forsyth barrel

[eph289]

I got a 62 cal 104 twist barrel from Rice a couple year ago. so far its just a 50 yd. rifle. It groups well at 50 , but after that it falls apart. I'm shooting a .612 ball .018 patch 185gr 2f with a vel. near 1800.
At 200yd I'm lucky to hit the target. Do you think I'm shooting knuckle balls.
I could try more powder but I don't think that 34 in. barrel can burn any more ,besides it's kicking the snot right out of me
Anyone got any ideas. Thanks!

 

[necchi]

185 grains of 2F is way over kill.
Back'er down to around 100 or less and experiment again.
No one is going to be able to give you a charge/patch/ball combo that will be the most accurate in your gun, you have to experiment and find the sweet spot yourself,,
But 185grn of powder is far beyond what you need for accuracy or even killing Elk for goodness sakes.

 

[cynthialee]

Somewhere between 90 and 125 grains of 2f should be the sweet spot would be my guess. 185 grains is a seriously overkill charge.

In a rifle I tend to go with the caliber x1.5 in grains of powder. Then adjust the charge from there upwards by 5 grains to a max of caliber x2. So for your .62 that would be 93 grains to start. Make it 90 for an even measure, and 124 grains for the high end.

 

[longcruise]

You are pretty much in the charge range that the barrel is meant for. How do patches look? I've tried a few loads that printed nicely at 50 yards but at 100 they spread way out. Turned out the patching was not holding up.

 

[dd832]

Pacific Rifle Co. shows a chart for the .62 at 175 grs. powder producing 1700 fps with velocity data out to 120 yds. - http://www.pacificriflecompany.blogspot.com/

R.J. Renner (he designed the Zephyr Rifle) on his blog talks about 1800 fps with data out to 150 yards - http://www.rjrenner.blogspot.com/ also here: http://rjrenner.blogspot.com/p/forsyth-rifling.html

I'm just speculating that you may have exceeded the useful range of the caliber & rifling combination at 200 yards. The .62 with Forsyth rifling is a real 'hammer', but not what I'd consider a bench gun, especially clicking out at 1800 fps. Look up the Talyor Knock-Out Values on the first Renner link above, where the .62 is compared to smokeless cartridges.

On Renner's Forsyth rifling blog he states that "our contention remains that the Round Ball of Large Calibre, driven to high velocity, is far and away a Superior projectile for dispatching large game in a humane and Sportsman-like manner, within reasonable sporting distances, that is to say, 125 yards."

Hope this helps some. There's a lot of good information on those links. Mike

 

[mr.flintlock]

Have you examined your patches to see if
they are burning through? And as already suggested, you may be burning too much powder. As with any rifle load, finding the right powder load, patch material/thickness, lube and ball size , finding the right combination is important. This sometimes takes lots of shooting but reading your patches is a good place to start.

 

[Zonie]

The roundball ballistics computer I have on my computer says if your shooting a .612 roundball at 1800 ft/sec muzzle velocity and the gun is sighted in at 100 yards, the ball will have fallen from the aim point at 200 yards, 36.7 inches.

In other words, at 200 yards the ball will be hitting 3 feet, 11/16 inches below the point of aim and it will be falling fast. 20 yards further downrange at 220 yards, the ball will be hitting the target 51 inches below the point of aim.



Your 1800 ft/sec muzzle velocity will have fallen to 836 ft/sec at 200 yards.

I guess it is due to modern ballistics that people get the idea that patched roundballs will shoot 200+ yards with great accuracy.
They won't.

I suggest you use the gun like it would have been used originally and keep your patched roundball shooting to distances below 120 yards.

'Course, that's just a suggestion. It's your gun to use as you see fit.

 

[varsity07840]

Wow! That's alot of powder in a .62. I have shot 150 gr of 2F Goex in my.72 Forsythe, but it weighs
14 lbs. I'd certailny back off on the charge and perhaps try a lubed shotgun type over powder wad that's fat enough to fill the grooves.

Duane

 

[eph289]

Duane I'd like to ask you some question seeing you have some experience with forsyth rifling. I tried shooting 200yd just once after reading an article that was written by wosika about long range shots during the revolutionary war. I'm more interested in 100yd shots. I have been bushel basket groups at 100, where as I can get
1 1/2 inch at 50yd. Something bad is happening between these two ranges. I can get this 50yd accuracy with loads with of 80gr 2f to 100gr 2f , I totally loose accuracy at 100yd.I use .018 pillow ticking with about 20gr cornmeal over powder.
I'd be interested in what you are doing with your 72 forsyth.
I mentioned wosika ,I believe it is Ed Wosika . But anyway google up wosika he has some very interesting thoughts on round ball ballistics.
I thank the rest of you guys for your input,because I've run out of ideas and I'd realy like to get some 100yd accuracy.
Thanks Gene

 

[varsity07840]

The ball is not stabilizing. The question is why.
The first thing I would try is a thicker patch. IMHO, narrow lands and wide grooves need more patch to fill up the space. I'd certainly look at
recovered patches to see if their blown or burned.
I'm not a fan of corn meal filler because of the residue that it leaves. Try an 18 or 19 ga. lubed cushion wad. I use a 12ga/.740 wad in my .72. You may want to try a bigger ball. Are you casting the ones you're using? Some shooters may disagree, but I think pure lead is essential for the ball to bump up on ignition to totally seal the bore with the patch, unless your patch/ball combo is so tight that you need to hammer it down.
As to my .72, I have it sighted in dead on at 50 yards because my eyes and open sights don't like each other anymore. It shoots one big hole. Given the limits dictated by
bifocals, it groups pretty well at 100, but I don't think I'd try that distance on a deer.

I'd also suggest posting your question on the shooting blackpowder forum on the American Longrifles site. There are several "regulars" there who are Forsythe shooters who may be able to help you. For some reason this post won't accept the link to get you there, so you'll have to google it.

Duane

 

[Tinker2]

Well you have my attention, I just get done reading this and the postman is at my door with a brand new
Rice .62 caliber Forsyth barrel with a 1:95 twist


I call that good timing



William Alexander

 

[eph289]

Duane Gene here.I thought I had done every thing you had suggested but you made me question the hardness of my lead.I test my lead by piercing it with a 60 degree punch with 200 lb of pressure.I do this in my drill press on a bathroom scales.I then measure the hole with a set of calipers and a magnifying glass. I checked a box 50 cal store bought balls and sure enough they were softer than what I was casting.I'm going to melt that box and cast them. Duane thanks a lot.

 

[Loyalist Dave]

Have you read The Sporting Rifle and Its Projectiles by Forsyth? I ask as Forsyth rifling is not simply a 1:104 twist. Forsyth rifling has much wider grooves than lands, and the grooves are shallow while the lands are sharp.

From Forsyth's Book:

P. 68
"I have found that a 14 gauge barrel rifled at the rate of one turn in 8 ft. 8 in., [1:104] if correctly made, will throw a plain spherical ball with sufficient accuracy for all practical purposes up to 200 or 250 yards. A rifle on this principle requires the grooves to be cut very shallow and broad, and the lands very narrow, almost knife-edged; the ball should just touch the lands, and no more, and the hold on the grooves is given by a very substantial patch; "

P.154
"...a 14-gauge barrel rifled at the rate of one turn in 8 ft. 8 in., may be depended upon up to 200 or 250 yards. It is evident that with this raate of spiral, the ball requires but a very slight hold on the grooves to induce it to follow the sweep of the rifling, and in practice, I have found, that the lead need not even be indented by the lands at all, a substantial patch giving the spiral motion quite as effectually. ... The tendency to strip, then, in such rifles being very small, the grooves may, and should be made as shallow as possible; seven or eight grooves very broad and shallow, the lands being almost knife-edged, having been found to answer best with these rifles."

Forsyth talks about loads for the 14 gauge rifle that he uses as an example, [.69 ..., his "minimum" for deer sized game] of 110 to 135 grains. So I wonder if the lands compared to the grooves in your barrel don't match what Forsyth specified, and thus may not work with his heavy loads out to the intended distances?

:idunno:

Forsyth though informing the reader that a barrel may be made for the shooter to be able to reach 200 to 250 yards with accuracy for "practical purposes"... mentions that he, himself, didn't shoot beyond 100 yards.

LD

 

[Scota4570]

The slow twist prevents the ball from skipping in the rifling.... Isn't that what gain twists were for? Anyone still offer such barrels?

 

[varsity07840]

The slow twist prevents the ball from skipping in the rifling.... Isn't that what gain twists were for? Anyone still offer such barrels?

I think Bobby Hoyt will make one.

Duane

 

[grey8833]

I shoot a Hawken mounting a 60 cal. Goodoien match barrel at 100 yards. I use only 75 grains of Goex 2F, a card and a .010 oxyoke lubed patch.

My 100 yard accuracy is a 6 inch circle - which has more to do with my old eyes than the rifle.

185 grains would kick like a mule and probably throw powder all over the range :shocked2:

Mike F

 

[jamesthomas]

Where (who) did you get the idea to shoot 185grns. of powder from? I would like to know so that I can avoid that area (or person). :shake: Your just lucky it didn't blowup, IMHO.

 

[Tinker2]

So is my new Rice .62 caliber Forsyth barrel with a 1:95 twist not the right twist?

Not a Forsyth?

Not going to shoot?

I was told it required heavy charges

Any who, why the change and what’s the word?


Thanks for any input

William Alexander

 

[jamesthomas]

No, its not, not if you bought it thinking it will shoot out to 200 yards, and you can use 185 grain charges.

 

[Tinker2]

No, its not,

Not a Forsyth?

“ not if you bought it thinking it will shoot out to 200 yards, and you can use 185 grain charges.”

I don’t normally shoot heavy charges. Shooting at long range was not my initial plan.
My thought was that I had heard that you could shoot shot with it without affecting your pattern
Should have more accuracy then my .62 caliber smooth bores



Thanks
William Alexander