Working up a load for the new double rifle

[Jagare]

For the last few days I've been trying to work up a load for the new Merkel 8x57Jrs Double rifle. When i bought the Merkel, 2 boxes of Norma 196grn Oryx ammunition were thrown in with the rifle. These factory round shot a reasonable hunting group. But reloading is a lot cheaper than factory ammo.
I bought a Magnetospeed V3 chronograph and shot 5 shots of the factory ammo over the chroni giving an average of 717 mtrs/s.
I had a box of Norma 196grn Vulkan bullets and worked up a load with Norma 203B that shot 713mtrs/s. The groups were OK but nothing stunning with the Vulkan bullets.
This morning it was off to the local gun shop and bought a box of Norma 196grn Oryx bullets and another tin of 203B powder. I loaded up 5 rounds with new cases, resized and trimmed. CCI LR200 primer, 44.5 grns of Norma 203B and a 196grn Norma Oryx Bullet. I used a Lee factory crimp die to give a light crimp.
This load chronied 722mtrs/s. So i loaded up 4 rounds too test off the bench. Range 60 mtrs. Results in the photo. I think i may well have cracked it. I'll load a few more tomorrow just to check .

 

[Southern]

Looks great! Is that shooting out of one barrel or two?

 

[Jagare]

Looks great! Is that shooting out of one barrel or two?

1&3 are the right barrel 2&4 are the left barrel. Two shots with the barrels cooling between each pair of shots. Shooting the Vulkan loads yesterday the individual barrels shot good groups but could not get the individual groups to come together better than about 65mm.

 

[sh1kar]

What can be interesting is to see the difference between shooting left then right vs right then left barrel and whether differential expansion of barrel impact POA
S

 

[Heym SR20]

Looks good - go hunting.

 

[Border]

Nice one. How is it grouping compared to the factory rounds? Did you load the homeloads to the same c.o.l as the factory rounds?

 

[Jagare]

Nice one. How is it grouping compared to the factory rounds? Did you load the homeloads to the same c.o.l as the factory rounds?

The home loads shoot better than the factory ammo. c.o.l is exactly the same as the factory round

 

[Mr. Gain]

Congratulations on an excellent result!

If only all load development went that smoothly!

Some things are evidently "meant to be"!

 

[Jagare]

Congratulations on an excellent result!

If only all load development went that smoothly!

Some things are evidently "meant to be"![/QUOTE

From what I've seen and read Merkel regulate there double rifles in the main with Norma ammo. Really only 2 types of Norma bullet in 8x57JRS they were likely to use and that was the Vulkan or Oryx. As all the Norma 8x57 bullets are easily available it was not such a great challenge to get a good load. The Magnetospeed Chroni was a great help and gave a good indication on where to start. I read up on the loads from Norma's website and a very good reloading book from Norway (Ladeboken #7) only available in Norsk. Ladeboken #7 is full of good tips on reloading and good bits for loading for a double rifle.

 

[Nojden]

That's a great grouping, I'm reloading the same round for my chapuis o/u, and got similar results with 44,3 gr N203B and Oryx at about 50 m with iron sights. But, to achieve acceptable groups with and without the scope attached and shooting at 100 m and 50 m respectively, I finally ended up with Norma 202 and the slightly heavier 200 gr sako hammerhead.
Just a few questions about your loads, for my own interest;
-The magnetospeed is attached to the barrels when measuring speed (I think?), I suppose you checked the grouping without the magnetospeed on the barrels?
-Do you have a scope for the Merkel and, in that case, have you tried your loads with and without the scope attached?
Please, feel welcome to contact me with pm if you'd like to write in Swedish

 

[timbrayford]

-The magnetospeed is attached to the barrels when measuring speed (I think?), I suppose you checked the grouping without the magnetospeed on the barrels?

That's correct, best to treat recording velocity and shooting groups as two separate exercises without the magnetospeed for the latter.

 

[Jagare]

That's a great grouping, I'm reloading the same round for my chapuis o/u, and got similar results with 44,3 gr N203B and Oryx at about 50 m with iron sights. But, to achieve acceptable groups with and without the scope attached and shooting at 100 m and 50 m respectively, I finally ended up with Norma 202 and the slightly heavier 200 gr sako hammerhead.
Just a few questions about your loads, for my own interest;
-The magnetospeed is attached to the barrels when measuring speed (I think?), I suppose you checked the grouping without the magnetospeed on the barrels?
-Do you have a scope for the Merkel and, in that case, have you tried your loads with and without the scope attached?
Please, feel welcome to contact me with pm if you'd like to write in Swedish

I was going to try shooting a group with open sights but with my old eyes i can't use open sights. So it scope only.
The magnetospeed is only on the rifle to check MV. Its taken off for shooting the groups. Norma 202 disappeared of the shelves for quite a while, but i see it available again. 202 is a great powder in my .308s but due to a lack of supply i went over to 201 for my Fmj range ammo i did have a little bit of 202 left but it did not group as well as the 203B in the double.

 

[8x57]

What are Norma Oryx bullets costing you in Sweden Jagare?
I take it that Norma bullets are readily available over there as opposed to in the U.K where RUAG only seem interested in selling ammunition and not components.

 

[Jagare]

What are Norma Oryx bullets costing you in Sweden Jagare?
I take it that Norma bullets are readily available over there as opposed to in the U.K where RUAG only seem interested in selling ammunition and not components.

Hej Mike, a box of 8mm Oryx would cost about £93. The £ against SEK is very poor at the moment. Plenty of 8 mm at the local gun shop.

Look at: Torsbo Handels AB - nya & begagnade vapen och kikarsikten

 

[Southern]

You might want to try a lighter bullet at at the same velocity, like the 175-gr Sierra at 717 m/s, using 46.0 gr of VV N-140 at a pressure of only 2,800 BAR.
Start a little lower, of course, but not much lower.

It would be interesting to see if it shoots to the same point of impact and tight groups.

 

[8x57]

Hej Mike, a box of 8mm Oryx would cost about £93. The £ against SEK is very poor at the moment. Plenty of 8 mm at the local gun shop.

Look at: Torsbo Handels AB - nya & begagnade vapen och kikarsikten

The 8mm Oryx seems to be pretty consistent in price throughout Europe then from what I have seen on the internet. Certainly not cheap but they are good.

Like you say plenty of 8mm in the local gun shop. I doubt if you could find more than four or five different brands and weights of 8mm bullet in the whole of the U.K. In fact you would probably struggle to find more than five boxes of 8mm expanding bullets in total, and that's no exaggeration. Well just a slight exaggeration maybe.

 

[Nojden]

Sounds poor,
There's another store in sweden called "vapex" and they have plenty of 8 mm bullets, about 10 brands and slightly over 40 different bullets.
8mm (.323) JS


Don't know if they sell abroad, but their website is available in English.

 

[Nojden]

That's correct, best to treat recording velocity and shooting groups as two separate exercises without the magnetospeed for the latter.

Ok, thanks for info. If you have the Merkel 141 I guess you're able to adjust the barrels by yourself? But with that grouping I wouldn't touch the adjustment
If you're looking for a cheap fmj for practice shooting I can recommend the S&B 196 gr, shoots almost exactly the same as 196 gr Oryx in my rifle, with a slightly lower powder weight (about 0.2 grains less of N203B as for the Oryx and 77 mm col)