I have a double rifle in 450/400 3". The dilemma that I have is a problem that is fairly common with rifles that have been used a lot. My right barrel has more wear and slugs .412, the left barrel slugs .411. Cast bullets are generally .001 over bore so do I go for .412 or .413?

I would try a few, 15 (+/-) or so at "0", plus one and plus two over to see just what is what...if there is any noticeable difference in grouping it should show up. I would pick the best size for each individual barrel then load for the individual barrel and color code the cases. You can also have separate sizers made and cast maybe plus 3 over then size back. I would have to have more information to actually advise, but not being a doubles man I would resort to individually testing.

You basically have two rifles...what would you do if the barrels were on separate receivers? Just treat it like any other rifle you have and want to get shooting cast bullets, you never know just what will happen until you make it happen.

You have to do a bit of shooting to see if the small amount of difference actually causes a dustup. I have a 458 American levergun that needs 0.461" over bore size for my 425 gr Accurate Molds GC cast lead bullet to shoot accurate enough for me, but the Oregon Trails 430 GC shoots great at .459" right from the box...go figure.

Good Hunting

you know your barrels diameter which is good to know.
the real question is will a .412 or .413 diameter bullet chamber in both sides.
if they will take 413 then I'd just go with 413 and start load development.
if not then 412 it is, either way is fine, the first is slightly more preferable.

Having just started casting for my 470 and also reading Graeme Wright again (4th time?) I do not see a problem using the same cast bullets in both barrels. Charge weight might vary a bit but you just may get the correct regulation.

Another option that should work is to cast at 412 and size them and powder coat them to 413 for both barrels.

I would get the NOE bushing dies 0.411 and powder coat.

I doubt a thousandth is going to matter, a cast bullet should not be effected by that small difference in constriction. Go with the 413 if it will chamber. I have the same situation in my 577/500 and the bullet sized for the larger bore does fine in both. I would avoid as much as possible different loads for each barrel.
Best.

I agree with the sentiment here....a thousandth or two will be insignificant. At the practical ranges for which the rifle is to be used....likely the group size differences will be immeasurable! memtb

I am way too lazy to have different loads for each barrel, but that would be a good idea for developing max accuracy. One of the problems is finding .413 400 grain bullets. It seems that most of the commercial castings are for 405 win and are in the 300-350 grain range. Now, for as little as I would need them, it would be easier and cheaper to buy them. From my searches, .412 is about as big as is commonly available, unless someone here knows of a source. I would think that a gas check bullet would be best as my bores are pretty good, but not perfect, considering all the years of Cordite use. I used to cast my own handgun bullets, but lost all my casting gear in a shop fire years ago. I think that Y'all are correct on starting with a .413, but I may end up with .412's as at least they are available. Thanks for all feedback.

Take a look at Accurate Molds (Utah, USA). He lists hundreds of different molds, and will custom build. You have almost unlimited choices of bullet design and weights....in aluminum, brass, or steel.

I had him build me a 4 cavity mold....2 cavities for my 460 S&W, and 2 cavities for my 45-70! memtb

http://accuratemolds.com/catalog.php

http://missouribullet.com/deta...ategory=5&secondary=

These are already powder coated & nominally .411 but should measure .413 with powder coat.

Should be great for practice. You will need to play with loads to get it to regulate.

I got some 340gr for my 470NE and I did the powder coating as I made the mistake of not specifying what I actually wanted. I had to boil out the lube 3 times!

Very cheap bullets for practice & plinking. they should be fun to hunt deer & hogs with.

quote:

Originally posted by lee440:
I am way too lazy to have different loads for each barrel, but that would be a good idea for developing max accuracy. One of the problems is finding .413 400 grain bullets. It seems that most of the commercial castings are for 405 win and are in the 300-350 grain range. Now, for as little as I would need them, it would be easier and cheaper to buy them. From my searches, .412 is about as big as is commonly available, unless someone here knows of a source. I would think that a gas check bullet would be best as my bores are pretty good, but not perfect, considering all the years of Cordite use. I used to cast my own handgun bullets, but lost all my casting gear in a shop fire years ago. I think that Y'all are correct on starting with a .413, but I may end up with .412's as at least they are available. Thanks for all feedback.

Lee, I had really good results with 300 grain WNFP bullets, .412 as I recall. I used 5744 for powder puff loads, maybe 1600 fps. I can check for you. They regulated perfectly, just needed to flip up second sight. No recoil, but really smacked hogs and deer. Bob

https://www.montanabulletworks...cbs-82086-400gr-bps/

These are .411 but expensive at $30 for 50 bullets.

Some 405 users have been using RCBS 416-350GC cast bullets sized down for their needs. My rifle slugs 0.4125" and I size my bullets using a 0.414 sizer. It fits and chambers well in my rifle. The bullet weighs in at around 370gr when checked and lubed. How that would work in a double rifle is another matter.

I'm all ears here. I have a 9.3 double coming to load for. I have cast in the past but mostly before powder coating became more common. Looks like a lot of good suggestions here.
I just reread Naki Hunter's post above. He mentioned Graeme Wright's book. You should get it and read it a couple of times. There is a lot of data and other rules to loading for doubles in that book. I'll say you probably will find something useful in it. Good shootin. Packy

Powder coating is the way to go. Easy and no mess. I am glad I learned this so quickly. You can see my posts on my thread here on casting.

quote:

Originally posted by packrattusnongratus:
I'm all ears here. I have a 9.3 double coming to load for. I have cast in the past but mostly before powder coating became more common. Looks like a lot of good suggestions here. Packy

I bought a 320 and a 400 from LBT for my 450-400, just tell Veral what size you want, he will do it. Mine cast at 412 with WW, changing to 1/20 went to 413. Got Lyman sizers from Buffalo arms and Lyman m-die style 2 step expander dies from them as well. Hornady seater has a 413 crimp ring in it, they will supply different sizes if you want them. And the 2 step expander guts will screw into the Hornady seater.

If Veral is out of pocket,I can cast you a few + you can size them yourself ;N/C. Glad to hear that Veral is not still "working for the gov."I wish him well.He has helped me numerous times in the past w/ custom moulds,+ lube. I made a point of buying lots of lube from his wife.Everyone has to eat,right?