Bullet choices for a 300 wby Mk V

powdergun

powdergun

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I have a Mark V weatherby in 300 wby mag that was handed down to me. It is a 70s production Japanese manufacture and a beautiful gun to handle and shoot but I have never really gotten the best accuracy out of it. 1.5 to 2" groups are about as good as I have been able to get. Decent but compared to the other guns in the rack definitely not up to snuff.

My question is what bullets do you folks use in this set up and what have you managed to achieve.
 
I hand load for my brothers Weatherby 300 in a Old school Sako...180 gr Nosler Partitions over 86gr IMR 7828...Groups MOA if you can handle the wallop @ 3250fps Plus...I remember his first shot after the load development that day...A crow at around 250 yards with a 2.5-8 Leupold.
 
I am using 200gr Nosler partitions, and Reloader 22 for powder. It's a hunting rifle, not a target rifle. That said, I have got the groups down to about 1 MOA. Accuracy was hit-and-miss until I restocked the rifle and had it properly bedded. Prior to that, I would get tight groups, then loose groups, at random. It's pretty consistant now.
 
The .300 Weatherby can be quite sensitive to bullet choice due to the free-bore. The easy way to de-sensitize it is to use flat based bullets and those with long bearing surfaces. Hornady Inter-locks for cheap practice and deer sized animals, Nosler Partitions for everything, or if its really being a prick the TSXs seem to thrive on the long jump. They will domesticate a wild Weatherby.

I'm not saying that the Weatherby won't shoot boat-tail bullets but don't be too surprised if it doesn't.
 
180 partitions here in mine.

70s mfg may have extra long freebore. Just something to be aware of. So don't even worry about the lands.
Mitigate cartridge run out and a leap don't hurt as long as the pole vault to the lands is a straight one.

As mentioned above. Flat based bullets, namely the partitions seem to respond well to more pressure. So don't pussy foot around. But work up safely and slowly.
 
I use Hornady 180gr SST's over 67gr of AA4350, Fed 215M primers, & Remington cases. Best so far 0.50" group at 100yds. 3 shot 1.25" group at 300yds. Rifle Weatherby Synthetic Vanguard VGD2. I have other bullet mfg's I was going to try but with results like these I don't think that's necessary at the moment. The 300 mag series of rifles (Weatherby, Winchester etc) were designed to work best with the 180gr bullet. Not saying that others are not good choices but that was the original idea.
Obvious question but have you verified that all screws etc are tight, barrel free floated, crown not damaged, etc, etc? How much was it shot in the past if known? It may need a scrub with something like JB Non Embedding Bore Cleaning Compound. Brownells has it.

Don't forget Weatherby rifles have a bit more free bore.

Memory's a little rusty here but I think the excessive "free bore" was more to do with the earlier FN and later JP Saur mfg Weatherby's before Howa took over production. Current free bore is .361 for 300Wby. Chime in if I'm incorrect.

Here is a quote from Shilen Rifles Inc " Weatherby rifles come with about 3/8ths of an inch of "free-bore" in them to help compensate for the high pressure the factory ammunition develops. If you intend to shoot factory ammunition in your rifle, then stay with a factory length throat as shortening the throat will probably show little or no increase in accuracy and may even prove detrimental. In fact, in Weatherby cartridges, this free-bore is necessary to avoid pressure problems when using factory ammunition" rifles.

If you seat the bullet too far out the neck tension may not be enough. Most people I have talked to that own Weatherby's seem to agree that seating a factory depths offers the most consistent accuracy. Don't forget though you have a hunting rifle and not a bench rest rifle so an inch to two inch isn't a bad group. The animal receiving the round isn't going to complain that your bullet hit 0.50" off where it was supposed to be (assuming your shooting within 200yds). As always you have to do your part.
 
Has anyone tried the 210 gr Matrix hunting bullets ? Since you guys are saying flat base may be the answer this looks promising.
 
Have had a 300 mk 5 since the late 80's. I used to run 180 gr partitions, and the rifle loved them back then. Bought a fresh box about 5 years ago and the best group was about 5 inches. I don't think partitions are what they used to be. I found them to suck in my 270 as well.
I switched to 180 gr nosler accubonds and they are good accuracy and run 100 fps faster with the same load of IMR 7828.
 
powdergun said:
Has anyone tried the 210 gr Matrix hunting bullets ? Since you guys are saying flat base may be the answer this looks promising.
Click to expand...

Given the success that some members are having I don't know why the 210 wouldn't be outstanding in the 300 Weatherby. More and more I think that Matrix should be the first bullet that Canadian shooters start with when working up a handload.
 
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