decent groupings beyond 300 yds with factory ammo?

[Taco280AI]

Only one way to really know, go out and try.

I've shot groups at 200 yards that were the same size as my 100 yards groups. I've shot "groups" at 200 that left me scratching my head as well.

Now that my rifle/loads have proven themselves at 100 (averaging  sub .4" with a 6x scope) I've changed my shooting. The last few times I shot in the mountains I wasn't going for groups anymore, just pick out rocks at different ranges and shoot them. If I can hit the rocks, I can hit the vitals. Have gone to 589 so far.

[Bill W]

The math guys tell me that group sizes don't get bigger in a linear fashion.    Wind and mirage have more of an impact on group size at the longer distances.

If I had a gun that grouped 7.5 inches at 500 yards per Jonathan's example I wouldn't rule out a 500 yard shot if the conditions are favorable.   The kill zone on a deer is 10 inches x 10 inches.

That 7.5 inches is not factoring human error though. Somebody who settles for 1.5 MOA probably settles for not that much range time 

The shooter has has a gun that he and the gun shoot 1.5 MOA.   To me that already has human error factored in.   Wind, mirage and group enlargement not being linear will increase group size.

[Bill W]

Only one way to really know, go out and try.

I've shot groups at 200 yards that were the same size as my 100 yards groups. I've shot "groups" at 200 that left me scratching my head as well.

Now that my rifle/loads have proven themselves at 100 (averaging  sub .4" with a 6x scope) I've changed my shooting. The last few times I shot in the mountains I wasn't going for groups anymore, just pick out rocks at different ranges and shoot them. If I can hit the rocks, I can hit the vitals. Have gone to 589 so far.

A method I've used that's along the line of shooting rocks.   Take a week and go hunt prairie dogs in Montana.   Walk the dogs up and use a bipod on the gun.   A shooting mat would be advised because of prickly pear.   Once you get to where you can hit a fair number of dogs at 500 yards there's close to no way to miss a deer unless the shooter gets buck fever.    I used to carry a Rem 700 Varmint Special in .223.  One needs to pay attention to wind with that one.   My longest hit was 550 yards as I didn't attempt any past that point.

[JDHasty]

Only one way to really know, go out and try.

I've shot groups at 200 yards that were the same size as my 100 yards groups. I've shot "groups" at 200 that left me scratching my head as well.

Now that my rifle/loads have proven themselves at 100 (averaging  sub .4" with a 6x scope) I've changed my shooting. The last few times I shot in the mountains I wasn't going for groups anymore, just pick out rocks at different ranges and shoot them. If I can hit the rocks, I can hit the vitals. Have gone to 589 so far.

A method I've used that's along the line of shooting rocks.   Take a week and go hunt prairie dogs in Montana.   Walk the dogs up and use a bipod on the gun.   A shooting mat would be advised because of prickly pear.   Once you get to where you can hit a fair number of dogs at 500 yards there's close to no way to miss a deer unless the shooter gets buck fever.    I used to carry a Rem 700 Varmint Special in .223.  One needs to pay attention to wind with that one.   My longest hit was 550 yards as I didn't attempt any past that point.

Me too.  I go through north of 4,000 rounds of ammo when I go over and by the end of the week I am pretty well tuned up.