Milling "windows" in the spring travel area of body

[Bad_Dog]

do you really think that the loss due to the air cushon is really going to affect anything?

the feed neck is already a ~0.7 diameter hole, you are right about the blow back theory because that was the reason why AGD introduced the HL-HR powerfeed bodies...

so how much of the air actually goes the path of the ball, and does it actually ave an affect on the ball's flight?

[luke]

An easy experiment, chrono your marker before you do the mod, then retest after..

I do think it will work, but my money says the price to pay will be air efficiency. My opinion is based on experiments that TK has done and a little common sense..

[warfinge]

I dunno. Heck it might even increase the feed efficiency by giving blowback a vent. Some get obsessive about shot count and tuning. Any rumor that a certain design can cost you 10 shots per tank is enough to stop modders from doing it.

[luke]

Do an experiment, take a barrel sick it in your mouth (seal off the feed port if it's a stock AGD barrel) and blow. A lot of air came out the end right?

Now do the same test but but hold the barrel 1" away from your mouth when you blow. I bet air came out, but not as much as before right?

Now, theoretically if you could blow hard enough, you could produce the same exhaust out the end of the barrel without sealing off the end. It would just take more effort...

[luke]

Any rumor that a certain design can cost you 10 shots per tank is enough to stop modders from doing it.

That comment right there confirms my hypotheses. I never said it wouldn't work, I just said it would use more air. I never said how much, because I don't have a clue...

[Bad_Dog]

Do an experiment, take a barrel sick it in your mouth (seal off the feed port if it's a stock AGD barrel) and blow. A lot of air came out the end right?

Now do the same test but but hold the barrel 1" away from your mouth when you blow. I bet air came out, but not as much as before right?

Now, theoretically if you could blow hard enough, you could produce the same exhaust out the end of the barrel without sealing off the end. It would just take more effort...

I can recall a professor of mine explaining a theory similar to this once. He had a very long slender plastic tube, made from a similar material to that of black plastic garbage bags, abut eight inches in diameter and around ten feet long. So imagine a garbage bag, eight inches in diameter, and ten feet deep... sealed at the one end leaving only one opening.

I dont recall exactly what he was discussing, or the theory behind the example, but I do remember the results.

He first unrolled the long 10ft tube, and asked the class if we thougt he could fill the entire tube with one breath of air. looking at the size of this tube, and knowing the volume of air it could hold, the consensus from the class was it would be impossible. The Prof. put the open end of the bag up to his mouth, and breathed a full breath into the tube. Our hypothesis was correct it hardley inflated...

Then the Prof. said no no no I'm not done here, he held the end of the bag open with his two hands, and this time blew into the tube from a distance about ten inches from the opening. Completly unexpected, the entire tube inflated, and to top it the professor closed the end of the bag and sealed it with a rubberband so we could all examine the plastic bag-tube for ourselves, he didnt cheat...


By blowing into the tube from a few inches away, the stream of air actually caused more air to flow into the opening; thus completly filling the tube. I never would have expected this result.

Maybe there is a possability that the blow forward from the bolt, could creat low pressure and actually pull more air down the barrel...

Man these discussions are way more interesting now that I've got some education behind me

[luke]

Perhaps my example is incorrect in theory. But the difference is we are trying to propel an object .. I offer machining services if you would like to put your money where your mouth is.

[luke]

I'm sure TK is smarter than both of us, I invited him to take a look at this thread...

I will gladly accept his answer as fact.

[RavishingEddie]

Would it be possible put these theories to the test by covering the feed tube?
Also wouldn't the pressure of air cause the the dirt to easier blow away since there is an opening to escape?
I predict that the dirt build up in my chamber is due to it being in enclosed. This is not a problem for me because every gun should be cleaned after a day of play. I'm just guessing that it might help.


Ah never mind!. Even if it gave you more efficiency and even self cleaned, a gun shot to that area would probably put you away and send you to the bench for some serious cleaning

Or would the self cleaning feature (if there is one) be strong enough to self clean?
Great now i'm really confused. Better get back to work.

[Bad_Dog]

I'm sure TK is smarter than both of us, I invited him to take a look at this thread...

I will gladly accept his answer as fact.

i'm curious to see what he has to say

[AGD]

Ok I am here.

Yes you can cut a window in the slug without bad effects (except dirt). The spring guides on the bolt.

Yes there is some blowback up the feed tube. This is minimized by having a good bolt to barrel match. We tried putting orings on the end of the blot back in 1990 but they kept rolling off. In all, the amount of blowback is minimal and while is does reduce efficiency a little bit, its way less problematic than dealing with orings for each size barrel etc. Other guns have a machined breach and a step into the barrel, thats how they get around it. The AGD alum bodies will in general work better for this reason.

AGD

[Sumthinwicked]

Ok I am here.

Yes you can cut a window in the slug without bad effects (except dirt). The spring guides on the bolt.

Yes there is some blowback up the feed tube. This is minimized by having a good bolt to barrel match. We tried putting orings on the end of the blot back in 1990 but they kept rolling off. In all, the amount of blowback is minimal and while is does reduce efficiency a little bit, its way less problematic than dealing with orings for each size barrel etc. Other guns have a machined breach and a step into the barrel, thats how they get around it. The AGD alum bodies will in general work better for this reason.

AGD

tom is the man this is why i still use mags to this day and will far after theyre done as long as the orings last LOL

[SocialD]

Couldn't you more or less test this by firing a couple of balls over the chrono with a hopper fill of paint on the marker. Note the velocity. Then, remove the hopper and load and fire one ball at a time over the chrono. Then, note the velocity change again.