4 or 6 groove

[calib]

i am seriously thinking a 22-250 ai in 1:12 twist i was almost gonna order and then was asked 4 or 6 groove what are the pro's and con's

[82boy]

One puts 4 marks on the bullet the other puts 6 marks on the bullet. The 4 grove will have silghty wider groves, than the 6 grove. There is not performance diference between the 2, and life span is the same. Basicly it comes down to personal preference.

[Eric in NC]

Fewer grooves may be a LITTLE bit easier to clean.

[calib]

not really any benifit why even have them then

[82boy]

not really any benifit why even have them then


Choice, Some like one better than the other, just like other things. Why offer stainless steel over blued steel? they both do the same thing. Why offer different degree in crowns? Why offer coated and uncoated cleaning rods? Agin it comes to personal preference, Some people prefer one over another.

[WYcoyote]

When I ordered my 3-groove barrel from Benchmark one of the advantages discussed of this compared to say a 6-groove was a possible slight increase in attainable velocity. Makes sense with less grooves cutting into the bullet.
It may be true because all the loads I've tried at or even over published maximums show absolutely no signs of high pressure.
The disclaimer may be that the barrel is also nitrided so this may factor in as well.

[efm77]

Agreed that the velocity increase makes sense. Less lands cutting into the bullet equals less friction. At least that's the theory. I've never had any barrels other than 6 groove barrels (except Marlin Micro Grooves which have even more).

[calib]

so there may be a slight benefit

[82boy]

Barrels are a strange thing, the each have their own personality. Some will produce more velosity, and some will produce less, and this is comming from one identical blank made right after another, and chambered with the same tooling. With rifled button barrels some times the twist will be faster than advertised, and sometimes slower than advertised.

Now to throw a monkey wrench in this though of less friction creates more velosity, I would argue the opsite. I know that when dealing with twist rates a faster twist rate such as a 1 in 8 in therory will create more speed, (Velosity.) that a 1 in 14 twist barrel. The reason is do to the higher twist creating more friction, and a better seal, less gas is escaping, causeing more pressure behind the bullet, and thust creating more speed. I would say that the barrel with more groves will produce a faster speed. Also when dealing with friction remember I said that the 6 grove barrel has thiner groves, it may produce less friction due to it having less contact area with the bullet, but touching it in more spots. The less groved barrel has thicker groves, and maybecause of this it will produce more friction, by grabbing a bigger surface area of the bullet, but touching it less.

Again it all comes down to personal preference, maybe some base thier preference do to their beilefs and therorys. Every barrel I own, but one, is a 4 grove. I can say that I do find that the 6 grove barrel is harder to clean, but I dont think it is because of the amount of groves, I contribiute it to having a tighter bore, it may have something to do with the steel as well. Who knows.

[efm77]

82boy is right in that there are many variables that come into play and some of them don't even make any sense sometimes. But how can it grab a bigger surface area but touch it less? Doesn't make sense to me. And if you have say a 3 groove barrel, what if the grooves are the same size as a 6 groove and the bore is just as tight? Seems to me you would have just as good of a seal and less friction and in turn get more velocity. I've never tested it so I don't know, it's just a thought. Where's 358Hammer on this one? I think he has a lot of experience in this department. He told me once he was using 3 groove barrels for some of his 338 projects and as a result was getting more velocity than the same load out of a 6 groove.

[caroby]

Calib...

It's really not the fact wether one gets a 3, 4, 5, 6 groove................ It's the fact that it's a custom HIGH quality tube... They all do shoot well on average....

One thing I have noticed... The lesser # wider lands "tend" to like a tiny jump in a wide range of calibers (.001 - .005 off the lands)... The lesser # of lands tend at the "end" of barrel life to be gentle in die'n... Not as abrupt in becoming a tomato stake...

I site two Popular Custom BUTTON Rifled Barrels, both 22-250 Ack 8 twists 416 SS......One, a 3 groove.. The other a 6 groove... The 6 groove gave the ghost noticably quicker... The 3 groove sustained accuracy a bit longer... Even though fire checking and bronze heat coloring looked the SAME in both throats, the 6 groove had a noticable "flatinig"/ errosion of the leade... The 3 groove still had the majority of it's leade angle, still a little "rounded" but mostly intact..... Still shooting to this day but on a slower death throw than the 6 groove.

The smaller width lands just errode faster, in height and width... I believe, they don't take firing heat as well either.. I've seen a number of one weekend AR varimnter barrels wrecked with fast firing, heat.. ALL 6 groove barrels........... Probably would have not helped if they were a 3 groove either... Cooked barrles man!

High intensity rounds are tough on barrel throats (22-250ack for one)... NO MATTER WHAT..... You should get a "bit" more "life" outta your barrel if you get the 3 groove... I would guess 200 - 500... But this is a generality... Though about what I have seen...

cale

[calib]

cale,
thanks a lot that is some good info and one point i was hoping to here

[caroby]

thanks a lot that is some good info and one point i was hoping to here
Calib,

Sure,
Even though my post was general findings, no FIRM scientific research.....
Will make a correction..... On myself... Your question is a 4 or 6 groove... I stated a 3 groove...
I believe you'll get "3 groove" performance with a 4 groove barrel.... That in a similar life span.

cale

[ellobo]

For a long time guys shooting Springfields in the military matches were using rifles that had the 2 groove barrels used for hurry up production at the beginning of WW2. Or replacing 4 groove barrels with 2 groove they could get cheap from the government or Numrich's. Most said they saw no difference in accuracy with the 2 groove. Those were on full military Springfields of course. The one I had for use (borrowed) had a 4 groove on a rifle made in the early 30's if memory serves. Not sub MOA but still pretty accurate at 600 yds (minute of bad guy).
El Lobo