Funny day at the range with my .270

[mpstan]

I had an interesting day shooting my first handloads for my .270. I worked up both RL-22 and N160 in one grain increments throughout the recommended loading range for sierra 130g soft points. Both shot OK but I think the N160 had a little tighter groups in general.

Most of my shots were roughly 1" above target at 100 yds. OK, here is the twist....... For fun, I pull out some old nasty Winchester 100gr cartridges I bought at a gun show for peanuts, and shoot nearly as nice of a group as any of my handloads...... but..... the groups are 5 inches above target. Why would that be?

Then I shoot some more of that 100gr at 200yds........ again nice groups, and this time at least 10 inches above target.

Does it makes sense to anyone that this round would shoot so much higher than 130gr rounds, plus higher at 200 than 100?

Thanks

 

[R.W.Dale]

Does it makes sense to anyone that this round would shoot so much higher than 130gr rounds, plus higher at 200 than 100?

YES! It make scomplete sense to me. Anytime you do something to change the harmonics of firing a bullet you can have POI shifts. Shifts that may or may not make any sense.

I've seen faster loads shoot higher, I've seen faster loads shoot lower. Heck I've even seen velocity changes cause POI shifts to the side

Powder burn rate, COL, velocity, temp all these can effect POI sometimes very dramatically as you noted, sometimes not at all.

This is why there's no computer ballistic program that can take the place of range time with your rifle and the load you intend to use