by Tom Gaylord
Writing as B.B. Pelletier
This report covers:
- How more air helps power
- Linked to the Baracuda FT test
- Fill the Edge
- The test
- JSB Exact RS
- H&N Finale Match Light with 4.5mm head
- RWS Superdome
- Sig Match Ballistic Alloy
- I wonder…
- Air Arms Falcon
- RWS R10 Match Pistol with 4.5mm heads
- More fun
- H&N Match Green
- Second group of Sig Match Ballistic Alloy pellets
- Ten shots
- Aluminum tape on the back of targets
Today I’m doing something fun — for me. I’m testing the accuracy potential of the AirForce Edge target rifle that reader Ridge Runner has modified by adding a larger firing chamber. There were some questions last time about how just adding an empty chamber after the regulator can add power to a regulated target rifle. Here’s how.
How more air helps power
We know that the regulator takes the high-pressure air in the reservoir and steps it down to much lower pressure. We also know — or should know — that a gun that gets filled to 3,000 psi does not put anything like that kind of pressure behind the pellet when it fires. If it puts out 1,000 psi, that’s a lot.
Air that is pressurized to 1,000 pounds per square inch does not have the same energy potential as air that’s pressurized to 3,000 psi. It’s like 6 grade-school boys pushing a car. They can push it and get it moving, but 6 full-grown men will get it going faster. However, if instead of 6 boys we put 15 behind the car, they can get it going faster, even though individually none of them is very strong. The firing chamber after the regulator allows more lower-pressure air (more boys) to get behind the pellet when the gun fires.
If the barrel was lengthened from 12 inches to 18 inches, the Edge should shoot faster. The extra barrel length gives the little boys longer to keep pushing the car, which keeps increasing in speed.
Linked to the BaracudaFT test
You will note that I also linked to Part 3 of the test I’m doing on the H&N Baracuda FT pellet. In Part 3 of that report I used the Edge to test the pellets, so that’s some accuracy data we already have gathered. That wasn’t a real accuracy test, though, because we have no idea whether that pellet is right for the Edge. That’s what I hope to discover today.
Fill the Edge
We know from Part 1 that this modified rifle gets 25 good shots from a 3,000 psi fill. I had just purchased an 88-cubic-foot carbon fiber tank that was life-extended from Pyramyd Air. I filled it from empty yesterday with the Air Venturi compressor and it took 73 minutes to go from zero to 4,500 psi. And there was a big surprise when I filled the Edge today.
The valve in the new CF tank operates very slowly and I was able to take about 30 seconds to fill the tiny reservoir on the Edge. My old CF tank filled it in less than 5 seconds and I had to watch it closely to avoid over-filling. This new one operates with much more control. And the cost of this tank is only a little more than half the cost of a new tank.
I’m shooting from 25 yards off a sandbag rest. I shot 5 pellets at each target because I wanted to test as many pellets as possible. I promised myself that if a pellet looked good I would shoot a group of 10 with it. I did not change the zero of the scope throughout this test.
I also put aluminum tape on the backs of the targets. I’ll have something to say about that in a bit.
JSB Exact RS
The first pellet tested was the JSB Exact RS. Five went into a group that measures 0.219-inches between centers. It earned the coveted trime recognition, even though it was only 5 shots.
The modified Edge put 5 JSB Exact RS pellets into this 0.219-inch group at 25 yards. The silver three-cent piece in the picture is called a trime by collectors. It is 14mm in diameter, where an American dime is 17.91mm.
H&N Finale Match Light with 4.5mm head
The next pellet I tested was the H&N Finale Match Light with 4.5mm head. Five of them went into 0.313-inches at 25 yards, but if you look at the group you can see that the first shot landed to the right of the next 4. Those 4 are in just 0.131-inches. No trime this time, but I will come back and look at this pellet again!
The next pellet I tried was the RWS Superdome. They weren’t as tight as the first two. Five went into 0.458-inches at 25 yards. That would be good for a spring-piston rifle but not for a 10-meter rifle that has a reputation for accuracy.
Sig Match Ballistic Alloy
The next pellet to be tested was one of my favorites — the Sig Match Ballistic Alloy wadcutter. We have seen some phenomenal groups from these in lower-powered air rifles. However, not this time. Five of them went into a very open 0.838-inch group at 25 yards! Wow! That is the largest group of this test! I never expected it, but there it is.
The Sig Match pellet is usually quite accurate in lower-powered air rifles. Is the modified Edge driving it too fast? It might be interesting to test it again when I remove the firing chamber and return this Edge to factory specs.
Air Arms Falcon
The next pellet I tried was the Air Arms Falcon dome. These usually are among the most accurate pellets in lower-powered air rifles. This time, though, they were mediocre, putting 5 into 0.465-inches at 25 yards.
RWS R10 Match Pistol with 4.5mm heads
The next pellet I tried was the RWS R10 Match Pistol pellet with a 4.5mm head. Five of them went into a group that measured exactly 0.4-inches between centers
I have been asked in the past to test H&N Match Green wadcutters. Several readers believe they are the same as Sig Match Ballistic Alloy pellets because they are both made by H&N, they both weigh 5.25 grains, both are made from pure tin and they look alike. I recently received some of them to test and I thought today would be the perfect time to begin.
H&N Match Green
The first group of H&N Green pellets was another one where the first shot went wide and the next 4 were tight. This group measures 0.342-inches between centers and the 4 that are together measure just 0.202-inches.
Well I could hear the chatter already! Several of you would start preaching to me about the necessity of “conditioning the bore” with a pellet before it begins to perform. So I just went and shot another group. All right — I was curious, too.
Okay — this time it worked! Shut up!
Well, if that doesn’t beg the question I don’t know what does. Is the Sig Match Ballistic Alloy pellet, in fact, the same as the H&N Match Green? Was I just “off” on my first group with them? Only one way to find out. Yep — shoot another group!
Second group of Sig Match Ballistic Alloy pellets
I know I was shooting better by this point in the test because I had settled down. That might have added an eighth inch or so the first time around. Or, was I just messing around before and I’d now get a super-tight group? Let’s see!
This time I got the same open group as the first time, though this group was smaller. This time 5 pellets went into 0.693-inches at 25 yards. So — the Sig Match Ballistic pellet is not a good one for this modified Edge. Also, I did shoot better the second time around — but this pellet still gives open groups at 25 yards.
And — drum roll — the Sig pellet and the H&N Green are not the same! Okay, you can now start inventing alternate universes in which they are the same.
I selected one pellet to shoot 10 times for the final target. It probably should have been the JSB Exact RS pellets that gave the best group today, but I went with the H&N Finale Match Light pellets that had 4 in a very small group and one that was to the side. What did 10 of them do?
Ten Finale Match Light pellets made a group that measures 0.341-inches between centers. Not too bad! Was that the right pellet to test? Who knows? What I do know is I was starting to burn out at this point, so I stopped shooting and started writing. I probably need to test RS pellets again.
Aluminum tape on the back of targets
The final target was shot with no tape behind the target. That pellet is a wadcutter, so, if you get wadcutters going fast enough, they don’t need tape, but it does seem to help domes cut better holes.
I don’t think I have found the most accurate pellet for this rifle yet. I think it might be nice to try some heavier pellets next. At this power level the Edge may favor them.
RidgeRunner wants me to try the rifle with an 18-inch barrel. That might be fun.
Howsoveryever — the whole reason I traded for this rifle was to get an Edge. I mean a real Edge that is a 10-meter target rifle. So that testing is yet to come. This one is serial number 10, so there ain’t nothin’ special been done to it — other than the firing chamber I told you about and the trigger work. If I do anything special in the future I’ll tell you as we go.
Gonna be a lotta fun ahead!