AO Research Team, Need YOUR Help ASAP!!!!!

[AGD]

Team AO,

We are in the middle of intensive research on the ball chopping issue and think we have made a breakthrough. For a long time we have wondered why some people chop and others don't. It seems that depending on what barrel ID you have, you get more or less blowback and ball bobble. Of course we know bobble can lead to more chopping.

We are trying to confirm this is in fact the case so we need your help. IF YOU HAVE AN ACCURATE CALIPERS, please measure the back end of your barrels ID. Please post the size here and please give us your best estimate on how many balls you chop per case. If you use an aftermarket bolt please state that too. Breaking down the barrel does not count, chops mean you get paint in your feed tube.

Thanks team we are counting on you!!

AGD

[-Jôker-]

well if this will help i have a boom stick and get bout 5 chops a half case= a day (dont have any clalipers)

[-Jôker-]

ok the inside measure of my barrel with a reg. ruler is 3/4 of an inch that help? im sorry if this dorsnt help i am just trying to help :p (thats a pun isnt it)

[X-Plosive]

Well mine is like .6879999999999999999999999999999999999999999999999 99999999999999999999999999999999999999999999999999 9999999999999999999999999999999999999999999... and so on but the manufacturer said it was .688. They lied. I chop about 1 ball every 3 cases and that only seems to be when shooting on my side. When i say my side I mean putting the gun at a 30 degree angle. I have no ball bobble what so ever wuth my bolt. AFter reading this thread I tested it and after each shot I do not see any ball bobble even after rapid fire. In all actuality I believe the only time people chop is when they don't have a parabolic powerfeed plug. It has solved the chopping problems on both of my guns. I also sent a parabolic p/f plug for free to an AO member who is called MightyMouse, it solved all of his chopping problems on his RT-Pro. For your information I use the AGD long nose bolts on both of my markers.

[AGD]

Thanks Xplosive thats the type of info we need.

Guys, if you don't have a calipers but there is a size engraved on the barrel we could use that.

AGD

[Flip540]

i chop only when i dont turn my revvy on or i turn my gun to far shooting out of the side of a bunker. i would say 2-4 out of a case.

[Miscue]

I don't think I've chopped a ball once on my Bigshot... several cases worth. Using extended nose bolt. I had problems with my Bigdaddy though.

Sorry, no calipers.

[X-Plosive]

Ohh by the way. I was talking about my boomstick in the previous post. My Bigshot is .688. I really prefer the bigshot it's nice and feels comfortable. My boomstick is 14"
and is good for balancing out a gun but its just to hard to find a good paint to barrel match for it. Anyway I really can't tell you which barrel I have less breaks in because there have been MANY variables and I have had the bigshot MUCH longer than the boomstick. Believe it or not the bore sizes on BigShots is inconcistent depending on which thread type it is.

[Magadeth]

Are you thinking that a larger bore= more blowback= more chopping? If so, in my experience this has not been the case. I have used the stock minimag barrel with no chops, a smartparts wich is smaller diameter (the paint, rps, fits tighter) with no chops, and an armson stealth (rifled with a larger bore) with no chops. This is all with a stock hr minimag. I think it must be related to trigger pull. I think paint quality may also have someting to do with it.

sorry if this is not what you are looking for, but I never chop. I do use ONLY rps marbelizers.

[Bad Dave]

Although it makes sense that a tight fit would increase blowback I think the overriding problem is that of the bolts design. As has been mentioned before to allow the bolt to cycle at very fast rates 20+bps blowback is the result, why not redesign the bolt so it has a maximum cyclical rate of 15bps or so?

Also paint quality is a really big probem I think. When the pros were using mags did they chop all the time? nope. Because they get the better quality paint through sponsorship or dealer contacts. Now newbies use mags the paint they feed them is of a much lower quality even if it is a quality brand it is the older paint or end of a run etc.

the two prestige tourneys i attended this year i had no probs with paint cos quality was high, i had 1 chop a case due to me outshooting my loader.

Ultimately poor paint will defeat any design of gun.

[Prezents]

14"Dye al, .692
12"Dye ss, .689
14" J&J ss .689
12" J&J Cer ..689
12" J&J ss .688
10" J&J ss .688
8.5 Taso Nickel .690

I Cannot really give a accurate breaks per barrel, now that I have upgraded to the Retro Valve and a Warp feed.
Last game I shot the jj 12" and had no breaks out of a case of paint:D
Will let you know after this weekend, will use different barrels to test.
Prezents

[Restola]

i just measured my barrel and its about the diameter of my thumb.

glad i could help.

[Maxd Out]

Boomer - .688

RPS Advantage- only paint i will use now

I never chop! The only time I chop, I know it instantly because I shortstroked like a fiend. That only happens once in a blue moon. Of all the empty RPS cases sitting around my room, I cant remember the last time I chopped using that paint in my boomer.

[rabidchihauhau]

.689
10"
brass
'straight rifled'
no porting

approximately 1 break per 5,000 rounds (erring on the side of breakage - but then the 'mag is the reason I stopped carrying a squeege anyway...)

Steve

[Riot[Z-Grip]]

Fairly new condition, AGD Longnose bolt, mostly PMI advantage but some marbs and 32* stuff, breaks not from occaisonal short-stroking= 2-3 per 1,500.

[X-Plosive]

Well megadeth I thought the same. I thought Tom's hypothesis was that a larger bore barrel causes less bobble because more air is able to fit behind the ball and not as much tries to escape up the feed port. The bore of the barrel is bigger therefore you have more space. I may be wrong but that seemed logical to me. I just thought of taking two straws, one with a larger diameter than the other. Poke a hole in the middle of the straw, that will act as the powerfeed. Then get some piece of a napkin, moisten it and plug the other end. The napkin will act as the ball. With the larger straw less air will be escaping through the hole because it has more room. The smaller diameter straw has less space so more air will escape through the hole. I don't really think I'm right but this is just what came to mind. By the way you would need the same volume and ammount of pressure going through each straw. The human lungs aren't to consistent are they?

[MENACE]

Automag PFHL
Smart Parts AA 14" - 0.694" at the ball drop.
ANS Automag Venturi Bolt
Mostly use All Star, Marbellizer. And then whatever the field paint is . . .
Rarely ever chop a ball, maybe one ball in every ten cases.

Hope this helps. :D

[magc68]

i never chopped with my freak barrel but with a boomstick .6878 i have had one chop out of 5 cases that i used that barrel

i used to own a carbon fiber barrel and i chopped all the time with that (atleast once a game)... i belive it ran .687-.688

i used to own a CP barrel and i chopped twice with that out of 2 cases. that was a .689 barrel as indicated on the barrel.

[FeelTheRT]

i don't have the acutal barrel nor gun right now but i still remembered all the good times...

DYE .688 and NO chops out of 5 cases. even short stroked a several times with out chopping :)

Edited: oh yah, and an AGD long bolt.

GL in your research.

[DarkPhoenix]

Thanks, Tom. You have just given me an extremely good reason to go out and buy those calipers for my tool box. I will get back to you with any information I can get.

[PsychoMag]

12" AA .689 I have run about 10 cases of ZAP Performance Plus without a break...but my DYE 12"SS I break about 10/case of ZAP. I use a newer RT PRo, with all stock internals.

[raider_o1]

Originally posted by AGD
Team AO,

We are in the middle of intensive research on the ball chopping issue and think we have made a breakthrough. For a long time we have wondered why some people chop and others don't. It seems that depending on what barrel ID you have, you get more or less blowback and ball bobble. Of course we know bobble can lead to more chopping.

We are trying to confirm this is in fact the case so we need your help. IF YOU HAVE AN ACCURATE CALIPERS, please measure the back end of your barrels ID. Please post the size here and please give us your best estimate on how many balls you chop per case. If you use an aftermarket bolt please state that too. Breaking down the barrel does not count, chops mean you get paint in your feed tube.

Thanks team we are counting on you!!

AGD

Just sold my ‘mag over an E-mag.

I used an Armson Stealth w/ a bore size of about .689. I know this because I callipered it once and also measured some balls that dropped through/got stuck/would not blow through/etc. I had a foamy bolt until I got a Hyperframe from Centerflag, then I used the foamieless bolt because the trigger mechanism chewed up the foamy bolt. I found that the foamieless would crack balls w/ the standard trigger frame but not w/ the Hyperframe.

But I digress. The most problems i had on chopping were always the result of low feed rate (low on ammo). Alternatively, w/ the standard frame I could get a good solid short _return_ stroke and punch the chambered ball halfway into the breach, dropping the next ball in halfway for a chop. I only chopped under rapid-fire conditions (duh, right) especially when I out-shot my revolution w/ the Hyperframe... until I got the Warp Feed. Then I had problems w/ non-parabolic feed plugs. (7-year-old plug) This was caused when the ball would get forced onto the lip of the barrel chamber and either slow or stop its decent, or when I swapped it for the power feed adapter plug stopping the balls at the adapter and negating the pressure behind the balls.

I digress again, but this brings me to a good point. Assume first that the airgun uses a powerfeed system, as standard feeds are obsolete. The powerfeed uses the involuntary blow back caused by gas escaping this gigantic hole behind the ball still leaving the barrel (which makes ports on a ‘mag barrel only good for noise reduction) to bounce the next ball off the top of the power feed and into the chamber; in addition, using the next ball to stabilize it (no bobble). Since gravity accelerates at 9.8 meters per second squared, I am sure that a human being (save that incredibly fast Flash Gordon that you will proclaim you are related to) cannot beat gravity out of that third ball dropping onto the second; unless there is not a forth and a fifth and a sixth... to speed it up. This is one of the reasons manufacturers have gone to longer vertical feed tubes. Some people may remember the old stick loaders of the _day_ (yes I am dating myself). Those worked on the principle that more weight behind it would have it drop faster. I wonder if we were pissing in the wind...

Alas, my point has been lost in my rant... The trigger cannot be pulled, by anything but a machine, in an effort to beat the next ball in the powerfeed (with many of its siblings behind it) from stabilizing the chambered ball, negating bobble.

Yes, I have seen the images of the ‘mag being cycled by a machine at exorbitant rates and the ball in the chamber bobbling. Show me someone who can match this machine's rate of fire, while using a standard 'mag mechanical trigger mechanism, w/ no change in rhythm; I will show you a 'cocker user.

Perhaps the hypothesis being tested is how the ball bounces off the powerfeed and ricochets around the inside of the chamber. It would not be possible for the ball to bound back out of the barrel any distance considering there is a ball or six right behind it. Sure, if it were the last ball in the stack I would firmly believe that the ball left the chamber enough to get chopped. However, what are you doing w/ an empty hopper, mister? You carry a thousand rounds with you on the field, right? :) Nevertheless, considering how the blowback just bounded the ball off the top of the powerfeed how would the expended gas then bounce it back out of the barrel? No, that is not what the original post says!

The problem is with the chamber being too big for the ball size being used. If a small ball is put in a large bore barrel w/ a large chamber then the bolt might catch the next ball in line.

Wait, if the blowback does not affect ball chopping, as I proved above, then the size of the barrel bore and porting does not matter. It is the size of the chamber... this must be ID, right? It seems that the barrel manufacturers would all make the chamber sizes the same to accommodate the bolt. There is of course a minimum size... but should the chamber match the bore and let the bolt rattle around in the chamber, or meet a standard. This may create a lip past the breach for big bore barrels; forcing a reduction in the size of the ball or risk breakage from squeezing a large ball past the smaller breach.

Maybe if we measured the size of the bolt; then matched the barrel to the bolt and the paint to the barrel; then there would be no more worries about bobble because any movement by the ball would still be in front of the bolt.

Correction! ID would be the guide portion of the barrel where it makes contact w/ the spacer in the body. Which is smaller than the bore (Armson). This would account for the bolt not rattling around in the barrel. Because if it rattled around in the barrel there would be more bolt stick from cockeyed bolts. Though I do not see as to what effect this might have on the ball. Maybe if the "ID" (Whatever that stands for, darn engineers always expecting everyone to understand their acronyms) is too big then the bolt nicks the next ball in line and chops it... which then is blown into the chamber, etc. I wonder if the same people who chop allot also suffer from bolt stick?

I am willing to say I may be wrong and there is a supper fast trigger pulling freak who can beat the flow of gravity. (You must make your girlfriend happy!) So that the ball which has just been forced off the top of the powerfeed jumps into the chamber. The balls behind it are only just making it to the opening in the chamber and the chambered ball ricochets back up the powerfeed. No, that will not work because the next ball has blocked the powerfeed and the chambered ball will just bounce around the chamber. So maybe the ball is hit by the bolt at a certain angle in its travel around the chamber. This may cause a break in the ball w/ paint on the bolt and feed. This does not happen to standard bolts. Why would you use any bolt but a standard mag bolt? It is already the best and aftermarket non-AGD approved bolts are not their problem... Is it the cheep barrel that does not meet the AGD specs and causes bolt stick? Shame! (Careful some expensive barrels are still cheep) Is it that small paint you are using in your big bore?

Take an Automag out of the box, put in some RPSherer Premium w/ a revi’ and go to town... no chopping. Besides your own short stroking finger. Throw in a quality barrel (Armson, I am biased) and no chopping. Put on a Hyperframe and a Warp Feed... no chopping, at all. Weird! Must be operator error! No, it could not be me I am perfect. I never short stroke, I never run out of paint, and I got all the right equipment. Yah, right, get over yourself.