New Whisper SBR Build (Updated Specs and Pics)
 

Just finished building this 300 Whisper/Fireball. She shoots like a dream. The first 4 rounds (220 gr SMK Subsonics) down the tube went into .875 inches at 100 yards. Things got better from there. Groups are averaging around .625 with my home-rolled subsonics. Cycling is flawless. John Noveske is the man!

Here's the specs:
Noveske 10.5 inch 1x8 Twist barrel
CMT Upper
DD 9.0 Forend
Young Manufacturing NM Bolt Carrier
CMT MP-Tested Bolt NP3-coated
PRI Gasbuster Charging Handle
GG&G 20 moa GS-1 Rail
ARMS #22L Rings
Leupy 3.5x10x40 M3 MilDot
SWR Omega Suppressor
Oly SBR lower
CMC Single Stage Match trigger
MIAD Grip
Standard M4 Buttstock
H-Buffer
http://www.hunt101.com/data/500/IMG_2221.JPG

What powder loading are you using for your home-rolled subsonics?

Chuck

Fairly standard Vanilla Subsonic load. 220gr SMK, Keith Davis Brass, 9.2 gr H110, 205M Primer, 2.190 C.O.L. Works great for me. Avg 1020 fps and just over half moa. Standard disclaimer - Use at your own risk.

awesome. I am waiting for my form 1.Have you tried any supersonic ammo in it yet? Did John advise against that?

Haven't tried supersonic stuff yet. John mentioned that these barrels were set up primarily for subsonic, but he did not specifically forbid the use of supersonic fodder.

I'm thinking of making this a select-fire weapon (as in semi-auto or manual bolt action) by using one of tp555's on-off pushbutton gas blocks and a Fulton side charging upper. In that configuration, I get the best of both worlds. Just in the tire-kicking stages right now. Got a lot of measuring/figuring/thinking-it-through kind of work to do first.

Finally got around to doing the bolt action AR. I wanted a selectable semi-auto/manually operated setup so that I could determine when to make the extra noise. Using tp555's on/off gas block let's me go back and forth between semi-auto and manual bolt action. Just got it all put together. Had to modify that gas block a bit to make it fit under the handguard. Gonna put rounds downrange tomorrow. Here's how it all shook out.

Final specs:
Noveske 10.5 inch 1x8 Twist barrel
Fulton Armory Side Charging Upper
JP VTAC FF Tube
tp555's on/off pushbutton gas block
Harris BR Bipod
Fulton Side Charging Bolt Carrier
CMT MP-Tested Bolt
Standard Charging Handle just to fill the hole
GG&G 20 moa GS-1 Rail
ARMS #22L Rings
Leupy MK4 2.5x8x36 M2 TMR Reticle
SWR Omega Suppressor
Oly SBR lower
CMC Single Stage Match trigger
MIAD Grip
Vltor A1-length Rifle Stock
Standard Rifle Buffer
http://www.hunt101.com/data/500/IMG_2306.JPG
http://www.hunt101.com/data/500/IMG_2308.JPG
http://www.hunt101.com/data/500/IMG_23091.JPG

That is pretty damn sweet!!!

Thanks steezo757. Proof's in the shootin' though. Hopefully we'll see how that works out this afternoon.

Ok...now that I have picked up my jaw from the floor, let's talk about that gas block.

To start off, I have the same exact barrel. Now for the questions:

2) Did you open up the gas port? If so, did you max it out at .110"?
3) Were you able to adjust the gas block to your load? Or is it just an on/off feature?

Left the gas port alone. Same as it came from Noveske. This block is a simple on/off affair. He makes adjustable ones though.