300 Win Mag Accuracy Testing

I bought a used Browning A-Bolt 300 Winchester magnum (Win Mag) that was built by a US Military Sniper for my personal use on safari in South Africa.  Odds are that this gun will shoot, right?  Well at least better than I can.  So if accuracy is poor, it can't be the gun.

The problem?  I was getting 1.5" - 2" groups at 100 yards, sometimes worse.  The outfitter in SA will have me check the gun upon arrival to ensure that it was not damaged or taken off zero during the flight.  He wants to see 1" maximum groups at 100 yards.  If I can't get that at home, there's no way to expect that in SA.

So I figure it must be the ammo - well that's what I'm hoping, or otherwise it's the operator and I do not want to face that reality.

Upon suggestion from others who have been on safari, I was shooting Hornady's Superformance ammo in 180 grain (the heaviest bullet available is recommended).  This is a great round, as it should be at $75 / box of 20.

Thinking (HOPING) I have an ammo problem, off to Gander Mountain I went.  I spent $175 on four types of ammo from different manufacturers in different bullet weights.  I bought 2 boxes of 180 grain and 2 of 150 grain.

And I also cleaned the gun - although it had less than 30 rounds through it.  Again, can't hurt right?

Off to the range for testing.   I set up 8 targets - 2 for each round.  I planned on shooting 3 rounds at each target to see which was the most accurate.

The first ammo I tested was Winchester's Deer Season in 150 grains.  Not only was this round more pleasant to shoot, it shot VERY WELL.  I think I might have found the problem.  But, this was with a cold gun.

I continued to fire, testing Remington's Core Lokt 150 grain rounds; Winchester Silvertip 180 gr.; and Hornady Superformance 180 gr.  Then I fired them all again in reverse order to test the rounds on a "hot" gun.  And I'll tell you this, the gun barrel was HOT.

I am unsure of the twist rate in the Browning's barrel, but I can attest that it prefers the lighter bullet.  Pictures included below to show the differences...

3-shot group using Winchester's Deer Season 150 grain ammo.  Cold gun.
2 rounds through SAME HOLE.  Distance center to center:  0.36 inches*

3-shot group.  Win Deer Season 150 gr.  Hot gun.
Distance center to center:  0.39 inches*


3-shot group.  Remington Core Lokt 150 gr.  Hot gun.
Distance center to center:  1.4 inches*

* All measurements taken with an electronic digital caliper.

Also, please note, Location on the target is not a concern as I can always adjust the scope to hit center mass.  What's important is that the rounds all impact TOGETHER.  I'll adjust zero later.

The BEST I could get with the 180 grain ammo was 1.75" center to center.  The Hornady's were the worst performers at 2.9".  Again, not slamming the ammo.  I'm just saying that MY GUN prefers something else.

It looks like I will be buying more Winchester Deer Slayer ammo to take with me to South Africa.
Damn right, this gun can shoot!  And thank goodness it wasn't a shooter error!

I guess I'm all out of excuses if I miss now...

Comments

Post a Comment

Popular posts from this blog

Cleaning Winchester SX3 / SX4 Shotguns

Image
The Winchester SX4 is my Go To shotgun for everything - clays, doves, ducks, geese, pheasants, whatever.  It is an awesome firearm.  The drawback?  There are multiple moving parts and a few of them like to collect carbon.  And this carbon sticks as if it were put on those parts with super glue! Specifically, the magazine tube and the gas piston are the main carbon collectors.  Those parts come out more black than silver & gold. The inner components of an SX3 / SX4 with highlights where carbon will form So what is my trick for cleaning those bits?  I drop the gas piston into my Hornady sonic cleaner.  Inside the cleaner I put in about a cup of Hornady's One Shot Sonic Clean Solution for gun parts, add some DI water, a couple squirts of Dawn liquid dish soap, and then top it off with a dash or two of the citrus version of Dr. Bronner's pure castile liquid soap.  I have found that the citrus Dr. Bronner's is awesome at removing grease and oil....
Read more

Winchester SX4 Trigger Assembly Update

Image
First, you need to read the post immediately before this one to understand why I had to take my Winchester SX4 shotgun apart - all the way apart - specifically the trigger assembly. Second, my bad.  I had neglected to clean the gun after returning from last October's pheasant trip.  I had about one bale of grass seed inside that gun, which in the end, may have kept the #8 pellet from getting out on its own.  Shame. Finally, I did not give up.  I watched four different YouTube videos on how to disassemble and reassemble the trigger group.  Sadly, no one did the SX4, only the previous version, the SX3.  Close enough.  Why did it take 4 videos?  Because no one explained HOW the damn sear goes back in.  Everyone either ASSUMED we all know how OR in two cases, the reassembly process was out of the camera frame.  Aggravating! The key, and this is more for me to remember, was on the fourth video, the author said, "The sear kinda slides down int...
Read more

Determine Sex of Deer from Tracks

Image
It IS possible to determine from a set of tracks whether the deer you are tracking is a doe (female) or a buck (male).  And, it's actually pretty simple if you know a few facts about deer. First, you have to know what a deer track looks like.  Deer leave a track that looks like the outline of a heart. Next, you have to know the direction of travel.  Deer are moving toward the "pointy" end of the heart.  So in the above example, the deer is traveling toward the top of this post, or up. Here is an actual photo of deer tracks in the wild so you can get a better idea.  Again, this deer is traveling up, or towards the top of this page.  (It is also clear that this deer was STANDING, not walking - well clear enough to me.  Read on to find out why I know that). Sometimes if the ground is soft or if the deer is traveling really fast (jumping), the track left will show the deer's dew claws at the rear of the direction traveling, like so: The ...
Read more