I am getting groups about 3.5" to 4.0"(max) center to center, same elevation, left barrel and right barrel are consistant. Is it possible to bring the grouping closer through loading or is this usually a regulation issue. This is a Sabatti that was redone, sorry to cause grief, I understand the difference in quality betwen rifles. Our Merkel 470 is much more accurate, but just curious if anyone has worked up loads that tighten up the spread of the right and left barrels. I'm shooting left handed and the left barrel is dead on for me at 50 yards, the right barrel is consistantly shooting to the right. Triggers have been worked on and are really good now, which has helped out with the shootability(along with adding a Kick Eze pad). Thanks for any guidance.

You are practically there; I have found that faster powders produce less recoil (Using less powder) and causes bullets to leave the muzzle before flip and jump flings them out. This is assuming you are at max velocity now. Sometimes this brings the bullets together. If you aren't at max velocity, increase it.

I am using IMR4007 SSC, I still have some more room to increase. I really appreciate the help. I'm seeing no sign of pressure either. The primers look great and no sticking of the cartridge during extraction. I've not noticed any witness marks on the brass that would cause concern either. I love shooting these big doubles, but doing them both in one day is like be in 15 to 20 car accidents in a day...lol. People at the range like to look, but nobody wants to help with pulling the trigger. I'll try speeding them up a bit.

dpcd is correct about powders. In my Sabatti 500 the best regulating loads were with RL-15. Everyone holds guns differently and the way the guns moves when you are shooting it can make barrels shoot apart. Michael458 worked up a really nice regulating load for my 500 while he had the gun using WW760. He shot perfect 1.5 groups with that load and when I tried it I was shooting 3 to 4 inches apart. I switched to RL-15 and got perfect regulation for me. You might also look at trying a lighter bullet if you can't get the barrels to come together at speed. Dan at CEB made me a run of 475 grain non cons and 510 grain solids for my Sabatti. These shoot great and in the same group as the heavier bullets in my Sabatti 500. These also recoil in this light weight gun.

What speed is your current load. My Sabatti likes them at 2100 or more. My VC 500 likes a lower velocity of around 1975 which is about what all current factory ammo is.

Have you looked at the 500 nitro work Michael458 and I did in the 500 A New Exploration thread? Lots of load data there that might help you.

I just printed the load data out, I'll be reviewing. Thanks for posting the data. I've got to get another chrono, I thought I could get by without one after I cut the wires on my old one. Finding out it's hard to do without. I've got plenty of RL-15 for several other cartridges I reload for, so this would actually be a better powder to spend time on. I kind of used a shotgun approach this time, and decided to try RL-17 and IMR 4007 SSC. Probably getting in too big of a hurry to get a load worked up. I've gotten spoiled with some other guns that worked well with my starting loads. I'm no longer a member of a club, so I don't spend as much time at the range as I used to. I may have to change that, I miss shooting, and I have a range/club within 2 miles of my house. So far they have let me stand while shooting, much better than trying to bench rest...lol.

All of our 500 NE work was done with my Sabatti. Even though velocites should be close to your gun every barrel is different so they will vary. The main thing is to find a load that regulates for you in your gun and at a pressure that would be safe. Velocity is not really a concern. Factory ammo is around the 1975 fps range so anything from that to 2150 fps should be fine.