Do Partitions shoot to different POI than all other bullets

martinbns · Oct 26, 2004

I have loaded partitions for four different rifles and have always found they shoot about 6 inches higher that other bullets in all 4 of my guns. any particular reason for this? The other rifles will shoot different bullets(similar powder charges) to roughly the same POI.
Just wondering

NOSLER · Oct 26, 2004

To answer your question, yes the POI will be different. This is due to not only a flat based bullet, but different B.C. To answer your question better what velocity are you using and what range are you shooting?

martinbns · Oct 27, 2004

100 yards and different speeds with different guns, 3006 about 2850 with 165's 260 rem about the same speed with 125's 264 win mag 3250 with 125's. They just seem to shoot higher than other traditional lead core bullets, with my 260 it shoots 120 ballistic tips, 129 hornady spirepoints, and 120 barnes XLC to about the same POI, 125 gr partitions about 6 inches higher.

mshaffer · Oct 27, 2004

I'm no expert 8) but I'd ask if you are sure the velocities are the same. My guess is that the Partition is likely causing a higher pressure situation in your chamber and riding out the barrel with more velocity, thus a higher POI on your target.

NOSLER · Oct 27, 2004

Matt-

I should put you as a moderator... Good answer, the Partition's bearing surface is a bit different thus causing a bit different pressures/velocities. 6" is a bit of a difference, the B.C. will effect .5". But vs. an X bullet or a Hornady bullet, jacket material is different and so is ogive.

martinbns · Oct 27, 2004

This isn't a big deal, i just have to keep track of the loaded Partition rounds from the others. There is no way bc could have this big an effect and it could be unique to the four guns I've loaded partitons for.

5Redman8 · Oct 28, 2004

It should be noted for those that do not know.....higher velocities do NOT ALWAYS cause higher POI.

Just hate for someone new to reloading or shooting to make that assumption from this post.

Kyle

longwinters · Oct 28, 2004

I have the same difference between accubonds and partitions out of my 280 Sako. The partitions are 5" higher. It would take an awfully large increase in velocity to make that big of a difference at 100 yds. But with H4831 the Partitions shoot 1/2" 5 shot groups so I obviously can live with it. But it was quite a surprise.

Long