Ultralight Ultralight Rifles

[KyleR1985]

I use the PRI modified mags from cavity back. Easy enough to modify them. But not that much more money to have them do it more efficiently.

Note* the edges of the ones modified by cavity back are very, very sharp inside. Do not stick your finger in the slot from front and slide it up and down. You will bleed a lot.

Mags are not my COAL limiter - mag well and upper/barrel extension are.

Can load to 2.35 with no issue. Plan to have that to 2.4 soon.

 

[Trackselk]

I use the PRI modified mags from cavity back. Easy enough to modify them. But not that much more money to have them do it more efficiently.

Note* the edges of the ones modified by cavity back are very, very sharp inside. Do not stick your finger in the slot from front and slide it up and down. You will bleed a lot.

Mags are not my COAL limiter - mag well and upper/barrel extension are.

Can load to 2.35 with no issue. Plan to have that to 2.4 soon.

I wanted to run longer COAL, but the lands on the Shaw only afford 2.35 (62 grain DRT'S) and that's jammed, so maybe 5 thousandths over the standard 2.25, which is insignificant. I'll see how it shoots, and if it's not amazing I might have my Smith ream it longer. Have you measured your barrel by chance with some 77's or??

 

[KyleR1985]

I wanted to run longer COAL, but the lands on the Shaw only afford 2.35 (62 grain DRT'S) and that's jammed, so maybe 5 thousandths over the standard 2.25, which is insignificant. I'll see how it shoots, and if it's not amazing I might have my Smith ream it longer. Have you measured your barrel by chance with some 77's or??

 

[Piker73]

Merry Christmas everyone. Been following the whole thread and been very interested. I bought the BCA bolt action upper. I pulled the barrel and replaced it with an Alexander Arms 11.5” 6.5 Grendel barrel and matched bolt. Tested it last week with wolf steel case 110 grain. No problems extracting or feeding.

 

[Thegman]

View attachment 811373View attachment 811375

That's about what my 77TMKs load to in my Shaw (2.45ish). 2.3 ish seems pretty short.

 

[Dukhtr3]

Merry Christmas everyone. Been following the whole thread and been very interested. I bought the BCA bolt action upper. I pulled the barrel and replaced it with an Alexander Arms 11.5” 6.5 Grendel barrel and matched bolt. Tested it last week with wolf steel case 110 grain. No problems extracting or feeding.

Did you by chance weigh the stripped action and bolt?

Sent from my Pixel 7 Pro using Tapatalk

 

[Trackselk]

Christmas recipe for you all:
Holds 3 as is, 4 with a little trimming. Just make it longer if you want more rounds. Next I'll "window" it for longer rounds, and probably drill some holes for a little more weight loss. Figure I can window it for 2-3 rounds for longer COAL without violating the top spot weld, which would probably ruin it (unless you weld thin aluminum...).

Easy with a hack saw blade, dremel cutting wheel, and a tiny file. Just slice open the end and use the hacksaw blade inside to cut or start the notches in the 'ribs'.
Almunium mag. I may change the follower to the "slicker" shiny duramag follower as it's feeding a little rough as is.

- steel mags will still give a longer COAL when you cut them, but it won't be much. I'll report back how the cut-out goes.

-Going to trim the little tab off and some other finishing touches.

Here are the mags, I think the duramag has a better follower, so that'd be my first choice. I'll be swapping the follower next, and probably avoid 'Swiss-cheesing' it, as it's solid and I don't want to waste another 2 hours for 2 tenths of an ounce.
Worst case,the duramag weights about 0.05 oz more after being cut down, and probably closer to 0.025oz more. The asc mag just has a rough textured follower...

Update: a little follower trim and it easily holds 4 rounds.

ASC AR-15 .223 / 5.56 30-Round Aluminum Magazine
SKU: 30-223-AL-OD-O-ASC
Color: Olive Drab Green

Duramag Speed AR-15 30 Round Aluminum Magazine - .223/5.56 NATO

 

[Taudisio]

Has there been a consensus on which magazine works best with the Solo 300 or is maybe the lightest to accompany these ULs?

I second the duramags that @Thegman suggested. Go with stainless steel and “window” them yourself for the longest coal.

 

[Piker73]

Did you by chance weigh the stripped action and bolt?

Sent from my Pixel 7 Pro using Tapatalk

I didn’t, to be honest just wanted to see how well it functioned. I will get a weight tomorrow and post it.

 

[Lentuk]

This slide charger or the new bolt action?

 

[Trackselk]

@KyleR1985
Definitely worth it with those long tipped bullets, I might even single feed if I ever get the 79gr DRT'S that I'm waiting for. Been out of stock a while. Was thinking of backing up my reloads with a mag full of factory stuff, just gotta make a longer dope chart...
-and throat the barrel longer

 

[passinggas33]

Christmas recipe for you all:
Holds 3 as is, 4 with a little trimming. Just make it longer if you want more rounds. Next I'll "window" it for longer rounds, and probably drill some holes for a little more weight loss. Figure I can window it for 2-3 rounds for longer COAL without violating the top spot weld, which would probably ruin it (unless you weld thin aluminum...).

Easy with a hack saw blade, dremel cutting wheel, and a tiny file. Just slice open the end and use the hacksaw blade inside to cut or start the notches in the 'ribs'.
Almunium mag. I may change the follower to the "slicker" shiny duramag follower as it's feeding a little rough as is.

-Going to trim the little tab off and some other finishing touches.

Can't seem to find these exact ones on their website. How long ago did you purchase them? Any chance there is a model number anywhere on them?

 

[Trackselk]

Can't seem to find these exact ones on their website. How long ago did you purchase them? Any chance there is a model number anywhere on them?

I'll be home tomorrow and try to remember to post the specs. I remember they were the 30 round ones. I think the duramag one I have is identical. It was 0.1oz heavier on the kitchen scale, but that's likely the follower + spring which are slightly different.

 

[passinggas33]

I'll be home tomorrow and try to remember to post the specs. I remember they were the 30 round ones. I think the duramag one I have is identical. It was 0.1oz heavier on the kitchen scale, but that's likely the follower + spring which are slightly different.

I didn't realize that you had taken standard aluminum mags and trimmed them down yourself. I thought those were some sort of "factory" ones. Thanks for helping explain that. Appreciate it.

 

[Trackselk]

I didn't realize that you had taken standard aluminum mags and trimmed them down yourself. I thought those were some sort of "factory" ones. Thanks for helping explain that. Appreciate it.

Yeah, I was rushing out the door, I'll keep adding to the post until I get it right YW

 

[Piker73]

The new BCA 23 degree throw bolt action

 

[KyleR1985]

The new BCA 23 degree throw bolt action

Please take this thing apart and take lots of pictures and share here!

 

[Trackselk]

Can't seem to find these exact ones on their website. How long ago did you purchase them? Any chance there is a model number anywhere on them?

I bought them just the other day. Updated the original post with the 2 mags of choice.

 

[passinggas33]

I bought them just the other day. Updated the original post with the 2 mags of choice.

Thank you. This is all starting to make more sense now.

 

[KyleR1985]

I’m new to reloading. Don’t take advice from me, just data.

That said, I found a stupid thing while messing with chamber measurement and trying to load long. With the hornady modified case tool -

if I put the whole bullet in the case, run it into the chamber, and then push the bullet into the lands with the rod, I’d get a shorter measurement than if I dropped the bullet into the bore, then ran the case up behind it and pushed rod to seat it into the lands. This only happened with the 95tmk, but didn’t try it with others.

Figured what was happening was the bullet was coming out of the modified case at slight angle, and contacting lands on only one side, short of the real measurement.

This could be happening to you?


I pulled my hair out for a half hour until I figured it out.

I wanted to run longer COAL, but the lands on the Shaw only afford 2.35 (62 grain DRT'S) and that's jammed, so maybe 5 thousandths over the standard 2.25, which is insignificant. I'll see how it shoots, and if it's not amazing I might have my Smith ream it longer. Have you measured your barrel by chance with some 77's or??