Double Rifle Load Development Shooting Distance

[Gavin Rorke]

I used 95-96 gr RL 15 in my .500 nitro when I could get it ? with many types of Bullets and I found the 570gr Barns flat fronted solids and the North Fork solids gave the best results, I had to settle on Somchem Powders as that's what we could get in Zimbabwe and my gun grouped very well using 98gr S355 and averaged 2180 fps, worked well for other PH s I loaded for as well but varied slightly in velocity depending on the Gun.
I also used half a foam wad even though the case was pretty full.primers were CCI 250. On all our tests and years in the field,a 500 nitro needs to be close on factory velocity especially for the angles one might get presented with.

 

[beginner]

Sir,
I feel your frustration, and may I offer a load that worked for me. After trying those powders listed in the previous posts (all good loads), I tried 92.0 gr. IMR 4320 under a 570 gr. Barnes Banded Solid seated on the second groove, over a half Kynoch foam, ignited by Federal 215M primer. 1.5" group at 50 yards, 3.5" group at 100 yards (2040-2050 fps through an Oehler 35P chrono) off sticks. The same powder (93.0 gr) for the 570 gr. Barnes expanding.
Hope that helps,

 

[Hunt101]

Thank you everyone for all the helpful load recommendations. I'm still moving forward with the project trying to figure out my own load, considering my hunt is in July I'm not going to do anything drastic such as re-regulation at this point. Here is a promising target with RL15 93.5 grains, Fed. Primers, and NF Solids 570, these were all running just a little under 2000 fps. I'm going to get another batch and bump them up a bit in charge and see if that will help.

 

[raimanparoni]

Hi

For doubles I have I made shooting table that I can shoot standing. Just put sandbags on it and resting my front hand on sandbags. Effect of recoil is different if you sit or if you stand. Also the gunsmith that make barrels to my first shotgun based dg said that regulation is different if you use scope or open sight. Effect of recoil is also bigger when you have a ammo that is heavy and slow because bullets barreltime is longer.

I think you all know these facts but my way to solve problems is start with basics

 

[Frederik Badenhorst]

Hi there

I feeling like I am having déjà vu reading this thread. My 450 NE 3.25 that was regulated with Hornady ammo did exactly the same thing.

Crossed at the regulation distanse and shot 2 inches high. I actually shipped the rifle back to the factory and they reregulated the rifle for me. They sent it back with the new regulation target, looked beautiful....but it shot almost exactly the same way as before.

I was pretty dissapointed, but I’m still plugging away and trying to play around with powders and seating depth to try to find the sweet spot.

It is more a mental thing that is in the back of your mind that niggles away at you constantly . It almost feels like you can’t trust the rifle

Please let me know if you find a magic remedy

Kind regards

Ps Hope the hunt went well

 

[norfolk shooter]

Hi there

I feeling like I am having déjà vu reading this thread. My 450 NE 3.25 that was regulated with Hornady ammo did exactly the same thing.

Crossed at the regulation distanse and shot 2 inches high. I actually shipped the rifle back to the factory and they reregulated the rifle for me. They sent it back with the new regulation target, looked beautiful....but it shot almost exactly the same way as before.

I was pretty dissapointed, but I’m still plugging away and trying to play around with powders and seating depth to try to find the sweet spot.

It is more a mental thing that is in the back of your mind that niggles away at you constantly . It almost feels like you can’t trust the rifle

Please let me know if you find a magic remedy

Kind regards

Ps Hope the hunt went well

How hav you been getting on with your double?? I too am having the same issues but i think I might be onto a winning load.

 

[Frederik Badenhorst]

How hav you been getting on with your double?? I too am having the same issues but i think I might be onto a winning load.

I pulled about 10 Hornady factory cartridges and got an average of 96.6 gr of powder that looks very similar to H4831 SC,some of the cartridges differed by more than 1.5 gr!

So I chose a load of 97 gr of H4831Sc and the initial results is much better......it seems to regulate between 2000-2050 fps.

With the big seasonal temperature variances in British Columbia my testing is on hold for now

Now to get a solid bullet that will regulate.........

 

[norfolk shooter]

I pulled about 10 Hornady factory cartridges and got an average of 96.6 gr of powder that looks very similar to H4831 SC,some of the cartridges differed by more than 1.5 gr!

So I chose a load of 97 gr of H4831Sc and the initial results is much better......it seems to regulate between 2000-2050 fps.

With the big seasonal temperature variances in British Columbia my testing is on hold for now

Now to get a solid bullet that will regulate.........

How much powder did you use before?

 

[Frederik Badenhorst]

How much powder did you use before?

Anywhere from 93 grains up to 100gr

 

[norfolk shooter]

Anywhere from 93 grains up to 100gr

I only ask as I’m wondering if the +- 1 grain of powder will make much difference

 

[MMAL]

As always, this forum is a wealth of knowledge, thank you. I will add a new twist to this regulation topic. I own a Kreighoff Classic in 500/416 NE and have been trying to find a load that works. My problem is that my left barrel is high by 2-3 inches compared to my right barrel at 50 yards. Within an 1/2 inch width wise. To compound the issue or the cause of the issue, I consistently get velocities on average 90 fps more from the left barrel than the right. Same powder, primer, bullet. I cannot load two different loads for each barrel, that is kind of ridiculous! Any thoughts. Have tried woodleigh/barnes softs. Different impact point for each type but same problem and velocity issue.

 

[PHOENIX PHIL]

As always, this forum is a wealth of knowledge, thank you. I will add a new twist to this regulation topic. I own a Kreighoff Classic in 500/416 NE and have been trying to find a load that works. My problem is that my left barrel is high by 2-3 inches compared to my right barrel at 50 yards. Within an 1/2 inch width wise. To compound the issue or the cause of the issue, I consistently get velocities on average 90 fps more from the left barrel than the right. Same powder, primer, bullet. I cannot load two different loads for each barrel, that is kind of ridiculous! Any thoughts. Have tried woodleigh/barnes softs. Different impact point for each type but same problem and velocity issue.

Just venturing into the DR world myself, so I'm no use to you. But maybe @AZDAVE would have some input for you?

 

[DonT]

MMAL, Two things to check.
1. Slug the barrels and see if they have different groove depths.
2. Check the OAL on both rounds (left and right), load gun and fire the right barrel ONLY. Pull left round and check OAL.

Variations in either could be effecting your impact point and speeds.....

DonT

 

[MMAL]

I was thinking of doing number 1 above by checking the depth via an oal gauge. I believe that would give me the same result. Correct?

I did not think of number 2 but a very solid thing to consider. I did not crimp the reloads and I can see the bullet sliding out and creating more pressure. Great point. Thank you. It will be awhile before I get back to the range. Again thank you.

 

[DonT]

MMAL,

Actually to slug the barrel what I do is drive a lead slug (usually a lead round ball, just make sure it is soft lead like for a Muzzle Loader not a cast bullet as it is to hard) that is slightly larger than what the bore is suppose to be thru a clean bore, lube the slug before starting and push it with a brass rod, you may be able to get by with a wooden dowel but do NOT use a steel rod as it will damage the bore. Push the slug from the reach to the muzzle and make sure and rest the muzzle on a towel that has been folded a couple of times to protect the crown of the barrels. The slug will start hard to begin with but after it forms to size it will slide relatively easy. As you tap it thru feel for any loose or tight spots. this will tell you if there is an issue in the bore. Let me know what you find.

Here is a hint, if the round ball is too large, say .600 when you need .500 you can "roll" it between two flat steel plates to elongate it (make is look like a tootsie roll) to reduce the diameter or drill a hole the size you want and drive the ball thru it and that will shave sides to the correct size.

Once you have done this just measure the diameter of the slug with dial caliper or micrometer. You should have a perfect representation of the interior of your bore.

As far as number 2: the bullet sliding out a little would typically reduce the pressure in the cartridge, UNLESS if moves out enough so the bullet is much closer or into the rifling, then the pressure goes up and it can be a lot. My suggestion is to use a bullet with a Cannure you can crimp into. If the bullets you want to use do not have that then you will need to put a pretty decent crimp on them. The other thing you can try is to put a bullet in the right barrel, shoot, open load the left (leave the spent cartridge in the right) and fire as quickly as possible. Not a perfect solution but should indicate if the bullet movement is contributing to the issue.

Finally as someone mentioned have you tried a filler. I shoot a .350 Griffin & Howe with 41.0gr of IMR3031, that leave quite a bit of space between the bullet base and powder so I use 2 Grains of dacron filler to take up this space. This improved my groups substantially. It holds the powder back against the primer even after firing the right barrel. With out this the powder may be laying in the bottom of the case in the right barrel and be up against the bullet base in the left from the recoil.

Just some food for thought. Be sure to keep us informed on your progress as it helps us all learn...

Good Luck..
DonT

 

[MMAL]

All excellent points. thank you. I got some work to do.

 

[Hallgeir Gravråk]

What ammo are the double regulated with?
I also heard that you shoot the same pattern as the manufacturer.
In my Krieghoff they say that you shoot right, so left, because of the differences in each barrel.
May by this will be different/wrong if you shoot the left , right.
In my merkel Doublerifle drilling with the singel trigger the right barrel goes first.

 

[spike.t]

@Hunt101 never heard of special regulation loads as the rifle maker will usually regulate with factory ammo of your choice...or use factory standard ammo from one maker....they will then supply you with the regulation targets and ammunition make and type used in said regulation as that will be what most owners will then use. And 65 yards is usually what the distance used is. I cant see any builder of double rifles making one and then not letting you know the ammo used to regulate it.....as the whole effort of getting it to shoot correctly is a waste of time....as without knowing the ammunition used you are in the dark......

 

[CTDolan]

In my opinion new double rifles should be regulated with Kynoch ammunition. If an owner chooses to tinker they can take it from there.