Ultralight Ultralight Rifles

[Luke S]

I have been thinking a lot about the 6x45 a lot since .243 is the minimum cal in my state for elk, black bear etc. for a light rifle but more so for a kid friendly elk rifle. Now that you have had yours for a while:

Would you be confident on short range elk with the 87 gr v max? Or look at other options?

Anything you would change barrel wise?
I’m looking at x-caliber 16 or 18” spaghetti profile, no gas port. They have a 7.5, 7.7, and 1:8” twists? Are you happy with that twist with the 80-95gr bullets?

I think those are my biggest questions at the moment. If not for the state law I think I would be happy sticking with 5.56 heavies but the 6x45 seems like the easy button for this platform being a do-all kids rifle/ ul packer where I’m at. Thanks

I'm not a 6x45 expert but I think Taudiso mentioned a while back that his was pretty "snappy" because it's so light. And Stupidlight mentioned that he plans to start his kids with a 7 pound rifle not a UL UL rifle. So maybe make it but don't go crazy on light parts for the kids?

My parts are still in the mail but I like the poly lower I have sitting there. One nice think will be that a plastic/fiberglass AR is not as cold in your hand as an all aluminum AR. Looking forward to that. I'm still working out my plans because there are so many options. Right now I'm thinking of an AR pistol with a suppressor that will be a "backpacking" gun partly because I have the barrel already. I think that one will prioritize light weight over all else and it will not be a primary hunting gun. Later, I'll look at something with a 16 inch barrel a better scope on it that would be an actual hunting rifle.

 

[Taudisio]

I'm not a 6x45 expert but I think Taudiso mentioned a while back that his was pretty "snappy" because it's so light. And Stupidlight mentioned that he plans to start his kids with a 7 pound rifle not a UL UL rifle. So maybe make it but don't go crazy on light parts for the kids?

My parts are still in the mail but I like the poly lower I have sitting there. One nice think will be that a plastic/fiberglass AR is not as cold in your hand as an all aluminum AR. Looking forward to that. I'm still working out my plans because there are so many options. Right now I'm thinking of an AR pistol with a suppressor that will be a "backpacking" gun partly because I have the barrel already. I think that one will prioritize light weight over all else and it will not be a primary hunting gun. Later, I'll look at something with a 16 inch barrel a better scope on it that would be an actual hunting rifle.

You are completely correct. I skipped over that part. I think a 6 pound rifle would be about the lightest I would hand to a “kid” (like 12+y.o.) depending on their size. 7 pounds would be more appropriate for any sized kid.

My rifle, pre-suppressor, gave me a bruise every time I went to the range. I’m 6’ and 215 pounds, my 8lb 9oz 30 nosler does not give me a bruise as a reference.

 

[ezwy]

I'm not a 6x45 expert but I think Taudiso mentioned a while back that his was pretty "snappy" because it's so light. And Stupidlight mentioned that he plans to start his kids with a 7 pound rifle not a UL UL rifle. So maybe make it but don't go crazy on light parts for the kids?

My parts are still in the mail but I like the poly lower I have sitting there. One nice think will be that a plastic/fiberglass AR is not as cold in your hand as an all aluminum AR. Looking forward to that. I'm still working out my plans because there are so many options. Right now I'm thinking of an AR pistol with a suppressor that will be a "backpacking" gun partly because I have the barrel already. I think that one will prioritize light weight over all else and it will not be a primary hunting gun. Later, I'll look at something with a 16 inch barrel a better scope on it that would be an actual hunting rifle.

Ya. That’s a good point. I have a lot of heavy parts laying around to swap on. Big squishy buttstock, handguard with bipod and will be suppressed. Bigger scope with more eye relief and zoom for kids too.

 

[packgoatguy]

Came across this article about a straight pull AR in 6mmArc. Sorry if its been shared before.

https://www.firearmsnews.com/editorial/custom-backpack-survival-rifle-6mm-arc/505590#replay

 

[KyleR1985]

Came across this article about a straight pull AR in 6mmArc. Sorry if its been shared before.

https://www.firearmsnews.com/editorial/custom-backpack-survival-rifle-6mm-arc/505590#replay

That’s our guy @StupidLightweight here!

I’ll be trying the 6ARC with TMK’s and no gas today. I had the gas turned off on the SA gas block but still connected. It was painless extraction every time with standard charging key.

I’m positive it will be a pain to extract. But I’ve blocked the gas port and removed the block and tube to give it a shot.

Probably not the best idea while I’m doing load development and may have to take apart a rifle haha! Oh well

 

[goalie]

Came across this article about a straight pull AR in 6mmArc. Sorry if its been shared before.

https://www.firearmsnews.com/editorial/custom-backpack-survival-rifle-6mm-arc/505590#replay

That article says "Cycling the carrier after firing a round requires effort. This isn’t smooth like a traditional bolt-gun."

Didn't most people trying the ARC based cases here say bolt pull was incredibly difficult????

 

[KyleR1985]

That article says "Cycling the carrier after firing a round requires effort. This isn’t smooth like a traditional bolt-gun."

Didn't most people trying the ARC based cases here say bolt pull was incredibly difficult????

Yes.

I wonder if some sort of lubrication could assist in primary extraction - think case lube for reloading. Yes, it can cause other problems in the gun apparently. But I can’t help but wonder if some sort of dry lubrication would help with extraction, and then you just need to clean bolt and barrel extension/chamber here and there.


I’ll know by end of day if there’s even a point in trying.

I don’t really know why I’m trying - the 6x45 will do everything I need and want with a manual extraction AR. I’m pretty sure this is going to end with me owning a 10-12” 6x45 and .223 barreled rifle for deer hunting inside of 300 yards.

And my 16” gas 6mm ARC upper will handle anything to 600.


But, I’m gonna try. Haha.

 

[StupidLightweight]

That article says "Cycling the carrier after firing a round requires effort. This isn’t smooth like a traditional bolt-gun."

Didn't most people trying the ARC based cases here say bolt pull was incredibly difficult????

It's been a year since I used that 6 ARC barrel. At the time, it wasn't smooth to operate, but it was usable. An important note is this: At the time, I was clueless about removing the gas rings and extractor O ring, so I never used it correctly in my traditional upper modified to be a straight-pull. Again, it worked but required effort.

When I swapped that barrel for a port-less .223 barrel from Shaw, it felt the exact same until I removed the gas rings and O ring. That made it a lot easier to cycle. Part of me wonders if the combination of my custom upper, carrier, bolt, and 6mm ARC barrel would perform better. It likely won't, but until I try that combo, I won't know for sure.

I shipped that 6mm ARC barrel to Thegman for testing with a SOLO 300, and he said it didn't work well. The takeaway is this: If you need a 6mm straight-pull, go with the 6x45.

 

[goalie]

Freaking enablers around here. I don't even have my Solo 300 action yet, and I'm thinking about a 6x45.......

 

[KyleR1985]

I just ran 10 rounds of factory hornady 6ARC 108’s with gas port blocked off and tube removed. With standard charging key. Aluminum bcg. It was easy as pie.

I’ll swap to my side pull steel bcg next range session.

This was a promising result.

All gas rings and o rings still installed.

 

[Trackselk]

I just ran 10 rounds of factory hornady 6ARC 108’s with gas port blocked off and tube removed. With standard charging key. Aluminum bcg. It was easy as pie.

I’ll swap to my side pull steel bcg next range session.

This was a promising result.

All gas rings and o rings still installed.

Now you have me thinking about rechambering to 22Arc (if possible), it never ends!

 

[KyleR1985]

Now you have me thinking about rechambering to 22Arc (if possible), it never ends!

Honesty not sure it would be worth it.

I’m getting 2700+ from .223 77tmk in brand new 16” barrel.

I can’t imagine getting the gun(me) shooting well enough to have the 22arc make a difference for me distance wise.

I could see it being useful with the 88’s or bigger, or if you wanted to build an SBR.

Just not seeing the juice worth the squeeze with potential extraction issues, cost and availability of brass, etc.

What specific use case are you thinking of?

 

[gtriple]

Honesty not sure it would be worth it.

I’m getting 2700+ from .223 77tmk in brand new 16” barrel.

I can’t imagine getting the gun(me) shooting well enough to have the best 22arc make a difference for me distance wise.

I could see it being useful with the 88’s or bigger, or if you wanted to build an SBR.

Just not seeing the juice worth the squeeze with potential extraction issues, cost and availability of brass, etc.

What specific use case are you thinking of?

That's where I'm at. Mine is above 1800fps to 450yds...

 

[Trackselk]

Honesty not sure it would be worth it.

I’m getting 2700+ from .223 77tmk in brand new 16” barrel.

I can’t imagine getting the gun(me) shooting well enough to have the 22arc make a difference for me distance wise.

I could see it being useful with the 88’s or bigger, or if you wanted to build an SBR.

Just not seeing the juice worth the squeeze with potential extraction issues, cost and availability of brass, etc.

What specific use case are you thinking of?

Yeah, that makes sense. I was thinking a little more range for me an I run monos and want 2k at impact, but I'm guessing it'd only extend the range 25 yards. I'll have to run the numbers. Plus, I don't need the expense of more dies etc right now

 

[Thegman]

It's been a year since I used that 6 ARC barrel. At the time, it wasn't smooth to operate, but it was usable. An important note is this: At the time, I was clueless about removing the gas rings and extractor O ring, so I never used it correctly in my traditional upper modified to be a straight-pull. Again, it worked but required effort.

When I swapped that barrel for a port-less .223 barrel from Shaw, it felt the exact same until I removed the gas rings and O ring. That made it a lot easier to cycle. Part of me wonders if the combination of my custom upper, carrier, bolt, and 6mm ARC barrel would perform better. It likely won't, but until I try that combo, I won't know for sure.

I shipped that 6mm ARC barrel to Thegman for testing with a SOLO 300, and he said it didn't work well. The takeaway is this: If you need a 6mm straight-pull, go with the 6x45.

Well, it would work okay on the Solo with the caveat that you carry a rubber mallet while you're hunting to tap the bolt handle a few times. For whatever reason, it stuck more in the solo than with the steel bolt carrier. Maybe due to more inertia from the steel bolt carrier at the end of the recoil impulse, and that there was no "detent key" in Stupidlightweight's build helping hold the bolt closed(?). Those are the only variables I can think of.

Fortunately 5.56 and 6x45 are both very capable in and of their own.

One point on the 6x45 @ 18": X-Caliber says max length for the Spaghetti contour is 16", which I'm sure is also close enough to an 18" barrel that there would be no practical difference in the field, not that that should stop anyone...

 

[ACHILLES]

Anyone tried a nitrided barrel? I would think going with a nitrided barrel/chamber could help reduce some resistance when extracting arc/Grendel cases.

 

[Thegman]

This might be a good place for the .177 boresnake that I keep at camp in case anyone sticks their muzzle in the snow or mud. Works for all calibers without putting a ton of friction on the delicate crown.

One more point I thought about: One of the keys to getting these small game loads to work well is to get the pressure up as quickly as possible because it drops off very quickly as volume increases, which reduces the powder burn rate. Volume increase is both from larger cases and increasing volume as the bullet moves down the bore.

I think this is one of the reasons smaller cases like the 300BO are more consistent, and cleaner, than when I used larger cases like the 30-06 and 308. Also why the 223 works pretty well, I think, due to small case volume and smaller bore volume. To that end, on all these loads, I crimp the bullet pretty tightly if possible. I use a Lee FCD on the cannelure of the 46 grain FP and that seems to help with consistency and accuracy. I think the tighter the crimp the better; I doubt one could crimp too much.

 

[Thegman]

Anyone tried a nitrided barrel? I would think going with a nitrided barrel/chamber could help reduce some resistance when extracting arc/Grendel cases.

I haven't, but that's a good thought. The 30 HRT and 6 ARC barrels I've tried in the solo are both stainless. Robtattoo tried a 7.62x39 as I recall, but I don't know what barrel he used. He said the 7.62 didn't work well.

 

[Trackselk]

Well, it would work okay on the Solo with the caveat that you carry a rubber mallet while you're hunting to tap the bolt handle a few times. For whatever reason, it stuck more in the solo than with the steel bolt carrier. Maybe due to more inertia from the steel bolt carrier at the end of the recoil impulse, and that there was no "detent key" in Stupidlightweight's build helping hold the bolt closed(?). Those are the only variables I can think of.

Fortunately 5.56 and 6x45 are both very capable in and of their own.

One point on the 6x45 @ 18": X-Caliber says max length for the Spaghetti contour is 16", which I'm sure is also close enough to an 18" barrel that there would be no practical difference in the field, not that that should stop anyone...

Might the aluminum be less rigid/ more malleable and flex more, allowing the brass to expand more?

 

[Trackselk]

One more point I thought about: One of the keys to getting these small game loads to work well is to get the pressure up as quickly as possible because it drops off very quickly as volume increases, which reduces the powder burn rate. Volume increase is both from larger cases and increasing volume as the bullet moves down the bore.

I think this is one of the reasons smaller cases like the 300BO are more consistent, and cleaner, than when I used larger cases like the 30-06 and 308. Also why the 223 works pretty well, I think, due to small case volume and smaller bore volume. To that end, on all these loads, I crimp the bullet pretty tightly if possible. I use a Lee FCD on the cannelure of the 46 grain FP and that seems to help with consistency and accuracy. I think the tighter the crimp the better; I doubt one could crimp too much.

Very good points, I'm loving the 223 more and more every day! Nothing better than grouse stew when you don't get any other camp meat that day...
Edit: and I just happen to have that crimp die as well!