Deeper rifling grooves?

[westrayer]

I remember seeing a post about someone having the grooves deepened slightly in a production gun. I imagine in an effort to improve accuracy?
Anyone have actual experience with this?

 

[rich pierce]

A lot of matches have been won with shallow groove production guns. Most shooters I know who want more out of their production gun get a drop-in barrel that is longer and has deeper grooves. A guy in the club I belonged to in St. Louis won a lot of matches using TC guns with Green Mountain and other drop-in barrels, 36-42” long. .

 

[Grenadier1758]

Like @rich pierce, I lost matches to the same guy.

In general, most of the top shooters in that club prefer barrels with relatively deep, square cut grooves and slow twist. The lands are polished smooth. The tightly fitting patches are lightly lubricated with a variety of lube mixtures and cut at the muzzle. Wiping between shots is also common.

 

[hanshi]

I have a fairly strong preference for deep grooves in rifle bores. My flintlocks have rifling of around .010" - .012" with square cut grooves up to radius cut grooves of about .016". There is an accurate percussion rifle in my safe with approximately .006". I'd like deeper rifling in this rifle but the accuracy with those shallow grooves is already amazing.

 

[akroguy]

Fouling retention trenches.

More loads between wipes?

 

[Grenadier1758]

Deeper grooves, better engagement of the ball and patch to the rifling.

 

[olskool]

the most important thing for accuracy is located behind the bore past the barrel, it is the shooter. there is a lot of sweet music left in a worn-out fiddle, as long as the man playing it knows how,,,,,,,,,,,,,,,,,,,,,,,,,

 

[Ruben44]

I had Bob Hoyt refresh the rifling in a T/C Renegade I built in 1990. She was still shooting good, but the deepening of the rifling he did, really tightened up my groups at 50 and 100 yards. Really good on my old hunting gun!

 

[westrayer]

the most important thing for accuracy is located behind the bore past the barrel, it is the shooter. there is a lot of sweet music left in a worn-out fiddle, as long as the man playing it knows how,,,,,,,,,,,,,,,,,,,,,,,,,

To a degree... but in all rifles, there is still only so much you can do for improvement. But why not try to achieve that max benefit?

 

[olskool]

To a degree... but in all rifles, there is still only so much you can do for improvement. But why not try to achieve that max benefit?

I am 67 years old and have been handloading since I was 10. over the course of my existence, I have done some shooting too and saw a bunch of different shooters and have had the chance to train quite a few in my life. the hardest person to train to shoot is a man that has been a casual shooter that really can't hit the broad side of a barn. the easiest to train is a woman that has never shot. a man thinks he just supposed to know how to shoot because he is a man, and it goes in one ear and out the other. a woman will listen and follow orders, on a gun range anyway my point is you definitely need to know how to shoot before you start trying to get all the accuracy out of a gun that you can. not saying that about any of the people that have chimed in or the original poster, just sayin most guns can shoot better than the shooter to start off with,,,,,,,,,,,,,,,,,,,,,,,,,

 

[flconch53]

A lot of matches have been won with shallow groove production guns. Most shooters I know who want more out of their production gun get a drop-in barrel that is longer and has deeper grooves. A guy in the club I belonged to in St. Louis won a lot of matches using TC guns with Green Mountain and other drop-in barrels, 36-42” long. .

I am 67 years old and have been handloading since I was 10. over the course of my existence, I have done some shooting too and saw a bunch of different shooters and have had the chance to train quite a few in my life. the hardest person to train to shoot is a man that has been a casual shooter that really can't hit the broad side of a barn. the easiest to train is a woman that has never shot. a man thinks he just supposed to know how to shoot because he is a man, and it goes in one ear and out the other. a woman will listen and follow orders, on a gun range anyway my point is you definitely need to know how to shoot before you start trying to get all the accuracy out of a gun that you can. not saying that about any of the people that have chimed in or the original poster, just sayin most guns can shoot better than the shooter to start off with,,,,,,,,,,,,,,,,,,,,,,,,,

Also the easiest person to train on a flintlock is someone who has never fired a modern gun

 

[oldramrod]

I have "refreshed" several CVA and Italian barrels that had shallow groves and deepened them to .010 deep with good results,It improves grpups with patched round ball.

 

[M. De Land]

A lot of matches have been won with shallow groove production guns. Most shooters I know who want more out of their production gun get a drop-in barrel that is longer and has deeper grooves. A guy in the club I belonged to in St. Louis won a lot of matches using TC guns with Green Mountain and other drop-in barrels, 36-42” long. .

I use a lot of Green Mountain barrels for muzzle loaders and black powder cartridge guns. I can highly recommend them as to rifling uniformity, bore diameter consistency and they are made of gun barrel certified steel both 1134 and 4140-50 alloy.
I usually have to lead slug lap them with 400 grit a bit or they cut patches for about a hundred shots the rifling corners are so sharp.
I believe they where or are broach rifled.

 

[westrayer]

The best shooting rifle that I have ever owned was a T/C Renegade in .54 with a Green Mountain RB barrel. When I got it I went to the range and tried my tried and true load of 90 grains of FFFg and .530" ball with .020" patch. First three shots cloverleafed. But The Renegades don't have enough stock drop for me, and I experience more recoil. At 32" long and 1" across the flats, that gun was heavy. But it shot like a good centerfire bolt action.

 

[M. De Land]

Deeper grooves, better engagement of the ball and patch to the rifling.

Generally true with cloth patch use but there is a balance as in all things that can be taken to far.

 

[Grenadier1758]

Yes, @M. De Land, which bring up the discussion of deep round (radiused) grooves and square cut grooves for accuracy. I have found that a depth of the groove of 0.010 to 0.012" to be a good depth. Deeper grooves will have more of the gas blow by. It is all about attaining the proper balance and it's never easy.

 

[Relic shooter]

~EARLY ENGLISH & EUROPEAN GUNMAKERS SET WORLD STANDARDS FOR ACCURACY~

Grenadier 1758 & M.DeLand are both correct, deeper rifling will produce superior accuracy, but only
if the correct ball diameter & patch thickness is used.
*When I was younger & still able to compete with my original .70 cal. Jeager with 80 gr. 2F I would normally shoot
three matches before wiping just minimal fouling from the bore with a damp patch.

FOULING never an issue with deep rifling if the correct ball diameter, patch thickness & lube is used.
Same goes with shallow rifling, blow-by will occur when excessive charges & undersized patch & ball loads used.


Being an avid history buff I started collecting, hunting & competing with original muzzleloaders 65+ years ago.
Originals were easier to acquire than replicas at this time & I was fortunate to have an older more experienced shooter-collector &
gunsmith who was willing to show me how to evaluate condition & how make them safe to shoot.

*Top priority for shooting an original percussion rifle or pistol that was replacing nipples.
My gunsmith friend showed me a couple of percussion guns that had their hammers severed from the tumblers axle when fired because the nipple's throats were so enlarged due to corrosion.

My first rifle was a big bore percussion English sporting rifle that showed lots of use & deeply rifles fast twist bore was lightly pitted throughout.
It slicked up well with lapping & won many shooting matches.


Typical bore specs for original English & European flint & percussion large bore sporting rifles I've owned;
I came to personally favor European firearms, especially Jeagers because of their lighter weight, accuracy, lock & trigger workmanship that seldom showed wear or failed.
*The majority of the original rifles I've owned featured rifling twists of very close to 1 turn in length of the barrel.
*Rifling depth seldom was less than .012 deep & usually ran .014-.018 deep.

It's been my personal experience in later years that rifles & pistols I built with custom faster twist & deeper rifling performed best.
We're fortunate to have custom barrel & lock makers around today that still make traditional style components

Note;
Shooting vintage historical firearms isn't for everyone.
If your going to venture into this arena try to buy from an experienced seller/shooter or have the gun examined by a gunsmith who is qualified in restoration of antique firearms.
>Smoothbores can also be accurate & a hoot to shoot !!!
Relic shooter, now I'm the relic