What's the point of three groove rifling?

raythemanroe

Sergeant
Full Member
Minuteman
Apr 5, 2012
193
1
45
NY
Hey, I was just wondering about three groove rifle barrels...Are they faster? Do they last longer? more accurate? Why do some companies only make them in the slower twists or certain twists?
 
Re: What's the point of three groove rifling?

I'm not sure but if you figure anything out let me know. I can say my 300WM has a Lilja 3 groove barrel and is very accurate. However the 11" twist can be a pain in the ass with certain bullets.
 
Re: What's the point of three groove rifling?

Lilja with 3, Krieger with 4, Obermeyer with 5, Remington with 6...

Don't make a lick of difference. They're all good to go.
 
Re: What's the point of three groove rifling?

My understanding is that the 3 groove has wider lands and grooves while maintaining the same ratio of lands to grooves as a barrel with more grooves. It was described to me that this can help with getting more barrel life from the barrel burner type cartridges because there is more meat and therefore could resist throat erosion a little better. I'm sure someone here may be able to confirm or deny this, however I can say both of the 3 groove Lilja barrels I shoot are super accurate and much easier to clean than any others I have experience with.
 
  • Like
Reactions: PhantomWorks
Re: What's the point of three groove rifling?

The theory goes that odd numbers of lands are better than even because pressure is not being applied to the bullet at at points directly opposite of one another. The idea is that the staggered pressure points that odd numbers of lands cause will deform the bullet less than even numbers of lands would. Less deformation is good from a flight standpoint as well as from a fouling standpoint.

As for less lands, less lands means that they can be wider and will therefore take longer to erode and last longer. I have also read that low land numbers when combined with asymmetrical lands can yield a tighter fit as there isn't really a groove to speak of but rather only a higher and lower side of each land. This is supposed to diminish the cutting caused by high pressure gasses escaping around the bullet and also to increase velocity some.
 
Re: What's the point of three groove rifling?

All the things mentioned above make sense in my head, but I have yet to see any emperical data favoring any specific groove counts. If the groove count makes a difference, I personally don't think it's significant enough to worry about. Then again, I have very little experience compared to some.
 
Re: What's the point of three groove rifling?

I shoot a .243AI with fairly hot loads. What I have noticed between button rifled 3 groove and button rifled 5c style rifling, is that the radius on the edges of the lands do not seem to erode as quickly. I have many more rounds through the 5c barrel without having to chase the lands as much.

Like I said, just my 2 cents.
 
Re: What's the point of three groove rifling?

I've got a 3-groover in a Noveske barrel in a Mk12 profile. I don't know how it compares to more traditional rifling offerings. There was no marketing jargon when I selected the barrel for a Mk12 build and it isn't their normal polygonal offerings as it was an oddball run for a builder.
 
Re: What's the point of three groove rifling?

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">So your saying it does not last as long? I was told it is a equal amount of material just three instead of five or six..</div></div>

Lets say that it is exactly the same amount of material for simplicity. What kills barrels is the throat being eroded by the hot gasses during firing. This erosion eventually has the same effect as pushing back the lands since they have been somewhat disintegrated near the chamber.

Like all erosion, the rate of throat erosion is dependent on surface area not volume. Think about how much more quickly a smashed up bullion cube dissolves in water than a whole one. With the same total volume (material) of lands each land in a three land gun will be bigger than each land of a five land gun. This larger size will result in a larger volume to surface area ratio. Since the erosion rate is a function of surface area having your equal amount of land material in three large lands with a higher volume to surface area ratio will erode slower than 5 small lands with a high surface area to volume ratio.

As for the purported accuracy advantage of odd land barrels I also have to admit to less than conclusive first hand experience. The land number certainly doesn't seem to be the most important factor by any stretch. Krieger doesn't seem to be getting dumped on for lack of accuracy in their barrels because of their even land numbers but than Lilja doesn't seem to have any problems with the odd numbers either.
 
Re: What's the point of three groove rifling?

Good thought..I have to agree that the larger surface area would hold up to heat better...Marlin tried micro groove rifling once with no prevail..
 
Re: What's the point of three groove rifling?

What im saying is from what Ive seen from two different barrels with diferent styles of rifling. On my 3 groove barrel you can clearly see the leading edges of the lands being eaten away at. And my thought is that square edge of the lands being sharp wear faster.

The Broughton 5c rifling looks alot like the rifling in a glock no sharp edges. I have no rock solid data except what I seen in the chamber of the two different barrels.

Im no expert by any means, just sharing my thoughts on the two barrels I have shot out of my .243AI shooting 115gr DTAC's at 3125fps.

Im not trying to say one is better than the other as I have 3, 4 and 5 groove barrels too. I would like to try on of Kriegers 5r barrels and see what happens.
 
Re: What's the point of three groove rifling?

I use 115g bullets in my 243 win at roughly 3000fps..Almost instantly the lands starting laying over or flatting out...Hart 27" six groove 416r ss...shoots great though..
 
Re: What's the point of three groove rifling?

My .243Ai is a switch barrel rifle so whenever I swap out the barrel I get a better look at the rifling and take measurements.

Im not trying to start a debate but rather ask about the style of rifling along with the land and groove count.
 
Re: What's the point of three groove rifling?

I really don't understand your question..My question was basically what is the advantages or point of 3 groove rifling like lija and others, hart makes it to..
 
Re: What's the point of three groove rifling?

You may get more info from a benchrest forum. If memory serves me corretly the 3 groove rifling became popular for benchrest and varment hunters shooting hot small caliber centerfires like the 22-250. They got longer barrel life for the small caliber barrels. I think that Big Fish has a spot on statement with the suface area comment.

I am not sure that the 5c comparison is apples to apples. Broughtons 5c barrels are not traditional. (The c stands for Canted rifling and Broughton does state that they last longer. I really like the Canted rifling but if comparing grooves 3,4,5,6 they need to be the same style of rifling.

Also the larger the bore the more lands are probably needed to even out pressure and create a good seal. I couldn't imagine a .470 NE with 3 grroves.
 
Re: What's the point of three groove rifling?

I don't have any personal experience with a three groove but everything I've read seem to mention a 20% longer life. Also easier to clean. I've tried all the others maybe I'll give a 3 groove a try some day. Think I read an article in PS shooting that its difficult to do cut Rifling in 3 grooves or less. That's why you see mainly button rifled barrel companies doing them.
 
Re: What's the point of three groove rifling?

If your wondering if they shoot as good.

My 6mm Lilja 3 groove chaimbered in 6x47Lapua runs 105s in 1/4 M.O.A.
Also this is my second Lilja 3 groove and I cleaned my last one every 200-250 rounds and it cleaned really easy and neaver had copper fouling.
 
Re: What's the point of three groove rifling?

For the most part this is no difference in accuracy or barrel life with the number of grooves. I've shot 2 groove thru 6 groove in calibers up to .338. No difference.

I do believe that the odd number of grooves (not a 3 groove because lands to groove ratio could be wider in some makes of barrels) that the lands don't directly oppose one another. To me in a 5 groove barrel this will help in distorting the bullet less as it enters the rifling and this will help with bullet failure.

6mm caliber light weight bullets (55gr. to say 75gr.) don't like the 5R style rifling. They'll shoot good (down around upper .2xx's to low .3xx's for group sizes) but nothing better. I believe this is because of the short bearing surface of the lighter bullets but if you shoot heavy 6mm bullets like 105gr. etc...no difference in accuracy. That's why in the 6ppc benchrest game the dominant barrel is a conventional 4 groove. Accuracy is way better with the light bullets that they shoot.

Again though for the most part though no difference in accuracy or barrel life with the number of grooves.

Later, Frank
Bartlein Barrels
 
Re: What's the point of three groove rifling?

Can't speak for any added barrel life but I have a 15" Lilja 3 groove 1:8 twist on my LR 260 pistol and that thing is scary accurate. Just a few quick passes with a brush and a couple of patches and it's ready for the next match. Usually try to do that around 400 rounds but could go a lot longer in between but just don't seem to need cleaning and have problems with accuracy falling off like some gun/barrel combinations.

Accuracy wise even in the short barrel it's equal to most of the rifles that shoot our 1000 yard matches, just a bit harder to shoot in the pistol configuration but if we do our part it has no problem even on the 1000 yard targets. Concerning the 3 groove being any faster, I haven't seen it comparing my 15" 3 groove at 2525fps against my 28" Shilen Select Match on the rifle at 2820fps. Both guns use identical loads and the loss is pretty close to 23fps per inch which is about what most consider standard when shortening any rifle barrel.

So, not sure if the 3 groove is any more accurate since our Shilen Select Match barrels on our rifles and also other match type guns we own all shoot well. Is there a difference? No idea but at least I can say the 3 groove barrels shoot as well as any other custom barrel we've shot or seen used and do plan on putting the same 3 groove on when it comes time for a rebarrel for our little short guns.

Topstrap
 
Re: What's the point of three groove rifling?

My opinion. lets just say three grooves has the same amount of contact surface as six groove..okay, than the same amount of friction and gas seal should take place right? the only difference to me would be the three groove would have less pressure points to deform the bullets...that would be my final opinion:)