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Raw liver..............................?





WAUAGHHhhhhhhhhhh!






That SHINES!



GTC <img src="/ubbthreads/images/graemlins/cool.gif" alt="" />

Hi timberlake,

I have been away enjoying a New Year break.

Didn`t know your question was directed to me. I live in the deep far south - Western Australia, BPCR competition of the types you guys and ladies shoot don`t exist here and never seen one, so I cannot answer your question... Someone else may be able to answer...

Cam...

I'm thinking Crossfire pretty much nailed it with his remarks about wall thickness. It makes no difference(in theory) to a column(your barrel) what shape it has IF the bore is centered in the barrel. In reality none are so perfectly formed, each having minor or great variation...which leads to what results....I'd speculate that octagon forms may have an advantage in dealing with these flaws because the orientation of minor dimensions directs barrel gymnastics in predictable planes. You don't have a clue what a round barrel will do until you fire it. Common belief is that barrel harmonics are vertically oriented....a concept that leaves me breathless from laughter insofar as round barrels are concerned. There are MINOR factors that bend(no pun intended) in that direction, none of which IMO will overcome flaws in axial oreintation and unrelieved stresses. I note with some curiosity whilst developing loads for smokeless rifles that groups often mutate in string form, vertical to horizontal...and the dreaded diagonal(there's one that will queer long range accuracy fer ya!), then if I'm lucky winds up with a concentric wad when I find my load. That is all about harmonics...and maybe some heat. This is far more common with production barrels than fine custom tubes, but certainly is not unknown to them.

If one were to launch into a study of cause and effect on the subject I'm thinkin' you would wind up right back where you started...round is easier and cheaper to manufacture, octagon is more stylish(subject to opinion) and more expensive. All else being equal and fine points of detail attended to by the barrel maker...the difference in accuracy between the two would be lost in statistical clutter. JMO.

Timberlake, if we go to the real basic fundamentals of machining theory, and start playing with the "order of 10" axioms...........It is 7 times more difficult, or challenging to make a Perfectly ( Or as close to perfect as possible) symetrical Octagon profle, than a round.

Given that a possibility for error surfaces as you multiply machining steps, this makes sense.

The fact is, that with good high tolerance capable tooling, and care and attention lavished on the job at hand, a well done octagon profile will deliver the goods, and comparation of 2 barrels, 1 oct., 1 round, of equal quality ....................

Well, I best quote DD here,

"All else being equal and fine points of detail attended to by the barrel maker...the difference in accuracy between the two would be lost in statistical clutter."

I'll buy into this,

GTC

In the benchrest circles there is a rarity known as the "HUMMER". It is an uncommonly perfect specimen of a barrel that apparently is (near) perfect... meaning everything about it is (almost) right! By this I mean EVERYTHING about it is (about) as close to perfection as it can get... including, but not limited to, the hole down the MIDDLE, the equal mass around that hole, and the length tuned to a harmonic 'null'. (I say "about" and "near" as NOTHING is "exactly" perfect)

These 'HUMMERS' reportedly are considered both rare and Godly, inthat they have apparently supernatural abilities to consistently shoot through minor climatic irregularities, load variations and shooter error. In Benchrest competition, it is my 'guess' that the people with the big bucks and/or the established 'winners-circle' folks skim the Cream from the barrel manufacturers production, and only an occasional 'Hummer' slips by to the general clientel.

THAT would be my 'wild-a$$' assumption as what would equally apply to ANY shooting discipline using a barrel to direct a projectile downrange. <img src="/ubbthreads/images/graemlins/crazy.gif" alt="" />

Well, .....yeah! Ya know what? The Jersey used to lob 16" shells(grossly imperfect) thru long whippy barrels(profoundly flawed) that were on a platform bobbing, rolling, and going somewhere while all that transpired. Beyond 20 klicks one could adjust fire in 10 meter increments...bustin' bunkers with 2000# shells may seem unfair, but being of the Patton school of warfare.... and Army 8" SP howitzers did the same out to about 16 Klicks as I recall. You'd think a guy could park his azz on a firing line with a Sharps and simply wreak havoc at 1000 yards? <img src="/ubbthreads/images/graemlins/confused.gif" alt="" /> There is more to this than meets the eye.

They did have a pretty fancy Fire Direction Center, or something with a name similar... <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

Tell 'ya what, when they're in a good state of tune, and proper ammo is fed to 'em, these can be damned amazing Rifles. <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

GTC <img src="/ubbthreads/images/graemlins/cool.gif" alt="" />

Dan,
If I got it right, a 16" shell that is holding 10M (390") @ 20K is roughly 2 MOA. I just got in from a bit of load testing @ 1000 and all 5 test groups did that or better (except for one shot that went 3' right in a wind gust- should have held that shot until the condition came back). So I think that the accuracy is there for our guns- just takes staying consistently dialing in the wind to keep it in the 10 ring or better! And we don't use computers to take into account the spin of the earth! ...Dennis
PS. This new Goex Express looks like it wants to work pretty well- tried 78 grs. 2f behind a 555 gr. LZII & 10 rds. went under 2 Moa. I didn't chrono it , but the same bullet with 79 Swiss 1.5 (apx 1300 fps) shot about 1 Moa higher.

Blowin' so damn hard here today the dog wouldn't go out to Pee, unless I tossed him.............very gently, just fast enough that his teeth would snap together 4-6" down range from m' digits. <img src="/ubbthreads/images/graemlins/shocked.gif" alt="" />

Wind's up Dennis, come on down and we'll play........I reckon it'll be calming down now .............................oh, early June.

GTC <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

Greg-- sent in my app. to Steve for Feb. at Ben Avery- you going? ...Dennis

Probably not in view of the damned re-assesment on my place. Crap, been here just over a year, fixin' busted windows, pipes, and shoveling DIRT out of the old house, replete with mumified scorpions and other little as$holes.........plant a bit of a garden, and the property goes up $20,000................?????

Nope I think I might be over at the county seat, with the rest of the lynch / tar / feather party, that weekend.

best regards, GTC

Well good on ya! And thanks for the figgerin'...now I never doubted some wee groupage can be had by you fellas...maybe I shoulda said "Why can't I..."?

Now I do think 2 MOA is pretty good too, from a moving, rolling ship. Thing is, the ol' gal didn't "hold" 2MOA really. What I meant by adjusting fire in 10 meter increments is that ya drop one here, then move the next intentionally 10 meters(direction your choice)...then another 10...such was the drill in bunker revovation projects "over there". The Jersey could put two successive shells in the same hole at 20 Klicks. Computin'...winds aloft/humidity/atmospheric pressure/Coriolis Force/temperature/angle of fire/ship speed/target speed/target altitude...it goes on and on and on and on... and it was inspiring! Transcendental!!

'Twas a sad day when the BBs were mothballed...

Well, keep 'em in the black!

I'm lost!

Kelley O.

Naw, just put Polaris over your right shoulder and walk. When you reach the Pacific you might me in California... hope that helps.

One of the more exciting R & D projects that I know of, today, is Shilen's work with 17-4 PH stainless. The last I heard, they were still working out bugs. This is nowhere's near an easily machineable material, and I can state that based on personal experience. Made some rocket nozzles on a defense contract once, out of this stuff.

I'll be looking foward to seein' how that turns out, it's NEAT material.

GTC

Crossfire, what do it do? Haven't heard of the stuff, and what is Shilen doing?

Bearing in mind that I'm just "the fool on the tool" <img src="/ubbthreads/images/graemlins/crazy.gif" alt="" />, the crank turner as it were, this is what I know about it.

Once "Passivated", the material is almost supernaturally resistant to corrosion, and will stand up handily to peroxide rocket fuels...................the stuff that used to disolve those poor WW2 Kraut test pilots, in their "Super Weapon" rocket planes. <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

It can be heat treated to super material hardness specs., without giving up its "Toughness"

If you "Scuff" ( Tool breakage, a tool edge giving up on a cut, or just trying to "sneak up" on a dimension, and not taking a heavy enough cut).....................the stuff "Work Hardens" in a heartbeat.

Defence, and aerospace engineers seem to be infatuated with it, and I've seen it called out in applications that needed no where near that quality of material...................hey, they've got all of our money in the world, though.

It more than likely can be classified as a "Super Alloy", and at the very least aerospace grade material.

It is not considered a weldable material ( Niether,for that matter, is 416R stainless).....but I have seen some advanced process discussed, for same, by AWS.

I think it will make a GREAT barrel, but they will be proportionately, and rightfully , expensive. <img src="/ubbthreads/images/graemlins/shocked.gif" alt="" /> <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

Do you want me to send you a sample to play with?

GTC <img src="/ubbthreads/images/graemlins/cool.gif" alt="" />

If it is of any consolation, the "Aszzeszzor AZZHOLEZ" are EVERYWHERE!
My vote is to 'tar and feather' ALL of the BAZTARDZ... (what ever happend to that old ritual anyway???)

It would be ever so much easier , these days.......

a Case of that cheap spray on undercoating, or tree-pruning tar.......... <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

Some old pillows............. <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

Good to go. <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

GTC <img src="/ubbthreads/images/graemlins/cool.gif" alt="" />