BLOG #23 TESTING NEW AIR RIFLES EXPLAINED.
Due to the fact that 95% of my customers buy on-line, they do not have the luxury of trying out the air rifle of their choice, let alone testing it and sorting out any teething issues that sometimes accompany a new gun. Further to that, many firearm dealers do not have air rifle experience or interest in air rifles, therefore they bring very little to the table other than price.
On the other hand, air rifles are all that I do: OK, I sometimes do buy in a Weihrauch HW60 or HW66 but that is a rarity and an ‘order in’ only. Air rifles are my passion and as I shoot almost daily they are a very large piece of my lifestyle and hence my knowledge base.
Why I test each Air Rifle when selling one.
There is seldom a week goes by that I do not get a call that goes something like this: “Hi, I just bought a XYZ air rifle and it shoots like a scatter gun, all over the map. It is a piece if junk (not actually that word)”.
OK, so that is another dealer’s problem and not mine you say, except if that was you. I cannot afford the time or cost in sorting out a gun across the width of Australia having just sold it. So that I exactly why I test them and over the last few years I have expanded the testing and customised some software to make the recording and transfer less painful and a lot quicker.
No matter what make of rifle, there are problems that arise on occasion and it is better if they become evident here with me than when they arrive into the customer’s possession. OK, so some of the problems are only minor and in most cases only adjustment issues but if you had just spent $3k or $4k on an air rifle, should YOU have to adjust it?
Then there is the case of accuracy as all air rifles including PCPs have a preferred pellet that shoots somewhat better than other types. The testing we do will select one of the better types of pellet and while it may not be the best performing pellet for that rifle, it will be up there with the best as we have access to 30+ different types.
Spring air rifle tests.
Spring powered air rifles are the most inconsistent type of rifle to test due in part to the fact that they are not ‘run-in’ with the spring ‘setting’ its’ self, the seal bedding in, barrel leading and the high occurrence of dieseling in new springers.
These factors make it difficult to say with 100% certainty that the rifle is performing at its best and so we have modified the testing to factor this in. As the dealer margins are very small on Weihrauch spring air rifles there is little room to move in regards to a more sophisticated testing procedure and so we concentrate on ensuring that the rifle delivers the correct speed and from there we select the best performing pellet.
Unlike the PCP air rifles, springers do not perform their best until at least 1500 shots have been put through them, at which point the owner should then start experimenting with different pellets in an effort to increase the accuracy. The following test sequences are now done with spring powered air rifles below $500:
As you can see we have only tested the rifle using 1 pellet type although I generally shoot 2 or 3 types through it first to get an idea of what to expect. In this case the Baracuda Hunter showed some promise and actually grouped better than the Baracuda so I used it to do the test. By the time I finished this test I had used around 25 pellets. When we are dealing with margins on these cheap springers of $50 and less there is no room to move.
For Spring powered air rifles costing over $500 the following test sequence is done:
Here we test the rifle using a minimum of 6 pellet types that are selected by target grouping results. If one of the above pellets had abnormal grouping then it would be dropped and an alternative pellet selected to replace it.
As with all our tests, either springer or PCPs, we start off with the H&N Baracuda as this pellet is available in .177, .20, .22 and .25 calibres, making it a good base level pellet to compare to. The rifles are test fired to get rid of any dieseling and to let it settle down, this can take anything from 20 to 50 pellets in some cases. Once the airgun is zeroed and is starting to establish a consistent group, it is then we begin the Chronographing results you can see above.
Total pellets used in this test will range from 50 to 100 and on occasion more. Obviously there is no way I can put a time on this testing as it depends entirely on the gun in question. If I have to pull it down and do some polishing and replace a seal or whatever it takes, then before long the day is gone as I have to answer phone calls in-between all this. All this for a springer that quite often ends up costing me money to sell it. All the tests come with Target scans, be it springers or PCPs.
PCP Air Rifle Tests.
Due to the higher costs of PCP air rifles like the Daystate models, we test them to a greater degree with a more complex graph results as these include power, speed, Standard Deviation (SD), pellet decay, shot count and of course accuracy. This is done when we first receive a new model and we test it fully like this Brocock Compatto test.
The following test results are the current templates that Gun Room is using for the present and no doubt will get further improved once I have caught up with the data logging – currently running at around 3 weeks behind though I expect to have most completed with a week or two from now.
The following graph set is what to expect with a PCP purchase (these are actual results):
This graph gives you the actual Chronograph results that we take and place into graphs to make visualisation easier and quicker, allowing the eye to make immediate comparisons in the data results.
From this graph above we can derive much of the following data:
The graph above has the Stand Deviation results at the top in light green bars where the lower the reading the better as it shows that the Hunter Extreme has the closest matching pellet speeds. The middle results in blue show the maximum power in Foot Pounds of Energy (Fpe) and you can immediately compare the results this way. The lower bars in red show the difference in speed measured in feet per second.
As we fired each string of 6 shots the speeds rose and then fell as can be seen in Graph #2 and these results have then been redefined in Graph #3 to demonstrate the Pellet Decay fall. When looking at the Graph #3 it should be noted that we started the chart with a full tank of air and with Baracuda pellets. After the final pellet test that was JSB Exact Jumbo Monster, we reverted back to Baracuda (Shot #37>) where we continued to shoot until the speed dropped below 500 F/s, what we call the ‘Plinking Limit’ for accuracy.
This is the Standard Deviation chart and probably the least understood of all the data collected. Rather than write a book about SD I will explain it this way for you guys new to Chronograph readings.
When a string of shots are fired through a Chronograph their speeds are measured and the Chronograph list them under Extreme Spread. This is the difference between the lowest speed recorded and the highest speed recorded in a shot string. So if we take the graph above we will see that the first string of 6 shots returned an Extreme Spread of 10.8 feet. Literally speaking, if you fired all 6 shots at once and froze them in flight after 1 second, the slowest pellet would be 10.8 feet behind the fastest pellet.
The Standard Deviation is a formula based on averages that gives us an average between each shot that is worked out by formula as each shot is not consistent with the last or the nest shot. Suffice to say here, that if we have a SD of below 5 then we are getting close to similar speeds between each shot. I have had SDs of .8 and once we had a SD of 0 where the pellet speed difference over 6 shots was an Extreme Spread on just 8 inches!
The point I am making here is that the closer the speeds are with a particular pellet in a specific air rifle, the better as the trajectories, energies etc., are going to be very similar. The more similar the pellet behaviour the better performance can generally be had in accuracy and grouping. The better quality the air rifle and the pellets the better chance you have of achieving consistent results. You need to also be aware that ALL rifles vary and you can get 2 air rifles, 1 serial number apart, using pellets out of the same tin and yet they have markedly different results.
Air Rifle Testing Summary.
The idea of testing is to fault find (if any) before the air rifle leaves our possession, and to provide the new owner with the results that allow him/her to start shooting using a tested pellet type that will provide immediate results. These are not said to be the best results obtainable with that particular gun, because we do not test every type of pellet, but it allows the owner to jump start the pellet selection process without the unnecessary additional financial pain.
So there we have it guys, that is what pellet selection is all about. I can usually complete a pellet selection test and adjustments in a couple of hours but on occasion it has taken many hours to get the gun shooting correctly. In saying this, you can see that it is difficult to predict how long it will be before I finish testing a specific gun as the test procedure is often interrupted by phone calls, messages, customers walking in and numerous other interruptions. So please, before you ring me and chew me out over the delays, understand this, I am doing my best and want YOUR gun OUT as much and probably more than you want to receive it; and as is usually the case, there are other air rifles ahead of yours…
Author: Ian McIntosh February 2017