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-   -   Carmatech announces Nemesis Precision Rifled Barrels for January 2018 (https://www.mcarterbrown.com/forums/paintball-news/306681-carmatech-announces-nemesis-precision-rifled-barrels-january-2018-a.html)

uv_halo 12-16-2017 07:58 PM

Carmatech announces Nemesis Precision Rifled Barrels for January 2018
 
Carmatech has announced a new barrel design called the "Nemesis Precision".

https://www.youtube.com/watch?v=Q8A8euAS_pE

It appears that the barrel is being compared to the existing HH/Carmatech barrel and the LAPCO .683 barrel, and appears to make no references to using the Nemesis barrel with regular paint.

It's hard to be certain but, it appears to have a different style of rifling (four 'splines') and a spiral ported muzzle break (that appears to have a similar twist rate/direction to the barrels rifling).

It is claimed to:
  • Be More efficient (15%) than the original hammerhead barrel designs
  • Have a better twisting grip on projectiles (30% vs HH, not too much better than other probably LAPCO barrel)
  • Impart a higher Muzzle RPM (12000 vs 1350 HH or the 4500 RPM theoretical max of the LAPCO)
  • Have a Tighter (85%) Grouping*

* The whole grouping plots are interesting, to say the least. The first things I noticed were that the competitor barrels (LAPCO and HH) were shown to have spread biases (LAPCO Vertical, HH Horizontal), while the nemesis barrel appears to have no discernable bias and, it spreads less. I also noticed that the Nemesis is specified as the "Nemesis 20" in the plots (presumably a 20" barrel) and it's possible that there may be other lengths offered at some point. I'm assuming that the numbers are in inches.

I duplicated the plots to crunch the numbers and I found that the Nemesis plot is missing a shot (other barrels had 15shots plotted while nemesis only had 14). The standard deviation of the vector** shows a roughly 36% improvement over the competitor barrels in the advertising.

If I remove the largest single outliers from the HH or LAPCO plots, the numbers don't change all that much but, that's not the greatest way of doing things anyway.

** Vector represents the standard deviation (in inches) of the shots from 0,0 on the plot. Double this number to get a radius that 68% of your shots will land within, double it again to get the radius covering 95% of your shots.

Two questions I'm left with:
  • Why were only 14-15 shots recorded?
  • Does chrono data (per shot) exist for these shot groups?

I hope that someone can get their hands on one of these barrels and do some rigorous 75yd indoor shooting. Interestingly, the earlier indoor HH and LAPCO/Tiberius rifled barrel testing that Punkworks did (with my support) showed vectors closer to the Nemesis than what is shown in this video.

The Flounder 12-17-2017 08:39 AM

If you want to see some really interesting, take the Lapco shot diagram, rotate it 90 degrees and flip it 180 on the long axis. Then lay it over the HH shot pattern.

They plan to sell them in several lengths up to 20 inches in a few threads. Only SAR12 owners will be able to purchase th 24 inch version.

Deuce 12-17-2017 08:48 AM

The "Groupings" are highly suspect, but I'm still watching to see what comes of this.

Slappadapink 12-17-2017 02:46 PM

Not to knock Carmatech but the commercial had a very info-mercial feel with some data that seemed like I did the testing while I was trying to lick my elbow.

Interested in seeing these but wondering if the claims are accurate and replicable.

freedummy 12-17-2017 04:41 PM

1 Attachment(s)
I'm taking all the marketing specs with a grain of salt, but what excites me is this -

Attachment 59708

- Which shows the cuts from the spline rifling in FSR Lou Arthur shot with the barrel and recovered. No slipping or shearing, actual rifling engagement!

uv_halo 12-17-2017 05:17 PM

Quote:

Originally Posted by The Flounder (Post 3442332)
If you want to see some really interesting, take the Lapco shot diagram, rotate it 90 degrees and flip it 180 on the long axis. Then lay it over the HH shot pattern.

They plan to sell them in several lengths up to 20 inches in a few threads. Only SAR12 owners will be able to purchase th 24 inch version.

Numerically, I've taken the LAPCO Data, Swapped the X and Y values and I think it illustrates what you're talking about (on the Graphs page). All of the points appear to correlate except for the 1,-7 shot (LAPCO) which should be 2, -7 on the Hammerhead chart.

Very suspicious indeed.

uv_halo 12-17-2017 05:18 PM

Quote:

Originally Posted by freedummy (Post 3442393)
I'm taking all the marketing specs with a grain of salt, but what excites me is this -

Attachment 59708

- Which shows the cuts from the spline rifling in FSR Lou Arthur shot with the barrel and recovered. No slipping or shearing, actual rifling engagement!

Very Interesting!

tymcneer 12-17-2017 08:42 PM

Some "simple" math...

FSR fins are about 1 rev per 12" of flight.

At 300 fps this means 18,000 rpm, assuming everything is "perfect"

After a discussion with uv_halo, we decided the Lapco is about 1 rev per 48" of flight, which translates to 4,500 rpm

He and I agree that the Hammer Head and the Lapco use about the same rifling rate, so the 1,350 rpm number is either measured or concocted.

I am glad to see that someone has finally figured out that bullet style rifling is not as good at gripping a "soft" shelled round, as pellet gun rifling.

Ty

freedummy 12-17-2017 09:29 PM

There's some discussion on the Facebook pages about that. Despite the same rifling rate, the HH is larger bore than the Lapco, so the lower RPM is due to more slippage.

TCPaintball 12-19-2017 11:35 AM

no CCI threads then i dont want it lol since thats the only FSR marker i have

Unless a nice short AC barrel for my R7 is available


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