Why not more attention given to the NAS3 cases and their advantages?

[Antares]

https://rokslide.com/forums/threads/nas3-5-56-cases-tikka-223-w-88-tmk.444901/

 

[AM_Hunter]

For me, it is because the company states this,
View attachment 1049416

but then states this in the FAQs.
View attachment 1049414

I believe the reloadable for versatility note is about their pistol cases, which I read are reloadable. The rifle cases they do not recommend reloading.

 

[AM_Hunter]

I've been playing around with them a little. Did a ladder test to 49gr of Varget for a pressure test and saw no signs of pressure. My old load was 44grs of Varget, which I was pushing a 168gr TTSX at about 2680fps out of a 21" barrel. At 49gr in these cases I got around 2860fps.

My main concern is going to be if the accuracy changes. I was getting sub .75" groups with my old load. I loaded up 10 rounds at 49gr to test accuracy and will hopefully get to shoot them this weekend. I also loaded up one at 49.5gr and one at 50gr to see if I get any signs of pressure but those loads are starting to get compressed.

They are also notable lighter than standard brass. Picked up the whole bag of 250 cases and it felt as light as 100 rounds of brass, maybe even lighter.

I was able to neck size the fired NAS3 .308 cases with a Lee Neck Sizing only die. The shoulders started out shallow at like 1.616" before first fired and bumped out to 1.625" after firing. My standard fireformed brass shoulder is at like 1.624". With the neck sizing and the shoulder within spec I may be able to get a second firing out of them. Not sure yet if Ill try it. The neck-sized case did cycling in my rifle with a slightly stiff to close bolt.

 

[B_Reynolds_AK]

I don't even load most conventional brass cased cartridges to SAAMI max pressures.

Bet you’re the life of the party huh?

 

[Touchdown88]

If I can get ahold of some 6mm ARC cases, I'd build a hunting load that would hopefully be close to a 6mm Creed but in a Howa mini action. With that, I don't really care that the cases are a one-time use. I've got plenty of other brass to plink with.

 

[Cherokeeguide]

On the other hand if I had a 6.5
Creedmoor that I wanted to press into usage for elk these new cases (at reasonable ranges) gives me that option.

If I had a 6.5 Creedmoor, and that was all I had, and wanted to go elk hunting, I'd go elk hunting with regular old-fashioned brass-case ammo, confident that the elk I'd tag with it wouldn't know the difference between being killed with it or with the .270 Winchester that I've tagged 7 of the things with.

 

[4IDARCHER]

If I had a 6.5 Creedmoor, and that was all I had, and wanted to go elk hunting, I'd go elk hunting with regular old-fashioned brass-case ammo, confident that the elk I'd tag with it wouldn't know the difference between being killed with it or with the .270 Winchester that I've tagged 7 of the things with.

While far from my first choice I agree that within 250 yards or so a 20 inch barreled 6.5 creed with proper shot placement will kill any elk that has ever lived. But what are the disadvantages of being able to add 200-300fps onto that same cartridge simply by switching ammo? The NAS3 cases give you options of stepping up to the next power level without having to swap rifles.

 

[bnewt3]

I am not convinced that higher pressure rounds will necessarily have higher barrel wear. Admittedly, I have never been involved with an FMEA on barrel wear, but the old rule of thumb "powder volume to bore ratio" doesn't account for it as well as the classic "barrel burner" cartridges tend to have slow powder. Which I would take to assume the pressure in the area of the barrel that takes the beating (throat) is rather low in fact.

no way around physics. Something has to give.

However, with something like 308, even if it goes from 8000rds avg barrel life to 4000(which I highly doubt it would drop that much)...... thats still multiple lifetimes for most hunting rifles.

 

[JFK]

There are so many cartridges these days I don’t really see the benefit. Buy the one that gets the velocity you want without fancy brass. I reload so enjoy using fire formed brass and some of the efficiency in re-using brass. Not being able to optimize shoulder bump for accuracy is another downside. Alpha OCD is the answer for brass that holds up to slightly higher than sammi pressure, and its reloadable.

 

[Sundodger]

no way around physics. Something has to give.

However, with something like 308, even if it goes from 8000rds avg barrel life to 4000(which I highly doubt it would drop that much)...... thats still multiple lifetimes for most hunting rifles.

I completely agree there is no free lunch in this world, but the point I am trying to make is I am not convinced pressure is a large driver to wearing out barrels.

Given that cartridges that are typically given the "barrel burner" reputation don't produce high bullet velocity at the throat and are slower to build pressure, my uneducated hypothesis is that the unburned/partially burned powder abrading away the metal is a primary driver of throat erosion. Like a torch and sandblaster all wrapped up into one.

So the lower powder volume and high pressure combination could actually be an improvement in barrel life, especially if internal ballistics are anything like internal combustion engines where higher pressure leads to improved combustion efficiency (less/smaller particles hitting the barrel).

This is all just me spit balling though, I have no inside knowledge.

I bet there are some tribology engineers working for defense contractors that know this for certain, would sure like to sit them down for a few beers and chat.

 

[UnckleBob]

I don't have a 308 or 6.5CM. If they made it in 243, I would definitely try it.

 

[mtnbound]

So the lower powder volume and high pressure combination could actually be an improvement in barrel life, especially if internal ballistics are anything like internal combustion engines where higher pressure leads to improved combustion efficiency (less/smaller particles hitting the barrel).

Maybe I'm just misunderstanding what you are trying to say, but most folks using these cases aren't using less powder; they are using more, since the cases hold more.

 

[BBob]

So the lower powder volume and high pressure combination

Cases are thin walled allowing for a larger volume along with a stronger alloy for the higher pressures.

 

[Chris in TN]

Maybe I'm just misunderstanding what you are trying to say, but most folks using these cases aren't using less powder; they are using more, since the cases hold more.

I think the point was that with higher pressures, any given level of ballistic performance can be achieved with a smaller case.

The question then becomes, if you want to shoot, say, a 6mm116 at 2900', and you could do it with an 18" barrel with regular cartridge ABC at 62kpsi, or you could use these steel cases to do it with cartridge XYZ, a smaller case crammed full of a faster powder, at 80kpsi - which would be better for barrel life?

You could use quickload or GRT to make some estimates of what sort of case capacity (and powder choices) it would take to achieve these new levels of performance, and there are barrel life estimators that will spitball an estimate that factors pressure into the equation. I'll admit that concept has some advantages - most importantly, it would allow me to use something like a 6GT or 6Dasher to get the speeds I want from a 16" barrel. But I sort of see that as a wasted advantage if there's no receiver with broad aftermarket support that is short enough to make the switch to those short cases worthwhile. Something the length of a Remington Model 7 would be awesome.

*shrug*

I wasn't born to be an early adopter or experimenter. I'm still waiting on a 6mmCreedmoor I can run at 58k-60kpsi and have long brass life and never worry about popping a primer. But I'm boring like that.

 

[bnewt3]

So slightly more of a significantly faster burning powder.

Barrel life could be a wash? Maybe?

Whats barrel life on like a 4" 357 sig?

 

[KingOfTagSoup]

If I can get ahold of some 6mm ARC cases, I'd build a hunting load that would hopefully be close to a 6mm Creed but in a Howa mini action. With that, I don't really care that the cases are a one-time use. I've got plenty of other brass to plink with.

Is there rumors that Shell Shock is going to produce 6 ARC cases?

 

[Chris in TN]

So slightly more of a significantly faster burning powder.

Barrel life could be a wash? Maybe?

Whats barrel life on like a 4" 357 sig?

So, playing with some numbers here in Gordon's Reloading Tool and comparing a 16" 6mmBR to a 16" 6mmCreedmoor with a 115DTAC and N540 in the former, N550 in the latter, it would take 80kpsi to get the former to 2700' and 64.5kpsi to get the latter to 2700'.

If I take the two respective powder charges and plug them into the barrel life estimator found here:

https://www.accurateshooter.com/technical-articles/excel-formula-predicts-useful-barrel-life/

It shows a clear advantage to the smaller case running at higher pressures. The numbers I estimated indicated roughly an 1100 round count for the 6cm versus 1400 for the 6BR. Or, it weighs powder charges more heavily than pressure.

Would that bear out in reality? I have no idea. None whatsoever.

My aversion to popping primers and having gas leak towards my face (or my kids' faces, as they shoot my reloads, and I won't load anything I wouldn't let them shoot) will likely stop me from ever knowing firsthand.

 

[ezwy]

Maybe I'm just misunderstanding what you are trying to say, but most folks using these cases aren't using less powder; they are using more, since the cases hold more.

That’s what I understand. Some of these small ammo makers loading them now say that because of thinner case they have more internal volume, so you can load them to the SAME pressures with slightly more powder and increase your velocity.

 

[RME]

So slightly more of a significantly faster burning powder.

I haven't looked into it, are people using significantly faster burning powders? Seems to me that would spike peak pressure which is counterproductive to increasing velocity.

 

[Chris in TN]

I haven't looked into it, are people using significantly faster burning powders? Seems to me that would spike peak pressure which is counterproductive to increasing velocity.

The thing is, IME it's awfully hard with long bullets in small cases, to go beyond maybe 105% load density, maybe 106% or 108% in a very few narrow use cases, so at some point if you want more speed/pressure you have to drop back to a faster powder. Any given case stuffed 105% full of H4350 will make more speed than the same case stuffed 105% full of H1000.