What has been your experience with best load/bullet in this barrel?
What about diameter, are the TCs typically 0.375"?
Larger?
Smaller?
A friend tried cast in his Ruger # 3 and it would NOT shoot any cast bullet well. It would stack the 220 Hornadys though.

Any other good choices for jacketed bullet loadings in this caliber?

From one factory and one custom shop .375 Win., cast bullets were pretty much a joke in the accuracy department. Jacketed bullets could be counted on for 2-3" groups at 100 yards. But when I picked up a used .375 Winny barrel by Eabco, which had the same twist as the 38-55 Ballard rifles, cast bullets and jacketed projectiles alike gave wonderful accuracy. It would print 3-shot, 100 yard groups in the 3/4" range with just about any load I cobbled together -- and that's not too shabby for a big-bore caliber with hunting ammo.

Aside from the 220 grain Hornady, the 200 grain Sierra does very well as the velocity level attainable by this cartridge in a pistol-length tube.

Sorry...forgot one of your questions.

As to the diameter, you'll be best served by slugging you own barrel. I've checked several TC factory .375 Wins over the years and there seems to be a pretty wide discrepancy -- enough so that the task of slugging it would be worthwhile if you plan on shooting cast bullets quite a bit.

What I found in mine was the twist rate is really too fast. It would shoot cast gaschecked bullets with very good accuracy if they were cast really hard and driven no faster than 1200 fps. I won quite a few IHMSA bigbore matches with that barrel. (14 inch factory TC) but you could forget plainbase bullets or trying to go very fast with them. Herco worked quite well for powder, as did FFFg black powder. I used the Lyman 280 grain gascheck mould, shot them as cast at about .379", the chamber is plenty loose to release bullets that big. I had a Browning 38-55 at the same time that needed them that large, so never bothered to size them down for the Contender even though it slugged out at .376".

Hey Guys . . .
I guess you realize this is NOT what I wanted to hear!
Dang I had hopes for that barrel as a cast bullet hunting barrel, but it appears that I may have just a jacketed bullet shooter.
That was not the plan, but then many plans go to H_LL when put into motion!

Oh well I hope I can get something to work with the 325 Cast in the 45-70s.

I had a 375 win up till a couple of months ago.It was a great shooter with 200gr or 220 gr jacketed bullets .A buddy gave me a box of Mount Baldy 265 gr hard cast bullets in 375 caliber.I tried for a while to make them shoot but nothing worked unless I slowed it down to around 1000 - 1100 fps then it was still shooting a 5" group at 50 yards.I gave up on the cast bullets.

Sounds like everyone's results have been about the same with cast bullets in the factory .375 Win barrels. But get a good barrel with a real throat and the proper (slower) twist, and it can stack them nicely no matter if you are shooting cast or jacketed projectiles.

Bobby; To get decent results with my 21" Contender I had to go with a .381 dia 265 gr from Dan Lynch @ Mountainmolds.com 1 1/2" - 2" @ 50 yd in the 1500-1700 FPS range. Don't completely give up on cast in that .375. Fit the throat and use a big meplat.

Yancey-Thanks for the info. I will pass it along to the local .375 Win. shooters. But for me, it wouldn't be worth the hassle as I don't shoot the larger bores in the TCs very much. And when you can get a used custom barrel for about the same price as a new TC factory version, I always opt for the custom barrel. Then, you don't have to try and compensate for a misaligned chamber, a sloppy throat or the complete lack of one...

Read this thread a while back, nothing to add at that time.
I have since then dug mine out and fired right around 150 rounds through it. I had some 375WW brass and used that for the most part, had some 30-30 brass so I went that route also. I slugged this barrel and went with a .377 sizer. The bullet I used was a Lyman #375449 cast of WW and FWFL lube.
I pan lubed about 10 as cast, could not get them to chamber at that size, did nothing further with them. This was with the 375 and reformed 30-30 brass.
I then put all of them togeher with the .377 bullets and a load of SR-4759. I forget off of the top of my head, but it was in the Lyman book as a start load along with being their accuracy load. Closest thing I had shot to this was a 35 Remington rimmed with 180's. Recoil was some what more than the 35R but not bad. Got this thing on paper at 50 and went to 100M. I was suprised as to how it shot considering some of the comments I had seen here along with other places. I did what little load work with iron sights, no scope. I averaged right around 2"+ at 100M.
I wanted this for the following weekend for an IHMSA match an had decided to shoot all cast bullets if I could. So I didn't have time to fool with it much, got lucky again maybe. I ended up with a 36 in unlimited with this gun. Not bad for me considering I had not shot any iron sighted stuff in this catagorie since 96". I missed the first chicken, my fault as i knew I had to hold way low as I couldn't get the sight set up to go an lower. I then missed a pig at 100M, my fault again. Then here is the kicker, nailed all 10 turkeys at 150M. I hate turkeys! After that I could have missed all 10 of the 200M targets and I would have been happy. I missed 2 rams at 200M no big deal as a hit with these heavy bullets any where will take them over . I am curious as to what is going on at 200M with this combo. It shoots pretty flat out to the 150M line but needs a bunch of elevation to get to the 200 line. So my conclusion is that it may be dropping to sub sonic and getting a little wild. The shots were some what scattered on the rams considering that I nailed all the turkeys.
Like I said I had my doubts on the 375, but had read a lot of negative on the 35 Remington in the past. I also am to the point of thinking that store bought cast bullets are not real user friendly when it comes to needing sized to the right diameter. I had shot a few bulk cast bullets in different calibers, more leading with them than I have ever had from ANY of my cast bullets. I am also liking a little softer lube more and more. You have to watch the heat in hotter weather, but seems to be worth it. 4-5 patches of Kroil through the bore and it is clean as a pin.
Jeff