I have a Ruger 77 in .270 Win. with 6 grooves... and a .270 WSM Browning A-Bolt with 4 grooves. Both are shooters!!

Your thoughts?

I don't think it makes much difference. One might give slightly higher pressure than the other but other than that, I see no difference.
Paul B.

quote:

Originally posted by Paul B:
I don't think it makes much difference. One might give slightly higher pressure than the other but other than that, I see no difference.
Paul B.

fully agree
Even many of the old two groove barrels were quite accurate.

Further when one looks closely at the amount of cpper compressed by the lands....it makes little to no difference in the amount of pressure required to push it into the rifling.....hense I don't think pressures are affected at all.

I frequent Douglas Barrel Co. from time to time and upon asking the owner, what the difference is between the two, his answer was simply, two grooves!! Have been told that some military purchasers request four groove over six and as to exactly why, not sure, but I figure they have a reason??

quote:

Originally posted by dsiteman:
I frequent Douglas Barrel Co. from time to time and upon asking the owner, what the difference is between the two, his answer was simply, two grooves!! Have been told that some military purchasers request four groove over six and as to exactly why, not sure, but I figure they have a reason??

I think it is due to a belief that pressure is less in a four groove barrel as the bullet is distorted less.

The other difference - in past times - when rifling was cut groove by groove rather than button rifled is two thirds the time and two thirds the cost.

Your lucky both guns are shooters. Seems from your own experience there isn't much difference between 4 and 6 grooves. I have a .30-30 Marlin with Microgroove barrel that shoots great (I've not counted the grooves, but there are more than 6).

percentage of groove diameter to bore diameter plays an important part once the bullet clears the throat, conjoined with restraining force created by each groove. roger

Split the difference and get a Rock 5R, they are some fine shooters!

FWIW, I have never noticed any difference. If there is a diference, it's so small that it's not noticable. Lou

I like barrels with an odd number of grooves. This puts a land opposite a groove and stresses the bullets less.

I prefer a bbl, regardless of land/groove numbers, that shoots well.

I've got 3, 4, 5R, and 6 groove barrels and every single one shoots very well, much better than I can do.

In an article of the Jan/Feb 2003 issue of Rifle magazine, Glen Weeks discusses this very subject. Glen is the "New Product Engineer" for Winchester who headed development and engineering of the .270 WSM, 7m/m WSM and .300 WSM cartridges for Winchester Ammunition company and Browning/USRAC. The Winchester/Browning/USRAC joint project spent a lot of time and money trying the cartridges with many of both 4 and 6 groove barrels, to assure best possible production rifle accuracy.

The results were that Winchester found the 4 groove barrels averaged 0.3 MOA better accuracy than 6 groove barrels in the.300 WSM, which was the first of the three new cartridges to be fully developed. So, .300 WSM M-70s ended up with 4 groove barrels.

They expected to find the 6 groove barrels to be more accurate in the 7 m/m WSM, as "conventional wisdom" has always held that 6 grooves is the "correct" number for 7 m/m barrels. But what they found was that in the 7 m/m WSM, there was no statistically significant ifference between 4 groove and 6 groove barrels. So they went with the 6 groove barrels anyway, just to keep the traditionalists from bitching.

In the .270 WSM, which was the last of the three to be developed, they started with the 4 groove barrels because that was the number which had worked best over the years in the plain Vanilla .270 Winchester. Those barrels shot so well in the .270 WSM that they didn't even bother to test the 6 groove ones for that chambering. They also are produced with the 4 groove barrels as a result.

I don't know what that tells you, but it tells me that there sometimes is a difference large enough to make experimentation worth while, but not always. And when it IS significant, it may not be the way one expects it to be.

Long live empirical experimentation!!

quote:

Originally posted by Fjold:
I like barrels with an odd number of grooves. This puts a land opposite a groove and stresses the bullets less.

Frank , You lost me. roger

I suppose that down thru the years no one either in the large companies or the individual experimenters has come up with a good answer for there being any difference at all. The last barrel i bought was a Lilja 3 groove and it shoots far better than I can and I have an 03 Springfield that has a 2 groove that also shoots good groups. Have never owned a Marlin 'MicroGroove' with a bunch (don't know how many there were) so don't know about them. From my meagre 50 years+ experience I can't tell ANY difference between any of the. Seems no one else can either.

quote:

Originally posted by zimbabwe:
From my meagre 50 years+ experience I can't tell ANY difference between any of the. Seems no one else can either.

Your allusion to "the big companies" in your post suggests you have read the above post about Winchester's experience. That is one "someone" who thinks they can tell a difference. Not knowing why it occurs is not quite the same as not being able to tell it is happening. And even if they think they do know why doesn't mean they are going to share the knowledge. They might consider it a "trade secret". I know some national governments do.

Why do you suppose you HAVE a 3-groove barrel? Probably because some barrel-maker thought three grooves made a barrel enough better for some particular uses to justify their making and selling it.

Ditto the makers who sell 5-R barrels, and the whole Russian match barrel industry, which developed that 5-R form of rifling for their winning Olympic competitors well before Boots Obermeyer ever worked with it.

Personally, I have no idea IF ANY number of grooves is better than another number, or if the best number depends on the barrel bore size, or any other reason why.

But, I do know that some very experienced and well-funded barrel makers and users think there is a difference in certain circumstances. To say there isn't is simply to admit that WE don't know as much as they think they do about barrel performance under those circumstances.

And who is to say they do not "know" what their experiments and experience appear to have shown them? They certainly have made more barrels than you and I combined.

Just curious as to what the number of grooves is with barrels on the Centerfire Benchrest Circuit? What do those shooters prefer?
Anybody know?

Don

Don, the 100, 200 and 300 yd crowd, that I shoot with, run the full gambit. I shoot a 3 groove 30BR Lilja(possibly the best barrel I've ever owned), a 4 groove Shilen 6PPC, a 6 groove Kostysyn 6PPC, a 4 groove HS Prec 22 PPC .100" short.
Like one of the posters above, I like any number of grooves as long as it shoots well.

As to number of grooves in the barrel, I find it interesting that Douglas offers the 458 cal. barrel in an 8 groove?? So does Ruger in their RSM 458 Lott rifle and perhaps the caliber of that size requires such rifling? Bore diameter, pressures, accuracy, etc. may be part of the reasoning in these larger bores, but will check it out for an answer and perhaps someone here knows the reason??

My .270 barrel by Lilja has 3 groove
- .333 jeffery has 7 groves (metford)
- 10bore double has 12 grooves
- 8mm mauser(oberndorf) has 4 grooves.

I also have a Lilja with 3 grooves on my 300H&H.

Supposst to be easier to clean and give you better barrel life.

2Likewise, I've had rifles with "unusual" numbers of lands/grooves which shot very well indeed.

I once owned a Remington Model 700-V in .308 made by Remington with a 12 groove barrel (they did that for part of one year). Factory stock and unaltered except for mounting an appropriate scope, in the hands of a fella named Ward Bailey it won seven matches in a row (IIRC) before I got it from him.

It is now owned by a fella here in Oregon who is a "Distinguished"high power competitive rifleman, and is still shooting quite well 29 years after I acquired it.

I also am happy with any number, so long as the barrel shoots well enough to accomplish its purpose(s). In hunting Mule Deer, that includes even two-grooved Springfield barrels...

quote:

Originally posted by bartsche:

quote:

Originally posted by Fjold:
I like barrels with an odd number of grooves. This puts a land opposite a groove and stresses the bullets less.

Frank , You lost me. roger

Roger,

If the bore has an even number of lands, there are two lands opposite each other. The .308 diameter bullet is compressed to 300 (assuming a .004 land height) between the two lands.

With an odd number of lands, each land has a groove opposite it which means that the bullet is only compressed to .304 diameter.

quote:

Originally posted by eddieharren:
Don, the 100, 200 and 300 yd crowd, that I shoot with, run the full gambit. I shoot a 3 groove 30BR Lilja(possibly the best barrel I've ever owned), a 4 groove Shilen 6PPC, a 6 groove Kostysyn 6PPC, a 4 groove HS Prec 22 PPC .100" short.
Like one of the posters above, I like any number of grooves as long as it shoots well.

Eddie,

Thanks.
That's interesting info, especially about the Lilja three groove.

Don

The English made two-groove 303 barrel has a .304 bore (mine) with two narrow grooves. The bullet gets completely swaged! What does that do for pressure? (I have heard it does nothing).

Fjold, the bullet gets 'swaged' to .300 regardless of the position of the grooves. Well, the lands of the barrel impress grooves in the bullet to a depth of 0.004". At least with an uneven number of lands, the bullet is evenly supported should it not contact the groove firmly - or so I would have thought?!

quote:

Originally posted by Doc:
I prefer a bbl, regardless of land/groove numbers, that shoots well.

Classic Doc, Classic!