Weatherby freebore in Vanguard?

[meatmachineman]

I went back and looked at Lyman #47 Manual (1967) just out of curiosity about what the used then. The then current load for 1967 was: 73.0 grs IMR 4350, @ 2808 for the 220 grain bullet. The 180 gr Weatherby .300 Mag load was 79.0 gr, IMR 4350, @ 3194 fps. My how times have changed! The currrent 180 grain load for IMR 4350 in the .300 Weatherby is only listed at 73.0 grains and just over 3000 fps! Looking at these old loading manuals, I am surprised that I still have all my fingers, considering my age and how long I have been loading?

I just checked my load data from the 220gr gamekings... I topped out at 70.0gr of IMR 4350 and was getting an anemic 2550 fps over the chrony.

 

[Oldtrader3]

My bad, I got twitchy fingers typing, which is not hard for me. I changed it to Edition 44, dated 1967. Back then, they only added new powders and changed editions occasionally, about every 15 years.

 

[Guest]

This is an interesting thread. Thanks all!
For my Vanguards in 257 I worked my way to max loads with no visible issues. For what it's worth, the groups were ok but really didn't get tight until right at what the Nosler book said was max.
Dewey

 

[Oldtrader3]

Most Weatherby's seem to group better at fast muzzle velocity.

 

[meatmachineman]

Most Weatherby's seem to group better at fast muzzle velocity.

Any idea why that is? My only guess at this wee hour of the morning would be freebore. The faster the projectile overcomes that jump, the better to my thinking.

 

[SJB358]

Most Weatherby's seem to group better at fast muzzle velocity.

Any idea why that is? My only guess at this wee hour of the morning would be freebore. The faster the projectile overcomes that jump, the better to my thinking.

I tend to think it is true of alot of cartridges, at least relatively new, high performance cartridges. You are near 100% powder load, the bullet is pushed hard enough to seal into the bore, and the case expands to seal the chamber, so those three lend themselves to overall consistency.. Just my thoughts on it, but I haven't found many that shoot well when you aren't in the 60K range. Not saying it doesn't happen, just it hasn't been my experience with hunting rounds.

 

[Guest]

I tend to agree with you, Scotty, on the whole powder fill issue. I have a moderate pressure load for my 270Wby using 150gr Speers and Accurate 8700 (sadly discontinued right as I discovered this load...) that is the most accurate thing I've fired in any rifle. It's pushing that 150 along at 2900fps, and estimated pressure is around 50-52kpsi, if I recall correctly. Consider that against the normal max velocity for that round with a 150 being in the 3250-3275fps range. But the case is right at full, with almost no powder sounds when I shake it. That's pretty close to 100% with a ball powder like 8700. Case fill is one of the key things I look at when I choose a powder now, because of that load.

 

[FOTIS]

They have too or else there would be a law suit everytime one blew up with a WBY factory round.

 

[BeeTee]

All rifles chambered for factory Wby cartridges should have SAAMI chambers. Otherwise it could be dangerous to use factory ammo.

I've got quite a bit of experience with loading the 300Wby with 7828, at least with the Nosler 165 BT. I've found cases vary considerably. Through the years I've found some brands and lots were soft that showed overpressure early, some were harder that allowed for hotter loads, and some have significant variation in weight.

Last year, we shot some Wby factory 165s over the chrony, which produced just shy of 3300-fps. They were pretty hot loads. It took 83gr of 7828 to almost exactly duplicate the factory rounds (within 30-40 fps). BT

 

[super-7]

I haven't talked to my BIL for a couple years but I remember what he was saying. I guess his Remmy could have a tight spec Sammi chamber, and the vanguard on the looser end of the spec. I admit they should both be a Sammi chamber, some reason there is a difference.
I ran some factory loads of 300 be 200gr PT's over the chrony this fall and had a consistent 3000 fps. I figured 180's we be up a bit , and 165 's would be sizzling.

 

[Rigbymauser]

tend to agree with you, Scotty, on the whole powder fill issue. I have a moderate pressure load for my 270Wby using 150gr Speers and Accurate 8700 (sadly discontinued right as I discovered this load...) that is the most accurate thing I've fired in any rifle. It's pushing that 150 along at 2900fps, and estimated pressure is around 50-52kpsi, if I recall correctly. Consider that against the normal max velocity for that round with a 150 being in the 3250-3275fps range. But the case is right at full, with almost no powder sounds when I shake it. That's pretty close to 100% with a ball powder like 8700. Case fill is one of the key things I look at when I choose a powder now, because of that load.

If you can find Norma MRP, 73 grain to a 150grain bullet will bring .270wea right up where it ought to "Bee".

 

[Oldtrader3]

Norma has a new powder now, designed just for magnum, over bore cases. It is called Norma 217, if you can find it here?

 

[SJB358]

Norma has a new powder now, designed just for magnum, over bore cases. It is called Norma 317, if you can find it here?

That perks my interest a little.

 

[Oldtrader3]

It is supposed to be ideal for the .30/378 and .338/378 and overbore cartridges from .264 on up.

 

[Rigbymauser]

We have a Norma MRP2 which is suppose to be THE powder for truly over-bore cartridges. Haven´t heard anything about the Norma317.

 

[DrMike]

The Norma web site (http://www.norma.cc/en/Products/Components/Powder/) indicates that MRP2 has been replaced by Norma 217. I suspect that the poster mistyped the powder number.

 

[Oldtrader3]

I apparently did mistype the powder, it is Norma 217, not 317.