I don't know what the figures are for poly. Zak says he gets right about the same velocity as an M4 barrel with his afgan. I would expect some increase in velocity due to the tighter chamber and bore and smoother rifling. That is noted in good rifle barrels, like 5R's. I would expect at least 50 fps more than a standard 10.5, but would not be crushed if I didnt get it.

Quoted: I've got the ABS barrel, if there is a velocity increase it is too small to have any practical effect. It is pretty easy to clean though.

What velocities are you getting?  WHat barrel length? What rifling type?

Quoted: Where did you get the data that Pac Nor rifling would increase velocity that much?  I have seen no evidence of polygonal rifling increasing velocity that much.  I have heard increases from ABS barrel lining in the 75 fps range and will have to see that for myself as well.  I will have to see any of these velocity increases for myself to believe them.  Mike should have my barrel completed around Thanksgiving due to his heart attack and I am NOT anticipating 2700 fps with 75 grain 5.56 TAP like the boosts would suggest I will get from my 11.5" polygonal and over 2750 with suppresor.  This means that somehow barrel rifling, linings and suppressors can make a barrel plus suppressor have BETTER velocity than a 16" standard barrel of the same overall length where the last several inches are not even rifled bore.  I find that impossible to believe.

I've seen it with my own eyes... It averaged a 152 FPS boost over a Colt 10.3" CQBR (also with Noveske KFH) upper with late production M855. I've got the velocities scribbled down on a piece of paper. No elevation or any other specs, I had just written that it was 78 degrees, and this was in the general area of Pitkin (sp?), LA.  10.3" averaged 2698 FPS, the Noveske was at 2850 FPS on the dot.  Both were pretty well worn, and it could have been a fluke, but... I don't think it was. Both had Colt "2" buffers.

A 14.5" barreled Colt M4A1 averaged at 2901 FPS with the same ammo.

Who knows, it could be that the Poly rifling only performs nominally under certain conditions, with certain kinds of ammo, and only out of the shorter barrels.

I saw Zak's data, and don't doubt for a second that those were his results. I just think that this needs to be investigated fully before we accept or dismiss any possible result.

I've got a ton of data, but it's from everyone else... The above and the MRP data is the only I've witnessed first hand. I'll have more data when I get my Noveske (14.5" 6.8, LW 6.8P) upper, and my ABS barrel.

I'm trying out everything before i decide on what's best for what i plan on building. Either way, this is costing way too much money to be fruitful at this point. But hell, it's a lot of fun!




My Noveske build is simply a 14.5" Afghan in 6.8 set up for the LW piston setup. It'll have the:

LW low-profile GB
LW ACB
GP ARM-R/M
SF FA68A and adapter (which is now available!!!)
Troy BUIS
Low power variable optic (Probably S/B PMII or Ill Flashdot, 1.1x+ or 1.5x+) of some kind
My (CDI) lower
AS trigger w/ ISMI springs
VLTOR DE Clubfoot Modstock
TD DE grip, rail panels, VBG, and possibly bipod
SF M60LZ61 (SF M97LT170-XM06 in kitbox)
LAMSA SLA-IR
BFG EDC sling (coyote)
ISMI M4 recoil spring and Enidine buffer
PRI Gasbuster CH
PRI 15 and 25 round mags
Magpul DE Ladder panels

It'll all be tucked inside a Noveske deployment case. There will be some other small touches as well.

Is that the way it'll stay? Hell no, that's why this is a concept gun. It's not the only one, and it sure won't be the last.

The reason why there's so much crap is that I'm allowing enough stuff  to make the rifle perform multiple roles with little mods (flipping a throwlever and trading lights, for example).  All of the stuff is not meant to be on the rifle at one time, it is meant to allow the enduser to configure it as needed. So don't bitch at me for having so much crap on the list

Quoted: My Noveske build is simply a 14.5" Afghan in 6.8 set up for the LW piston setup.

can't imagine the wait time on this build.

Be aware that depending on manufacturing tolerances, different barrels of the same type can differ in velocity quite a bit.  

And even if two barrels start out the same, if one is shelved and the second is pounded by 15,000+ rounds, that second barrel will end up noticably slower than the like-new barrel due to throat erosion.   I've seen 50BMG barrels that have lost OVER 250fps this way (obviously in a lot fewer rounds!).  Eventually you can't add enough powder to get back up to the original velocity without blowing primers.

It would be more meaningful to take 5 or 10 of each type (new or similar round count) and chrono them with several types of ammo.

Comparing single data-points is not really reliable.

With regard to my data point, also note that the Black Hills commercial ammo is NOT as hot as 5.56, and so will gain less from every incremental inch than 5.56-spec will.

Have you actually used that Enidine buffer?    Seems like it's getting away from the KISS principle.  

The only other caution I would add to this thread is that fussing over every minute detail and adding a lot of shit to a rifle won't help you shoot any better.  I guarantee that buying a stock M4 and taking a 2 or 4 day "fighting rifle" class from good instructors will leave you in a better position than spending 6 months or a year getting together the "Ultimate RECCE".

After you've shot the number of rounds  it'll take to degrade one of the top-tier barrels to where you can notice in any practical context (ie field prone), you will have spent 5-20x the cost of the new barrel on ammunition (223/556, depending on ammo quality-  in 6.8SPC, it'll be closer to 20-40x).  

With those two points in mind, the specific details are not that important.  Pick a vendor known for building 100% reliable uppers and who guarantees 1 MOA accuracy, choose the optic appropriate for your most common use (e.g. Aimpoint, ACOG, or M/RT), and then buy lots of ammo and shoot it.

Quoted: Quoted: I've got the ABS barrel, if there is a velocity increase it is too small to have any practical effect. It is pretty easy to clean though. What velocities are you getting?  WHat barrel length? What rifling type?

Maybe 40-50fps over what a new DPMS 16" M4 barrel was producing with the same ammo. About 100-150fps over what my 16" HBAR with 9k rounds was doing. This was with a 16" 1/7 barrel that has since been returned and replaced by ABS. That is all the information I can share with you for now.

Quoted: I guarantee that buying a stock M4 and taking a 2 or 4 day "fighting rifle" class from good instructors will leave you in a better position than spending 6 months or a year getting together the "Ultimate RECCE".

Truer words are seldom spoken.


I get in as many tactical training classes as I can.  In both training and tactical style shooting matches, you will quickly find out what works and what doesn't.....and what is really NEEDED on your gun and what isn't.

Quoted: Be aware that depending on manufacturing tolerances, different barrels of the same type can differ in velocity quite a bit.   And even if two barrels start out the same, if one is shelved and the second is pounded by 15,000+ rounds, that second barrel will end up noticably slower than the like-new barrel due to throat erosion.   I've seen 50BMG barrels that have lost OVER 250fps this way (obviously in a lot fewer rounds!).  Eventually you can't add enough powder to get back up to the original velocity without blowing primers. It would be more meaningful to take 5 or 10 of each type (new or similar round count) and chrono them with several types of ammo. Comparing single data-points is not really reliable.

I think that might have a lot to do with it. I'm planning on comparing with multiple barrels, but won't have that opportunity for a few more months. As it is, I'm going to see what i can get with the ones that are inbound, and see if it's worth justifying more testing.

With regard to my data point, also note that the Black Hills commercial ammo is NOT as hot as 5.56, and so will gain less from every incremental inch than 5.56-spec will.

Which makes perfect sense, but... I'm also thinking that the heavier rounds will have less gain per incremental inch. Is there actual reasoning behind my madness? Not really... It's just a WAG.

Have you actually used that Enidine buffer?    Seems like it's getting away from the KISS principle.

Close to 600 rounds through one in a day. There are some quirks with it (releasing the bolt with the bolt release instead of charging handle to avoid slapping yourself in the face with your off hand) but if its failure point is over 50K rounds, as I've heard, it shouldn't be a problem. This isn't a serious defensive rifle as of yet, and won't be until everything has been tested fully. It'll see a lot of rounds and a lot of revisions before it's done. Nothing is set in stone, it is merely to demonstrate a concept at this point. Heck, if it fails i'm still left with a 3.5 oz buffer that'll work like the OEM unit.

The only other caution I would add to this thread is that fussing over every minute detail and adding a lot of shit to a rifle won't help you shoot any better.  I guarantee that buying a stock M4 and taking a 2 or 4 day "fighting rifle" class from good instructors will leave you in a better position than spending 6 months or a year getting together the "Ultimate RECCE".

After you've shot the number of rounds  it'll take to degrade one of the top-tier barrels to where you can notice in any practical context (ie field prone), you will have spent 5-20x the cost of the new barrel on ammunition (223/556, depending on ammo quality-  in 6.8SPC, it'll be closer to 20-40x).  

With those two points in mind, the specific details are not that important.  Pick a vendor known for building 100% reliable uppers and who guarantees 1 MOA accuracy, choose the optic appropriate for your most common use (e.g. Aimpoint, ACOG, or M/RT), and then buy lots of ammo and shoot it.

Ain't that the truth. Hell, I suggest that anyone get enough experience with the system and review their particular needs before dropping the super amount of cash for a system. There's no need spending $1500+ on an upper if it won't do anything in your particular scenario that a bone stock M4 with a light will do.

Training is paramount. All the gadgets in the world won't help if you don't have an understanding of the rifle system and how to implement it properly.

A class from EAG or Larry A Vickers should be on the list of priorities. ITTS also puts on one helluva class. You'll never see anything else like it, believe me. And, Tac Response is also damned good.

As soon as Larry Vickers and EAG's schedule becomes clear for '06, I'll be beack out there launching ammo... Trying to figure out what does and doesn't work for me

Although I don't say it as much, I agree on the training. I'll be getting more training as time allows.

Quoted: Which makes perfect sense, but... I'm also thinking that the heavier rounds will have less gain per incremental inch. Is there actual reasoning behind my madness? Not really... It's just a WAG.

Here are two general principles...

A lighter bullet will gain more absolute FPS because for the same pressure it is accelerated more (ie, A = F/M).

A heavier bullet provides more back-pressure (similar to an overbore cartridge) and can keep the pressure curve higher longer.   So you could say that a heavier bullet will take more advantage of a longer barrel than a lighter bullet.

But the specifics will depend on the actual load and powder used.

Nothing is set in stone, it is merely to demonstrate a concept at this point. Heck, if it fails i'm still left with a 3.5 oz buffer that'll work like the OEM unit.

What is its benefit?  I run all carbine buffers.  It seems like its selling point is that it adds "dead" delay to the rear of the stroke, which directly increases cycle time but also reduces bolt carrier group velocity.  Assuming we're not shooting FA and we have don't have a malfing upper, why would I want one?

tag.

Before comparing velocity of two types of rifling, you need to have the same chamber reamer. A tighter chamber will increase velocity.

I want polygonal rifling, but I am very BS sensitive after the Arms Tech fiasco article which claimed their 9.5 inch upper had velocity equal to a Colt 14.5. It simply had the velocity of about a 10 inch barrel. not a 14.5. When I asked Arms Tech to confirm or deny, they said something like "We were not there for the test, but such and such reported X." They were living off that article for years, and refused to correct it. How could they not know from their own testing it was BS?

A little off topic, but what?  

Quoted: Have you actually used that Enidine buffer?    Seems like it's getting away from the KISS principle.   Close to 600 rounds through one in a day. There are some quirks with it (releasing the bolt with the bolt release instead of charging handle to avoid slapping yourself in the face with your off hand)

 Is the Enidine "loaded" when the bolt is locked back?  

My plan is to have a do it all gun with more than one opic option for shooting out to 400 yards.  My Noveske Recon barrelled upper should be shipped from Denny soon.  Have a TA31F and a Larue mount for it on the way.  I am looking for some thing with more magnification for more precision and longer range work.  Selling my Jtac recce upper to fund the optic.  Looking at the Nightforce 2.5-10 or the Leupold MR/T.  Any reason I should get one instead of the other?