Ultralight Ultralight Rifles

[Taudisio]

If someone finds an aluminum bcg for under $70 shipped, let me know. I’ll order it and give the smith one to play with and make a bolt or two. It just MIGHT give a little more leverage for the larger cases, and I have an arc upper I can turn the gas off and try it

 

[ChrisAU]

I still haven’t even shot my 10” 350 Legend. Just no time and too hot. I need to get after it before I wind up putting the upper in the classifieds lol.

 

[David Walter]

I think the 350L in a short AR with a can might be a good house gun. My 16” 300 HAMR Predator stands that watch these days.

 

[Big_wals]

That doesn't look functionally different from the KaliKey, and the KaliKey conversion uses your existing parts.

At a fraction of the cost. I'm thinking of a KaliKey and a JP low mass bolt for my Faxon-Barreled 6 ARC.

As a minimum, the buffer should be expendable, as it's function is taming bolt travel.

I just sent this question to KaliKey:

Does the KaliKey system require a spring to keep the bolt in battery or locked?

I wouldn't think so.

If not, this would allow the addition of folding stocks vs. traditional AR stocks with tubes.

See this conversation for back ground on the growing bolt action AR movement.

Ultralight Ultralight Rifles

I posted some info on the 77TMK thread about my experience on trying out the 77TMK on this black bear. There was some interest in the rifle used so I'm posting some info about the whys and hows on some of what I've put together over the last year or so. I've been carrying lightweight bolt...

rokslide.com

Wow, great thread guys! Some really cool builds in here. Tagging in to see what reply you get from KaliKey.

 

[Taudisio]

....Ultralight-Ultralight Summer Special Olympics...

Taudisio and I came up with a plan for baseline rules for the Summer Special Olympics.

Weigh your rifle with optics (and bipod if you run it that way). Don't worry about mag, ammo, sling etc.

Rifle weight as above has to be under 5# to qualify for the Special Olympics.

Post actual 5-shot group size and adjusted "handicap" group size.

In order to not to have arbitrary weight classes, blah, blah, blah, we decided on a simple "handicap factor" and "handicap group size" especially for people shooting the lightest and heaviest Ul-Uls

Handicap group size is your actual group size multiplied by the Special Olympics "handicap factor" which is your rifle’s weight to the nearest ounce divided by 4# (4# is the somewhat arbitrary "standard Ultralight-Ultalight rifle weight" as that seems to be around where they typically land with optics.)

So, for example, if your rifle weight is 4# 9oz, your "handicap factor" is 73(oz)/64(oz) = 1.14

Handicap group size would be actual group size x 1.14.

I think actual group size is still the most interesting, but I'm hoping I can maybe win a Participation Trophy.

All that said, the basics:
5# upper limit
4# "Standard Weight"
8" Paper plate with 1" circle drawn in the center.
200 yards
Hunting field position of choice (preferably shot how the shooter actually shoots at game at distance - e.g. mine will be prone off my pack)
Post picture of your plate(s) on your rifle(s) with notes written about:
•Rifle Weight
•Cartridge and bullet
•Actual 5-Shot Group Size (center to center)
•Handicap Group Size

Once we get through the 200 yard baseline, feel free to move out further in whatever 50 yard increments you wish to and post those too.

I know this is kind of goofy, but I'm really interested to see how people do, especially myself. I haven't done any systematic field testing like this and it will be pretty helpful for me.

I plan on shooting my big-boy rifles at the same time and seeing what difference there is. I know I make consistent hits with them out to 300 yards or so (which is as far as I typically shoot at game) and have never bothered doing this with them either.

I did some thinking on this, since I am under 4lbs, I get a bonus smaller group? Say I shoot a 3” group, and rifle weight 3lb 12oz 60oz/64=.9375x3”=2.8125” handicapped group sized. Then add suppressor, 68oz I would need to shoot a 2.647” group to get the same score. That seems like a big advantage to the lighter rifle. I’m excited to see what I can get. Hopefully I can make it up the hill this weekend!

 

[Thegman]

For the question about doing this on an AR10 platform.

CD-10 DIY Kits

DPMS High pattern straight pull bolt action uppers. This includes the BARE MINIMUM proprietary parts to build your own CD-10! No buffer system is required! We have now added the option to include the picatinny buffer adapters so you can bolt any MCX brace or stock on any mil spec lower! These...

atloppshop.com

Apparently they extract okay for them (?). No idea about weight you could hit, but if someone is interested in trying it out...

 

[WyoJeff]

So im getting closer! Have everything except the forearm and its on order...JAG 10.5 that should add another 3.5 oz.....so under %lb WITH a Leupold 2-8x36mm
havent fired it yet but....bolt will NOT slide OVER a gen 3 10rnd magpull...not a bad thing , kinda like the empty mag slide stop on your 1911....everyone experiencing this?
Bolt WILL ride over old USGI MilSpec 30rnd and SOME of my older 20rnd PMAGs not a deal breaker just interesting

 

[JBradley500]

Can you get low enough on the stock to look through the scope?

 

[WyoJeff]

barely, marginally, went with simplest med high rings to keep things simple but thinking ill end up with high extended rings before its all said and done. So far trying to use on-hand parts

 

[David Walter]

Kali Key Support <[email protected]>​	2:35 PM (6 hours ago)
to me

David,

Thanks for the email. You don't need to keep the spring or buffer tube if you don't want.

We will check out that thread!

Please let us know if you have any other questions. Thank you

That doesn't look functionally different from the KaliKey, and the KaliKey conversion uses your existing parts.

At a fraction of the cost. I'm thinking of a KaliKey and a JP low mass bolt for my Faxon-Barreled 6 ARC.

As a minimum, the buffer should be expendable, as it's function is taming bolt travel.

I just sent this question to KaliKey:

Does the KaliKey system require a spring to keep the bolt in battery or locked?

I wouldn't think so.

If not, this would allow the addition of folding stocks vs. traditional AR stocks with tubes.

See this conversation for back ground on the growing bolt action AR movement.

Ultralight Ultralight Rifles

I posted some info on the 77TMK thread about my experience on trying out the 77TMK on this black bear. There was some interest in the rifle used so I'm posting some info about the whys and hows on some of what I've put together over the last year or so. I've been carrying lightweight bolt...

rokslide.com

 

[David Walter]

I think its because the charging handle locks the BCG in place, and only locks when the BCG is fully forward, and so fully rotated and locked into place.

 

[Thegman]

So im getting closer! Have everything except the forearm and its on order...JAG 10.5 that should add another 3.5 oz.....so under %lb WITH a Leupold 2-8x36mm
havent fired it yet but....bolt will NOT slide OVER a gen 3 10rnd magpull...not a bad thing , kinda like the empty mag slide stop on your 1911....everyone experiencing this?
Bolt WILL ride over old USGI MilSpec 30rnd and SOME of my older 20rnd PMAGs not a deal breaker just interesting

Mine won't ride over my Duramag followers. I figure you'd see the same thing in a gasser but the bolt stop pushes the follower down enough to let it pass over. Does yours have the bolt stop installed, and still won't ride over the follower? Mine would ride over with the bolt stop depressed, but I've since removed all my bolt stops as they're not really necessary.

 

[WyoJeff]

Any downside to removing bolt stop?

 

[Thegman]

Any downside to removing bolt stop?

Not really that I can see. It does give the lower a little bit of a buffer if you ever accidently dropped the hammer without the upper installed, but that's about all I can think of.

 

[JBradley500]

It adds some force to the mag drop, does it not?

 

[ChrisAU]

It adds some force to the mag drop, does it not?

Barely. It’s designed to allow the magazine follower to push it up, so yeah it’s pushing down a bit but I don’t see it making any real world difference.

Meanwhile, I finally function tested 350 Legend 10” double stamp rattle can special last night. Louder than expected with suppressed subsonic loads, but interestingly enough recoil was non-existent. Like 22 LR territory.

 

[Taudisio]

I set up trail cams this afternoon and found a small clearing through the trees to set up the plate on a stump. Yardage was 124.8, shooting position was standing and leaning on a big Doug fir (most likely how I’d use the rifle chasing blacktail). I felt the two I pulled. There is a big difference between the two triggers, this one has the plastic NFA lpk and trigger. Rifle weighs 3lb 4oz. Group is 4.5” on the dot. Adjusted score is 3.66” for the East of the Mississippi category. I know I (and the rifle) can do better but this was my honest first go at it.

 

[Taudisio]

Also got this done. The 77gr tmk had basically identical results from the 87gr vmax. My only skewed part is I collected more of the small pieces from the TMK than I did with the 87gr. I believe the tmk is a hair more fragile and will send a little more “shrapnel” into the goodies.
I wrote 100 yards on there, it was more like 70-75yards. I was looking at my other sticky notes and writing it.

 

[Thegman]

Barely. It’s designed to allow the magazine follower to push it up, so yeah it’s pushing down a bit but I don’t see it making any real world difference.

Meanwhile, I finally function tested 350 Legend 10” double stamp rattle can special last night. Louder than expected with suppressed subsonic loads, but interestingly enough recoil was non-existent. Like 22 LR territory.

View attachment 722511

That's badass...

 

[johnnyboots]

Well last night I did myself dirty and bought an 12" 8.6bo barrel to try and replicate my 300bo build but with a larger caliber. I love the idea behind that Atloppshop CD-10 (AR10) but damn that cost is a killer. I haven't asked Solo300 if he's willing to sell his detent separately but he wouldn't sell a 7" handguard buy itself so...

@Taudisio if your machinist is willing to make the detent I'd be interested.

For the 8.6 I was thinking following the same path as some others. TN ARMS AR10 lower, NFA LPK, lightweight brace, minimalist handguard. Whether I can get this done in time is up to my wallet!