge teflon tubing over it. The extra area of the dual side by side wire along with the teflon on the wire and the lighter spring action should do the trick. If it works I may not even bother with the AGD plastic detents.

Railgun
05-01-2007, 08:25 PM
Doubt this is your problem but it happened to me.

One of my twistlock barrels would untwist itself. A ball would only partially feed because the barrel and body were not alighned and then my level 7 bolt would chop it.

Easily fixed if this is the problem.

Mine actually notches into place quite nicely. Needs a firm twist to unseat it.