I am new/ I have some 175grain bullets hollow point 308 but not sure of the brand. Can I load them with a recipe for that weight bullet without the brand of bullet. When I look at my manuals the same weight bullets different brands gives different velocites and pressure. Please explain why a different brand with the same shape (spitzer, boat tail) give different effects when reloading. I will be loading 30-06 and 300 Weatherby.

Yes, you can load them generically...with one stipulation...maybe two.

The first is that you start low and work-up slowly, until you either get the accuracy level you desire, or the first signs of pressure start to show. If the pressure shows first, change powders and start all over again.

The second is that if they are coated bullets, then get the manufacturer's manual. Coated bullets havve a life of their own...

Different bullets have different designs and different bearing surfaces. The greater the bullet�s bearing surface the greater the chamber pressure. As long as the bullets are not overly tarnished, they should be safe assuming you have measured them and verified the caliber. In regards to loading, follow ricciardelli�s good advice and start out slowly. If you are only talking about a few bullets, it is best to toss them anyway. If you find they are incredibly accurate, you apparently will have trouble finding them again.

A bullet is a bullet is a bullet...NOT!

Although the same weight, the ogive my be different, yielding a longer\shorter bullet. The metallurgy of the jacket material may be harder\softer. The internal construction could be as simple as all lead to as complex as a Failsafe. Or it could not have any lead at all like the Barnes 'X'. All will give different internal ballistics.

ricciardelli is on the right track, use his advice. Just because you don't know the bullet's manufacturer doesn't mean they have to be thrown away. Be mindful of overall length. My suggestion would be to use new or once-fired [in your gun] brass only to work up these loads. Not some brass that's been work-hardened by multiple loadings. It always pays to err on the side of safety. Happy shooting.

The other caveat to starting low and working up is, use a chronograph. Pressure signs are overpressure signs, and the clearest way to know what the pressures is doing, is to see how fast the bullets are leaving the barrel. If your mystery bullets are achieving higher velocity then a known bullet with the same powder charge, then the mystery bullet is generating more pressure.