Please chime in if you have any advice or insight! I have specific questions posed inside the post that I have bolded and undelined in red.
I recently purchased an Air Arms S510 Carbine. I love the quality, ergonomics, and style of the rifle, but was disappointed in the consistency and shot count.
I mostly shoot paper with my air rifles and 100 fps extreme spread and a severe shot curve wasn’t going to cut it. Thus, I am trying to tune the rifle to eliminate its perceived shortcomings. My goal is to tune the rifle to shoot a flat shot string for 50 shots at as high energy as possible.
What I Did: Install Regulator and Reduce Hammer Weight
I installed an Altaros regulator to flatten out the shot string. I chose the Altaros because unlike other regulators, it allows the rifles pressure gauge to keep telling the air pressure inside of the reservoir. The installation also doesn’t require the reservoir to be drilled and is 100% reversible.
Reduced the hammer weight to increase shot count. The Air Arms does not have a screw to adjust the hammer spring tension with, or I’d have gone that route instead. I planned to start with as light of a hammer as I could get and to add weight back to the hammer until the best weight was found.
I weighed my stock hammer and guide and headed over to a local gunsmith to see what he could do for me. 20 minutes later my hammer weighed 29.8 grams and looked like this:
The Data: I installed the regulator and new light hammer. I decided to adjust the regulator settings first with the 29.8 g hammer. The results were:
The regulator seemed to struggle if set too low or too high. This surprised me. The shot count did not go up when set to a low 100 BAR and the velocity didn’t go up when set to 145 or 150 BAR. I’m not sure how to interpret the results other than to think the regulator is not working very well. Comments or advice?
The most promising setting to me was at 135 BAR. The 1st 40 shots had an average velocity of 813 fps (26.6 FPE) with a respectable 2.7 fps standard deviation. The shot string is shorter than I want, but none of the settings I tested seem to get me where my goal is (50 shots).
Hammer Adjustment Data:
Having settled on 135 BAR to test hammer weight adjustments, I reset the regulator and went about changing the hammer mass. I accomplished this by wrapping thin copper wire around the hammer. Electrical tape was then wrapped tightly around the wire to keep it from unwinding.
As suspected, the lightest hammer weight gave the longest shot string of about 46 shots. As the hammer weight climbed, the velocity climbed but the shot count dropped. Since my goal is 50 regulated shots, It appears I have to keep the hammer in the 29.8 to 33 gram range.
Important Note: The data for the 29.8 gram hammer is lower in velocity but higher in shot count than the previous test. I suspect this is because significant estimation is required to set the Altaros regulator. There are no markings made between 100 and 150 BAR. I therefore assume that the reg setting for this data is slightly lower than that of the previous data set. This might be a clue that I can get my shot count up with a slightly lower regulator setting. I opened the rifle back up and lowered the regulator setting a very small adjustment. I then again collected data on the 29.8 gram hammer to compare:
The shot string did indeed get longer. I hope the extra shots didn’t come from accidently adding more air into the reservoir than before. It is here that I really wish the Air Arms had a digital pressure gauge. I have been using the gauge on my air tank instead of my gun to try to keep the fill amount the same each test. Even that gauge is not very precise.
I notice that the velocity of the shots rose for a few shots at the end of the 29.8 g data. This rise caused the standard deviation of the shot string over 50 shots to be the same as that for the 32.9 g hammer weight shot string that dropped when off the regulator. Does this indicate that a slightly higher regulator setting is better? Would it remove the hump at the end of the shot string?
I recently purchased an Air Arms S510 Carbine. I love the quality, ergonomics, and style of the rifle, but was disappointed in the consistency and shot count.
I mostly shoot paper with my air rifles and 100 fps extreme spread and a severe shot curve wasn’t going to cut it. Thus, I am trying to tune the rifle to eliminate its perceived shortcomings. My goal is to tune the rifle to shoot a flat shot string for 50 shots at as high energy as possible.
What I Did: Install Regulator and Reduce Hammer Weight
I installed an Altaros regulator to flatten out the shot string. I chose the Altaros because unlike other regulators, it allows the rifles pressure gauge to keep telling the air pressure inside of the reservoir. The installation also doesn’t require the reservoir to be drilled and is 100% reversible.
Reduced the hammer weight to increase shot count. The Air Arms does not have a screw to adjust the hammer spring tension with, or I’d have gone that route instead. I planned to start with as light of a hammer as I could get and to add weight back to the hammer until the best weight was found.
I weighed my stock hammer and guide and headed over to a local gunsmith to see what he could do for me. 20 minutes later my hammer weighed 29.8 grams and looked like this:
The Data: I installed the regulator and new light hammer. I decided to adjust the regulator settings first with the 29.8 g hammer. The results were:
The regulator seemed to struggle if set too low or too high. This surprised me. The shot count did not go up when set to a low 100 BAR and the velocity didn’t go up when set to 145 or 150 BAR. I’m not sure how to interpret the results other than to think the regulator is not working very well. Comments or advice?
The most promising setting to me was at 135 BAR. The 1st 40 shots had an average velocity of 813 fps (26.6 FPE) with a respectable 2.7 fps standard deviation. The shot string is shorter than I want, but none of the settings I tested seem to get me where my goal is (50 shots).
Hammer Adjustment Data:
Having settled on 135 BAR to test hammer weight adjustments, I reset the regulator and went about changing the hammer mass. I accomplished this by wrapping thin copper wire around the hammer. Electrical tape was then wrapped tightly around the wire to keep it from unwinding.
As suspected, the lightest hammer weight gave the longest shot string of about 46 shots. As the hammer weight climbed, the velocity climbed but the shot count dropped. Since my goal is 50 regulated shots, It appears I have to keep the hammer in the 29.8 to 33 gram range.
Important Note: The data for the 29.8 gram hammer is lower in velocity but higher in shot count than the previous test. I suspect this is because significant estimation is required to set the Altaros regulator. There are no markings made between 100 and 150 BAR. I therefore assume that the reg setting for this data is slightly lower than that of the previous data set. This might be a clue that I can get my shot count up with a slightly lower regulator setting. I opened the rifle back up and lowered the regulator setting a very small adjustment. I then again collected data on the 29.8 gram hammer to compare:
The shot string did indeed get longer. I hope the extra shots didn’t come from accidently adding more air into the reservoir than before. It is here that I really wish the Air Arms had a digital pressure gauge. I have been using the gauge on my air tank instead of my gun to try to keep the fill amount the same each test. Even that gauge is not very precise.
I notice that the velocity of the shots rose for a few shots at the end of the 29.8 g data. This rise caused the standard deviation of the shot string over 50 shots to be the same as that for the 32.9 g hammer weight shot string that dropped when off the regulator. Does this indicate that a slightly higher regulator setting is better? Would it remove the hump at the end of the shot string?
