I hunt with a winchester 270wsm with a 3x9x40 nikon scope. The ammo I use is winchester 150gr psp. I have about 10 rounds left a

[flint lock]

I hunt with a winchester 270wsm with a 3x9x40 nikon scope. The ammo I use is winchester 150gr psp. I have about 10 rounds left and would like to use these up first, then start using 150gr remmington ballistic tips. Some friends tell me I would have to sight my rifle back in. Others tell me I won't have to because a 150gr bullet is a 150gr bullet. I know if I would go to a havier or light grain bullet I'd have to sight in again. But, just changing to a different 150gr bullet would I have to? Thanks, Flint lock

[Bo]

I have found that in the past I have had to resight my gun just changing the lots of the same companies ammo. Some that I had purchased the previous year did not shoot the same as stuff I had just bought. Doesn't always happen, but it can. Back when I was reloading for my .44, I could tell a difference in the different batches.
It may not make that much difference, but if someone tells you that it won't, it will. Just because they tried to give you a hard answer. There are many variables to be figured in and different lots may shoot differently.

[PAShooter]

They probably will shoot differently.

[seadog]

I can't add much to what Bo & Kody already said. You should take your rifle to the range and shoot with the new ammo. You'll probably find that you only need to make a slight adjustment. But, in my opinion, you should do that anyway before hunting season even if you don't change ammo to make sure your scope hasn't moved or come loose (stuff happens).

[Chris Johnsrud]

Ditto all of the above. Different bullets will have different trajectories.

[Old Salts]

Some barrels will shoot the same point or very close to the point of aim, many will not, just got to give it a whirl!

[tpbesone]

The most important bullet characteristic to look at would be the ballistics coefficeint of each load. Your muzzle velocity should be about the same if the powder is the same, but depending on the Ball. Coef. you will get more or less drop.