POF GPU vs ADDAX GPU

[bondmid003]

Chris what is the difference between your ATAC Grendel Upper and the ATAC 6.8 SPCII Upper?

[Addax]

do you have pics of the SPR

One of my recent builds in 6.8SPC for a LE customer.

I used 18" White Oak-Shilen 4 groove 1:11 twist Mid-Length gas barrel.
DD 12.0 FSPM Lite Rail, and BRO Billet Upper Receiver.
PWS Short Stroke Piston System.

My customer had my logo laser engraved on his lower.

He is currently conducting accuracy testing, and he will provide me pics and info. as soon as he is done.

[blindluck]

pm sent to OP.

[evollep3]

One of my recent builds in 6.8SPC for a LE customer.

I used 18" White Oak-Shilen 4 groove 1:11 twist Mid-Length gas barrel.
DD 12.0 FSPM Lite Rail, and BRO Billet Upper Receiver.
PWS Short Stroke Piston System.

My customer had my logo laser engraved on his lower.

He is currently conducting accuracy testing, and he will provide me pics and info. as soon as he is done.

very nice chris

[bondmid003]

Chris, any word on my question?

[Addax]

Chris what is the difference between your ATAC Grendel Upper and the ATAC 6.8 SPCII Upper?

Other than caliber.

The 6.5 Grendel Upper is built with a Sabre Defence chrome lined 16" Mil-Spec barrel.

The 6.8 SPC uppers are built with White Oak-Shilen stainless barrels, and we have these Cerakoted in Graphite Black.

We will eventually offer the 6.5 ATAC GPU with an Alexander Arms stainless barrel once we can get our backorder filled from AA.

Chris

[RaymondMillbrae]

If I may ask...what is the difference between a "heavy contoured barrel" and a "medium contoured barrel"?

Are there pros and cons to each?

Where would you benefit from a heavy contoured barrel, and where would you benefit with a medium contoured barrel?

Thanks, just trying to edumacate myself.

In Christ: Raymond

[NSR500]

Difference in contours would be weight/thickness of the profile/cut.
As for the effects, a barrel with more material will handle heat differently than one with less material. The barrel profiles between light, medium, and heavy handle barrel whip differently too.
If you want to really give yourself a headache, start thinking about barrel lengths, twist rates, rifling, etc...

[bomb_on_bus]

2.5 inch moa?

Is that a shotgun or a rifle?

Pof all the way and shoot inside a dime.

One sick looking setup!

I am pretty much running the same thing now.

American Defense 30mm scope mount.
Leupold mk4 3.5x10x40.
Magpul 308 PRS stock.
20inch 308 POF gun.

[xxG3xx]

I would go with addax....but I don't like the way the new rails look...I like the older style.

[RaymondMillbrae]

Thanks for all the responses, folks.

It's been an informative thread.

In Christ: Raymond

[tvfreakarms]

What is the difference between a short stroke vs. a long stroke gas piston system? Is one style better than the other?

[THT]

What is the difference between a short stroke vs. a long stroke gas piston system? Is one style better than the other?

Military Morons has a nice write-up:

Now we get to the heart of the ATAC; the long-stroke piston system. As I mentioned above, the system is very similar in both looks and operation to the AK system. The gas block has no adjustment. It bleeds gas from the barrel port into the gas block, which expands and pushes the piston to the rear. When the piston head moves past a certain point, gas is bled out through a port at the bottom of the piston tube, above the barrel. The gas tube hole in the front of the upper receiver has been opened up to accept the piston.

Why did PWS come up with this new system? Simplification and ease of maintenance. When looking at the short stroke system, one of the drawbacks is that the front knob and piston would become difficult to remove due to carbon build up. The knob would need a wrench to turn it, and the piston would need to be pushed out of the piston tube from the back by the operating rod. Note that a sticky piston that didn't move freely back and forth under its own weight in the piston tube didn't affect function while shooting. There were also small parts in the short-stroke system.

http://www.militarymorons.com/weapons/ar.uppers3.html

[X-NewYawker]

The new Addax gas system does everything I want.