3 groove barrels-mullerworks

[Alex Wheeler]

No problem, I got the just of what I wanted lol. I'm still on the fence because the difference is only $25 between mullerworks and bartlein but I do like to atleast say I tried something new so I dunno.

Go with the Mullerworks. If for no other reason than Bartlien customer service SUCKS! If you get one that wont shoot they will do nothing for you, because they "dont make bad barrels" : Brux has awesome service as well as Krieger.

 

[tenring]

I had a 6.5x284 PcNor 3 groove that was put to holding up a tomato plant in the garden after 368 rounds.

 

[potatoe]

LOL, at least you got some use out of it.

 

[Macropod]

Got me thinking.... 12 twist at 3000fps = 180000 rpm so 1000yd time of flight say 1 and a 1/2 seconds, roughly 4500 revolutions approximately. Not accounting for spin decay.

 

[Dusty Stevens]

Hard for some to believe but a bullet only spins 3 revs in a 24" 8tw barrel.

 

[sdean]

As M61 said they decrease after awhile, but they increase spinning for a time after they leave the muzzle, that's why when you shoot a light bullet out of a fast twist barrel to fast it will sometimes come apart at some point downrange. If it were spinning at that rate in the barrel it would be coming apart closer if not at the muzzl

You might be wrong. Bullet speed starts to decrease as soon as it leaves the barrel. If speed is in the RPM formula then seems like RPM's should start to decrease as soon as it leaves the barrel.

Dusty if it makes 3 revs the first 2 ft. How many revs do you think it makes in the next 2 ft.?

 

[Ledd Slinger]

No problem, I got the just of what I wanted lol. I'm still on the fence because the difference is only $25 between mullerworks and bartlein but I do like to atleast say I tried something new so I dunno.

Go with the Mullerworks. If for no other reason than Bartlien customer service SUCKS! If you get one that wont shoot they will do nothing for you, because they "dont make bad barrels" : ...

Bartlein must have got it's customer service skills from Dan Lilja...LOL

 

[WayneShaw]

After all this talk of rpm's, my point was, if there are any imperfections inside the barrel, the bullet takes on those impefections and with the rpm's it's not hard to realize how it can effect accuracy.

 

[JRS]

Hard for some to believe but a bullet only spins 3 revs in a 24" 8tw barrel.

I hope you aren't saying what bdale believes, that the bullet is turning 3 RPMs.

This is as simple as I can convey this:

With a velocity of 3000 FPS in a 1:8" twist barrel 12" long, the bullet will spin 3000 revolutions per SECOND (because it is traveling exactly one foot) thereby making one complete revolution in 1/3000 of a second. To convert to RPM, simply multiply by 60 since there are 60 seconds in one minute.

Is that REALLY so hard to understand :-[

 

[Ledd Slinger]

Hard for some to believe but a bullet only spins 3 revs in a 24" 8tw barrel.

I hope you aren't saying what bdale believes, that the bullet is turning 3 RPMs.

This is as simple as I can convey this:

With a velocity of 3000 FPS in a 1:8" twist barrel 12" long, the bullet will spin 3000 revolutions per SECOND (because it is traveling exactly one foot) thereby making one complete revolution in 1/3000 of a second. To convert to RPM, simply multiply by 60 since there are 60 seconds in one minute.

Is that REALLY so hard to understand :-[

JRS,
Will you please start reading and at least trying to understand what people are saying before heckling them? He said "3 revs" (revolutions) in 24" with an 8" twist, which is correct...Nowhere in Dusty's statement do I see anything about revolutions per minute.

 

[JRS]

Hard for some to believe but a bullet only spins 3 revs in a 24" 8tw barrel.

I hope you aren't saying what bdale believes, that the bullet is turning 3 RPMs.

This is as simple as I can convey this:

With a velocity of 3000 FPS in a 1:8" twist barrel 12" long, the bullet will spin 3000 revolutions per SECOND (because it is traveling exactly one foot) thereby making one complete revolution in 1/3000 of a second. To convert to RPM, simply multiply by 60 since there are 60 seconds in one minute.

Is that REALLY so hard to understand :-[

JRS,
Will you please start reading and at least trying to understand what people are saying before heckling them? He said "3 revs" (revolutions) in 24" with an 8" twist, which is correct...Nowhere in Dusty's statement do I see anything about revolutions per minute.

The REVS (revolutions) are calculated per SECOND, not per minute. Is muzzle velocity calculated per minute? or per second? There is nothing abusive (heckle) about trying to show how to calculate RPM.

 

[Ledd Slinger]

Hard for some to believe but a bullet only spins 3 revs in a 24" 8tw barrel.

I hope you aren't saying what bdale believes, that the bullet is turning 3 RPMs.

This is as simple as I can convey this:

With a velocity of 3000 FPS in a 1:8" twist barrel 12" long, the bullet will spin 3000 revolutions per SECOND (because it is traveling exactly one foot) thereby making one complete revolution in 1/3000 of a second. To convert to RPM, simply multiply by 60 since there are 60 seconds in one minute.

Is that REALLY so hard to understand :-[

JRS,
Will you please start reading and at least trying to understand what people are saying before heckling them? He said "3 revs" (revolutions) in 24" with an 8" twist, which is correct...Nowhere in Dusty's statement do I see anything about revolutions per minute.

The REVS (revolutions) are calculated per SECOND, not per minute. Is muzzle velocity calculated per minute? or per second? There is nothing abusive (heckle) about trying to show how to calculate RPM.

A revolution is a a revolution. One full rotation of an object around another object or about it's own axis. And besides, I don't see where he mentions anything about muzzle velocity either. :

Hopeless...I'll leave you to your own world now

 

[LHSmith]

jrs- no disrespect intended.....but...."here's your sign"

 

[JRS]

Hard for some to believe but a bullet only spins 3 revs in a 24" 8tw barrel.

I hope you aren't saying what bdale believes, that the bullet is turning 3 RPMs.

This is as simple as I can convey this:

With a velocity of 3000 FPS in a 1:8" twist barrel 12" long, the bullet will spin 3000 revolutions per SECOND (because it is traveling exactly one foot) thereby making one complete revolution in 1/3000 of a second. To convert to RPM, simply multiply by 60 since there are 60 seconds in one minute.

Is that REALLY so hard to understand :-[

JRS,
Will you please start reading and at least trying to understand what people are saying before heckling them? He said "3 revs" (revolutions) in 24" with an 8" twist, which is correct...Nowhere in Dusty's statement do I see anything about revolutions per minute.

The REVS (revolutions) are calculated per SECOND, not per minute. Is muzzle velocity calculated per minute? or per second? There is nothing abusive (heckle) about trying to show how to calculate RPM.

A revolution is a a revolution. One full rotation of an object around another object or about it's own axis. And besides, I don't see where he mentions anything about muzzle velocity either. :

Hopeless...I'll leave you to your own world now

Oh my : I think i'll go out in the garage and polish my truck with my 3000 RPM buffer ;D

 

[hogpatrol]

 

[Eddie Harren]

"Better'n the funny papers!"

 

[JRS]

I'm not disputing the fact the bullet is making 3 revolutions in an 8 twist 24" long barrel. Go back to responses #13 and #15. This is where the question as to RPM started. The source that propels the bullet takes place while in the barrel. As soon as the effect of propellent is gone, it starts losing forward motion. The bullet has no power source of it's own, and generates it's RPM and velocity while in the barrel. Once the bullet exits the barrel, kinetic energy takes over.

Good one Donovan

 

[BOB LEE SWAGGER]

Why wouldn't you propose the RPM question to Bryan Litz and be done with it?

 

[JRS]

Why wouldn't you propose the RPM question to Bryan Litz and be done with it?

Bryan Litz actually addressed that question:

"Air friction slows down the spin of the bullet". Modern Advancements in Long Range Shooting contains a chapter (spin rate decay chapter 4) discussing it. To say there is nil (zero) decay to a bullets RPM in flight, is not quite accurate.

 

[BoydAllen]

sdean,

A ways back in this thread, you asked me how many revolutions a typical 6PPC bullet would make on its way to a 100 yard target. The calculation that I used went like this. The typical twist rate of a 6PPC is one turn in 14 inches. If we convert the distance from yards to inches it is 3600 inches. At that point all we have to do is divide 3600 by 14 and we get 257 turns. Of course this does not account for any slowdown due to air friction, but at that distance, I doubt that there is much of that, and truthfully, even if there was a significant amount, I would not know how to calculate it.