Micro-groove rifling on an original New England rifle

[rich pierce]

I noticed this but hadn’t got a decent picture. This is a lot of grooves!  The rifle was originally flintlock. The style is very similar to Silas Allen. The rifling is still in terrific shape as you can see. Slow twist; guessing slower than 1:48”. Anyone else encounter this on a flint period original?  Or has anyone shot round ball in such a barrel on a contemporary rifle?  I have a John Getz .54 with micro grooves but never built anything with it. It was a gun show spur of the moment purchase.

[Bob Roller]

I have seen polygroove barrels on muzzle loading pistols but never heard reports about accuracy.No reason to NOT making a gun with one and no reason to think it can't be accurate until testing.N.G.Whitmore,maker of the fine rifle for General Grant made 12 groove barrels as a standard thing and they outshot everything and were declared as unfair competition according to the writings of Ned Roberts.Whitmore's test of the Grant rifle at 110 yards said all 10 shots went into a circle the size of a percussion cap box and he did not use the telescope sight.
I tried for years to get Bill Large to try Whitmore's idea and he was aware of the performance of the Grant rifle which is a 38 caliber.
One groove every 30 degrees shouldn't be too hard to do again.
Bob Roller

[Mike Brooks]

I had a Durs  Egg fowling gun with micro groove  rifling like that. It was 14 bore and straight rifling for shooting shot.

[Seth Isaacson]

I am working on the catalog listing of a short takedown rifle from New York with similar rifling right now and have seen it on a few other New York rifles. Some looked like they were smoothbores when just looking at the muzzle but clearly had this style of rifling when you shine a light down the bore. The Model 1819 Hall rifles use "polygroove" rifling as well.

[45-110]

When I had my 1819 Hall's I found it very easy to muzzle load and was accurate. Interesting multi groove bore and also it was counter bored smooth at muzzle.

[rich pierce]

This might be straight groove; gotta check.

[Roger B]

I have examined Ruxton's percussion rifle at Casa Esquela & it has a micro groove bore. No hint of previously being flint, but the buttplate was changed from flat English to American crescent. That was done by the original maker at Ruxtons request for his second trip West which was ended by cholera before it went past St. Louis.
Roger B.

[hanshi]

A micro-groove bore, well that's a first for my eyes.

[jgraham1]

A micro-groove bore, well that's a first for my eyes.

Never knew they existed.  Would also like to know how common they are.

Jerry

[MuskratMike]

Like Hanshi micro-groove, that's a first for me also!

[Mike Brooks]

there was a time in England that they were fairly common on fowling guns. Ca, 1780 give or take 10 years. Straight rifled to improve the shot pattern. I have never seen it on American guns. Something new for me.

[EC121]

I had a .40cal. William Barnhart, Ross County, Ohio rifle that was rifled that way.  1855 or so.  The bore had a bad spot so I never shot it.

[Curtis]

Tip Curtis had an antique barrel like that in his shop years ago, way cool!!!!!  It was about .54 cal or so.


Curtis

[alacran]

The Arizona Historical Society has a circa 1775 15 3/8-inch barreled Spanish rifle with straight micro grooves. It sports a beautiful patilla or miguelet lock.

[Daryl]

Good picture, Rich.  Taylor's 1853 Joseph Lang has a bunch of grooves as well and more than most, but not as many as your rifle.
This one has a 48" rate of twist with 10 lands and 10 grooves.



link uploaded net

[Tim Ault]

Generally on these barrels is the rifling considerably shallower than on traditional barrels ?  Whenever someone says “micro groove “ my mind automatically thinks marlins RF and CF barrels which have very shallow groove even by modern standards of that type of rifle

[wolf]

well i guess marlin arms company wasn't the first after all!

[Bob Roller]

Maybe a test barrel could be made by a barrel maker with 8 grooves and another with 12 or 13 and tests with weighed powder charges and uniform weight balls or bullets and get more data.The Whitmore guns of the long ago proved the 12 grooved idea worked really well and the idea may be worth revisiting.
Bob Roller

[rich pierce]

I’ve got a John Getz barrel with micro-groove rifling. Not in a stock yet.

[Dphariss]

Its not “Micro-groove” which is a modern thing with extremely shallow grooves (thus the “micro”). Barrels with many grooves were common in England and Europe. But the people buying rifles in England, for example, could afford to pay for the time needed to cut 15 grooves as opposed to 7.

[Levy]

I sold a pair of French pistols that had a lot of grooves in the barrels.  I have a half-stock rifle that was built by Arthur Huscusson in Franklin, NC that used an old hand forged barrel.  He had the barrel recut by someone that bored it to .40 and rifled it with 10 grooves.  James Levy 

[rich pierce]

Its not “Micro-groove” which is a modern thing with extremely shallow grooves (thus the “micro”). Barrels with many grooves were common in England and Europe. But the people buying rifles in England, for example, could afford to pay for the time needed to cut 15 grooves as opposed to 7.

I guess Marlin gets to own the term. Not sure what it would have been called back in the day. Maybe many-groove. For sure it’s not as deep as conventional round ball rifles of the flintlock period. It may also be common on straight groove barrels.

[Marcruger]

I like that Lang rifling.  Wide grooved with narrow lands.  I hope modern makers take note.  Narrow, deep grooves are a blight in my opinion. 

[rich pierce]

I like that Lang rifling.  Wide grooved with narrow lands.  I hope modern makers take note.  Narrow, deep grooves are a blight in my opinion.

They were only done that way because it was easier, I think. Less power needed to scrape a narrow groove. It’s especially bad on large caliber barrels. Having re-cut the rifling on a number of original barrels done this way, I think they may have used the same cutter on various calibers. Grooves are often around 0.100”, though I’ve seen narrower. On anything larger than a .45, cutting 7 grooves .100 wide results in lands wider than grooves. Not fun to load.

[Carl Young]

Ditto to what Rich said. Having made my own barrels for a long time, I can attest to the effort to pull the cutter through the bore (manually powered machine)! Also agree with the same cutter thought; I have several but they are used to rifle within a range of bore sizes, the time and effort to make a different cutter for each bore size wouldn't be a good use of time (in my application). Also the cutter rod would probably need to be considered, and if a new cutter didn't fit you would need a whole new rod assembly, which is more time, effort and cost.

Years ago I made a 14 groove barrel by mistake. A visitor played with my rifling machine while I was away and left the square guide bar indexed 90 degrees to where I left it. Oops...but that barrel was suitably accurate (one slightly ragged hole off the bench at 50 yards when proofed) Just my opinion (opinions are like belly-buttons, we all have one!)

Best,
Carl