I'm thinking of building a .300 H&H using a Winchester Model 70 .375 H&H donor action.

I know that a 30.06 barrel can be re-chambered to .300 H&H and that .300 H&H only needs a 24" barrel with the same 1:10 twist, but can I take the barrel from an Model 70 30.06 rifle and use it on the .375 H&H action.

(I'm also planning to re-barrel the 30.06 action in 6.5x55SE.)

Both donor actions would be new post 2012 CRF.

Any advice greatly appreciated.

stoats_tail

Depends on if the extractor cutouts are exactly the same.-muddy

I talked to a gunsmith about this once and his take on it was they would probably all need to be set back and rechambered. He cited the iron sights and extractor cut for the reason and said I might want to think about another barrel as the labor would be about the same.

All pre 64 Win 70 barrels were the same shank except 22 Hornet; there was a high chance of interchange.

Post 64 Win 70 pushfeeds had only one shank size/style and would interchange well.

Classics with CRF had only one size/style shank and would interchange.

The FN's have differing threads depending on calibers. I would almost bet that the shank is the same size/style on a 30-06 and a 375 H&H

The threads are the same but what is the chance of the extractor cut out lining up? Same for the irons assuming it has them.

P.S. It's a question, not a statement. I'm not a gunsmith.

Food for thought. Unless the donor .30-06 barrel is a proven "good shooter", you might be money ahead to go ahead and just buy a new high quality barrel. Nothing more frustrating that spending good money having a used barrel re-fitted, only to find out that it is only a marginal shooter, or finicky about which loads it likes.

Don't ask me how I know this...

Thanks guys for all of your comments - you kind of echo my own thoughts!!

Both donor actions will most probably be brand new - a Super Grade in 30.06 and a Safari Express .375 H&H out of the FN factory, so no issues with iron sights, just the extractor cut out, and the 30.06 will be rechambered to .300 H&H anyway.

Obviously the ideal solution would be to put custom barrels on both (definitely happen in the long term) but just exploring the feasibility of making use of the super grade barrel as a means of getting the .300 H&H sooner/in time for a planned trip to Namibia in 2017.

I may end up just taking the 30.06 (plenty of gun for my trophy shopping list) and adding a couple more trophies to the trip!!

I'll sound out the gunsmith and let you all know his response (I anticipate a lot of tooth sucking!!)

Happy hunting!

Stoats Tail.

I've got a pre 64 270 FW barrel that has been on and off an action just to see of it would shoot. It does and the extractor cut out indexed correctly. Headspace was also fine.

My smith says sure it can be done if everything lines up.

Pre-64s are timed so that you can take the barrel off one action and it will fit on another action just fine. The model 54s were the same. Any gunsmith that tells you that it will need to be rechambered? Just fishing for your money.

That is not the case with Post-64s, they are luck of the draw. Too bad!

RickF is correct. The Pre-64's were timed and all will fit to any action. Weatherby's are also timed.

Not true at all. Most pre 1954 with swap no problem. 1955 and later also had bolt faces relieved for final headspace instead of reaming chamber deeper. A deep chambered pre 1954 barrel and a 1956 with a deeply recessed bolt face is not gonna headspace.

ETA: That combination is most likely .015-.020" over a NoGo. Been there and done it too many times; bought the T shirt.

Most pre 64's have like a 99.5% chance of indexing properly, as in sights and extractor cuts. Headspace is as above.

ETA: Strictly an assumption. I would think QC will let the newer ones swap just fine.