Why I have no idea but I just have to have another 458. The question is how do you get a standard type of throat in the 458 win. My understanding is that standard reamer specifications calls for a very long throat with lots of bullet jump. I would like to have the chamber cut with a standard lead ( spelling) with minimal safe bullet jump with the standard 500 grain RN bullet.

Does that call for a custom reamer.

Dude your back! I want an elephant story!!!

I have hopefully a partial answer to you question. I was checking out the same thing, and of course custom reamers are available. However PacNor shows a 458 no throat reamer available. So I called them and asked about it, and was told that they will cut the chamber, then cut the throat you your specs, and matched to a specific bullet if that's what the customer wants. That's a pretty straight-forward solution if a PacNor barrel will do for you. It works for me.

Alternately, my gunsmith checked his 458 reamer and told me that it has a 3/10 of an inch throat. I think that's .030", which isn't SAAMI spec, I think. Yet he has made several 458 WM rifles, to shoot a variety of bullets.

Now, I hesitate, since I'm not sure which way to go. I'm still thinking about it.

KB

Hope you guys don't mind if I put in my experience here? While I worked at Gander Mountain, Winchester was kind of trying to "sort out" their problems with high heat conditions/pressure plagues they were dealing with.

We sold a PH from ZIM a 458 which he took out and chronographed it with factory ammo...about 1800 FPS!....really!

The throat was REALLY long. As a service to him, I set the barrel back two threads,and rechambered with a shorter throat...velocities came up close to factory advertised.


I always felt a little uneasy about that job..but I couldn't see him backing up a bad shot with what was essentially a 45-70.

I THINK the 458 woes are behind us, but would sure like to see latest SAAMI specs (I suspect they've changed a lot over the years)..maybe not..maybe just powders??

By and large, the 458 is a great cartridge..maybe growing pains?

Kabluewy

3/10 of an inch would be .300 not .030.

Thanks for the replies. My gunsmith has the barrel but has never chambered a 458 before and will need to rent/ buy a reamer. I have an old mark X 458 that I believe has the long throating. and it gives less velocity with factory ammo than my 458 Lott does.!!!.

bwanamrm. Yep back and still kicking. I'll give you a call.

glad you made it back... tell the story....

els,
You might keep in mind some of the .458 bullets are two diameter bullets. The nose is land diameter.Nothing ahead of the cannelure is larger than .448 to.450. The shank behind the cannelure is the only full .458 diameter on the bullet.

quote:

Originally posted by SR4759:
els,
You might keep in mind some of the .458 bullets are two diameter bullets. The nose is land diameter.Nothing ahead of the cannelure is larger than .448 to.450. The shank behind the cannelure is the only full .458 diameter on the bullet.

I didn't know that! I'm partial to woodlieghs and hornaday bullets. at my first chance I'll measure them.

When you buy/rent a reamer does it come with a fixed throater. Or can the Gun Smith chamber and then throat in a different operation?

quote:

Originally posted by els:
When you buy/rent a reamer does it come with a fixed throater. Or can the Gun Smith chamber and then throat in a different operation?

A typical RN .458 bullet will measure .458.

If you buy a reamer off the shelf it will come with a fixed length throat. You can have a custom reamer made and specify what length throat you need. If you rent a reamer, it will have the throat fixed. I grind the throats off my reamers so that I can set the length of the throat to whatever the customer needs using a separate, minimum diameter, low angle throating reamer.

On .458's I try to keep the throat as close to 1 diameter as possible, plus, the one and a half degree leade. If I need more, I can come back in and increase it.

thanks Westpac. I will have to see what kind of reamer we can find.