I have to agree with scootertrash 100%. None of this was caused by the use of JB or poor cleaning procedures. When its used as its supposed to be, and he definitely sounds like he knows what he is doing, JB will aid in cleaning a barrel. It will not harm a barrel. I have used it for years on small caliber barrels when they appear to need a little extra cleaning, and I've yet to see a barrel go south as a result. For the Bore Snake fans here, it's a heck of a lot less likely to harm a barrel than a grit inpregnated Bore Snake can and will
What some folks fail to realize - and in some cases refuse to realize - is that when you shell out $500 for a new factory rifle, you are getting a barrel that cost the producer in the range of $20 to have made. This is simply a case of poor quality steel not wearing evenly due to its poor quality, and probably a bore that was not uniform in land depth to begin with due to the quality of the steel. 2k+ rounds later....this is what you have left....
Those of you who want to blame this on cleaning have probably never ever shot a rifle enough to see what can happen to a barrel over time. As a result, you're fishing in the swamp without a hook on your line and attempting to spread more Internet "facts and information" that don't float in a real world punch bowl.
-BCB
If you guys have time....
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scootertrash
- Junior Member
- Posts: 88
- Joined: Tue Feb 28, 2006 3:58 pm
- Location: Lake George, Colorado
Re: If you guys have time....
I haven't received a reply from Al, but did get this bit of interesting input. I say interesting, because this was also a button rifled barrel.
"Mike, we ran into this back in the mid-80s with some National Match .308 barrels from a well-known barrel-maker, after the third one they sectioned it and found the same thing you describe with the lands completely gone in spots. Ten barrels were pulled from the Benchstock(This was at Lackland) and air-guaged. What they found was wide-spots in the lands. Not much but enough that over time, they allowed enough gas to pass the bullet that it eroded the lands in those spots. Remember, the gas is at a higher potential velocity in the barrel than the bullet. This leakage around the bullet was occuring in a matter of nano-seconds so it wasn't noticable until the barrels were gone. they lasted about 3,000 rounds. BTW, these were Button-rifled barrels. When they went to cut-rifled barrels the problem stopped.
Theory was the button was hitting spots of varying hardness in the barrel and these spots were somewhat softer. This actually caused the button to expand slightly as it hit them."
This about concludes this chapter of the rifle. The new PacNor is already shooting in the mid to high .3's. I stayed with the 10X and 39 grain pills, and settled on a load of 24.6 and .030 jump. The velocity from this 11T runs about 50-60 fps than the old barrel. This could be the twist itself, or because of just three grooves, possibly being less resistant. The barrel being tighter, and less tooling marks due to better lapping, could also attribute to this.
Velocity over the last two five shot groups was 3820 fps, with a ES of 12. I shot these groups in a rather stout 25 mph left to right wind, and thru my own stupidity probably let two back to back groups in the .2's "blow" away. But I'm extremely pleased, it's a heck of a lot better than fourteen inch vertical groups, and pdog time is just about here!
Have a good rat smackin' season y'all.
Mike
"Mike, we ran into this back in the mid-80s with some National Match .308 barrels from a well-known barrel-maker, after the third one they sectioned it and found the same thing you describe with the lands completely gone in spots. Ten barrels were pulled from the Benchstock(This was at Lackland) and air-guaged. What they found was wide-spots in the lands. Not much but enough that over time, they allowed enough gas to pass the bullet that it eroded the lands in those spots. Remember, the gas is at a higher potential velocity in the barrel than the bullet. This leakage around the bullet was occuring in a matter of nano-seconds so it wasn't noticable until the barrels were gone. they lasted about 3,000 rounds. BTW, these were Button-rifled barrels. When they went to cut-rifled barrels the problem stopped.
Theory was the button was hitting spots of varying hardness in the barrel and these spots were somewhat softer. This actually caused the button to expand slightly as it hit them."
This about concludes this chapter of the rifle. The new PacNor is already shooting in the mid to high .3's. I stayed with the 10X and 39 grain pills, and settled on a load of 24.6 and .030 jump. The velocity from this 11T runs about 50-60 fps than the old barrel. This could be the twist itself, or because of just three grooves, possibly being less resistant. The barrel being tighter, and less tooling marks due to better lapping, could also attribute to this.
Velocity over the last two five shot groups was 3820 fps, with a ES of 12. I shot these groups in a rather stout 25 mph left to right wind, and thru my own stupidity probably let two back to back groups in the .2's "blow" away. But I'm extremely pleased, it's a heck of a lot better than fourteen inch vertical groups, and pdog time is just about here!
Have a good rat smackin' season y'all.
Mike
Factory Custom
