3 R rifling

[Baddog 0302]

Gathering info on two builds , a 22 BR and a 6 MM something {either a 6 GT or a 6 x 47L}. Found a barrel maker that offers a 3 R rifling in .224 & 6 MM.
Anyone have ACTUAL experience with the 3 R rifling .

 

[ohiofarmer]

No experience with 3R to share, just 3 groove. (Lilja) Who makes 3R?

 

[MNhunter1]

Harrison/ARPerformance has done a bunch of work with 3R and 5R rifling in AR barrels. Might be worth a call or message to pick his brain a bit.

My take is the 3R reduces engraving force and should have lower pressures for a given powder/bullet combination. Sounds like his real world observations have not really shown a velocity increase as one would expect.

 

[Supersubes]

As long as the barrel is made properly, the number and shape of the lands and grooves means nothing.

 

[BurnOut]

As long as the barrel is made properly, the number and shape of the lands and grooves means nothing.

That's pretty much my gut feeling as well, based on reading that I've done... but I don't have the apples-to-apples experience to back it up.

I have an AR Performance barrel installed on an upper that I recently finished building, but I have not shot it yet... however, it is the only barrel I have in that chambering/length, so I won't be able to offer any meaningful comparison between the performance of the 3R barrel and any other barrel I have.

 

[Baddog 0302]

No experience with 3R to share, just 3 groove. (Lilja) Who makes 3R?

3R in .224 & 6MM

 

[Dobbs02si]

I've HEARD(no first hand) the 3g are more prone to causing blowups with thin skin pills. I'm using 180 hybrids from a 3g 8 twist lilja around 3k fps with no issues yet. Time will tell.

 

[Baddog 0302]

I've HEARD(no first hand) the 3g are more prone to causing blowups with thin skin pills. I'm using 180 hybrids from a 3g 8 twist lilja around 3k fps with no issues yet. Time will tell.

And I've herd just the opposite, the more L&G's the more the bullet is deformed. My reshearch shows that none of the top tier use anything "lower" that a 4 L&G, and a 5 R Top tier barrel makers

 

[newguy2k3v2]

I have 2 noveske 3 groove barrels. A 18" 5.56 and 24" 6.5 creed, both 8 twist. I can't complain about either.

 

[Dobbs02si]

Until I see otherwise, it's an urban myth to me.

I mean I get the concept. Only 3 leading edges that actually "bite" the bullet. But the area of the rifling is supposed to be the same as a comparable 5-6g so the amount of distortion would be the same just in different more/less places. The limited number of leading edges is the only merit I get from it though.