Home Forums Gear Free Classifieds Need 270 STW load info

Hellow folks I am wanting 270 STW Load info , anything on this cal. would be a big help . Thanks

I would think using 270 Weatherby starting loads would be a good way to begin.

Try berger reloading manual they had 6.5 and 257 stw loads

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This is the classified forum, not the reloading forum.

I didn’t know that was even a caliber, but agree a goo 10% below .270 WBY would be a good starting point.

Ya, we know it’s the classifieds, but that shouldn’t stop people from helping.

You might also post it in the gunwriters forum to see if Mule Deer can point you in the right direction. He may also know how to get ahold of Layne Simpson (?) - the fella who worked up all the other STW cartridges.

Good Luck,

Bob

Using 270 WBY data is not going to be a real good starting point. The STW case holds about 11 gr more water than the WBY case. That makes it about 13% larger. The STW case is based off of the 375 length magnum case. The 270 WBY is based off of the standard mag length such as a 338 mag. There may be confusion here as the 300 WBY is based on the longer magnum cartridge but the 270 is not. The closest comparison you are going to have is looking at 7mm STW data compared to the berger data that an earlier post said was out there for 6.5 STW. That is basically comparing same case capacity in .264 caliber and .284 caliber to arrive with loads for .277 caliber. I wouldn’t recommend using information such as this for starting data without expert level of experience reloading as well as an advanced level of physics knowledge. This all boils down to a WAG (wild ass guess) where your pressures are actually at. My recommendation would be to scrap that barrel it is WAY overbore for a 270. Have someone put a barrel on the rifle that has pressure tested data available.

How many rounds dowm the tube? How much does the rifle weigh?

.277 vs .284?? It is not that badly over bore. Not compared to the 6.5 STW.

Some of the old Sierra manuals listed loads for the 6.5-300 Wea, and for the 7mm-300 Wea. The STW case, synonymous with 8mm Rem mag case is very, very close to the 300 Wea in capacity.

An experienced loader could interpolate a starting point looking at these similar cartridges. I would start with RL 33 with heavy bullets. Magnum, Retumbo, and MagPro would work with 130s. H1000 with 110s.

I have adopted a couple of cartridges before load data was commercially available. The work up is very satisfying.

Check with dave7mm

I think he shoots one.