Semi-Scientific 22LR Ammo Test
I'm not a serious competition bench rest shooter. I'm just a guy who likes to go to the local range and see how precisely I can shoot using pretty low-end equipment and reasonably priced (if this term has any meaning these days) ammo.
If you're the kind of person who could trade your gun for a BMW or if you actually measure the relative humidity before each target card (and makes adjustments based on that reading) then stop reading now.
I recently discovered that I had previously mounted my Lowey barrel tuner further forward on the barrel than the manufacturer recommends. Of course, after I moved it back 10cm, I had to re-tune it. When I finished re-adjusting the tuner weight position, I decided to run a little ammo test using 7 different types of 22LR I had on hand.
Yesterday there was absolutely zero wind in the morning. I used my Savage MKII FV which has been bedded to a Boyd's Barracuda laminated stock. It has a Mueller 8.5x25x44 Scope and, as mentioned previously, a Lowey barrel tuner. I shot from a bench rest at a card containing twenty 1.5" diameter targets at 50 yards using a Bald Eagle front rest. I launched 5 rounds at each bull, followed by a second set of 5 on the adjacent bull. Then I changed the type of ammo and continued this routine until I had fired all 7 types. Finally I more or less repeated the first test sequence using most of the various ammo brands/types, especially the ones which showed the most promise. I quit as soon as I could detect the first breeze of the morning.
My test is only semi-scientific for several reasons. There were some parameters I did not or could not account for. First of all, it was me doing the shooting, not some machine. Therefore, the POA was no doubt slightly different for each shot. I simply did my best to squeeze off the most precise round I could for each and every shot. My equipment is pretty low on the food chain when you compare it to high-end bench rest competition equipment. But it probably represents something close to what a recreational shooter might use. I don't have a chronograph, so I couldn't reject a flyer by recognizing the velocity of a particular bullet as significantly out of the normal range for that batch of ammo. Also, It is widely believed that changing ammo requires several "fouling" rounds because the bullet lubrication varies from one manufacturer to another. I fired a couple of "sighters" when switching from Eley to Lapua for example. But I didn't when switching from Eley Club to Eley Match; the excuse being the Eley lube is either all the same, or very similar. On average, the second group of 5 did not exhibit increased performance; therefore, I don't think the bullet lube syndrome was a significant factor
In spite of these limitations, I think my test is meaningful, or at least interesting, in spite of its relative simplicity. I took careful notes, I scanned and scored the targets with On Target software, and I examined the data in an Excel spread sheet. This allowed me to not only measure group size (Center to Center) distances very accurately, but it makes measuring "Mean Radius" (Average to Center) quick and easy. I put quite a bit of emphasis on the Mean Radius, which is the average distance of each shot from the center of the group. I think it's a better measure of true precision than group size. Unfortunately, measuring it by hand is so tedious that almost nobody ever does it. You really need a scanner and some kind of scoring software to keep from losing your mind.
There is always a lot of "noise" when gathering data like this because there are so many other variables lumped in with the different types of ammo. The job of extracting meaningful data from a sea of noise is something of a crap shoot and requires the shooter to do his utmost to reduce the effect of everything except the variable under consideration. It's not easy.
I know one thing for sure; you can't do this reliably by eyeballing group size at the range, especially if you're testing more than two types of ammo. If you don't use some sort of computer assistance to score and study the data, you are unlikely to successfully pick the fly s**t out of the pepper, so to speak.
Here is a bar graph showing the data I gathered. It is sorted by Mean Radius with the best on the left. Remember, a lower number is better, including price per round.
The graph shows the best well as the average for the test parameters under consideration. It is repeated for each of the 7 different types of ammo.
[IMG]https://farm9.staticflickr.com/8732/...7ccdbae4_o.jpgAmmo test 403 by Mozella55, on Flickr[/IMG]
Several facts emerge. Cost is not directly related to performance, at least in my rifle. Frankly, I wish it were. Eley Match is the ammo I had hoped would shoot the best even though testing it a few months back produced really disappointing performance. After some reflection I decided that I was damaging the bullet when I cycled the bolt. Match and Tenex both have a unique semi-flat bullet and they don't feed properly in my bolt action MKII. I thought I must be denting or stripping some lead off the bullet nose during my earlier tests.
This time I gently hand-fed the Eley Match rounds, being very careful not to cause any damage to the shape of the bullet. Sad-to-say, the performance was still disappointing. I confess I don't know why it performed worse than the considerably less expensive Eley Target and Eley Club in both this test and my previous testing.
I suppose the good news, is that the affordable Eley Target finished in second place. Finding moderately priced ammo which your rifle "likes" is nice. But, still, as someone educated in the sciences, I feel uncomfortable with that conclusion.
My rifle is a thing, not a person. It doesn't have a name. It seems to me that "liking" certain ammo is not a trait which should be used to describe a rifle. But until I can come up with a scientific explanation more meaningful than "every rifle is different", it will have to do............ I guess ................... sigh.
I'm pleased to see that Lapua Center X and Eley Target both produced best groups of less than 1/2 MOA and both averaged below 3/4 MOA. Perhaps I've found my "fun ammo" and my "serious ammo". As far as I'm concerned, those results are quite tolerable for a cheap rifle handled by a shaky old man with a bum shooting eye.
