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What the heck! Theres holes in my barrel!!

Posted: Mon Sep 19, 2005 8:35 pm
by James
I was shooting the kite without pellets to see/feel how well the compensator worked, and i felt air come out of the top of the barrel!!!!

Well There are 3 holes there, but I didn't think they went all the way through.

Sure enough i held it up to the light, and there are holes in the barrel!!

What airgun manufactuerer has the guts to drill holes into a fine lothar walther barrel.

I dont know what it does to the pellet, but I assume the holes are to reduce muzzle flip, but this I have never before seen.

That means that the pellet is only accelerated for 3.5 inches! before air escapes through the holes.

This gun must have very efficient valving to get 200 shots off a cylinder only 7 inches long.

Posted: Tue Sep 20, 2005 1:30 am
by Axel
Same on Steyr lp10, Feinwerkbau p34 and p40. And yes, holes reduces mussle flip, at least in theory.

Posted: Wed Sep 21, 2005 1:39 am
by Dan
just out of curiosity and since you mention it yourself...whats your idea of what a compensator actually is and how it works?

Posted: Wed Sep 21, 2005 3:39 am
by Guest
I have found the movement of the pistol when fired with a pellet and when empty to be quite different.
There is much more upward movement of the muzzle when a pellet is discharged.
I think to test a compensator, don't bother if a pellet is not fired.

Posted: Wed Sep 21, 2005 4:50 am
by Hans A.
Dan, basically compensators work by compensating the upward movement of muzzle (muzzle jump) by creating a counter torque as the gas comes out of the gas ports (holes).
I have found the movement of the pistol when fired with a pellet and when empty to be quite different.
There is much more upward movement of the muzzle when a pellet is discharged.
You will feel there's more upward movement with a pellet discharged because the pressure is increasing faster (because of slower increasing volume), therefore, so do the torque.
I think to test a compensator, don't bother if a pellet is not fired.
I think if you don't fire a pellet, then the muzzle jump is smaller, so is the downward movement caused by the compensator. Then it becomes harder to see the effect, no?

If you want to test how effective your compensator is, maybe you could try covering the gas ports first, then fire your gun. After that, open the covers, then fire your gun. Compare the result.
(WARNING: I suggest don't try this "experiment").

Posted: Wed Sep 21, 2005 5:14 pm
by James
Guest, i was seeing how it works.....I was wondering if air actually came out from the slits, and how much.

Thanks for clarifying Hans, i wasn't exactly why the muzzle flip was more substantial with the pellet.



When shooting with correct followthrough there is no movement.

but when i shoot and i happen to move during the shot, it moves upwards.

So the pistol relys on the weight of your hand/arm to have no movement, it dosnt totally negate the muzzle flip, just reduces it to the point where it is not felt.

Unlike the steyr or nygord, the compensator on the benelli has the slits on the side rather then top.

Posted: Thu Sep 22, 2005 12:39 pm
by Fred Mannis
James,
The holes on the top of the barrel are there to reduce muzzle flip. The holes/slits on the device on the end of the barrel are used to vent gas away from the pellet as it exits the barrel. This is said to reduce tubulence and improve accuracy. Depending on the design of the device fitted to the end of the barrel, it may reduce muzzle flip as well as decrease turbulence.

Fred

Posted: Sat Sep 24, 2005 2:10 am
by superstring
For a complete explanation w/pics:

http://www.airgunsonly.com/frames.html

Look under Tech Tips, then "Muzzle Compensators"

Posted: Sat Sep 24, 2005 8:42 am
by Hans A.
At the bottom of the page provided by superstring, we can notice that the holes on the barrel has a zig-zag pattern (right-left-right-left). Anybody can explain why are they located like that? If I want to drill holes just for compensating purpose, I think I will drill all holes in line one another. Is it because of the dynamics of the gas travelling down the barrel?

Posted: Sat Sep 24, 2005 9:39 am
by James
My benelli has 3 holes inline.

Whats interesting is that pardini says they dont do anything, and they dont put it on their guns.

Basically calling the lp10 and benelli kite a bunch of fancy bs.

There may be more gun to the benelli then the price reflects.

William's kite young does not have holes however. Must be a new feature.

Posted: Sat Sep 24, 2005 10:51 am
by Fred Mannis
Hans,
I think that the holes in the picture you refer to are drilled at an angle so that the gas exits the barrel at oblique angles rather than at 90 degrees only. If the drilling and assembly of the drilled barrel are done properly, I do not see a need for this.

Fred

Posted: Sat Sep 24, 2005 1:42 pm
by Walter
James wrote:My benelli has 3 holes inline.

Whats interesting is that pardini says they dont do anything, and they dont put it on their guns.
Pardini's new air pistol has holes now too.
You can also get a Hammerli ap40 with holes.

Pardini K2

Posted: Sat Sep 24, 2005 4:11 pm
by Bill177
I have a K2 and it is vented along the barrel. I also have a Nygord compensator on it. There is no movement when it is fired. Must be a good combination.