11.7x51R HELP

[GRUMPA]

Folks this is in reference to this project I'm working on for someone else:http://castboolits.gunloads.com/showthread.php?t=131876&highlight=GRUMPA
Now I'm getting to the ammo part of this project and I think I may need some guidance on it. I just got my LEE 459-405-HB Mould and cast just a few because I'm going to have to open this thing up to .466-.467 dia. for this project.

I've already done a chamber cast trimmed 45-70 brass down to 2.01 and did all the trimming on the head to make it work.

Now with micrometers they drop out at .460-1 and I already know I have to lap it out, boolit needs to be at least .466 dia. Right now I'm using COWW because I wanted something harder when I lap it. The end alloy result well be 20:1 which I know well be a softer boolit.

Now this is the first time for me so lets be gentle, I've only shot cast through the high powered stuff in relation to this. But I normally have given them about .015 free-bore on the finished product. This one I've made up a dummy round and I can just barely insert the boolit in the case and it just falls right in the chamber with a COL of 2.840. If I put the boolit all the way inside the case the COL is 2.430 and according to my math that's just around .400+ freebore. Is this normal for a Danish RB?

Plus when I insert the COWW boolit in the case itself and pop it back out it decreases in size by .002. I know when I get to casting with 20:1 which well be a softer boolit it'll shrink even more.

How do you guys do this stuff? Get a larger expander plug? I pretty much figured I'll have to lube this thing by hand, I have some of Bullshops LOTAK leftover, and that sticks to anything and everything.

The owner of it wants it set up for smokeless so the powder that seems to be one a lot of folks are using is SR4759 and I plan on starting out with 22gr with a max of 23gr. The owner just wants it to work and be able (according to him) to get an elk with it.



http://i1193.photobucket.com/albums/aa341/grumpaboo/Picture0062160x1620.jpg

[Chicken Thief]

The danes had 5 production lines of theese rifles and in 1896 when they started converting to smokeless and jacketed they discovered: That the Go/No Go plugs waried by 0.5mm~0.02", so barrels are from .443"-.463"!!! To compensate for that they made generous freebore and a slightly undersize jacketed bullet.

I have never met a Danish RB that i could not get to shoot good with the 459-405HB.
If i was you i would not worry about the boolit being slightly undersize, after all that's what the HB is there for.
You will find that when fireformed the brass will accept the boolit without shaving it dovn and then only a slight crimp is in order.
If you seat long then the boolit will obturate better at firing thus fill the barrel perfect.


Some data to fit your other thread:
The Danish military only used the 11.4x41.5R (original BP rim fire) and the 11.4x51.5R (smokeless and jacketed bullet).
The 11.4x46.5R was a cartridge used by the shooting assosiation because they wanted to use reloadable center fire brass but keep the military loading. It was after all for reserve troop training.
The 11.4x56R was an experimental round in the transsision to smokeless and only that long to avoid high pressures. But the cartridge was found to long to handle fast so the 11.4x51.5R was the final result with a slower powder.

[GRUMPA]

OK another thing I forgot to ask, with 22gr in the case and the boolit seated it seems like there is a lot of room in there. Should I use dacron as a filler or just let it go?

[Chicken Thief]

I dont know how position sencitive that powder is but i bet it cant hurt. Gives better ignition.

[kodiak1]

When loading smokeless I use 5744 and use 24 grains with the 459 HB.
Those old roller shoot very very well.
I have shot it with paper patch also.
The majority of the time I load ffg and load it like any other BP cartridge.

I notice that you said you checked all the casing heads, that is one place at first that i did run into some trouble the 45-70 brass would go in the chamber but wouldn't fire. Rim was to thick.

Good Luck and have fun Ken.

[GRUMPA]

I figure I'll update this for future information. Loaded up just 1 with the COWW boolit which I hand lubed. That part was easier than I thought but I had some soft lube on hand. I used a Remington large rifle primer with 22gr of SR4759 but added 1gr of Dacron to it. Went outside to the range (back yard) and fired it.

Now being the first time I ever fired a rolling block this was a new experience for me, the recoil was minimal to me as I have always shot the high powered stuff. I have no clue how much pressure this type of rifle can handle but I'm not one to find out either, so I think I'll just take it 23gr of SR 4759 with 1gr Dacron and call it good. And an added note it fire formed just perfectly.

[Chicken Thief]

http://i295.photobucket.com/albums/mm153/Chickenthief/Blandet/Smilere/A.gif

Now all you have to do is get it on paper.

[GRUMPA]

OK this is another update as it seems information on this particular ammo is limited.
This data is for this particular rifle only and use at your own discretion.

Primer Remington Large Rifle
Powder SR4759
Parent case FC
Boolit Wheel Weight with 1% tin added
Mould LEE 459-405-HB
Mould was Beagled with size being. .463

The above were used solely for the purpose of fireforming the case.
Chronographed results as follows. (10 shot string continuous fire)
1) 1287
2) 1267
3) 1169
4) 1299
5) 1298
6) 1253
7) 1268
8) 1273
9) 1232
10) 1256
ALL the above used 22gr SR4759 with 1gr Dacron (No COL to include in this because that can and will vary according to individual).
Ambient Temp. 41deg.

ALL these below are using 23gr SR4759 with 1gr Dacron 10 shot consecutive string using the same boolit.

1) 1323
2)1385
3) 1322
4) 1270
5) 1330
6) 1353
7) 1318
8) 1340
9) 1319
10) 1365

Now the accuracy part:
I couldn't set up my target stand being as the snow was melting I wasn't going to be walking in mud, rather I picked out a known boulder about the size of a beach ball and nailed it each and every time. Being the first Rolling Block I ever shot in my life this thing for lack of a better term was very sweet to use with it being very accurate at 300yds. My only regret is that I have to give it back to the owner, but if I ever come across one just like it, it's going to follow me home one day.

Another thing to mention is this rifle I'm sure was meant for Black Powder, And I'm not going to push the rifle to see how fast I can get it to go, so the velocities are being kept at the safe side of things.

[Chicken Thief]

If the action is marked: "KIØBENHAVNS TØIHUUS" the barrel steel is German and above standard, thus loaded to 1600bar ~ 23200psi. The Remington marked guns was equipped with a Sheffield barrel and only loaded to 1200bar ~ 17400psi. That is numbers from the Royal Danish Arsenal and is what was loaded with jacketed and smokeless back then!