Finally getting to shoot my Searcy 375 flanged. I started to work up a load for it when I first got it and noticed it was piercing a few primers. Sent it off to Butch and he fixed it up. told him I was shooting 270 grn bullets. He worked up a load, but I cant find where I saved that. Will e mail him later.

anyway, I'm using the old GS custom bullets with no driving bands. (mostly because I have about 200 of them and run 300s in my bolt gun) 59.5 grn RL-15 running 2450 and a little less. 26 inch barrels. Rt barrel shoots almost 1 inch at 100 yards off both sand bags and my shooting rest. left barrel is 6-7 inches off to left and 3 -5 inches higher. Yes I realize the doubles are not "long range" guns, but would like to be a little closer if possible. If I understand correct, if the bullets are spreading, they need to go faster?

So question's are,
Should I try a lighter bullet
Different brand of bullet
Push these a little faster even though most data I can find has 270 grn bullets' no faster that 2500 fps and I generally don't like to load to max with these type of rifles.

This shooting is with leupold 1.5-5. would put a red dot on it if there is a mount made for it.

thanks for any thoughts in advance.

My advise is to get the load from butch if he has it and not use up bullets and powder. If you really can't wait,lol, try a couple loaded lighter with the same powder. And if that doesn't help try switching powders

375 Flanged can be touchy. I would get the load from Butch. And I personally would add a couple grains more powder and see what you get. Faster should pull the groups down and closer together.

If you can get your hands on some RL-17 I would try that as well. It was the ticket for my 375 Flanged.

https://imgur.com/3DQW3yc

So went to 250 ttsx at 54 yards. first two shots 2400/2384 rt to left, skipped a grain of powder then second two shots 2507/2548. Same POI. Gun is very accurate with just a few rounds so far. I guess the best I can do is split the difference and keep track of spread if I have a long shot?

I think you can do better. With 250's I would speed them up another 100-150 and see what happens.

From memory my Heym took close to 300 rounds before I found a great load.

I would assume that Butch regulated your gun with a 300 grain bullet? I would start there.

Try some Norma factory loads or load their equivalent from their data. Norma 203b powder is apparently a lot of RE15 which is what I use.

Haven’t shot mine (H&H double) for a while, Covid, too wet, but found just over 2400fps with a Woodleigh 300gn to be good.

Each one seems to have a mind of its own!

Yes, get the load from Searcy. I have a 450 from him and only that load works, and it works very well.
Now, the regulation of DRs is not just velocity; it is how the bullet got to that velocity that matters just as much, and how much recoil is produced in the process. Totally unlike a bolt action; many DR shooters get frustrated trying to "develop" loads for one,
It don't work that way.
Velocity, muzzle flip, and jump, are all vital components of the regulation process. Which is why changing powders doesn't work, even thought you got the same velocity.
If you are spreading shots, you need less recoil/ flip, or more speed, thereby sending the bullet from the muzzle earlier in the recoil cycle. But if more speed means more muzzle flip, then it becomes counterproductive. Maybe a faster powder. There is no formula; it is all trial and error. But there are rules. Loose ones. But important NTL.

Before you do all his. shoot 4 shot groups with each barrel, the worst grouping barrel is all you can expect and are going to get..Now with that information in hand you can put together a proper load for that rifle..If not come on down this summer and we will get-er done...Most doubles are partial to Woodleigh or Hornady's close copy. Butches loads are all with Hornadys these days..H-4831 or IMR4831 and Rl-15 as a rule...Ive done a number of doubles and Seacys are the most accurate doubles rifles Ive shot..Butch won the double rifle trials with my 470 and wanted it bad, so he built me a 450-400-3" and it shot as well, the 470 an inch for 4 shots, the 450 shot shot 1-1/4" on my 70 yard range..Ive never seen any other double that well...I find 3 or 4 inches the good norm..about the size to fit a buffalos eye socket..