# of grooves/barrel??

salukipv1 · 07-13-2010, 10:42 AM

So what's the deal with the number of grooves in a rifle barrel?

I believe 6 tends to be pretty standard? but was reading that a .458lott had a 8 or 9 groove barrel? also I think some barrles have 4 grooves?

Why would you want more or less grooves? some theory behind this?

goatbrother · 07-13-2010, 11:48 AM

You will find anywhere from 2 to 12 groves in barrels. A lot of different opinons on the subject.

Sheridan · 07-13-2010, 03:34 PM

Here's Chuck Hawks anyway...............................I know, he doesn't know anything and he never says anything he isn't paid to say.

Rifles have been rifled with from two to eight fairly deep grooves. Another approach, called "Micro-Groove" rifling by the Marlin Company, uses many shallow grooves. Barrels for standard centerfire cartridges of .30 caliber or smaller are usually rifled with 4 grooves. Barrels for most cartridges above .30 caliber are rifled with 6 grooves, as are .22 rimfire barrels.

bigbulls · 07-13-2010, 07:05 PM

It doesn't make any difference how many lands and grooves the barrel has.

07-13-2010, 07:13 PM

Quote:

Originally Posted by bigbulls

It doesn't make any difference how many lands and grooves the barrel has.

Better not tell the wildcatters that. Or anybody that does pressure testing. That must be your own little private secret.

Have you ever experimented with any pressure simulation software like quickload or others? Did you have to put the particulars about the lands and grooves and dimensions?

SchuLace · 07-13-2010, 07:24 PM

Quote:

Originally Posted by bigbulls

It doesn't make any difference how many lands and grooves the barrel has.

I would think more grooves would allow the bullet to spin more which would allow for more stability.

bigbulls · 07-14-2010, 06:25 PM

Quote:

Better not tell the wildcatters that. Or anybody that does pressure testing. That must be your own little private secret.

So enlighten us all oh great one.

Quote:

I would think more grooves would allow the bullet to spin more which would allow for more stability.

Spin is imparted by revolutions over distance. IE: 1 revolution in 10 inches. The number of grooves doesn't have anything to do with the twist rate.

07-15-2010, 06:49 AM

Quote:

Originally Posted by bigbulls

So enlighten us all oh great one.

Well, ole clownone

Number of grooves and depth of those affects pressure. Just that simple. Hense microgroove and its shallowness. The burden of how much pressure lies with the gun mfg. If you added more grooves to a 308 caliber barrel, you better make them more shallow than .3" bore. You have to keep .308" groove diameter. You can get custom rifling from most barrel mfg.

Ridge Runner · 07-15-2010, 12:12 PM

I know that some bullets can't stand fast twist low groove number barrels at high velocity, a 257 Allen Mag with a 7 twist, 3 groove barrel will rip the jackets off 100 gr nosler ballistic tips as they leave the barrel at 3800 fps, with a 4 or 6 groove they do fine.
RR

07-15-2010, 12:35 PM

Quote:

Originally Posted by Ridge Runner

I know that some bullets can't stand fast twist low groove number barrels at high velocity, a 257 Allen Mag with a 7 twist, 3 groove barrel will rip the jackets off 100 gr nosler ballistic tips as they leave the barrel at 3800 fps, with a 4 or 6 groove they do fine.
RR

Wasn't this the same with microgoove for marlin? They planned for 45-70's to mainly shoot fast jacketed bullets? Where the ballard rifling was more suited for deeper groove, good for lower velocity cast?