257 wby accuracy frustration

[Montucky]

A bullet you might try is the swift scirocco. My .300 bee and .257 love them. Plus they have pretty good BCs and are a quality bonded bullet as well. Both those loads seem to favor 7828, the .300 takes a hot load and the quarter bore likes a moderate load. The .257 also likes a 100 grain Speer SPBT that I use for coyotes and plinking.

Also what flavor of solvent do you use? This might sound trivial but a lot of copper  fouling occurs when you send a bullet through at 3300 to 3600 fps and many solvents do a poor job of breaking it down enough to get a good clean and your barrel my be getting progressively more fouled. I like butches bore shine, but any quality copper erasing solvent will work.

Secondly how precise are you measuring powder? When reloading for high pressure/ high velocity calibers a couple tenths of a grain variance can flat ruin accuracy.

Thirdly have you checked for debris between the barrel and stock? I mention this only because I nearly rebarreled my .300 two years ago because it went from half moa to 4 moa one season. Turned out that between shooting prone and belly crawling I had got some sand in there and every shot changed pressure points and therefore changed the following shot.

Best of luck with your project and please let us know if you crack the code. Your end solution might save me the next time I am beating my head against the wall causing a tighter group

[Stacy]

I don't own or shoot a 257 Weatherby but I am a big fan of Barnes bullets. I think the 100 grain TTSX will open up at 500 yards. Using info from the Barnes web site and Hornady's online ballistic calculator, assuming your muzzle velocity starts at 3500 fps, your velocity will still be 2192fps at 500 yards. That's well above the velocity threshold Barnes claims their bullets need to expand. (1600-1800fps depending on caliber and weight) 

If your rifle likes the 100 grain TTSX I'd use it with confidence.     

[Gary]

12, I live in Az also.  I have a .257 WBY Vanguard which was barely shooting the factory guarantee with factory ammo.  I free-floated the barrel and bedded the factory B&C stock, experimented with some handloads and it now shoots sub-MOA out to 600 yds. with temp stable powder.  The extreme swings in temps here were killing my groups with some powders.

[.257]

I don't own or shoot a 257 Weatherby but I am a big fan of Barnes bullets. I think the 100 grain TTSX will open up at 500 yards. Using info from the Barnes web site and Hornady's online ballistic calculator, assuming your muzzle velocity starts at 3500 fps, your velocity will still be 2192fps at 500 yards. That's well above the velocity threshold Barnes claims their bullets need to expand. (1600-1800fps depending on caliber and weight) 

If your rifle likes the 100 grain TTSX I'd use it with confidence.   

+ 1 to Stacy, 100 grain TTSX is my hunting load using 74 grains of RL 25. Have used Barnes bullets sense 1980's have yet to have a problem. If you plan to shoot to 500 yards than you should be shooting from a bench at 300 yards to see where you gun is hitting at longer ranges

[dixie1]

i have gotten good groups with mine w/115 partition and rl25 and col set to the manual. The col was giving me problems and had to buy a diff press to load. The dillon has just a tad bit of play on tool head,needed to get rid of that.

[jmnyckt]

Brought mine to the range with black box factory rounds (.257 Sporter, DNZ mounts with Nikon scope). Did the break in procedure not completely, 18 rounds. After cooling the barrel and cleaning it this is a six shot group at 100 yards (had to shoot 6 because of the stray, it would have botheted me). I dont reload, and my 4 Weatherby rifles and my PA-08 slug gun seem to like the inexpensive factory loads. Also, have you checked your mounts and optics?