Hi,

I just bought a Weatherby 30-378 in stainless steel. It looks very impressive for a small caliber rifle. I bought it in hope to covert it to a big bore rifle one of these days. Does anyone have any suggestion about a big bore project for this particular gun? I like the 495 A-Square a lot but again I am also open for other calibers. Would the 500 Jeffery work on this Weatherby action? Since it is a stainless unit, I have to stay below the 60k psi limit.

Any info will be appreciated.

Thanks!
Ming

Ming,

First off,the whole "stainless isn't as strong" thing is bull.You know how much stainless is in that Weatherby?Just enough to make the metal change colors,belive it or not.You can put just as much pressure in a stainless gun as you can a blued gun.Your 30/378 is over 60,000 PSI BTW.

As for cartridges,why not stay with the 378 case and go for the big 500 A-Square?About the same ballistics as the Jefferys (or maybe more?),with cheaper brass.OR,why not just go with the good old 460 Weatherby and have much cheaper bullets?

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"Only accurate rifles are interesting"

I've never heard of anyone buying a 30-378 and intending on building the wby action up to a big bore.
Unless you plan on shooting out that 30-378 barrel and re-barrelling it.
Could've found a cheaper and more direct route in your bigbore pursuits.

Thanks Brian for the suggestion. I talked to an engineer from Weatherby and he told me that their stainless action is not strong enough to take the pressure of a 460 Weatherby. I would take his words for it since it comes directly from the source. I like the 495 AS but will take a closer look at the 500 AS. Does anyone have any real experience loading data for the 500 AS besides those from the AS manual?

Hey Matt77,

What are you saying man? My objective was to have a 50 cal stainless rifle so the Weatherby stainless action would be my choice. I paid less than a $1000 for my 30-378 so what is the big deal.

I know that I could get a 550 CZ Mag for $600 but that is not stainless and this action may even require more work and more cost to build should I decide to built a 495 AS or a 500 AS. Also the Weatherby action is very unique and designed to handle the utra high pressure of the 460 Weatherby (not stainless though)so there is no question about it handling other big bore cartridges. I hope you the picture.

Later!

Ming,
I am assuming your 30/378 is the Accumark wit the fluted barrel?If so that is not a stainless action.Also,the 30/378 is much higher pressured than the 460.A guy on the HA board called and some woman at Weatherby told him the 460 would blow a stainless BARREL to bits!Just because they work at Weatherby doesn't mean they know much.

A carbon steel Weatherby action will take 200,000 PSI but a stainless will only take 60,000 PSI?60,000 PSI maximum rules out every cartridge made by Weatherby on the 378 case,including the 30/378.I should send them a nasty mail condeming the idiots they have working there.

The Weatherby,whether blued or stainless,is the strongest bolt action made today.It will handel any and all Weatherby Magnum calibers,up to the 460 and beyond.60,000 PSI?Gimme a break!Even a 300 Weatherby Magnum is coming very close to that,let alone a 30/378!

Sorry to be steaming about this!

P.S-Mitch has a 500 A2 and loves it.He should respond on here pretty soon.

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"Only accurate rifles are interesting"

[This message has been edited by Brian M (edited 11-26-2001).]

Ming, I rebarreled a 460 wby. to make up my 500 A2. I have owned this rifle for more than 8 years with no problems. Brian is right the stainless Weatherby action can handle cartridges that exceed 60,000 psi, as he stated most Weatherby cartridges exceed 60,000 psi.

Thanks Brian and Mitch for the info.

Hi Mitch,

Please share some of your load development for the 500 A-Square if you don't mind. As much as I like the big bore stuff, I would rather stay on the "mid-range" side of loads. Can the 500 AS be SAFELY loaded with 500 grainers at around 2200 fps? I think this is all I need.

Hi Brian,

My 30-378 is not the Accumark. My is the Mark V stainless with a real stainless bolt, receiver, and barrel. The barrel is not fluted. I think the magazine box is also stainless. It is an awesome looking action especially in stainless steel. I like this action a lot since it has a very strong and massive looking system in the bolt/receiver. I do not know why they told me the stainless is not strong enough for the 460 WB. I will probably call them again to confirm this. I will also check on the young modulus and tensile strength for the carbon steel and stainless steel.

Cheers!
Ming

Ming,
Heck,maybe you got someone who had the same knowledge as the woman who told the other poster that the 460 would blow a stainless barrel to smitherines.Go ahead and call them to confirm,but you shouldn't shoot your Weatherby in the meanwhile,as the 30-378 is higher pressured than the 460,which kind of throws what they said out the window.Like Mitch said,most of the Wby. Mags are over 60,000 PSI,espically with Weatherby's loaded to the max ammunation.

Be sure to ask when you call why the 30/378,which is higher pressure,will work in the stainless gun but not the lower pressure 460.If they say the 30-378 is lower pressure than the 460,be sure to ask for their supervisor or boss as they obviously don't know squat and shouldn't be answering tech questions.

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"Only accurate rifles are interesting"

ming, just that was a first for me.
cruise over to huntamerica and as Jbelk.
He knows a thing or two about guns, and he might be able to help you with these pressure problems and the weatherby lady's claims.

Ming, I am not aware of a good 500 gr. bullet for the 500 A2. The lightest good bullets would be the 570 gr. Barnes X. or the 570 gr. Woodleigh SN. I would use 110 grs. of IMR 4350 or 102.0 grains of Reloader 15 with this bullet to reach 2200 fps. However since these bullets are heavier you might want to slow it down to 2100 fps. if you want to keep recoil as low as possible.

[This message has been edited by Mitch (edited 11-26-2001).]

60 000PSI with ".308" catridge is not 60 000PSI with ".458", simply because F=P.S, so very simplified :

60 000 PSI with .308 bullet create same back force like about 27 100PSI with .458 bullet . . I know it is very inacurate, but for only explanation . . .

When I called a couple of years ago to ask about getting a .378 Weatherby in Accumark, I was told that the reason it was unavailable in that line is that they were having problems with the recoil lug with the big boomers, but they were still working on it. I guess they are still working on it.

I don't want to be rain on anyone's parade, but you must consider feeding on that conversion. Two things:

1. The 495 A2 is shorter than the 338-378 and may not feed properly. THe 500 A2 would be a better choice.

2. The feed ramp of that rifle is probably set up for those pointy little bullets, and you will need to have it widened and recontoured to feed those big fat round nosed bullets.

To continue what Jiri and Wolverine have written, the problem is probably not chamber pressure, but rather the bolt thrust pressure. Just as the recoil of the .460 is greater than the .30/.378, so is the rearward force on the bolt. Since stainless steel is more suseptable to galling than carbon steel, I imagine that there would be a tendency to lock the bolt. Not a good thing on a caliber intended for dangerous game. Incidentally, the thrust issue is why the TC Contender can handle the .223 at 53,000 psi and not the .30-06 at 50,000.

Loud-N-Boomer,

You are correct,but even the stainless Weatherby's still have carbon steel bolts.

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"Only accurate rifles are interesting"

Thank you so much everyone for your info.

Yes, I called WB again and asked their custom shop if they could build me a 460 WB in stainless. The answer was NO due to the strenght of the material but they did not mention anything about back thrust.

Anyway, I think that I will leave it alone or trade it in for a 460 WB should I decide to build a 500 A-Square. I still have not had time to sit down and do some detail calcualtions to confirm the difference in strenght of the material between chromoly and 410 stainless. The modulus of elasticity of 410 stainless seems to be lower than chromely but again a detail analysis would be a better way to comfirm this. Anyway, at this point, it seems like it is a risk that I would not want to take, especially after investing a lot into it.

Later!
Ming