Bullet impact point changes

[300 whby]

Hi guys, I shoot a 300 whby mag mainly with 215 berger hybrids out to 1000mts & they group around 3/4" at 100 mts most times sometimes smaller if I do my part,the cold bore shot is always right on the money, however if I change to 190 nosler long range accubond ( which also shoot 3/4 in groups) without cleaning, the point of impact (about an inch & a half ) is different to where it is if I cleaned the barrel & shot the 190's..
What it seems to me is a different coppering pattern in the barrel, I'n not complaining, I was just wondering if anyone had noticed something similar, or am I just been anal,,

 

[TXAoudadKlr]

I may be anal as well. I clean my barrel throughly when I switch bullets in my gun just to have a blank slate so no additional factors are at play.

 

[Frank in the Laurels]

First off your switching bullets, Berger/Nosler....also your changing weights 215/190...heck your lucky their not a foot apart with those big two changes, let alone an inch or two. I've see bigger changes than that with just changing primers! Some barrels, most in my 60+ years of sending them will have a change in poi with a clean vrs Fowled bore. I don't think you fired enough shots to copper the barrel that bad to worry about. I don't think anal is involved here just your rifle reacting to differences in your loads, which is good !!

 

[geo4061]

TX your shooting Allen Magnum rifles. I would be anal too. Frank you nailed it.

 

[TXAoudadKlr]

TX your shooting Allen Magnum rifles. I would be anal too. Frank you nailed it.

It certainly didn't help. About the time I got into LRH, I got anal about cleaning my barrels on my rifles when switching ammunition or bullets.

With exception to the time with my 7rem when factory Remington Partitions and Sirocco's were availible and had a poi shift of just vertical of .5" at 100 yards. I was zeroed with Sirocco's which I used for LR situations and the partitions for closer ranges.

 

[tbrice23]

Hi guys, I shoot a 300 whby mag mainly with 215 berger hybrids out to 1000mts & they group around 3/4" at 100 mts most times sometimes smaller if I do my part,the cold bore shot is always right on the money, however if I change to 190 nosler long range accubond ( which also shoot 3/4 in groups) without cleaning, the point of impact (about an inch & a half ) is different to where it is if I cleaned the barrel & shot the 190's..
What it seems to me is a different coppering pattern in the barrel, I'n not complaining, I was just wondering if anyone had noticed something similar, or am I just been anal,,

I think I know what you are actually asking,

Clean barrel + 190s = bullseye
215s then 190s = 1.5" off bullseye.

I am aware and I've heard about this several times in the past.

I sometimes use hornady bullets to foul a clean barrel when trying a different powder but since the POI is always different with the new powder I haven't noticed the difference.
Next time I clean a barrel I'll make sure I take note of my zerro then foul with a different brand of bullet and compare POI.

I am anal enough that before a match or zeroing before a hunt I definitely use the same bullet for fouling.

 

[300 whby]

Thanks for the comments gents, I should have mentioned that these 2 bullets shoot to nearly the same point out of a clean barrel, which is why I run them..But I'm glad to have some positive feedback, I shoot pretty much everyday on my 1000 mt range with a variety of long range rifles 6.5/284, 7mm Rem mag & the 300 whby. I use the 6.5 most of the time (cheaper to run than the others) also makes me read the wind more carefully.The other guns are cold bore hunting rifles, not group shooters..Good to know that if I'm a tad anal I aint on my own..