[i][/i]To keep it short: acquired a rem mod 721 that Was chambered in 300 H&H mag, it is now in 300 win mag. The question; would a smith just ream out the chamber leaving a long throat? Or do you think the barrel was removed and the threads cut back some and reinstalled? The barrel is still 26” long.

Shoot it, the brass should fire form and you can look it over and tell maybe. Compare to a factory load.

barrel should have been cut back, thee 300 winny is fatteer at the shoulder than thee 300 H&H, and is shorter.

The previous owner should be jailed. I have a 721 in 300 H&H and it is one of my favorite rifles and calibers.

X2.

I hear yuh! But for $100 with a vortex scope on it? Why not?

3 different boxes of factory ammo only produced 1.5-2” groups at a 100 yds.

best and safest way would be make a chamber cast, you will know for sure then

Thought about doing that as well.

I do have dies, and thought about seating a bullet far enough out of the neck till I contact the rifling.

I have a suspicion that this rifle has a long throat and will take reloading with 200-220 gr bullets to be accurate.

Certainly wouldn't hurt to have someone with gages check the head space.

Cotton's suggestion would also be valuable.

So you think the barrel was shortened but its the same length??? Really??

Sorry, was referring to what would be the protocol for a procedure like this. Normal to cut back one or two threads?

the 300 H&H cartridge case length is 2.850", the 300 winny is 2.620, so to do it right a couple threads would have to come off to rechamber and have the proper leade

Weatherby calls it Freebore.

X3. Just can't fathom what some people are thinking.




For $100 into it, one can afford to put a new barrel onto her and have a shooter.

Probably had trouble finding H&H ammo and saw 300win on every counter so had it rechambered.

Ridge runner is right, probably took 4-5 threads off and rechambered it.

The difference between the length of the Win Mag and H&H is less than a 1/4". Factory rifles with a claimed 26" barrel are often more than 1/4" over or under 26", depending on manufacturer. So without having another rifle of the exact same model and caliber available to compare it to, I doubt he can tell if the barrel has been shortened with a tape measure.

Load a dummy round (no powder or primer) with the bullet seated way out and chamber it to see how far out it is to where it contacts the lands. May have to try this a few times seating the bullet at different lengths, but you can get a fairly accurate measure of throat length this way. Some guns/bullets shoot well with a significant jump to the lands, others not so much. That freebore does reduce pressure (why Weatherby designed his magnum rifles with so much of it) but can affect accuracy, it doesn't always though.

If your shooting abilities are decent, then you need to have some work done to it. If a gun like that can't be made to shoot under 1" at a hundred yards, then you don't have much.
I'd find me a competent gunsmith to take a detailed look at it and pay him to either rechamber it again or have him put a new 300 win mag barrel on it.

Ditto.
The 300H&H is one of the sexiest cartridges ever made.

Personally I’ve never liked the magnum .300’s in any configuration. Only thing worse are the hopped up 7mm’s. My .338 win mag and my .375 H&H are my babies!!