I've read some discusions regarding "slow barrels"

What's a slow barrel?
What makes it slow?
Are there any solutions short of rebarreling?

Unless it is twist you are referring to, a slow barrel is one that doesn't live to the the average accepted velocity levels for that particular caliber/barrel length. Unless the difference is great, which isn't likely, I wouldn't worry too much about it. After all, a deer isn't going to know if the bullet left the barrel at 2850 or 2975 fps...

If it's twist you are referring to, a 1:14 is considered a "slow" twist in a .308 WCF while a 1:8 would be considered a "fast" twist. The readings simply indicate how many inches a bullet must travel before making a complete revolution. Thus, a 1:8 would be twice as "fast" as a 1:16.

A slow barrel is every barrel on any gun in my safes. It seems that I don't own a gun that will reach the same velocities as other internet reloaders.

quote:

Originally posted by Fjold:
A slow barrel is every barrel on any gun in my safes. It seems that I don't own a gun that will reach the same velocities as other internet reloaders.

And here I thought I had the only pile of rifles like this, and now I find evidence of others with the same malady.
Fjold, ya just brightened my whole Christmas!!

Most barrels are pretty standard,but every once in a while an odd ball shows up.I had a 264 that was almost all lands,just great,a high friction barrel in a spikey caliber.Even below book velocities ,the primer fell out.That one got rebarreled.

By slow ,you can mean high friction or low pressure.The latter is more common one with generous factory chambers.

quote:

Originally posted by Fjold:
A slow barrel is every barrel on any gun in my safes. It seems that I don't own a gun that will reach the same velocities as other internet reloaders.

Thank you sir.....in other words....a slow barrel is a figment of some folks imagination.....

A slow barrel was any gun that the former poster RAY did not own his were all very fast barrels.

His vel always beat any body elses.

There also seems to be a correlation between fast barrels and accuracy. The same guys whose barrels are routinely 100 fps faster than every one else’s, are also always ½ moa groupers. We mere mortals can only look on in admiration

quote:

Originally posted by kaboom:
There also seems to be a correlation between fast barrels and accuracy. The same guys whose barrels are routinely 100 fps faster than every one else’s, are also always ½ moa groupers...

Hey Ray, My current Slow Barrel rifle is just the exact opposite of that.

I've had others, but the current Slow Barrel is a S&S M700 7mmRemMag which has a "tighter Bore" than the previous B&W(changed to Synthetic) M77 7mmRemMag. Bore brushes which felt worn out in the old rifle are still nice and tight in the new rifle.

The new one also seems to have a slightly "Smaller" Chamber than the old rifle. This can be seen on the PRE readings.

The old rifle would hit a SAFE MAX with 4.0gr more of H1000 than the new rifle. Likewise, the Velocity was a bit higher(as if it made any difference) in the old rifle.

The old rifle was accurate, but not as accurate as the new Slow Barrel Tight Bore rifle.
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In my situation, the Tight Bore and Smaller Chamber cause the Pressure to Peak faster than the old rifle. And since the new one burns 4.0gr "less" powder, the Velocity is a bit lower, or what I call a Slow Barrel "relative to" the old rifle and the Manuals as well.

It doesn't concern me at all though, because of how well it shoots and kills.
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I'm old enough and had enough different firearms to realize having a rifle known to be 100-150fps SLOWER than other rifles of the same caliber is something to be seriously concerned about though!!!

quote:

Originally posted by kaboom:
There also seems to be a correlation between fast barrels and accuracy. The same guys whose barrels are routinely 100 fps faster than every one else’s, are also always ½ moa groupers. We mere mortals can only look on in admiration

I have a slow barrel on my 9.3x62 but it´s a tack driver.

Go figure.

The slowness of a barrel is dependent on the steepness of the slope one is rolling it up, the degree of fullnes ( or MTness ) and the strength or weakness of the rollee. Of course clever rollees make it easier by MTing the barrel of it's contents and then say "Who the hell cares".

Here I was thinking that a slow barrel was just not too smart.

I have a Winchester Model 70 in 30-06 that would certainly qualify for the slow barrel catagory. It has been consistantly 200-300 fps slower than any book listings for corresponding loads. Still, every once in a while, I can find a powder that will get me within 200 fps, but accuracy usually is not that good.... meaning about 2-3 moa. It's almost like having a 30-30 performance from a 30-06. Kind of frustrating, but I haven't re-barreled it, so I just keep trying different combinations. Someday I will hit on the powder and bullet combination that make it sing.

IMO it has to do w/ the very tiny differences in bbl I.D. A bbl w/ a slightly tighter int. dia. will produce a different pressure than a bbl w/ a slightly larger ID. I.D. acommpanied by chamber dimensions, twist, number of lands, and type of lands are the reasons for "slow" or "fast" bbls IMO. You could take two bbls that were built on the same tools and get diff velocities due to very minor differences between the two.


For examples, I load for one slow 270 that will only push a 130 grn bullet a little over 2900 at max pressure loads, by many, that's considered very slow.

I also load for a 300WSM that will push a 165 grn bullet at 3260+ fps out of a 24" tube w/ charges right below Book max from several diff. manuals yet, it doesn't show any visable pressure signs. I can meet the book max velocities w/ mid range loads in that bbl w/ no hassle. Quite a "fast" bbl you might say.

Reloader