coloradokevin
Member
- Joined
- Mar 22, 2008
- Messages
- 3,285
I have been piecing together a lightweight AR-15 build for a while now, and I finally weighed the rifle last night. I built this off of an 80% lower, and I plan to Cerakote the bare upper receiver when I finish piecing everything together.
The good news is that this thing is light; the lightest I've ever built. It tips the scales at a mere 4.296 pounds (68.7 ounces). The bad news is that I was targeting a build of less than 4 pounds.
Here's where I've saved weight so far:
1) Pencil barrel
2) lightweight steel BCG
3) Ultralight carbon fiber hand guard (seriously the lightest one I think is made).
4) Ultralight carbon fiber buffer tube/stock (again, the lightest I could find).
5) Ultralight Taccom buffer.
6) Ultralight backplate.
7) Ultralight castle nut.
My goal was to come in at less than 64 ounces, so I'm 4.7 ounces overweight at the moment. I also don't have the forward assist or dust cover installed at the moment, though I'm thinking of a forward assist plug, and a lightweight dust cover. I will also add that I elected to use a 16" barrel, rather than a shorter barrel with a pinned muzzle device.
While I may or may not do anything else to this rifle, where would you look to shave weight at this point, if you were trying to do so? I worry that further decreases in weight might come with substantial decreases in reliability or durability, and will only arrive at significant additional cost. I originally set out to build this rifle with the goal of making a lightweight rifle my wife would enjoy (she's 105 pounds). But, the addiction of going lighter took hold, and the goal of breaking 4 pounds is strong. NOTE: I know there is no need to go lighter, it's really just a goal I'm exploring here, as a proof of concept!
Here are my ideas, and my reservations on each of these:
1) I could go with an aluminum BCG, and that would probably make up most of the difference between my goal and my current weight. But, aluminum BCG's aren't known for reliability or longevity.
2) I could save maybe an ounce with an ultralight compensator in place of the A2 flash hider. No real downfall here other than $$$.
3) I could go with an ultralight gas block, though the adjustable gas block I am currently using is pretty darn light, and adjustability is something I consider pretty necessary with the low mass BCG and low mass buffer.
4) I could buy ultralight hardware for the lower. However, this stuff is really expensive for a marginal savings in weight.
5) I could go with a lightweight receiver set, instead of a standard receiver set. This might save the most weight, but with potentially a great increase in cost, an inability to use the receiver I milled myself, and potential durability issues (I've heard of magnesium receivers cracking, and can't even find those for sale these days, and I've heard plenty of problems with polymer receivers).
6) I could start drilling or cutting pieces from the receiver for weight savings. I worry that this would look like a hack-job, because I don't have CNC equipment to do this! Also, I'm not sure how much weight I could save without compromising strength on critical components.
Anyway, the attached pictures show the rifle as it currently sits. And, no, I didn't design it to match the trash can... that just happened by accident! And, normally the wife looks a lot happier, except when I drag her away from writing an e-mail to hold a rifle for a picture (she'd kill me if she knew I was posting it anyway). The upper will eventually be Cerakoted to either match the lower, or change the entire color of the finished rifle.
The good news is that this thing is light; the lightest I've ever built. It tips the scales at a mere 4.296 pounds (68.7 ounces). The bad news is that I was targeting a build of less than 4 pounds.
Here's where I've saved weight so far:
1) Pencil barrel
2) lightweight steel BCG
3) Ultralight carbon fiber hand guard (seriously the lightest one I think is made).
4) Ultralight carbon fiber buffer tube/stock (again, the lightest I could find).
5) Ultralight Taccom buffer.
6) Ultralight backplate.
7) Ultralight castle nut.
My goal was to come in at less than 64 ounces, so I'm 4.7 ounces overweight at the moment. I also don't have the forward assist or dust cover installed at the moment, though I'm thinking of a forward assist plug, and a lightweight dust cover. I will also add that I elected to use a 16" barrel, rather than a shorter barrel with a pinned muzzle device.
While I may or may not do anything else to this rifle, where would you look to shave weight at this point, if you were trying to do so? I worry that further decreases in weight might come with substantial decreases in reliability or durability, and will only arrive at significant additional cost. I originally set out to build this rifle with the goal of making a lightweight rifle my wife would enjoy (she's 105 pounds). But, the addiction of going lighter took hold, and the goal of breaking 4 pounds is strong. NOTE: I know there is no need to go lighter, it's really just a goal I'm exploring here, as a proof of concept!
Here are my ideas, and my reservations on each of these:
1) I could go with an aluminum BCG, and that would probably make up most of the difference between my goal and my current weight. But, aluminum BCG's aren't known for reliability or longevity.
2) I could save maybe an ounce with an ultralight compensator in place of the A2 flash hider. No real downfall here other than $$$.
3) I could go with an ultralight gas block, though the adjustable gas block I am currently using is pretty darn light, and adjustability is something I consider pretty necessary with the low mass BCG and low mass buffer.
4) I could buy ultralight hardware for the lower. However, this stuff is really expensive for a marginal savings in weight.
5) I could go with a lightweight receiver set, instead of a standard receiver set. This might save the most weight, but with potentially a great increase in cost, an inability to use the receiver I milled myself, and potential durability issues (I've heard of magnesium receivers cracking, and can't even find those for sale these days, and I've heard plenty of problems with polymer receivers).
6) I could start drilling or cutting pieces from the receiver for weight savings. I worry that this would look like a hack-job, because I don't have CNC equipment to do this! Also, I'm not sure how much weight I could save without compromising strength on critical components.
Anyway, the attached pictures show the rifle as it currently sits. And, no, I didn't design it to match the trash can... that just happened by accident! And, normally the wife looks a lot happier, except when I drag her away from writing an e-mail to hold a rifle for a picture (she'd kill me if she knew I was posting it anyway). The upper will eventually be Cerakoted to either match the lower, or change the entire color of the finished rifle.