Ease of Cleaning Fast-Twist Barrels

[Harold M]

Recently, I've experimented with fast twist barrels (8" Lilja, Hart) and low-drag bullets. It seems that the fast

[MrMajestic]

No trouble here with any of mine.

[Larry in VA]

I’ve got an 8 twist AR-15 (chrome lined) and it is one of the easiest barrels to clean. But then again it is chrome lined and so far I’ve only shot 55 gr VMax which has a lot less bearing surface than the bullets you’re using.

[kenbro]

Harold,
It seems obvious as you know, it will take more effort to push something through a faster twist, but do you mean it takes more passes of whatever you push through to achieve the same result?
Ken.
Ps. Did the snow get you?

[montdoug]

Is it only on the one barrel or have you experienced it on others? Sometimes it seem to me that even with good named barrels one will just be a bit more difficult than it should be to clean IMO, and that's even though I used the same break-in process as always??
Other that AR's I have no experience with fast twist barrels as I'm not a "mortar man" so to speak so I was just guessing at other possibilities?
Keep us posted as to what you figure out .

[Chickenthief]

Usually longer/heavier bullets have longer bearing surfaces ie. 1 long bullet might foul as much as 2 shorties.

[Kevin Gullette]

As has been mentioned, longer bullets, much faster rpm/higher torque/higher rotational land pressure.

I'll add that the effective land/groove "length", that each bullet rides through, is longer.

For example, a 28" barrel with a 14"twist.......versus a 28" barrel with a 7" twist. The bullet in the 7" twist has to rotate 4 turns.......while one in the 14" twist only rotates 2 turns. Therefore a "point", on the bullet's bearing surface, rotates through twice the effective distance......in the same 28" barrel length.

Clear as mud, huh? My head hurts.

Kevin

[Daryl]

6.5mm fast twist barrels have never given any trouble cleaning for me & they are 7 1/2" to 8" twist normally.
I suspect a smaller bore might work the bearings in the rod a bit harder, or be more prone to skipping with a rod that is not working correctly - I have one of those.
It makes sense they might foul more due to the steepness of the hill the bullet must climb. I would think 3 grooves would clean easier than 4 to more. 9 twist .172 Pac-Nor cleans easily.

Maybe it's all subjective on equipment used.

[MIBULLETS]

Lots of things come into play like if the barrels are chambered for a faster cartridge, barrel to barrel differences, and the other things already mentioned.

[rick w.]

Ask your brush how it likes going up against the steeper walls.......