I'm considering buying a new scope for my deer rifle.  I'm shooting a Browning A-bolt in 308 and currently have a Vortex HS-LR 4-16x44 on it.  16x is more than needed here, I've never had the rifle turned up past 8x while hunting.  Since shots can range from 25 to 300+ yards, I'm wanting a simpler scope where I don't have to worry about adjusting parallax, or exposed turrets getting bumped.

I'm looking at a Vortex HS 2.5-10x44 BDC or Leupold VXR 3-9x40 w/ Ballistic firedot.

I think the Firedot would be nice for low light situations when deer are moving at dusk or dawn or dark haired animals but don't know that it's needed.

I will also be taking this rifle to Africa in May for a plains game hunt.  So I'd like to get this in the near future so I have some time to practice with it.

I cannot speak regarding the vortex.  However, I do have a Leupold VX6 2-12 with the illuminated firedog wind flex reticle.  I VERY much like the firedot.  It isn't needed 95% of the time, but it it EXTREMELY helpful in low light.  I am impressed with the dot, and with its timeout and awaken-on-movement feature.

As far as magnification range it depends on the distances you'll be shooting and if it will primarily be on a rifle used for big game hunting. You mentioned up to 300 yards shooting ranges. Deer and larger sized game at that range don't require a high magnification scope at those distances. I'd want a more compact rifle-scope combo if there's no advantage to having a higher magnification scope. A 2-8 or 3-9 variable would be more than enough for that purpose.

My go to scope for a medium/large non dangerous game HP rifle is a VX3 (now VX3i) 3.5-10X

Look at Sig’s line of hunting optics I hav Attached File
e a whiskey 3 3-9x4 with illumination it’s really nice and not expensive

I bought the Swarovski z6i (this was the first year I used it) and I can tell you the illuminated dot is incredible.  I Shot 2 deer (at 100, and 50 yds) this year through thick woods on an overcast day.  If you hunt in that sort of environment, you know how well deer blend in. The dot was a tremendous help and allowed me to get off shots very quickly.  I didn’t even bother to look for the crosshairs.

I have a vortex 2.5-10, but don't know what model it is.  I have it on my Grendel and think it is perfect for everything other than paper punching over 100yds.

The 3-9 is hard to beat for most hunting.  If you are going to go shorter with an AR, I'd maybe go with a LPV, but if you are going to stand hunt, the smaller objective might be bad.

I shot a goat last year with the Vortex, and 2.5 was plenty fast when I snuck up on a sleeping goat who almost got up to run off before I put him down.

Leupold VX5 2-10. I have a VX5 3-15 and I love it. You can get it with or without the CDS, and with it has the zero lock for the elevation knob.

I know I replied earlier....  Your comment about never using more than 8x makes sense.  For years all my big game rifles had lower powered scopes:  1.5-5x on the muzzle loader, 1.5-6x or 1.75 -6x on the centerfires.  After taking dozens of deer, some caribou and moose, I've never -  not once - needed more than the 6x on my rifles.  Shooting was done largely between 100 and 300 yards.

I've gone to more power lately, but its not because its needed for big game at 300 yards.  The newer 6.5 Creedmoor doubles both as a blind rifle for deer and as a precision rifle for use on chucks ad crows and general "lets have fun shooting".  Its got a 2-12x, but its virtually never dialed in over 6 or 8x when used on deer.  It simply isn't needed.  However, the really WIDE field of view afforded by the lower 2x most definitely DOES get use.  Your thoughts regarding something like a 3-9x make perfect sense (or at least a ton more sense than something like 4-14x would ever be on a shorter range deer rifle).

This what I decided to go with.  A 3.5-10x40 VX-3i should meet my needs.