Ultralight Ultralight Rifles

[C Bow]

Well this is my first try at a ul build but I thought I would share some progress i am lucky enough to work with some old nascar people so I ask them about the mods to this lower

 

[packgoatguy]

Well this is my first try at a ul build but I thought I would share some progress i am lucky enough to work with some old nascar people so I ask them about the mods to this lower

Is that a Tennessee arms carbon15 that has been skeletonized?

 

[C Bow]

Yes

 

[C Bow]

Pic

 

[C Bow]

I have ti mag release and ti pivot pins and smoke composite buffer tube plate coming

 

[packgoatguy]

I have ti mag release and ti pivot pins and smoke composite buffer tube plate coming

Very cool! And if you want to shave a few more grams, I've found that the poly mag release works great, and is a bit lighter than the ti. Also, it doesn't look as good... but the I've just ditched the buffertube plate entirely. Saves a few more grams.

 

[C Bow]

Please post pic of the rear of your lower so I can understand

 

[packgoatguy]

Please post pic of the rear of your lower so I can understand

 

[C Bow]

So the small hole on bottom right that the take down pin and spring goes in I am guessing you leave out ?

 

[packgoatguy]

So the small hole on bottom right that the take down pin and spring goes in I am guessing you leave out ?

I do personally. It works fine for me. Some have noted previously that it also works to install the spring and detent and cap the hole with a tiny screw or shove in a small piece of plastic with a dab of superglue to hold in the spring.

 

[C Bow]

I got it I appreciate the help Thanks

 

[Trackselk]

@KyleR1985
So the best way I know of is you jam the bullet into the rifling with idk 15 lbs of force roughly, and then when you pull the case out the bullet stays put, jammed in the rifling. Sometimes I have to use a cleaning rod to slightly tap it out, shouldn't take any real force. This assures you are "jammed" and centered. That's my max COAL. I then subtract 10-20 thou as a starting point.

Edit: just gotta make the modified case a loose fit on the bullet. I had to sand down a bullet for a good fit recently. Don't enlarge the modified case...
And I press the bullet into the rifling with the hornady tool you mentioned
*do this procedure twice, and you should have 2 very close measurements. Use the shortest, and I always subtract for some jump.
*also, when you put the bullet back in the case still attached to the locked down tool, and measure tip to head, this is your COAL not OAL if I'm not mistaken. I edited that above.

 

[David Walter]

Have a friend that does similar, but he lubes the loaded-long bullet after seating and then jams the loaded dummy round into the chamber.

Comes back out easily, and doesn’t leave the bullet stuck in the bore.

 

[Trackselk]

Have a friend that does similar, but he lubes the loaded-long bullet after seating and then jams the loaded dummy round into the chamber.

Comes back out easily, and doesn’t leave the bullet stuck in the bore.

Makes sense, definitely 6 ways to skin a cat. I prefer that it sticks in the rifling so I'm 100% sure it's where it should be. But, if anything, coming up a little short is safe, not so much if you load them too long. As always, for the new guys, start low and work up!
-half the time I can lightly tap the butt on the floor and the bullet falls out.

 

[Trackselk]

The beauty of this cut off buffer tube setup, is that you can screw the entire stock/tube off and be much shorter and more compact for the pack in a few seconds. No need to bother with an expensive and heavy folder...

 

[ezwy]

So the small hole on bottom right that the take down pin and spring goes in I am guessing you leave out ?

You can get a rear detent screw and just thread it right into the plastic. It will hold the spring in without the plate.

 

[Taudisio]

You can get a rear detent screw and just thread it right into the plastic. It will hold the spring in without the plate.

I did the same thing. I put a dab of superglue (with a pinch of baking soda) on the back to ensure it never backs out.

 

[Piker73]

Here pictures of the BCA 23 degree bolt throw. There are the weights and some comparisons to the gen 2 solo upper.

 

[KyleR1985]

Here pictures of the BCA 23 degree bolt throw. There are the weights and some comparisons to the gen 2 solo upper.

How does the bolt on the BCA lock into the lugs in barrel extension? Does whole bcg rotate, or just the bolt?

Does the bolt handle attach to the bolt or the carrier?

 

[Piker73]

if you look at the bolt carrier you will notice the cam pin channel is cut straight in line with the bolt. When you rotate the bolt the 23 degrees you rotate the bolt.