577 NE 2.75 " and 777

i was @ the range today with my 577 NE 2.75" case. I have an Army & Navy double Gun. appox 1890 - 1910-. I have decided to work up a Pleasing Load using 777.
I have shot Factory Kynoch's. but Intense recoil has been To much for Me Lately. Loaded up 10 Round Using 85 Gn T7 behind a Barnes 750 GN FMJ , Wonder wad Between Bullet and powder. Velocity appox 1700
The rifle shot well @ 50 yards with a Very stiff Recoil but not Overwhelming . Group was appox 6 " non Regulated. Next round looking to Increase4 to 87 - 90 GN .
Clean burning no residue
anyone else shooting This

I've never shot T-7 in anything so can't speak to how well it would work. With plain old Black Powder the solids that are ejected from the muzzle add to the recoil according to reports from the guys that shot both when the change over started. I'm wondering if you will get more or less recoil from your loads and if regulation is possible with a less punishing load. I am surprised that your gun would want 750 grain bullets as I was under the impression that all the 2.75" Nitro Express guns were regulated for the 650 grain bullet. Have you considered cast bullets?

Do you know who built your rifle? Army & Navy was the retailer. What type of action, lever over guard, top lever, hammers, hammerless? Pictures would be nice.

my rifle is an Under lever , Hammered, I have an good amount of 750's on hand thats why the choice. . cast is an Option.
As to the actual i would Have to chect the proofs is possible

You probably won't find anything on the rifle to tell you what bullet weight and charge it was regulated for unless it is a late light cordite rifle.
There are a couple things you may want to comment on.
What was column are you using with that light of charge?
What type of rifling does it have?
Are the barrels fluid steel or Damascus?
What does the rifle weigh - this can be a clue as to whether it was built for heavier loads or not.

Is your 6" group all over for lefts and rights or can you discern any spread or crossover for each barrel? I doubt you would ever cross with heavy bullets and lighter charges though.
In fact you may not get anything satisfactory with those bullets and a charge that light.

The original 1880s Kynoch load was a 530gr solid or 480gr hollow cast bullet with 160grs of powder.
Taylor lists the 2.75" as having either a 520gr copper tubed or a 560gr solid cast bullet with the 160gr charge.

Also, after a cursory search on the NE forum, it looks like 777 is quite corrosive on brass so that's something to think about too.

To answer part of The question. Wad was a fiber ungreased 1/4 ' wonder Wad.
Fluid steel Barrels weight 12 Lb's
The right barrel did not cross the left

T7 is corrosive. I would not under any circumstances use it in a fine old rifle such as that. I would get a hard cast 480 grain flat nosed bullet and some good 2f black powder and load it with that. I don't care how many 750 grain bullets you have, the rifle was not designed to shoot them, nor was it regulated with them. Worst case scenario, you could cause the solder on the ribs to separate using those bullets. Treat the rifle with respect, as you may own it, but you are also now its caretaker.

Thanks for Your advise On the 750's but I have No intension to Use Black. . I have been Using T7 for Years without Problem. Have plenty of original rifles Using this without Problem.

Shouldn't be hard to work up a NfB load for that rifle rather than the triple seven but if you insist on using that, then I don't see an issue if cleanup of your brass and bores is up to snuff and you go to a GG or paper patched boolit of proper weight..
777 is also known to be erratic in pressures. Add a very heavy bullet to the equation and ?...

12lbs is pretty weighty for a 2.75" gun so it may be made for heavier loads. That may make attaining decent regulation with lighter loads a bit of a challenge. Maybe not though as the 577s are very forgiving by double rifle standards.

There is a lot Of Load Data In Wrights Book. I was shooting , I had previous Loads 78 Gn H4198 behind a 650 Boolit
But want to use T7 for a change

I was going to suggest 4198 as I use it extensively in NfB loading. In fact, I haven't tried it in my 577 3-1/4" yet but would like to try it once I get a proper mold for it. So far I have just used black and a GG boolit made for the 577 Snider without the hollow.
Sure is fun!

There were some lever over guard hammer guns proved for smokeless but they are not very common. I suspect that it is a Black Powder Express rifle and would have originally been loaded with 520 to 560 grain lead bullets and 160 grains of Curtis & Harvey #6 black powder. The proof marks will tell you whether the rifle is nitro proved, if it is great, if not be careful.

I suggest that you invest in a copy of "Shooting the British Double Rifle" by Graeme Wright, in it you will find what I believe is the best current information on these lovely old rifles.

Enjoy your rifle but be careful.