300 H&H in a 300Wby question

[lksmith]

I have recently acquired a Weatherby Mark V Deluxe in300WBY Mag which I just couldn't pass on. It was $600 with Leupold bases on it, action was smooth. Only problem I have been able to find is that the floor plate and last 3" from the muzzle had the bluing worn off obviously from carrying and sliding in and out of a case. A few mins with some oxphoblue and it looks new.
I was able to get a box of Weatherby ammo for $30, which I have since shot and reloaded at least 20 times apiece. I have been looking and would prefer to stay with Weatherby or Norma (Norma makes/loads Weatherby ammo) brass since I have read that other brass (Rem. etc) have less case capacity so would have re-work up my load for the different brass.
Looking at Midwayusa 300 weatherby is not available from Norma or Weatherby but 300 H&H is and is the same price.
The load I am currently using in the weatherby is 88.0grs RL22 (Lyman manual says 90.0 Max safe), under a 150gr Hornady SST. Average velocity is 3,636fps with a Std Dev of 20fps XS of 62fps not perfect but only 1.7% of my velocity (Normally load for under 1%) and will certainly suffice for the upcoming season that has snuck up on me
With 300 H&H being the parent ctg to the Weatherby can one safely load and fire 300 H&H (with 300H&H data obviously) in a 300WBY to make more Weatherby Brass?
I have read in several places that it is safe, especially given the lower operating pressure of the H&H and the strength of the MkV action, and the brass being never fired virgin. Also the tolerances of the two overlap on the length and both head-space off the belt

[oneokie]

Yes, the fire formed cases may be just a bit short.

[Clay M]

Cabelas has the 300 weatherby mag ammo in stock.I shoot a 270 Weatherby and it shoots great with the factory ammo. I chronographed the 130 loads at 3650 .I have never been able to get close to that with handloads.They use a powder that is unavailable.The only thing I have noticed is you have to keep the copper out of the barrel.It tends to build up quick at those speeds.

[376Steyr]

Fireforming 300 H&H in a Weatherby chamber is okay to do. I have to ask, why are you so certain that Norma H&H brass will match case capacity with their Weatherby cases, but Remington brass will not? Have you actually weighed any Remingtons?

BTW, Grafs has Weatherby brand brass in stock today.

[lksmith]

Fireforming 300 H&H in a Weatherby chamber is okay to do. I have to ask, why are you so certain that Norma H&H brass will match case capacity with their Weatherby cases, but Remington brass will not? Have you actually weighed any Remingtons?

BTW, Grafs has Weatherby brand brass in stock today.

no remington cases to weigh but the Norma and Weatherby cases are the same according to the Weatherby website.
I don't recall offhand where I read about the differing case capacities though

[NVScouter]

I have about 200 pieces of Weatherby brass and around 300 Remmington brass. I think the Remmington is a bit softer but case fill is the same. I really like my Remmington brass. I also bought Remmington brass for my 375 H&H and perfer it to the Norma. I only shoot cast in that so even my stout loads arent a hard on the brass as factory ammo.

The 300WBY was designed to take comercial 300 H&H and shoot it if need arose.

[lksmith]

I tried the 300 H&H with a mid-level load of 63gr of IMR4064 with the same weight bullet since I had the most of that on hand and it worked beautifullly. Despite being almost 500fps slower it shot to the same POA as my Weatherby loads and aside from the headstamp you can't tell which started out as 300H&H and which started out as 300Wby.
Thanks