Paintball

[Scougar]

Originally Posted by EL17E 76

Nemesis is a spline drive rifled barrel - as opposed to a traditional land groove rifled barrel

Thanks. Much better worded that the words I strung together

[Bang*Bang**]

Spline. Hmm. Interesting.

I'm curious what your thoughts are on this backyard science video

A couple of thoughts for the OP.

Apparently, Tom Kaye (Automag) did some tests back in the day and found that the actual pressure behind a paintball in any maker is roughly 100-150 psi.

So I would hazard a guess that when markers, like the MG100/Emek, claim 105 psi operating pressure, what they're really achieving is efficiency upstream of the firing chamber or breach.

There may be little to no actual difference from the perspective of the paintball flying down the barrel.

To throw in my current understanding of round balls and smooth bore barrels. The guy at Parabolic (maker of the Phi one piece barrel), did tests recently for his physics undergrad and found that the paint accelerates until about 8"-9" down the barrel before starting to slow down. That's why he flares his barrels (by 0.005-bore) at the 8.5" spot. His 8"-9" acceleration claim seems consistent with previous tests done by "Punk Works" and another group.

I'm not sure how much of this applies to rifled or spline drive barrels and shaped First Strike Rounds. But I am super interested to find out!

[firemage]

Just wondering how well do the Nemesis barrels work with normal roundball?

[Scougar]

Surprisingly well. I would not buy it for round ball only though.

[uv_halo]

Originally Posted by Bang*Bang**

Spline. Hmm. Interesting.

I'm curious what your thoughts are on this backyard science video

A couple of thoughts for the OP.

Apparently, Tom Kaye (Automag) did some tests back in the day and found that the actual pressure behind a paintball in any maker is roughly 100-150 psi.

So I would hazard a guess that when markers, like the MG100/Emek, claim 105 psi operating pressure, what they're really achieving is efficiency upstream of the firing chamber or breach.

There may be little to no actual difference from the perspective of the paintball flying down the barrel.

To throw in my current understanding of round balls and smooth bore barrels. The guy at Parabolic (maker of the Phi one piece barrel), did tests recently for his physics undergrad and found that the paint accelerates until about 8"-9" down the barrel before starting to slow down. That's why he flares his barrels (by 0.005-bore) at the 8.5" spot. His 8"-9" acceleration claim seems consistent with previous tests done by "Punk Works" and another group.

I'm not sure how much of this applies to rifled or spline drive barrels and shaped First Strike Rounds. But I am super interested to find out!

As for the backyard test, They did a pretty good job documenting what they did but, unfortunately, it being outdoors, there is a high probability that on scene winds had a negative influence on the quality of the data. Small crosswinds (those that we can't even feel) are capable of drifting FS rounds 53" off target at 64.3m. Given that you can see the effect of those crosswinds in the video (pay attention to the fog from the muzzle) this means that there was a crosswind. Unfortunately, given that we can only see the cross range component of the drift on the 2D video, we can't tell which directions the breezes (i.e. straight left-right, forward to the right, etc).

Are you certain that the physics undergrad found that balls slowed down in the barrel (vice a reduction of acceleration)? I'm fairly confident that's not what Punkworks ever found (they did find reductions in efficiency which isn't the same thing).

Now, with normal, rifled barrels (i.e. Hammerhead / LAPCO), it really depends on the bore fit. Switching from a smoothbore to a LAPCO .683 Rifled reduced the velocity of a FSR by about 20FPS. However, a Hammerhead barrel didn't have this effect to any significant degree.