Variable rifeling rifle barrels...... ? - The Firearms Forum

glocknut · 03-01-2004, 11:00 PM

I was looking at a friends magazine called Competitive Shooting (?) and saw an ad for a barrel maker that makes a barrel that starts out at something like a 1/12 twist and increases to a 1/7 twist at the muzzle end.....

The add said that this increases accuracy and makes more use of the powder charge by increasing veloctiy?

Anyone ever seen this type of barrel?
I don't know if it'd be necessary for an AR but it might be good for a bolt action? One of my pet projects is a .300 win mag with all of the goodies......this might be a good deal for it?

mike

Xracer · 03-02-2004, 07:05 AM

Since the stability of a bullet is determined by the rotational twist as it leaves the barrel, I fail to see how an increasing twist as it travels through the barrel would have any advantage over a constant rotational twist.

After all.....the final rotation is the same where it counts....at the exit.

glocknut · 03-02-2004, 08:02 PM

I dunno.....

Thought the diagram looked cool anyway....

mike

armedandsafe · 03-02-2004, 08:50 PM

My understanding is that gain twist rifling produces less stress on the bullet, therefore you can have a higher final rotation speed AND a higher velocity without stripping the jacket.

Pops

glocknut · 03-02-2004, 09:02 PM

Yeah....thats it!!

mike

03-01-2004, 11:00 PM	#1
glocknut Advanced Senior Member Join Date: Dec 2003 Location: THE FORUM MASCOTT... Posts: 12,482	Variable rifeling rifle barrels...... ? I was looking at a friends magazine called Competitive Shooting (?) and saw an ad for a barrel maker that makes a barrel that starts out at something like a 1/12 twist and increases to a 1/7 twist at the muzzle end..... The add said that this increases accuracy and makes more use of the powder charge by increasing veloctiy? Anyone ever seen this type of barrel? I don't know if it'd be necessary for an AR but it might be good for a bolt action? One of my pet projects is a .300 win mag with all of the goodies......this might be a good deal for it? mike __________________ Where O where are you tonight? Why have you gone and left me alone? I searched to world over and a thought i found true love... You met another and PTThhh you were gone.... -->

03-02-2004, 08:02 PM	#3
glocknut Advanced Senior Member Join Date: Dec 2003 Location: THE FORUM MASCOTT... Posts: 12,482	I dunno..... Thought the diagram looked cool anyway.... mike __________________ Where O where are you tonight? Why have you gone and left me alone? I searched to world over and a thought i found true love... You met another and PTThhh you were gone....

03-02-2004, 09:02 PM	#5
glocknut Advanced Senior Member Join Date: Dec 2003 Location: THE FORUM MASCOTT... Posts: 12,482	Yeah....thats it!! mike __________________ Where O where are you tonight? Why have you gone and left me alone? I searched to world over and a thought i found true love... You met another and PTThhh you were gone....

03-02-2004, 07:05 AM	#2
Xracer TFF Admin Staff Mediator Join Date: Feb 2001 Location: Minn-eeee-sota, ya, sure, you bet! Posts: 9,144	Since the stability of a bullet is determined by the rotational twist as it leaves the barrel, I fail to see how an increasing twist as it travels through the barrel would have any advantage over a constant rotational twist. After all.....the final rotation is the same where it counts....at the exit.

03-02-2004, 08:50 PM	#4
armedandsafe Former Guest Join Date: Dec 2002 Location: Moses Lake, WA Posts: 10,344	My understanding is that gain twist rifling produces less stress on the bullet, therefore you can have a higher final rotation speed AND a higher velocity without stripping the jacket. Pops