POA/POI difference with different brand ammo

[sswv]

me and my buddy got to talking about turkey guns, chokes and ammo today. he is convinced that shooting different brands of ammo thru his gun produces a different POI. no changes in the gun just different brands of ammo.  I've shot different brands of ammo thru the same gun and didn't notice any big difference but, I have noticed a difference in POI when changing choke tubes. interested in what others have to add on the topic.

[Big Jeremy]

I shot some new shells (EPIC) through my 870 yesterday and they hit about 3" higher and 2" left of my hand loads, but very similar patterns. So, yes, I've seen a difference. Not a huge difference, but enough of one to miss a bird at close range.


Sent from my iPhone using Tapatalk

[crow]

A gun I have that shoots most loads slightly to the right will shoot reloads loaded with Unique powder to the left, no matter the shot charge in them

[Dtrkyman]

Shot 3 different loads the other day at 40, all had a different impact, though all would have killed!

[Treerooster]

I had a TC Encore that would shoot different POI with different type/brand of shells. Sitghts not moved and same choke. Some of the differences were pretty significant. I've had other guns that weren't so eratic with different shells, but still some difference.

[Gooserbat]

Very likely to be an impact shift one load to another

[WV Flopper]

Since you brought it up.

I laugh at the guys sighting their gun in with low brass and calling it good. Getting it close is one thing, but finish it by checking your hunting load!

Different loads have different POI. You shoot them Apples to Apples on paper and you will see.

Kill, yes. Shift, yes. But why go through all the trouble to shoot something that does well and limit it's abilities by you being tight.

Test what you are hunting with!

[Bowguy]

Common that all loads will shoot slightly different. The newer chokes/loads make it more obvious.

[sswv]

I always do a final check with any new load/brand at 40 just to satisfy my mind but that wasn't always the case. when I was a boy I shot whatever my dad brought in from the company store and was happy to get them and killed loads of squirrel and rabbit just fine BUT, todays new guns, chokes and loads are waaay different. I agree that shooting low brass close in and calling it good is a bad mistake and will more than likely cause a missed or crippled bird.

[Dougas]

I have always, when zeroing my sight, shot with light loads to get close and finish the process with my hunting loads. After that I check my zero each year with a light load and then double check it with a hunting load. They hold their zero well year after year, but, it still must be confirmed each year and if I bump it, I confirm the zero before I go out again.

[Dtrkyman]

After dialing in your hunting load shoot a target load up close and save the target or take a picture, then you can confirm sights with the same targets loads, one box will last a while!

[Timmer]

Ok, someone needs to explain the technical details about a "different POI" to me as I don't understand how it is scientifically possible.  Yes, absolutely, different shells with different chokes provides different pattern density.  No doubt there.  But the POI is dictated by physical characteristics of the gun which remain constant between different shells.  If this is true can someone educate me on the science behind it?  The only factor I can think of is velocity vs gravity. Perhaps that is where the answer lies?  In my mind this would only be a concern for long distances.

[bwhana]

After dialing in your hunting load shoot a target load up close and save the target or take a picture, then you can confirm sights with the same targets loads, one box will last a while!

Solid advice!  I do the same.

[Old Timer]

The ones that drive me nuts the most is winchester lb. They seem to have a mind of their own. I use lead in my 835 12 and tss in my 20.

[GobbleNut]

Ok, someone needs to explain the technical details about a "different POI" to me as I don't understand how it is scientifically possible.  Yes, absolutely, different shells with different chokes provides different pattern density.  No doubt there.  But the POI is dictated by physical characteristics of the gun which remain constant between different shells.  If this is true can someone educate me on the science behind it?  The only factor I can think of is velocity vs gravity. Perhaps that is where the answer lies?  In my mind this would only be a concern for long distances.

I have to admit that I think along the same lines. I, too, would be interested in hearing the science behind a change in point of impact when the barrel of the gun remains stationary.  Now, I could see a pattern being higher or lower due to variations in the shell (as you state...velocity, gravity, etc.) but I have a hard time accepting that there would be any horizontal variation other than in the pattern and density thereof.

Now, I suppose variations in choke alignment to the barrel (in the instance of someone changing chokes) could explain a horizontal variation. Perhaps that is what is happening...