Home on the (Airgun) Range
Aug. 4th, 2018 09:26 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
thisnewdayMy Benjamin Trail NP-2 has been standing idle in my closet in part because, at 30 lbs, the cocking effort is quite substantial, especially for a guy of my age and stature.
The "NP" stands for nitro piston, which is what powers the rifle. It takes the place of the coiled steel spring which was used in earlier "break barrel" rifles and is still found today in cheaper guns.
"Break barrel" means that the barrel is "hinged," about two feet from its "business end," where it connects to the mechanism which compresses the gas piston and holds it in place until released by pulling the trigger.
My own NP-2 was chronographed at a consistent velocity of 850 feet per second using 12.3 grain .22 pellets. I know this because, before the rifle was shipped to me from PyramydAir, I had it test-fired and chrono-ed in their shop and all 20 of the test rounds left the muzzle at a speed of 850 fps or better.
The advantage of the nitro piston is that it's not only quieter and performs more consistently under varying conditions than its coiled steel counterpart, but it also eliminates the sort of "double recoil" which is characteristic of "springers" and is problematic for what it does to accuracy in general and to scopes in particular.
To achieve that kind of velocity, though, requires considerable force out at the end of, basically, a two-foot lever which, in this case, is the end of the barrel.
Ironically, I chose this rifle because it required the least cocking effort in its class and I wanted my daughter to be able to use it as well. The irony is that she's been working out, lately, and handles it as well or better than I do. Even so, she readily admits that it's a workout all on its own.
Being somewhat familiar with the market, I knew that there is also a pistol version of the BT and that it uses a detachable barrel extension to help with cocking, even though its nitro piston is obviously smaller. And so my first attempt at building a cocking aid for my rifle was to make a similar extension from a length of 1" PVC pipe.
The PVC fits almost perfectly over the suppressor, which encases the full length of the barrel from the point where it breaks to the end of the muzzle. And, because PVC is a type of plastic, it won't mar or otherwise damage the barrel.
However, this AIN'T your daddy's Daisy air rifle. Or the one you might've had when you were a kid. It probably weighs as much, and has a slightly longer barrel, than its powder-burning counterpart, the Ruger .22 LR. So any extension that I added to the barrel was going to be limited by my own reach and that, as it turned out, wasn't gonna be enough.
In the meantime, I'd been reading some of the airgunner's blogs and found out that I wasn't the only one with this problem. All of them loved the BT for its amazing range, accuracy, and consistency but complained about having to take time off from work for the resulting shoulder surgery and physical therapy, LOL.
One guy even joked that he'd considered putting the barrel in the crotch of a tree and breaking the stock towards it in order to cock the firing mechanism and open the breech for loading. Which, in fact, gave me an idea.
Which was that, instead of breaking the barrel with my PVC lever, I'd somehow mount the PVC vertically on my shooting platform, insert the muzzle into it from above, and break the stock downwards with the barrel held in place instead of vice versa.
Having not found what I needed at Home Depot, either in the store or at the website, I took a drive out to Lowe's this evening and found something that I think may work.
What I found was a whole assortment of specialty metal components manufactured in South Africa by a company called Steel Tek. They're very heavy duty, which I need them to be, but so are their prices. I'd spent about 5 bucks, to fabricate my barrel extension, while my new design, using Steel Tek components, was gonna cost about *gulp* 10 times that.
By the time I'd figured it all out and gotten it priced, they were kicking me out of the store in order to close for the night. Which has given me the time I needed, overnight, to rationalize the expense with nonsense like, "I'm doing it for my daughter" or, "That's a lot less money than an orthopedic surgeon would charge to fix my shoulder."
So, yeah, I came home and scribbled out a schematic and parts list and tomorrow I'll probably go back and get the pieces. Unless, of course, my daughter hears about it first and threatens to shoot me with a real gun, LOL.
Which means that we don't mention this to her, K?
LPK
Dreamwidth
8.4.2018
The "NP" stands for nitro piston, which is what powers the rifle. It takes the place of the coiled steel spring which was used in earlier "break barrel" rifles and is still found today in cheaper guns.
"Break barrel" means that the barrel is "hinged," about two feet from its "business end," where it connects to the mechanism which compresses the gas piston and holds it in place until released by pulling the trigger.
My own NP-2 was chronographed at a consistent velocity of 850 feet per second using 12.3 grain .22 pellets. I know this because, before the rifle was shipped to me from PyramydAir, I had it test-fired and chrono-ed in their shop and all 20 of the test rounds left the muzzle at a speed of 850 fps or better.
The advantage of the nitro piston is that it's not only quieter and performs more consistently under varying conditions than its coiled steel counterpart, but it also eliminates the sort of "double recoil" which is characteristic of "springers" and is problematic for what it does to accuracy in general and to scopes in particular.
To achieve that kind of velocity, though, requires considerable force out at the end of, basically, a two-foot lever which, in this case, is the end of the barrel.
Ironically, I chose this rifle because it required the least cocking effort in its class and I wanted my daughter to be able to use it as well. The irony is that she's been working out, lately, and handles it as well or better than I do. Even so, she readily admits that it's a workout all on its own.
Being somewhat familiar with the market, I knew that there is also a pistol version of the BT and that it uses a detachable barrel extension to help with cocking, even though its nitro piston is obviously smaller. And so my first attempt at building a cocking aid for my rifle was to make a similar extension from a length of 1" PVC pipe.
The PVC fits almost perfectly over the suppressor, which encases the full length of the barrel from the point where it breaks to the end of the muzzle. And, because PVC is a type of plastic, it won't mar or otherwise damage the barrel.
However, this AIN'T your daddy's Daisy air rifle. Or the one you might've had when you were a kid. It probably weighs as much, and has a slightly longer barrel, than its powder-burning counterpart, the Ruger .22 LR. So any extension that I added to the barrel was going to be limited by my own reach and that, as it turned out, wasn't gonna be enough.
In the meantime, I'd been reading some of the airgunner's blogs and found out that I wasn't the only one with this problem. All of them loved the BT for its amazing range, accuracy, and consistency but complained about having to take time off from work for the resulting shoulder surgery and physical therapy, LOL.
One guy even joked that he'd considered putting the barrel in the crotch of a tree and breaking the stock towards it in order to cock the firing mechanism and open the breech for loading. Which, in fact, gave me an idea.
Which was that, instead of breaking the barrel with my PVC lever, I'd somehow mount the PVC vertically on my shooting platform, insert the muzzle into it from above, and break the stock downwards with the barrel held in place instead of vice versa.
Having not found what I needed at Home Depot, either in the store or at the website, I took a drive out to Lowe's this evening and found something that I think may work.
What I found was a whole assortment of specialty metal components manufactured in South Africa by a company called Steel Tek. They're very heavy duty, which I need them to be, but so are their prices. I'd spent about 5 bucks, to fabricate my barrel extension, while my new design, using Steel Tek components, was gonna cost about *gulp* 10 times that.
By the time I'd figured it all out and gotten it priced, they were kicking me out of the store in order to close for the night. Which has given me the time I needed, overnight, to rationalize the expense with nonsense like, "I'm doing it for my daughter" or, "That's a lot less money than an orthopedic surgeon would charge to fix my shoulder."
So, yeah, I came home and scribbled out a schematic and parts list and tomorrow I'll probably go back and get the pieces. Unless, of course, my daughter hears about it first and threatens to shoot me with a real gun, LOL.
Which means that we don't mention this to her, K?
LPK
Dreamwidth
8.4.2018
