I’ve been building as much as this range test for just a few weeks now. Tweaking the rifle and gathering rim fire ammunition to squander.
I had two goals, besides the plain one of spending a day trying to wear out the Marlins barrel. I wanted a glance on the velocity numbers of various makes of .22 ammo, and that i wanted to pin down what the Marlin shoots best.
As a side bar, I was very curious if velocity consistency is a key to rim fire accuracy, as it’s in a center fire. With my heavy barrel varmint rifle I search for less than 20 fps variation shot to shot. This tells me I’ve a load with consistent internal ballistics. I expect the same from any match ammunition I load, including pistol rounds.
My plan for the times testing was to fire a twenty round string of every cartridge. All from the same rifle, same targets, same bench, same shooter, etc. Fired into four groups of five rounds each, this could provide a rough but fair result within the search for the most accurate (as far as this Marlin is worried, anyway).
Shooting every round over my chronograph and recording the information, I’d then have a good record of every brands average velocity and it’s variations. I wasn’t sure what the information would show, but it surely would be interesting to see the results and chart them.
The shooting day started at 9am for me, and abruptly came to a temporary stop at 9:05. A nest of yellow jackets had adopted the fifty yard back stop I chose, and my initial setup target was their new God.
I had planned to attach a dozen targets to a sheet of cardboard, cutting out some down time spent hanging paper. The Cardboard had a target on it I take advantage of to arrange and align the chrono. For some reason the little wasps thought this target was probably the most fascinating thing ever seen, and swarmed it. Hovering by the hundreds in front of it, worshiping like Obamaites on the convention.
Four partial cans of wasp spray only thinned them out somewhat, so I came to an agreement with the little buggers. I left them the target they loved so much, and i hung mine a few feet over to the fitting. The separation agreement worked well for all concerned. I proceeded to fire a dozen foulers, and set up the alignment of the chronograph. The remainder of the day I co-existed with the yellow jackets in a wierd form of shooty peace. Each time I looked through the spotting scope, I could see mounds of little wasps crawling over the big target. The smaller targets I used to be shooting for record they completely ignored.
Each target was numbered, for a complete of sixteen targets. The numbers matched those at the top of knowledge sheets I had preprinted and arranged in a binder. Each page was used to record the make and model of the cartridge, together with all the velocity data collected. The speed of each round fired was noted, along with average velocity, highs and lows, extreme spread, standard deviation, and average deviation for the string.
Accuracy was measured hours after the shoot, looking only at the numbered targets within the binder. Groups were checked and averaged without knowing what cartridge was mated to which target. The target data was then transferred to the cartridge data sheets for comparison. This round-about method helped me leave my very own ammunition prejudices aside as I looked for results.
In this first chart (click to enlarge for easier reading), I have listed each type tested, it’s average velocity, extreme velocity spread, and average group size.
At first blush, the results would appear pretty confusing. The ammunition with the perfect accuracy did not always have the least velocity variations. The question remains in my mind… how much of the info is flawed just because I needed to concentrate more….to shoot better?
Anecdotal evidence suggests this could also be a big factor. Many of the targets showed four shots touching, then a flier an inch away. The velocity numbers don’t always explain the fliers.
Some targets were clear, with large groups dispersed evenly across the bullseye. Others showed excellent promise for tight groups, till a blasted flier opened it up. Fliers are always a question….. was it the ammunition or the shooter?
The info showed that wide velocity variations were not solely the realm of cheap ammunition. While Federal bulk pack had an enormous spread, so did some very expensive RWS subsonic. In addition, accuracy appeared to be dependent on velocity numbers to only a small degree. Far more important were bullet weight and style. The ammunition loaded with lighter bullets of a more conical shape shot the worst from this Marlin 780. CCI Quik-Shok stood out from the gang in that manner, with very high velocity bullets fired into groups so large their was no reason to measure them. The Marlin clearly despised the Quik-Shok round.
Most impressive, velocity and accuracy wise, were the relatively expensive match rounds. Both the Eley and the Fiocchi shot a few astounding groups and both had the bottom velocity variations of the pack. Where the Federal bulk pack made consistently large groups, the Eley would land four rounds in a single wide hole, then another hole half an inch off the groups center.
On the other hand, at $70 a brick (500 rounds), I won’t be rushing out to buy a case of Eley anytime soon.
Within the range of reasonably priced ammunition, both the PMC Sidewinders and the Federal Champion 510 ammunition built promising groups without wild velocity variations, although 80+ fps continues to be a reasonably wide spread. CCI Subsonic hollow points did the same.
What did I learn, after firing sixteen different rounds with serious intent? Clearly I can go buy a couple of bricks of Federal Champion and have an inexpensive expectation it would perform decently on this Marlin. CCI Subsonics will make an excellent small game round for the rifle as well. Past that…..
The Match ammunition? For what it costs, I believe I will pass. I am not doing any shooting with this rifle that demands that kind of potential, especially at the value. 0.75″ – 0.80″ groups at fifty yards make this a fine squirrel rifle, and at $2.80 a box for the Federal I can shoot as much as I like.
I had planned to check half a dozen kinds of .22 short as well, but their accuracy was so poor from the Marlin that it became pointless. CCI CB Long was also tested, but its such a special animal that it does not belong in this mix at all.
One fact I did come away with… every rifle is very different. Replacing the Marlin 780 on the bench with my new CZ452, it was a distinct ball game. The Eley that had 40 fps variations in the Marlin had only a 13 fps spread within the CZ. The Federal bulk that had so-so accuracy within the Marlin grouped exceptionally well within the CZ. The longer barrel on the CZ resulted in lower velocities as well.
I would have enjoyed having the ability to announce “This .22 Ammunition is the best! Your rifle will adore it and you will be pleased!”. But…. I can not do that. Each rifle is different, especially in rim fire. The only conclusions I can draw are the obvious ones….. each shooter will have to run these tests (a minimum of the accuracy portion) for them self, with each different rim fire rifle they are thinking about.