.75 cal power

[Mike Brooks]

Thanks for all the info.First I don't intend to shoot beyond 100 yrds. or load that heavy.I was just gathering info to understand what it can and cannot do.Now if I'm shooting paper or silhouette how far out can I reach all things considered.

All depends how good of a shot you are.

 

[stalkerhawk]

I'd say I'm average.On A good day I can keep them in a 2-2 1/2 in dia.circle @ a 100 yards.With the rifle I'm currently using.

 

[Mike Brooks]

I'd say I'm average.On A good day I can keep them in a 2-2 1/2 in dia.circle @ a 100 yards.With the rifle I'm currently using.

That's good, but is it a .75?

 

[stalkerhawk]

No it's a .62 shooting a .600 ball 328 gr. and 120 gr. of 2ff black powder.Now I need help understanding the relationship between twist rate and powder charge I'm looking at a 1 in 72 vs. a 1 in 95 I'm clueless as to which twist to use,and what the differance is.

 

[rabjr]

Generally the faster twists let you do the same thing with less powder. So the 1-95 would be more for heavier powder charges than the 1-72.

 

[stalkerhawk]

I've been told with the 1 in 72 I might find the sweet spot between 80-120 gr. and with the 1 in 95 something like 160-200.So what are the pro's and con's I'm also thinking about recoil.

 

[bingo1952]

Cost of the powder for one thing. 35 shots per pound if you use 200 grains and 43 shots if 160 is used. That works out to about .26 cents a shot just for powder at 160 grains and .31 cents at 200 grains.

 

[stalkerhawk]

So what advantage to I have using the faster twist with less powder over the slower twist and more powder?

 

[stalkerhawk]

Ok.So ballisticly what is the differance between the 1 in72 loaded with 100 gr. and the 1 in 95 loaded with 180 gr. at 100 yards.

 

[slowpokebr549]

You get plenty of killing power without the cost and recoil. Look at some of the early Jaegers, they had pretty fast twists and big bores. It wasnt until folks started running into buffalo and grizzly that they started stuffing tons of powder down the front of a Hawken. I shoot a .690 in a smoothbore and I only use 75 grains of powder. It has plenty of whomp.With that big of a ball especially with a hard cast ball, aint nothin gonna stop it.

 

[Mike Brooks]

I've been told with the 1 in 72 I might find the sweet spot between 80-120 gr. and with the 1 in 95 something like 160-200.So what are the pro's and con's I'm also thinking about recoil.

Recoil in a 10 lbs gun in .75 cal won't be bad with 200gr, as long as you don't mind picking yourself up off the ground after every shot. :rotf:
Seriously, there is absolutely no reason to shoot that much powder in this country. If you're going to hunt tuskers and lions in Africa then by all means work up a load that kills at both ends.
I have killed most of my deer wit a .62 smoothbore loaded with 60gr of 2ff. Had it clocked once and was getting about 850 FPS. Never failed to shoot all the way through a deer and smash them flat on the ground. Big balls don't have to move fast to be effective, it's their mass alone that kills, not their speed.
The trajectory for anything over 100 yards is going to give you alot of trouble hitting anything, no matter how little or how big the charge. That big ball is going to have a rainbow curve. You better figure on a sight with several folding leaves past 50 yards and be one helluva good judge of distance.
If you're going to spend any time shooting this gun with large charges you better have it built to at least 14 pounds. I'd probably be happier at 16.
I doubt this .75 you have planned is going to do any more than the .62 you're already shooting....except hurt more when you touch it off. :haha:

 

[Mike Brooks]

You get plenty of killing power without the cost and recoil. Look at some of the early Jaegers, they had pretty fast twists and big bores. It wasnt until folks started running into buffalo and grizzly that they started stuffing tons of powder down the front of a Hawken. I shoot a .690 in a smoothbore and I only use 75 grains of powder. It has plenty of whomp.With that big of a ball especially with a hard cast ball, aint nothin gonna stop it.

Every short barreled german hunting gun I've ever seen had one twist in the length of the barrel. Really fast by today's standards. Tight ball/patch combo, light powder charge and shooting ranges less that 100 yards. They let the ball do the killing, not the powder.

 

[bingo1952]

If I were contemplating taking an African trip with thoughts of the Big Five on my mind I would want hard cast balls and at least a 10 bore and preferably an 8 bore. Read some of Sir Samuel Baker's writings. They are a real eye opener as to calibers used and their ability to handle dangerous game.

 

[stalkerhawk]

So loading up the charge has no benifit,and will only beat me up more.Yes I am a good judge of distance.I've been shooting primitive Bows instintivly since I was 15,But I am having a three blade English Express sight put on the barrel.

 

[Dphar]

Great info Dan. :thumbsup: Personally I wouldn't recommend a big bore loaded like that past 50 to 75 yards. I haven't seen any one yet that can hit the broad side of a barn with a big bore stoked with a healthy dose of powder. By the time it is sighted in the shooter has developed such a flinch that accuracy is long gone. Recoil with a 12 bore with that powder load is brutal, personally I'd go for a gun in the 12 to 14 pound class, and as Dan suggested, you better have it stocked by a professional familiar with big bore recoil, otherwise it will be shot a 1/2 dozen times and sold or stashed in the closet. :wink:
I have patterned a 10 bore for a customer with 140gr 3fff and 2 1/2 oz shot and I will tell you that 8 shots is about all I could handle in one day.....add another 100 gr to that and somebody would have had to call the mortuary! :haha:

I have a 16 bore, 10 pounds with 140-150 grains of FFG Swiss (1600-1650 fps) its a great hunting gun but takes some getting used to and long strings off the bench 10-20 rounds were brutal when I first started shooting is.
This or a 69 is about all that would be needed for any NA game when used within their range. For dangerous stuff like a G or Brown Bear etc 50-60 yards max.
This said the 16 bore shoots very well at 180-200. With *perfect* conditions its deer capable to this distance. But hunting is never perfect....
Just a little far for shooting game with barrel sights. Shooting too far at something with big teeth and a bad temper is just silly.
Gongs and paper? 300 probably. Never shot the 16 that far but I will do it I am sure.
10 bore could be scary with more than 150-180 grains and if light would be bad with l00 or so.
Ball is just too heavy for a light gun, under 12 pounds is too light.
BPCRs shooting similar weight projectiles at 1350-1400 with 100-120 gr of BP need to weigh 14-17 to be "fun".

Dan

 

[Dphar]

You get plenty of killing power without the cost and recoil. Look at some of the early Jaegers, they had pretty fast twists and big bores. It wasnt until folks started running into buffalo and grizzly that they started stuffing tons of powder down the front of a Hawken. I shoot a .690 in a smoothbore and I only use 75 grains of powder. It has plenty of whomp.With that big of a ball especially with a hard cast ball, aint nothin gonna stop it.

The Jeager was not a dangerous game rifle aside from maybe boar.
The English started shooting a lot of powder as soon as they started hunting in Africa and India.
I try for 1600 since it flattens the trajectory and makes the 16 "flat" for deer sized animals to 120 yards or so.
For dangerous game hardened lead is recommended as well.
16 shoots wheel weights and pure lead to the same point and the same accuracy.
I would also point out that the eastern shooter also used about the same powder charge as the western hunter for some purposes.
Mentions of 1/2 ball weight of powder were written in rev war times. While too much for bigger bores it works well as a max for most rifles under about 58 caliber. Bigger bore rifles only need 1/3 ball weigh to make about 1600 fps.
Dan

 

[J.D.]

Do some penetration testing with your chosen RB gun, comparing target loads to that monster "hunting " load you think is necessary. You will be very shocked to learn that the two balls will penetrate about the same distance. A 4 dram load of powder in a .75 caliber gun is still a lot of powder( 110 grains), and more than enough to push a RB out fast enough to kill any game in N. America. a 3 dram load makes more sense, IMHO( 83 grains) with such a large diameter ball.

One other point, as Paul says "monster loads aren't needed for shots with big bore rifles since you're going to be shooting at less that 100 yards. If it were me I'd shoot what ever load shoots the most accurate, not necessarily the load that kicks the worst.
I built a .62 for a customer years ago that insisted I sight the gun in and sight it in for 140gr of 3fff :shocked2: I stopped dumping in more powder when the group went all to hell, that was at 100gr. It loved 95 gr and shot exceptionally well. He was very annoyed with me, and went ahead and loaded it with 140 gr. anyway and then complained it was the most inaccurate rifle he ever owned. :surrender: :haha:

For what it's worth. My 75 cal bess shoots 80 gr FFG very well, but anything approaching 100 gr is getting punishing. The most accurate load, in this gun, is 90 gr FFG, but I shoot for enjoyment, and reduced the load to a more comfortable 80 gr. The lighter load shoots very well and will definitely shoot through a deer at 40-50 yards.

As a point of reference for recoil, an acquaintance who had a .62 cal Yeager rifle built for an African hunt, took a cape buffalo shooting 250 gr FFG behind a hard .610 RB. I witnessed a friend shoot that same rifle using 150 gr FFG, off hand. Recoil set him back a coupla steps, and he is a pretty big boy.

I might be a wuss, but based on Rick's experience shooting the "light load" in that 62, I would hate to be on either end of a 120 gr + load of a 75 cal anything.

I second Mike's recommendation of having that gun made by someone who understands the recoil that can be meted out by large bores and how to design a stock to reduce felt recoil.

I also second the suggestions for lighter loads, in addition to lots of practice so's you know where that gun shoots at various ranges.

For that matter, IMHO, your 62 should be more than adequate for anything on the North American continent. IMHO, a 75 cal is over kill.

God bless,
J.D.

 

[stalkerhawk]

The rifle is being built by some one who understands he has one him self.So I'm still not sure what twist rate I should go with 1 in 72 with smaller charges or 1 in 95 with larger charges.I don't think recoil is a big thing for me,but I've never fired a .75 let alone a .75 loaded with 180-200 gr.of powder.With the heavy carges would I have any more knock down power than I would with smaller charges out to 100 yards.Also did anyone read the artical in Muzzle Blasts Journal section titled Hunting with the patched round ball.He used a .75 slow twist with heavey charges.

 

[Dphar]

The rifle is being built by some one who understands he has one him self.So I'm still not sure what twist rate I should go with 1 in 72 with smaller charges or 1 in 95 with larger charges.I don't think recoil is a big thing for me,but I've never fired a .75 let alone a .75 loaded with 180-200 gr.of powder.With the heavy carges would I have any more knock down power than I would with smaller charges out to 100 yards.Also did anyone read the artical in Muzzle Blasts Journal section titled Hunting with the patched round ball.He used a .75 slow twist with heavey charges.

With the size animals you would be shooting knock down is not going to be greatly improved with extra powder. Find a load that works and get away from the modern mind set that says more powder is always better.
Deer are notoriously hard to stop no matter what you shoot them with so do not expect them to just fall over when shot. Speaking of western Mule deer and good sized WTs here.
This is based on a large number of deer shot by me, family members, hunting partners and people I was guiding. No matter what they tend to typically run 40 yards unless brained or spined. Some perhaps less some a lot farther. A few will drop at the shot.
I shot MD doe with the 16 bore at about 40-45 yards, ball entered beside the windpipe. Made a large hole where the top of the heart had been. Penetrated about 30" back into the deer. Ejected tissue back out the large entrance wound at teh place the deer was standing and the deer ran (not very well but ran) 55 long steps before falling. She would have likely made it a *little* farther shot with a 50 since she might have been able to run at full speed rather the 1/2 or 2/3 speed.
So don't get puckered if some run off with the .75. EVERY deer will react differently.
Find a load that shoots flat enough to 100. Bullet within 3-4" of line of sight to 100 is fine for deer. Probably dead on at 60-70 will work great.
Shoot the gun enough to get comfortable with it and understand how to hit stuff with it then go hunting.
In a 75 I would not be concerned with the 95" twist, I would rather have 95 than 72 in that bore size but that is just opinion. I have an 80" in the 16.
Dan

 

[Dphar]

Do some penetration testing with your chosen RB gun, comparing target loads to that monster "hunting " load you think is necessary. You will be very shocked to learn that the two balls will penetrate about the same distance. A 4 dram load of powder in a .75 caliber gun is still a lot of powder( 110 grains), and more than enough to push a RB out fast enough to kill any game in N. America. a 3 dram load makes more sense, IMHO( 83 grains) with such a large diameter ball.

One other point, as Paul says "monster loads aren't needed for shots with big bore rifles since you're going to be shooting at less that 100 yards. If it were me I'd shoot what ever load shoots the most accurate, not necessarily the load that kicks the worst.
I built a .62 for a customer years ago that insisted I sight the gun in and sight it in for 140gr of 3fff :shocked2: I stopped dumping in more powder when the group went all to hell, that was at 100gr. It loved 95 gr and shot exceptionally well. He was very annoyed with me, and went ahead and loaded it with 140 gr. anyway and then complained it was the most inaccurate rifle he ever owned. :surrender: :haha:

For what it's worth. My 75 cal bess shoots 80 gr FFG very well, but anything approaching 100 gr is getting punishing. The most accurate load, in this gun, is 90 gr FFG, but I shoot for enjoyment, and reduced the load to a more comfortable 80 gr. The lighter load shoots very well and will definitely shoot through a deer at 40-50 yards.

As a point of reference for recoil, an acquaintance who had a .62 cal Yeager rifle built for an African hunt, took a cape buffalo shooting 250 gr FFG behind a hard .610 RB. I witnessed a friend shoot that same rifle using 150 gr FFG, off hand. Recoil set him back a coupla steps, and he is a pretty big boy.

I might be a wuss, but based on Rick's experience shooting the "light load" in that 62, I would hate to be on either end of a 120 gr + load of a 75 cal anything.

I second Mike's recommendation of having that gun made by someone who understands the recoil that can be meted out by large bores and how to design a stock to reduce felt recoil.

I also second the suggestions for lighter loads, in addition to lots of practice so's you know where that gun shoots at various ranges.

For that matter, IMHO, your 62 should be more than adequate for anything on the North American continent. IMHO, a 75 cal is over kill.

God bless,
J.D.

I bet if they chronographed the 250 grain load they would find they were wasting powder. Bet verlocity gain per grain of powder really falls off by 150 grains. Velocity gain in my 30" barreled 16 really starts to fall off at 140-150 grains, in fact it drops off from 120 up.
Shooting over 1/2 ball weight in a 62 probably did nothing but make it kick more.
Round balls tend to move away quickly and this reduced the amount of powder that can be burned before the ball exits.
Dan