Looking to start a 458x1.5 build on a 110. Anybody done it?

Hello all,

First off, let me thank you in advance for your advice/help :)

I did try to search the forums (as any forum newbie should...) but I didnt find anything on building out a 458x1.5 (also called 458x1.5 Barnes)

I've got a 110 in 300 Win Mag that I'd like to use as a donor action, and here is a small list of questions that I've come up with so far:

• Has anyone bought a breech threaded barrel with a .458 bore (but not chambered) and if so, from whom?
• Instead of renting or buying a reamer, could I just bore/machine the chamber? I have a suitable lathe.
• What twist rate would you recommend to stabilize ~300 gr bullets. A bit of light research looks like 1 in 12" or 1 in 14" twist rates.

There are plenty of down the road questions about headspacing and feeding from a long magazine with a short round and.....
but for now, anyone got any advice to get me out of the gate as far as buying he necessary raw materials?

So thanks in advance, and apologies for dumb newbie questions you're likely to get if you respond :D

Thanks again,
Dave

To my knowledge it hasn't been done by anyone here.

Several thoughts on my part:

You would be wasting a long action and asking for feed trouble using it for 300grn bullets. If you want to use the long action just do a 458 Winny and down load it. Lot less trouble than what you're asking for.

If you really want one though, I certainly understand that!

I would go with a short action though and build from there. Feeding issues would be much easier to fix.

To my knowledge no one builds unchambered barrels unless you spec it that way.....which some will do then. You need to use a reamer to chamber with.......It is possible to chamber like you're talking about but unless you are a VERY experienced machinist or something like that I WOULD NOT even try it. Even then you would need a throater after chambering. Not sure where you could find a reamer to rent.......you would have to special order it. Then you have to consider dies.......

You want to LIVE after you pull the trigger one time.

300 grn bullets do not require a fast twist rate but the cartridge you're wanting to build was used to shoot special 458BT bullets at subsonic speeds during the Vietnam war. It was developed by Barnes for that purpose. This info is on the 10th edition of COTW book. If it were me, I would use a fast twist rate such as what you're looking at for the purpose of launching those big heavy bullets subsonic, just like the round was designed for.

If I were you, I would start with something a bit easier to build so you can get some experience at doing this kind of stuff before doing something this specialized.

What ever you decide to do BE SAFE and have fun!

On the 300gr .458 bullet, in the 45-70's I have a 1-20 twist is more than sufficient to stabilize 250-500gr bullets.

I agree a "machining" the chamber, it's not just a straight hole. The case taper is very slight and the throat for the bullet to start it's way into the rifling is also part of the reamer. I would ask what the purpose of the build is? There are some reamers around for similar, but slightly larger rounds (458x2) but are more common and might cost a lot less. Getting a rifled blank, and having it chambered and threaded would be my advice. Wildcatting isn't usually cheap.

This is a cool idea. I think the reamer may be the easy part. I'm not familiar with all the .458s, but one of them may have a straight case and you could just run one in the length you want. If not, it would solve the throating problem. Then it would take custom dies.
I agree a short action would be best.