Barrel Differences

[marvinvwinkle]

I just bought a Savage 12fv varmint rifle. I guess it has a heavy barrel and I'm wanting to know what the difference is between the heavy and bull barrels. Thanks in advance.

[McKinneyMike]

Bull barrels are approx. 1" at the muzzle vs. 0.80" at the muzzle.

[marvinvwinkle]

Is there much difference in performance, heat retention, etc?

[pdog06]

The bull barrels will take longer to heat up, but will also take longer to cool down after it does heat up.

Dont think there is a performance difference as far as just the contour goes. Maybe for the real long barrels it might help more with the larger contour, but Ive had and seen ALOT of varmint contour barrels that shoot really well.

[psharon97]

One observation I've had is, barrel lengths being equal, the thicker the barrel, the lower the report from the rifle. Comparing my custom 308 which has a bull barrel and comparing a ruger m77 with a pencil barrel, both shooting same loads, same weight bullets, same primers, my custom doesn't seem as 'loud' as the thinner barrel. A gunsmith i work for sometimes also pointed this out to me.

[marvinvwinkle]

Thanks everyone for the help. :)

[Uncle Jack]

One observation I've had is, barrel lengths being equal, the thicker the barrel, the lower the report from the rifle. Comparing my custom 308 which has a bull barrel and comparing a ruger m77 with a pencil barrel, both shooting same loads, same weight bullets, same primers, my custom doesn't seem as 'loud' as the thinner barrel. A gunsmith i work for sometimes also pointed this out to me.


I'm not sure I'm ready to buy this one. I certainly do not have any evidence to dispute the claim but, I just do not understand how a difference in weight of two barrels of the same caliber and length would have any effect on the number of decibels coming out the end.

As I have said before, please educate me.

uj

[borg]

I'm not sure I'm ready to buy this one. I certainly do not have any evidence to dispute the claim but, I just do not understand how a difference in weight of two barrels of the same caliber and length would have any effect on the number of decibels coming out the end.

As I have said before, please educate me.

uj

I would doubt that it has any effect on the number of decibels coming out the end of the barrel. I can believe, however, that it would have an effect on the number of decibels radiating from the sides.

[Snake River Marksman]

I just wonder if it could be related to the shape of the crown. Bull and varmint contours generally have a flat, target crown. Sporters typically have a radiused crown. Maybe it shapes the blast differently?

[Pete K.]

Bull barrels are approx. 1" at the muzzle vs. 0.80" at the muzzle.


Mike,

When I went to New Milford, Ct to Time Precision to fit a "Super Tuner" harmonic balancer on my VLP he measured at the end of the barrel and one inch from the end. He came up with .920" which is what he bored the ID of the turner to. So what is that considered? Heavy or Bull?

Pete K. ???

[Locosmith]

I can't buy it either. A db meter is the sound level, that would be when the bullet passes the crown. The vibration of the barrel or harmonics would be different but I don't know or can prove that would equal more sound???? ::)

[lostart]

pete

I think that they call that the varmint contour.

[placek59]

Not sure about everything else here, but my varmint barrels (factory .204 and .270wsm) measure .815 at the muzzle. I was under the impression that these would be the varmint contour and the bull barrel would be more like a straight 1.055. I'm not sure if savage ever made a heavy varmint that would be in between the two. My 28" Lothar Walther 6br barrel is .850 at the muzzle fwiw.

[borg]

I can't buy it either. A db meter is the sound level, that would be when the bullet passes the crown. The vibration of the barrel or harmonics would be different but I don't know or can prove that would equal more sound???? ::)

First, sound travels through all mediums, not just air. That has a lot to do with the "vibration" or "harmonics" you are referring to. Second, when a piece of steel vibrates it is definitely capable of transmitting those vibrations through collisions with air molecules to radiate sound. Think of a tuning fork. Because the amplitude of the vibration of a sporter barrel will be much greater than the amplitude of vibration of a stiffer, heavy contoured barrel, it makes sense that the amplitude of the vibration transmitted to the surrounding air will be much greater also. In other words, the sound radiating from the sporter barrel will be louder.

Just because a door is closed doesn't mean you can't hear what people are saying in the other room. If the walls are thin enough, you can hear every word.

[borg]

I just wonder if it could be related to the shape of the crown. Bull and varmint contours generally have a flat, target crown. Sporters typically have a radiused crown. Maybe it shapes the blast differently?

Possibly, but just trying to mentally picture the effect of the different crown shapes leads me to the opposite assumption. It is possible that the width of the crown is more critical, but I am not so sure. I don't really if or why this is true, but given the lack of evidence one way or the other I can at least accept that it is possible.

[psharon97]

Im just wondering what you guys thought hoping you had multiple contours of the same caliber to test. I only have 308 sporter and bull but nothing in varmint to test this. Borg's answer does seem to make the most since at least to me. Anyone with 3 barrels of the same caliber care to test this or should this go to MythBusters. :D

I don't have the cash to buy another 308 barrel to test this. :'(

[bootsmcguire]

I don't know about the "noise level to barrel countour" in the same caliber personally. I have a 223 with a standard pencil barrel that is a heck of alot louder than my 12FV 22-250. Both are using relatively mild loads of RL15 and 55gr. Sierra Spitzers. I belive that the larger barrel just being larger in diameter will block and help project more sound away from the muzzle than the pencil barrel. I think its kinda like setting off an M80 firecracker on the ground 3ft away and hiding behind a brick wall, or hiding behind a sappling tree. But maybe I am just looking at this the wrong way :-\

[Tony Gettel]

Well this is on the same line so I will chip in. My brother has a Win 94 30-30, my brother-in-law has a Marlin 30-30. When we are out shooting there is a difference in how those two guns sound. They both shoot the same shells. Barrel contour and size are very similar. We always figured it had something to do with the difference in the lands and grooves for causing the difference. ??????

Tony

[borg]

All I know for sure is the less powder you load, the less noisy they are.