I took my new Ruger 77/22 to the range this past week to seriously test ammo to find what this rifle liked best. I shoot a lot of ground squirrels so I tested seven different hollow point loads. I also tested seven assorted standard velocity, subsonic, and round-nose high speed loads.
I once read an article by Jim Carmichael where he tested several 22 LR loads against each other. He used five-shot groups at 50 yards. His targets looked fairly similar to FieldGrade's, in that it was hard to tell much difference from one group to another.
Mr. Carmichael then tested the two or three loads that seemed to be the best by shooting 10-shot groups at 100 yards. The results much more clearly showed a difference in group size and shape. He concluded the article by saying that in the future he would always test 22 ammo with 10-shot groups at 100 yards. I decided to take his advice for my testing.
I have also read that it was best to shoot enough of the next load to re-foul the barrel in order to get the best results, as hasbeen and others have mentioned.
I decided to shoot two 10-shot groups with each load before moving on to the next load. Then I would only compare the second group shot with each load against each other. I did not do any cleaning or bore-snaking during my testing session.
On Tuesday morning the conditions at the range were ideal. The air was quite calm, the sky was a high overcast, and the temperature was in the high 40s to high 50s during my testing. I don't shoot rimfire benchrest competition, and my eyesight has deteriorated with age, but my results are consistent, and I do get a lot of squirrels.
My results were quite satisfying, to me. Over several hours I fired over 300 rounds. In almost every case the second group was smaller than the first group, even if only by a bit. Only one first target was actually smaller than the second, and not by much. In some cases the first two shots of a new load were definitely outside the remaining eight shot group. Therefore, I conclude that it does improve results to re-foul the barrel with a few shots of the new load before shooting for record.
A ten-shot group provides a much better picture of how good the load is than a five-shot group. At only 50 yards you would pretty much just have a shaggy hole with that many shots, but at 100 yards you get a pattern.
As for my rifle, the best groups were right at 1 1/2" with American Eagle HPs, and Winchester Wildcat HPs, followed by Eley Target and Aguila Super Extra Standard and High Velocity round-nose, all at 2" or under. CCI Mini-Mag HPs were at 2 1/4".
The bottom half of the loads gave groups from 2 1/2" to 3" except for the worst load which was also the fastest, the Browning BPR at 1392 fps which produced a 3 1/2" group.
After finishing the test portion, I sighted in the scope by shooting some five shot groups at 100 yards and at 50 yards. I achieved a 1" group at 100 yards, and four consecutive 5-shot groups at 50 yards were consistent 1/2" groups.
I am fortunate that I recently bought several bricks of the American Eagle ammo from the same lot number as it is very good ammo in several of my rifles and the price was reasonable. All of my testing was fired through my chronograph. The velocity of the American Eagle ammo, based on 37 shots, averaged 1256 fps with an extreme spread of 77 fps. (The Eley Target had the lowest extreme spread of any of the loads, at 33 fps for 20 shots).
The Winchester Wildcat ammo that did so well was several years old (so not necessarily the same as current production) and it gave a velocity of only 1156 fps. I am glad the American Eagle beat it by 100 fps.
I am now ready to go after the ground squirrels with confidence. I am quite satisfied with the testing procedure of using two, 10-shot groups at 100 yards, and I recommend it to those looking for the best load for their 22 rimfire.
Good God.
I zero and go.
Bought 2,000 Stingers and I'm down to my last 200.
I miss with my CZ and 77/22. But not often.
Case of Browning HP's is getting cracked next.
Dave
