3 replies to this topic

[owmyquach]

Hey guys, I've been working on what you can call an aluminum Longshot priming "bracket" and ran into some issues, and just wondering if anyone has tried to attempt this before or have any useful tips they can give me. So the purpose of the bracket is similar to a LS shotgun fore grip where it keeps the priming handle straight by keeping the pressure of pulling the handle back with a strong replacement spring, except located in the back (I quite like the stock look of a LS and don't like carving them up). Here's a picture of it...



I drilled 2 holes for the priming handle "bar" to feed through, and since I am right handed and prime with my left, i made the right side hole a bit further up so there is always more pressure on the right handle than the left to keep it straight.

Okay here are my problems. One is that when I prime with it on, the top (picture of top will be below) bends when I prime, due to a necessarily thin bar to have enough room to go forward a bit more to not hit the prime indicator and the stock. I have tried to reinforce it, but it seems like I cannot find an epoxy or adhesive to keep extra aluminum reinforcement pieces on it. The bracket is already 0.032" aluminum, but I have to make it thinner since it presses up to the sides of the LS too much (which is another problem). I left extra space up top to add reinforcement.
The second problem is that the holes on the bracket aren't super precise so the bracket tends to rattle. I want to find a sort of washer or spacer to fit onto the bracket, or onto the priming bar to make the fit tighter and make it have a bigger area of contact to the bracket.



Not primed


Primed

[Carbon]

If you're trying to replicate some of the functionality of a shotgun foregrip, take a look and see how your design differs from the known, working design:

1) A shotgun foregrip is primed from the middle, rather than the side (this reduces twisting, binding action).
2) They are typically made out of PVC or polycarbonate, which is much thicker.
3) A shotgun attachment's handle is several inches long, helping it to resist twisting.

So, you have a bunch of issues working against you here. You're working with very thin aluminum, you've cut it into a flexy shape, and are priming it in a way that the shotgun attachment isn't used (really, a shotgun attachment's function isn't acting as something to resist twisting: it's serving as two pushrods that direct force against both sides of the priming rod equally.)

Long story short, thin aluminum isn't going to work for you.You may be better off with polycarbonate sheets screwed into a thicker sheet going over the top, or even a chunk of .5" wood. It's still going to bind, though, just based on how you're priming it, and the space you're working with.

Edited by Carbon, 05 August 2012 - 10:40 AM.

[zx532]

To add on to what Carbon said

To avoid binding you could have it going all the way around the stock somehow (but it would be a bit of a pain)
your best bet actually would probably just be to put a handle on it (something like the handle on the hailfire clip advance handle. seen in the video here)
you could do it with two pieces of the aluminum you have for the sides (but I would suggest against that, as it is a bit on the thin side) And then some PVC, or wood as the cross handle.

It would have the same effect, and would maintain the stock's ability to move back and forth.

On an unrelated note, I noticed what appeared to be the drill "skipping" across the surface of the aluminum where you drilled the hole. you can avoid that by taking a punch (or just a nail) and nailing it into the metal where you want the center of the hole to be (just enough to dent it, Dont bother trying to get it all the way through)

[owmyquach]

If you're trying to replicate some of the functionality of a shotgun foregrip, take a look and see how your design differs from the known, working design:

1) A shotgun foregrip is primed from the middle, rather than the side (this reduces twisting, binding action).
2) They are typically made out of PVC or polycarbonate, which is much thicker.
3) A shotgun attachment's handle is several inches long, helping it to resist twisting.

So, you have a bunch of issues working against you here. You're working with very thin aluminum, you've cut it into a flexy shape, and are priming it in a way that the shotgun attachment isn't used (really, a shotgun attachment's function isn't acting as something to resist twisting: it's serving as two pushrods that direct force against both sides of the priming rod equally.)

Long story short, thin aluminum isn't going to work for you.You may be better off with polycarbonate sheets screwed into a thicker sheet going over the top, or even a chunk of .5" wood. It's still going to bind, though, just based on how you're priming it, and the space you're working with.

I had some metal supports on the sides on my thinner "MARK I" steel bracket I made first as an idea and it worked out pretty well (although my epoxy came off after awhile). The bracket has the idea of keeping the priming bar straight which prevents the priming handle to not catch properly if it gets too crooked. I would think it does give some extra force on the opposite side if it worked more as I plan (probably if the flexing was gone), since the bracket is keeping constant pressure on the opposite side.

To add on to what Carbon said

To avoid binding you could have it going all the way around the stock somehow (but it would be a bit of a pain)
your best bet actually would probably just be to put a handle on it (something like the handle on the hailfire clip advance handle. seen in the video here)
you could do it with two pieces of the aluminum you have for the sides (but I would suggest against that, as it is a bit on the thin side) And then some PVC, or wood as the cross handle.

It would have the same effect, and would maintain the stock's ability to move back and forth.

On an unrelated note, I noticed what appeared to be the drill "skipping" across the surface of the aluminum where you drilled the hole. you can avoid that by taking a punch (or just a nail) and nailing it into the metal where you want the center of the hole to be (just enough to dent it, Dont bother trying to get it all the way through)

Thanks for the drill "skipping" tip, helps a ton with making things looking good.