4.8lb AR-15 build for $650

[titanhank]

I went and took some pictures to show why it may not be a good idea to run a carbine buffer in a rifle tube without a bumper.

The buffers are two different lengths. This could matter...but why?

Well this is the bcg pressed fully against a rifle buffer, rifle spring in a rifle tube. Notice the space left between the gas key on the carrier and the receiver.

The gas key never contacts the receiver during the recoil cycle.

Here is the carbine buffer, rifle spring in the rifle tube.

See how they touch?

If the gas system is perfect, then maybe it's not a problem. But if the key is contacting the receiver as the rifle cycles, then you may have problems down the road.

I see what you mean about the length after taking it all apart and looking at it. I think i have 2 options on this. I can either take my existing rifle buffer and put aluminum weights in it to match the carbine buffers 3ozs or order a jp lightweight rifle buffer. It is 3oz and $59.95. This will give me the protection of the correct length buffer and the 3 oz weight i am looking for.

Thanks for the tips. It just took me a little while to realize exactly what you were showing in you pictures. I will still have a 4.9lb rifle, but it will just cost another $60 to do it.

ALWAYS LEARNING!!!

 

[user 71]

I see what you mean about the length after taking it all apart and looking at it. I think i have 2 options on this. I can either take my existing rifle buffer and put aluminum weights in it to match the carbine buffers 3ozs or order a jp lightweight rifle buffer. It is 3oz and $59.95. This will give me the protection of the correct length buffer and the 3 oz weight i am looking for.

Thanks for the tips. It just took me a little while to realize exactly what you were showing in you pictures. I will still have a 4.9lb rifle, but it will just cost another $60 to do it.

ALWAYS LEARNING!!!

I am not the biggest fan of spikes (though I SBRd one of their lowers) but they do offer this, which could possibly help you out:

http://www.spikestactical.com/lower-parts-spikes-stt0-buffer-spacer-p-709.html

It may work for you and keep you from having to go the rifle buffer route.

Edit: requires a carbine spring which can be had for less than $5.

 

[titanhank]

I am not the biggest fan of spikes (though I SBRd one of their lowers) but they do offer this, which could possibly help you out:

http://www.spikestactical.com/lower-parts-spikes-stt0-buffer-spacer-p-709.html

It may work for you and keep you from having to go the rifle buffer route.

Edit: requires a carbine spring which can be had for less than $5.

Thanks, but it is 3ozs. It defeats the purpose of using a carbine buffer. The rifle bufer is 5.2oz.

 

[titanhank]

Guys, here is what i did to fix the buffer issue. I took the rifle buffer that came with the ace stock kit and took all the weights out. It started at 5.2oz and after removal of the weight, it came in at 1.6oz. I thought i would have timing issues, but it ran perfect through 2 mag dumps of monarch steel case ammo. This brought the final weight of the rifle to 4lb 13.2oz or 4.8lbs. I have matched the weight of the mag tactical rifle using off the shelf components and reduced the cost by $10 to $647 total. I think i am done with this one except for adding optics. I will update the first post to reflect the change in the parts list.

 

[Sneakypete]

Awesome info thread, I will be weighing mine tonight

 

[titanhank]

Awesome info thread, I will be weighing mine tonight

Let us know what it weighs. If anyone has beat 4.8 lbs without spending $500 on an aluminium BCG, i would love to know how. This rifle is stupid light.