NONAGONOGIN - The barrel diameter is 1.03-inch for the full length and the length is 27 inches, not to get more velocity but to add weight to reduce recoil. The pull length for the stock is 14 inches but the gun probably looks shorter in the photo because it was pointed away from the camera. With the 575-grain bullets I use 110 grains of AA8700 (for 1,625 fps). Looking at my records it appears that this is about a 3-MOA rifle and that I haven't fired it in over 6 years. Some un-burned powder is left in the barrel, which I think is because pressure is very low. If I substitute a 700-grain bullet also with 110 grains of AA8700 the velocity stays the about the same instead of decreases as one might expect. I think the powder must burn better with the heavier bullet and pressure must increase. An Accurate Arms Powder technician ran a computer program predicting that that 700-grain load would have a pressure of 24,000 psi. I have also shot 720-grain paper-patched bullets with 115 grains of AA8700 which gave a velocity of about 1,750 fps. Accuracy was about the same but recoil would get one's attention. I can vary the weight of the cast slugs used for hammer swaging so go with about 575 grains for recoil reasons. I have used 600-grain Barnes originals with 115 grains of AA8700 which gives about 1,600 fps and the same accuracy, but since their diameter is .510-inch and the barrel groove diameter is .507-inch I worry that pressure might be higher than expected. The multiple-ball load consists of three 187-grain 50-caliber balls (total weight 561 grains). There is a Polly Patch behind the bottom ball to act as sealing wad and Polly Patches between the balls to cushion them from each other so they stay round. With 57-grains of IMR4350 the velocity is about 1,220 fps. The balls pattern in 4 to 7 inches at 55 yards but patterns are spread way out at 100 yards. I think this would be a good short range deer load, but the trouble with the multiple ball loads is that it is easy to ruin a brass case when putting the balls and Polly Patches in, and I don't want to waste any cases. Also, I have a TCR-87 custom 20-gauge fully rifled slug barrel which I sometimes shoot with custom brass cases and 720-grain cast lead bullets. With 45 grains of AA5744 powder the velocity is about 1,000 fps and recoil feels OK in this 8.5-pound gun. It shoots 1-1/2 inch or better groups at 50 yards. - DON

Thanks again, Don...The barrel does look shorter than 27" from the pic. My Sharps weights 13.5 lbs which helps dampen the recoil with the heavies and the NEF about the same.

Yeah...brass has become gold...just as expensive and just as scarce. 50-70 is cheap and everywhere(last time I looked)...50-90 is showing up now and then, but 50-140...well....

The NEF receiver is originally a 12Ga USH rechambered by Rob to 3.85" and using his blown out 50 BMG brass with the 50-70 stub barrel originally from a 223 bbl, 1.10" OD, fitted and threaded 20 tpi about 0.900" od for 3", then 1.100" straight, roughly speaking, I didn't check my notes for the actual numbers.

I just ordered a 50-90 reamer from R.R...just couldn't leave it alone after this thread. It could be here tomorrow or Thursday for sure.

Checked my notes for the Sharps and for 590-680 gr cast the highest velos were 1900fs with calculated pressures below 28KPSI...all cases just fell out. Most all had lead wash-back around the case mouths. This was with AA2460 powder. I didn't have the 715 gr FNGC mold then and since receiving it and casting a couple hundred, I haven't tried them in the Sharps. The work very well in the 50-70 so far, turning in 1450 fs with RL7 and RL10 at ~35KPSI and 1000fs +/- a bit whisper velos, with Trailboss at 100% load volume at similar pressures.

I'll soon know what the 50-90 will do in the short barrel.

Powder is almost non-existent locally but starting to trickle in. I'm too tight to pay the UPS rip-off prices or drive 200 miles which is even more costly so I'm quickly using up all my supplies in the requisite burn rates.

Anyhow...I will play with the NEF 50-90 for a while then pop for a 50 cal, 1.25" OD McGowen bbl and find a donor 10 or 12 Ga USH barrel to fit.

Thanks again for the data.

NONAGONAGIN, where are you located. I've got lots of BP.

RIP, my idea of a 50 caliber rifle...an A-Square Hannibal in 500 A-Square. A 707gr mono solid at 2,250 fps.

D

Oh well. On smokeless, I use Rel 22 and 25, Retumbo, and H1000...mostly for LR stuff...then 4831 and Rel 15 for regular stuff.

No Darwin Award winners:

quote:

Originally posted by NONAGONAGIN:

It's amazing the turn I get when I mention my 20 Ga African elephant gun...lots of you can imagine the guffaws and retorts...that is until I whip out a dummy cartridge...then it gets very quiet and NO takers for the offered "take a shot"...Even quieter when the 12FGAFH with a 1000 gr brass slug appears. So far I see only retreating backsides as they depart very quickly. Even loads in plastic cases receive incredulous replies...and "No thanks, I'm late for a previous engagement." Hahahahahaha

Yep, the 50-140 3.25" is a light-recoiling, tack-driving, must-have, fun-gun in comparison to even the "20Ga Hellboy 3.5-inch" let alone the 12GaFromHell.

I found my thrill on the 12GaFH 3.85" hill ... 1400 grainers at 1800 fps in an NEFer: I'll never do that again!

RMC brass, 209M primer, and RL-17 give faultless ignition and low pressures.
Beat the hell out of me!
That is why am switching to a smaller bore like the 50-140.

D

Biebs,

The 500 A2 Hannibal has a 1:10" twist, too much like my slightly greater case capacity 500 Mbogo rifles with 1:10" and 1:9" twists.

1:10" 500 Mbogo:



1:9" 500 Mbogo:



They are great with modern bullets for 50 BMG, but playful curmudgeons want a slower twist option for cast lead.

NONAGONAGIN,
You are The Man if you can attach brass tips to lead bullets with concentricity.

Brakes: Burning 100 to 200 grains of any kind of powder in any .50 to .730-cal must surely make a brake somewhat useful.

12GaFH brake is a 1.5" O.D. Vais 50BMG brake bored out to .750" by Rusty McGee to let a .730-cal slug pass,
3.27 ounces of lead equivalent to a 5-bore that is way faster than any BP 4-bore of yore.
Even Cal Pappas cannot top those ballistics with his antique 4-bores shooting smokeless:



Two 12GaFH NEFers, one with brake and one with a steel AR-15 golfball launcher,
threaded same, to be used as a muzzle cap (muzzle weight) on both of them, interchangeably:



The 1.000" O.D. Vais brake is used on 500 Mbogo, 500 Bateleur and .500/.338LM(12.7x68).
Muzzle hole being .530", it will work great on the .510/50-140 Sharps 3.25":







A muzzle brake on a .510/50-140 Sharps 3.25" BPCR should make for a spectacular mushroom cloud with each shot.

D

I am thinking the .510/50-140 Sharps 3.25"
Will have a straight cylinder barrel of 1.200" diameter, on a Ruger No.1 stainless laminate.
Stainless for BP loads won't hurt anything.
It will have a full length picatinny rail as barrel-top rib.
Length of barrel? 26", 28", 30"?
I suppose the 26" would be better balanced with a barrel that fat for such a small bore.