Barrel grooves, 6,5,4,2...does it make a diff?

B

Bilrus61

Guest
I just ordered a Bartlien for a .22. They said that 5 grooves were their standard. I thought most match rimfires used 6 grooves. Some use two I know also. Is there a advantage/disadvantage to useing odd number of goove in a .22? Will 5 grooves be fine? I ordered it with 16 1/8th twist at the chamber and 16 at the muzzle.
 
There have been great barrels with each of the different groove counts. There are theorys but no proof that any different count is better than another. It's doubtful a gain twist will help a slow, lead, rimfire.
 
There was extensive testing of differing numbers of grooves in the early 19th century.
All other being equal it was determined that a three, five, or seven, groove bore was more accurate than a four groove and that a six groove was more accurate than a five or seven groove.
An unequal number of grooves allowed the lead bullet to better center itself to the bore, like a tripod centers its weight distribution equally on each leg.
A six groove acted as a doubled three groove.

I'm probably not wording this correctly.
Not sure if the same applies with jacketed bullets.
I believe the info can be found in "Bosworth on the Rifle" printed in the 1840's.
 
Of more importance will be the internal geometry of the barrel and the quality of the chamber. It's my understanding that its harder to cut a perfect chamber on a 2 groove barrel. Talk with your gunsmith and ask what he prefers. Broughton makes a five groove barrel that has been very successful. If Bartlein has someone who knows how to correctly lap a barrel and put in the correct amount of choke and if your gunsmith has the skill to cut a great chamber, you will be OK. If either of those things are not done properly, the number of groove or the type of twist will make no difference.
 
And to add to confusion Lilja makes a tightbore 4 groove that is supposed to be shooting very well.
 
I think everyone might be considering that it's the geometry of the bore shape that has effect on accuracy. That is accuracy is somehow influenced by the number of grooves, or by the lands shape. I think what may be more important, is how well you can manufacture the tool to cut the bore. If you can't easily and accurately build a cutter, broach, or other forming tool that will produce a smooth and accurate bore you probably won't get an accurate barrel. If the machining and tooling is right then maybe one bore shape is as good as any other.
 
Even more confusing

Shilen makes an Octagon bore barrel that has neither lands nor groves. Shoots lights out.
 
Check with Shilen

Danny Keeney, won the Indoor Shop Shoot last Saturday for the second shoot in a row. He has been hot lately. They should be able to give you more info at the Shilen shop.
 
Fred J said:
Shilen makes an Octagon bore barrel that has neither lands nor groves. Shoots lights out.
Click to expand...

I hope you're right. I'm getting one on my Anschutz.

You can see the muzzle on one here.
 
Last edited by a moderator:
Old Gunner said:
There was extensive testing of differing numbers of grooves in the early 19th century.
All other being equal it was determined that a three, five, or seven, groove bore was more accurate than a four groove and that a six groove was more accurate than a five or seven groove.
An unequal number of grooves allowed the lead bullet to better center itself to the bore, like a tripod centers its weight distribution equally on each leg.
A six groove acted as a doubled three groove.

I'm probably not wording this correctly.
Not sure if the same applies with jacketed bullets.
I believe the info can be found in "Bosworth on the Rifle" printed in the 1840's.
Click to expand...

I'm pretty sure than not too many of those 1840 match barrels are being shot today, not even in the patched round ball matches.
 
Groove Count

The great Eric Johnson used 8 grooves.
Lilja and Benchmark both make a three groove.The finest barrel I ever shot was a three groove Lilja.If I were to get a new barrel it would be a three groove.
I wonder if bore size counts more than groove count? :)
 
You must log in or register to reply here.
Back
Top