Do I want Radius groove?

[brazosland]

Rebarreling a .58 hunting rifle.

I don’t have any experience with Radius groove rifling.

Have read it cleans easier. It’s historically correct. But it can be harder to get a good load worked out?

Does it do better or worse with heavier powder charges?

Opinions appreciated. Thanks!

 

[Kansas Kid]

IMHO you will like it fine using a ball dia that allows a .02 ish thick patch as the grooves tend to be deep.

 

[Scota@4570]

Short answer....No.

I tried a 45 cal. The total groove width was the same as the land width. The grooves were 0.016 deep at the center. There was no way to have a loadable combination of patch and ball that sealed the bore. The accuracy was poor, by my standards. I scraped the barrel with about 200 shots on it. No body at serious matches uses deep radius grooves and wins.

IMHO ML patch ball barrel do not need the very deep rifling that we use today. TC used shallow grooves and were button rifled. The old TCs can shoot very well. I made MLs using barrels intended for 45-70. Those rifles always gave fine accuracy.

Deep radius grooves may clean easier. I did not notice any difference, with my barrel, but will not dispute the claim. If you want to trail walk and load without a short starter it may be fine. It will certainly spin the ball. A lubed cushion was under the patch ball might be beneficial from a gas blow by and accuracy standpoint while maintaining easy no cleaning loading. I only did limited experiments with that.

Not everyone is an accuracy OCD type, I am. I would not buy another.

 

[okawbow]

I use a deep, radius groove barrel on my .54 flintlock. Never have to wipe between shots. I’ve won most of the offhand and woods walk matches I’ve entered with that 48” barreled rifle. I’ve even won chunk gun matches with it. Shoots equally well at 25 yards or 100 yards, compared to everyone else.

I use a .010” under bore ball and .022” denim patches. Starts tight, but goes down smoothly. Great hunting rifle also...( wow! hit that buck so hard it knocked him upside down!)

 

[brazosland]

I’m looking at buying either a Rice barrel or a Colrain if that helps any. Both offer Square and Radius groove. Both have Radius as a standard, square on request.

A little perplexed by this issue...

 

[Jim Evans]

You will get a ton of different answers, my under standing is the square bottom is more accurate for the Rice barrel, and you pay a little more for the radius, as far as cleaning, its about the same.

 

[nkbj]

There's an infinity of possible shapes between a square bottom and a radius, not to mention bore diameter and number of grooves.

Why not design what you want to try and have it made?

 

[EC121]

.016" deep rifling is a solution looking for a problem. IMO it is a sales gimmick. Because I usually buy finished rifles(got tired of waiting 3yrs for a rifle.), I have both types. Like Okabow says you need an undersize ball and thicker patch to fill the round-bottomed grooves. I use a .526 ball in a .54 and a .480 ball in a .50. My .62cal. rifles use a .595 ball. Accuracy is equal. Cleaning is the same. People obsess about the rifling but all it has to do is spin the ball properly. Get the least expensive choice.

 

[lou puleff]

I’m looking at buying either a Rice barrel or a Colrain if that helps any. Both offer Square and Radius groove. Both have Radius as a standard, square on request.

A little perplexed by this issue...

Get the rice barrel !!

 

[jager43478]

Rebarreling a .58 hunting rifle.

I don’t have any experience with Radius groove rifling.

Have read it cleans easier. It’s historically correct. But it can be harder to get a good load worked out?

Does it do better or worse with heavier powder charges?

Opinions appreciated. Thanks!

I built a 50 call jaeger with a Colerain barrel 50grs at 50 yards on the bench will pretty much shoot a one hole group. You will find with radius groove u need a heavier patch material.

 

[EC121]

If I had to pick between them, I would pick the Rice barrel not because of the inside but only because it is already finished slick on the outside. You have to draw file the five exposed flats on a Colerain. Personally, I don't mind draw filing, but some folks might not want to do it. Besides I got my 5 swamped Colerains for $120 each on a clearance sale. I can draw file some for that much savings.

 

[brazosland]

If I had to pick between them, I would pick the Rice barrel not because of the inside but only because it is already finished slick on the outside. You have to draw file the five exposed flats on a Colerain. Personally, I don't mind draw filing, but some folks might not want to do it. Besides I got my 5 swamped Colerains for $120 each on a clearance sale. I can draw file some for that much savings.

Great point.

I also don’t like having to use a much smaller ball than standard. That’s a good point as well.

 

[Kansas Kid]

I’ll throw one other educated opinion on this. If the square cut barrel is not 10-12 thousands deep with lands narrower than grooves I would deduct points for that. If the square groove meets the above it will likely shoot about any load well.

 

[Stophel]

Most 200+ year old rifles I have seen have round bottom grooves. It is the more common historical choice, though square grooves were by no means unheard of. They also tend to have much faster twists than almost anyone puts in them today.

Rice is finally sending me my .45 caliber rifle barrel, which I have been waiting a long while for. Round grooves and 1-66" twist. I'm almost wishing it would be a faster twist, but I don't know. I figure it will be fine. It's basically gonna be a fifty yard gun, and if I can manage to hit a squirrel's head more often than not within that distance (and fifty yards is pretty far for me to see a squirrel's head), I will be happy.

 

[Scota@4570]

Most 200+ year old rifles I have seen have round bottom grooves. It is the more common historical choice, though square grooves were by no means unheard of. They also tend to have much faster twists than almost anyone puts in them today.

Rice is finally sending me my .45 caliber rifle barrel, which I have been waiting a long while for. Round grooves and 1-66" twist. I'm almost wishing it would be a faster twist, but I don't know. I figure it will be fine. It's basically gonna be a fifty yard gun, and if I can manage to hit a squirrel's head more often than not within that distance (and fifty yards is pretty far for me to see a squirrel's head), I will be happy.

Sounds like the barrel I threw away. "Round bottom CUT rifling .016 deep. Standard in swamp barrels. Square bottom CUT rifling to .012 deep. "

Hope you have better luck than I did. Mine shot about 4" at 50 yards off the bench with dozens of load combinations tried.

The originals I have examined favor 7 L/G and very narrow deep grooves. I am sure they shot better than a musket. They would not shoot as well as modern rifling with wide grooves. Very narrow grooves are easier to cut. With the crude tools available it makes sense. I would never buy a modern barrel like that if I cared about accuracy.

 

[Pete G]

I have 5 radius and 6 square groove. Both shoot well with standard charges. Radius grooves seem to easier to keep clean and perhaps a little more accurate because of this on any given day (but that can vary). Bottom line....for most shooters there is little, if any, difference.

 

[Grenadier1758]

I don't have the target I shot at 50 yards, but it was similar. My eyes were working for me that day.
1803 Harper's Ferry Track of the Wolf Kit Special Projects (at the time I bought the kit that meant Rifle Shoppe parts)
Lock from the Rifle Shoppe and assembled and tuned by them.
Barrel is Colerain radiused grooved.

I do believe there can be issues with deep grooves (0.016") and comparatively thin patching. There are members in my club that can not abide radius grooved rifles. Based on their performance with square cut grooves, they have a point.

 

[brazosland]

I ended up buying a square cut barrel from Rice. Talked to the owner on the phone. Great conversation, very professional. I have no doubt that I am going to be pleased.

 

[JackP]

Jason at Rice barrels is a super nice young man. I've had the pleasure of visiting his shop twice in the last 5 yrs.

 

[Scota@4570]

"I ended up buying a square cut barrel from Rice. Talked to the owner on the phone. Great conversation, very professional. I have no doubt that I am going to be pleased."

Good call!

It is not that "radiused" is bad. it is that the groove is a circular cross section, too deep and too narrow. I think radiused corners would be a good thing as long as the center of the groove was not too deep and the groove was not narrow.