300 AAC Blackout fad over?

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Re: 300 AAC Blackout fad over?

Post by gunnnie » 06 Jul 2019, 6:45 pm

SCJ429 wrote:Yes, you are right. I was thinking of the earlier conversation regarding using heavy pills at subsonic speeds. I see the upper end of the 300 AAC performance is probably similar to a 30/30. My experiences using a 204 have seen it blowing things apart with very frangible bullets.


In your question/query is your answer. Any projectile moving at ultra high velocities and RPm will have a higher propensity to fragment/blow up up on impact. This is simply dynamics of velocity. Were you to drive the same projectile slower you would find that it would penetrate further; simple ballistics!

Looking at a 30cal pill as a comparative argument. Drive a 150gn pill at 3600fps and it will fragment/blow up upon impact. But if you drive it at 2000fps it potentially will not fragment and will penetrate further.

Clear as mud???
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Re: 300 AAC Blackout fad over?

Post by SCJ429 » 06 Jul 2019, 9:36 pm

gunnnie wrote:
simple ballistics!

Looking at a 30cal pill as a comparative argument. Drive a 150gn pill at 3600fps and it will fragment/blow up upon impact. But if you drive it at 2000fps it potentially will not fragment and will penetrate further.

Clear as mud???


Unfortunately that is not how it works. Energy equals mass times speed. If you are using a bullet designed for penetration such as a solid or FMJ the faster you drive the bullet the more penetration you will achieve. You don't shoot armour piercing projectiles at tanks at subsonic speeds. This type of ordinance is delivered as fast as possible.

You are correct that for highly frangable hunting bullets are designed to come apart to dump their energy on the target and may blow up on mud caked pigs for example without achieving any penetration. If you deliver other projectiles at low speeds that does not induce fragmentation, they are likely to pencil through your target.
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Re: 300 AAC Blackout fad over?

Post by gunnnie » 07 Jul 2019, 8:11 am

Right! Now you're changing the parameters of the discussion by saying "if you are using a bullet designed for penetration"! Additionally, adding the armour piercing projectile at a tank aspect doesn't relate to the initial discussion regarding penetration of a high velocity 20cal as compared to a lower velocity 30cal projectile. There's a lot more that comes into play with an AP round on armour. The terminal ballistics includes more variables and known quantifiable values. It was also accepted in ballistics that increased penetration comes with increased diameter/weight, until metallurgy, design principles & improved powders came about - enter the APFSDS.

Now you wrote, " In what circumstances does it penetrate better than a 204? Both would use fairly frangable bullets I assume." to in2anity's post - right? Then you wrote, "I am wondering if you used a bullet with the same construction, how a 220 grain bullet going 1,010 fps was going to provide more penetration than a 40 grain bullet at 3,800 fps? Too lazy to do the maths myself." - right?

Going by your response above, you are saying that if a 20cal FMJ is driven at say 4000fps it will provide deeper penetration. Let alone doing the same with a 30cal FMJ driven at 4000fps or higher! Sorry but we'll have to agree to disagree on that thinking.
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Re: 300 AAC Blackout fad over?

Post by SCJ429 » 07 Jul 2019, 8:43 am

gunnnie wrote:[

In your question/query is your answer. Any projectile moving at ultra high velocities and RPm will have a higher propensity to fragment/blow up up on impact. This is simply dynamics of velocity. Were you to drive the same projectile slower you would find that it would penetrate further; simple ballistics!

Looking at a 30cal pill as a comparative argument. Drive a 150gn pill at 3600fps and it will fragment/blow up upon impact. But if you drive it at 2000fps it potentially will not fragment and will penetrate further.

Clear as mud???


I brought projectiles designed to penetrate into the discussion because you said "any projectile".
You said this was "simple dynamics of velocity."
The more speed you put into a mass the more energy it has. If you drive even a small mass fast enough you could get it to pass through anything.

Of course a 40 grain pill driven at 4000 fps has less energy than a 220 grain pill driven at 4000 fps.

You are saying that two identical 150 grain pills are shot at a target, one at 2000 fps and one at 3600 fps and the slower bullet will penetrate more. This is not correct. Shoot the two bullets at a steel plate to test your theory.
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Re: 300 AAC Blackout fad over?

Post by gunnnie » 07 Jul 2019, 10:51 am

What does the relevance of a steel plate have to living tissue? Steel plate is thin as compared to the broadside dimensions of an animal. Plus within living tissue there are variations in density, anything from hard (bone) to light (lungs). All of which influences how the projectile imparts it's kinetic energy.

How then do you explain the old buffalo hunters of the US west using large caliber lead projectiles, fired from black powder rifles, moving at relatively slow speeds, passing through bison at long range? Would the same be possible with a high velocity projectile!

From what is known, lead projectiles such as from a pistol, rifle of shottie slug, will not usually deform when punching through living tissue; skin/muscle/tendon/fat etc, without some form of special design aspect such as a hollow point. Without such a design characteristic, the values of velocity & mass then change the outcomes within what potentially becomes the physics of a hydrodynamic nature. Sporting projectiles, even projectiles for military use, are usually tested and calibrated on a simulated tissue, ballistic gelatin. This is supposed to replicate the resistance of living tissue. Just how accurate this is, is open to debate, but it is done this way as it provides a means of consistency & uniformity of quantifiable measurements/data. But ballistic scientists will quantify that such tests are not an 'accurate' indicator of the actual effect on living tissue.

Sporting projectiles aren't designed or tested for their penetration against steel plates. Though it is an interesting test of sporting projectile design and engineering parameters.
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Re: 300 AAC Blackout fad over?

Post by SCJ429 » 07 Jul 2019, 2:12 pm

It is very difficult to show the difference between the energy dumped onto an animal because each shot may hit different things but you can quickly see the difference on something like steel. The higher velocity round will penetrate more.

Most early buffalo hunters use large caliber cases with bullets often from 500 to 700 grain. They made up in mass what they lost in speed. Longer shots were rare because their rifles were inaccurate compared to rifles of today. Stories of long shots made it into folk law because they were rare and very impressive at the time.

There are instances where a 204 will outperform larger calibers where it makes up in speed what it lacks in mass. It can be difficult to make a bullet effective at subsonic speeds which is why it can be unethical to shoot at game at extreme ranges. Bullet speed and terminal energy is low. They tend to pencil through things because they don't have the energy to get the jacket to open up as it is designed to do. This can be mistaken for greater penetration but in fact the bullet has less energy.

Bullet blow up is when you hit something tough and the jacket come apart without getting to the vitals. This has nothing to do with more speed, just bullet design. A partitioner bullet is more appropriate where the front of the bullet expands but a separate lead core provides the penetration. If you really want to penetrate things that are very tough you would use a solid which you can drive as fast as you like. I am sure you already know this stuff.
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Re: 300 AAC Blackout fad over?

Post by mickb » 07 Jul 2019, 10:39 pm

Penetration for solid projectiles is not necessarily linear relationship to velocity, and does not hold across multiple medias. its probably better keeping armour piercing out of normal rifle debates especially, the mechanics behind it are beyond highschool maths. Penetration comes down to the qualities of the target, hardness relative to target, all the metallurgical factors relating to strength, stabilisation in the media etc. Projectiles may use mechanisms of cavitation, breaking, shattering, or causing stretch failure (like a 12 ga punching a plug out of light steel). Shooting soft metal a certain energy may get a certain penetration, but with hard metals you may have more of a pass/fail relationship, if it can't make it right through, it rebounds, in your direction!

There are also velocity nodes where more velocity causes less penetration. An engineer over at accurate reloading called Harald did a lot of tests of elephant gun solids at different velocities and sometimes found penetration dropped at some velocity point, then increased again at another. The theory was many of the traditional round nose FMJ in the elephant guns werent blunt enough. Blunt bullets are theorised to set up a cavitation bubble where they can continue to rotate gyroscopically. This stability is not actually possible iby itself in fluids being 1000x denser than air. ( Its why elephant gun FMJ and solids are blunt, not spitzers as spitzers are too prone to veering of course or tumbing after long wound paths in fluid animal bodies) . The theory was he was picking up rotational instabilities when the bullets were pushed at a certain velocity - relative to their shape..

Anyway its too complicated to describe every instance with a basic momentum or kinetic energy formula.
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Re: 300 AAC Blackout fad over?

Post by bladeracer » 08 Jul 2019, 10:17 am

mickb wrote:...or causing stretch failure (like a 12 ga punching a plug out of light steel).


An 8x57mm cast lead 180gn bullet at 2500fps punched a steel "plug" out of 8mm plate, I still have it somewhere.
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Re: 300 AAC Blackout fad over?

Post by in2anity » 19 Jul 2019, 8:44 am

Considering the forecast for Winchester powders in the Australian is looking bleak, I went back to revisit adi's AR2205 under the budget Speer 125gr TNT bullet. Sadly we cannot bank on Hogdons lilgun supplies in the foreseeable future :thumbsdown:

In the interim I've been learning more about differences between extruded "stick" powder vs double-base ball type powder. Lilgun is a type of ball powder. What does this mean? Well compared with extruded powders, ball powders are generally harder to ignite, and often give poorer standard deviations. Therefore lilgun really demands a magnum primer. And the harder magnum primers do not gel with with the (at least early model) RARRs (like mine). So in many ways, in my RARR 300aac it's actually more suited to an extruded powder like AR2205 (with a regular SR primer such as the cci400).

AR2205 was definitely a little finickier to get to group (at least compared with the lilgun loads), but thankfully I found a node with this powder+projectile+rifle combo last night:

speer.jpg
18gr AR2205 under Speer 125gr "TNT", light crimp. 4x scope.
speer.jpg (1013.76 KiB) Viewed 6736 times


For the record I went up to a compressed 19gn AR2205 load without any pressure signs (AR disclaimer in a bolt gun I might add!!). The 18gr load is yet to be chronoed, but from my previous findings, std-dev should be more than adequate with AR2205. I take comfort in knowing it's not the very hottest of loads as I was seeing primer pockets opening up with hot lilgun loads.

This journey has also brought into light the potential need for a crimp; not from an accuracy perspective, but rather the RARR seems to be fairly rough on the projectile as it feeds from the rotary magazine. I feel sometimes the gun would set-back the pill, leading to flyers and pressure spikes. I'll be crimping from now on just to relieve my anxiety about any set-back, which really makes a bullet with a cannelure (like the Hornady SST) a little more desirable... still a light crimp on the cannelureless Speer bullet certainly does not seem to do any measurable harm to group sizes.
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Re: 300 AAC Blackout fad over?

Post by gunnnie » 19 Jul 2019, 2:27 pm

Handy to know. Looks like it'll be worth while re-visiting loads for my RARR also.
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Re: 300 AAC Blackout fad over?

Post by JimTom » 19 Jul 2019, 2:31 pm

Mate I have been running the Hornady 125 SST WITH AR2205, no crimp and have had no issues at all.
I have just started experimenting with the Speer 130 HP. Whilst they shoot quite nicely, I have an issue with the last round feeding properly from the magazine. I initially seated the projectiles a few though of the lands however could not get them to feed at all. I am now loading them at spec length and they feed nicely with the exception of the last round out of the magazine. Any suggestions?
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Re: 300 AAC Blackout fad over?

Post by JimTom » 19 Jul 2019, 2:37 pm

Just to clarify mate I have the Ruger American Ranch with rotary mag.
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Re: 300 AAC Blackout fad over?

Post by in2anity » 19 Jul 2019, 3:52 pm

JimTom wrote:Mate I have been running the Hornady 125 SST WITH AR2205, no crimp and have had no issues at all.
I have just started experimenting with the Speer 130 HP. Whilst they shoot quite nicely, I have an issue with the last round feeding properly from the magazine. I initially seated the projectiles a few though of the lands however could not get them to feed at all. I am now loading them at spec length and they feed nicely with the exception of the last round out of the magazine. Any suggestions?


Don't really have any suggestions unfortunately JT - my rotary mag also has same problems with the speer bullet - some have suggested filing the feed lips a touch to get the round to feed a tad higher. Other than that - I picked up the Lucky13 10-shot mag. It feeds reliably, but only if you cycle the action with authority - if you limp-wrist it, the rounds jam. But the problem with that is it puts more wear on your brass... plus the L13 mag is a bit of a monstrosity on the little rifle. :crazy:
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Re: 300 AAC Blackout fad over?

Post by JimTom » 19 Jul 2019, 5:05 pm

Yep I can imaging it would be mate. I like the rotary mag being flush with the bottom of the rifle, bit easier on the back when rifle is slung whilst riding motor bike.
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Re: 300 AAC Blackout fad over?

Post by gunnnie » 19 Jul 2019, 10:58 pm

I have a box of those Sierra 130gn Hog Hammers but haven't got round to trying them in my RARR yet. Have been using Sierra 125gn and 110gn pills.
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Re: 300 AAC Blackout fad over?

Post by JimTom » 20 Jul 2019, 7:14 am

Me too mate, if you happen to try them before I do then post the results for us to have a look at.
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Re: 300 AAC Blackout fad over?

Post by in2anity » 20 Jul 2019, 8:59 am

Picked up a box of the Hornady SSTs - feeding 100% reliably out of the factory rotary. It’s a bit of a shame, as those TNT bulk packs are very well priced. You get what you pay for I suppose :unknown:

C32A29D4-4B79-4329-B11C-F898851D6291.jpeg
125gr TNT vs SST
C32A29D4-4B79-4329-B11C-F898851D6291.jpeg (1.66 MiB) Viewed 6678 times
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Re: 300 AAC Blackout fad over?

Post by JimTom » 20 Jul 2019, 10:45 am

Yep the 125 SST feed faultlessly out of mine too mate. Fortunately they are accurate and perform well on the hogs too. Seems the magazines just don’t like feeding hollow points.
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Re: 300 AAC Blackout fad over?

Post by SCJ429 » 20 Jul 2019, 11:12 am

in2anity wrote:Picked up a box of the Hornady SSTs - feeding 100% reliably out of the factory rotary. It’s a bit of a shame, as those TNT bulk packs are very well priced. You get what you pay for I suppose :unknown: ]


My experience with the Speer TNT is that they are very effective, at least as good as the SST. The TNT has accuracy potential way beyond its price point. I am betting the TNT works well for you too.
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Re: 300 AAC Blackout fad over?

Post by gunnnie » 20 Jul 2019, 12:46 pm

JimTom wrote:Yep the 125 SST feed faultlessly out of mine too mate. Fortunately they are accurate and perform well on the hogs too. Seems the magazines just don’t like feeding hollow points.

Seems odd as when you look at the two projectiles, they look almost identical in dimensions, location of ogive etc. You'd think that both would feed without issue.
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Re: 300 AAC Blackout fad over?

Post by JimTom » 20 Jul 2019, 1:17 pm

gunnnie wrote:
JimTom wrote:Yep the 125 SST feed faultlessly out of mine too mate. Fortunately they are accurate and perform well on the hogs too. Seems the magazines just don’t like feeding hollow points.

Seems odd as when you look at the two projectiles, they look almost identical in dimensions, location of ogive etc. You'd think that both would feed without issue.


Yes mate I agree. It is perplexing. The last round out of the magazine seems to drive straight up and jam.
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Re: 300 AAC Blackout fad over?

Post by in2anity » 22 Jul 2019, 3:48 pm

For those of you sporting the RARR - when slung-up, I noticed the factory bolt handle was uncomfortably small, to the point it was leaving the palm of my hand tender after a long session. So I swapped it for a Glades Armory version:

this:

IMG_9172.jpg
factory bolt handle for tiny hands
IMG_9172.jpg (551.8 KiB) Viewed 6456 times


became:

IMG_9177.jpg
no more sore hand after a long slung-up session
IMG_9177.jpg (544.32 KiB) Viewed 6456 times


No dramas coming through AUS customs. Much easier to cycle the bolt now :drinks:

Oh BTW I shot an arbitrary test load of 18gr AR2205 under the 125gr SST at 100m - group was pretty horrid. Back to ladder tests for me now...
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Re: 300 AAC Blackout fad over?

Post by bladeracer » 22 Jul 2019, 8:26 pm

in2anity wrote:For those of you sporting the RARR - when slung-up, I noticed the factory bolt handle was uncomfortably small, to the point it was leaving the palm of my hand tender after a long session. So I swapped it for a Glades Armory version:

this:

IMG_9172.jpg


became:

IMG_9177.jpg


No dramas coming through AUS customs. Much easier to cycle the bolt now :drinks:

Oh BTW I shot an arbitrary test load of 18gr AR2205 under the 125gr SST at 100m - group was pretty horrid. Back to ladder tests for me now...


I just use the Hornady rubber balls that press onto the bolt knob.
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Re: 300 AAC Blackout fad over?

Post by JimTom » 22 Jul 2019, 8:51 pm

I am surprised that the 125SST didn’t perform for you mate. I am loading 17.5 AR2205 from memory and they go really well. Let us know what you come up with.
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Re: 300 AAC Blackout fad over?

Post by in2anity » 22 Jul 2019, 9:05 pm

bladeracer wrote:I just use the Hornady rubber balls that press onto the bolt knob.

Ha, did not know about those Blade - probably shoulda asked you blokes before spending that money :lol: certainly would have solved my problem with a lot less fuss
Last edited by in2anity on 23 Jul 2019, 8:54 am, edited 1 time in total.
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Re: 300 AAC Blackout fad over?

Post by in2anity » 22 Jul 2019, 9:09 pm

JimTom wrote:I am surprised that the 125SST didn’t perform for you mate. I am loading 17.5 AR2205 from memory and they go really well. Let us know what you come up with.

Conditions weren't great - dead-perpendicular gusts anywhere from 1 to 20km/h - so that was surely contributing to some poor shooting. My refined lilgun+Speer loads did shoot better however - it’s funny, my sling groups were basically as good as my bench-rest groups that day - go figure :lol:

A bit of ladder testing should do the trick I reckon - the nodes seem to be there, just gotta find em!
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Re: 300 AAC Blackout fad over?

Post by in2anity » 28 Jul 2019, 9:42 pm

SCJ429 wrote:My experience with the Speer TNT is that they are very effective, at least as good as the SST. The TNT has accuracy potential way beyond its price point. I am betting the TNT works well for you too.


Now that I found my node, the Speers indeed do group pretty consistently. They just don’t feed well in that Ruger. In contrast they feed faultlessly in the Tikka 308 - but I prefer the little blackout for a stack of other reasons.

I also picked up a box of Noslers to try - they are notably more expensive than the Speers and Hornadys.
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Re: 300 AAC Blackout fad over?

Post by JimTom » 29 Jul 2019, 11:59 am

Have you varied the length mate to see if it helps feeding? I had mine originally just off the lands and they wouldn’t feed period. I then loaded them at advertised length in ADI loading data and they go well with the exception being the very last round sometimes plays up.
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Re: 300 AAC Blackout fad over?

Post by in2anity » 29 Jul 2019, 12:40 pm

JimTom wrote:Have you varied the length mate to see if it helps feeding? I had mine originally just off the lands and they wouldn’t feed period. I then loaded them at advertised length in ADI loading data and they go well with the exception being the very last round sometimes plays up.


Loading to spec JT. I think it may be related to the hollow point - both the nosler and hornady with their ballistic tips seem to feed fine.
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Re: 300 AAC Blackout fad over?

Post by in2anity » 30 Jul 2019, 8:41 am

mixed.jpg
mixed bag of 125gr pills at 50m over AR2205
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JimTom you were on the money with your suggested 17.5gr load under the Hornady SST!

And SCJ429, I think you are onto something with your observations that the Speer Bullet shoots way above its price-point. Given my overall experiences with the 300aac, I think the Speer bullet does group fractionally better than the Hornady. Nevertheless, the Hornady bullet feeds very reliably, so I guess I'll stick to the Hornadys when reliability really matters (like during a comp or when hunting).

I've only shot that one (arbitrary) Nosler load. I'm sure it would also have some sweet spots, but compared to the others it's just so darned expensive, so I'll doubt I'll pursue that line of enquiry. I'll back-burner that one for a rainy day.

At this point, I'm going to say the little RARR-300aac is a true one-minute gun. The cartridge is certainly a lot finickier than say a 223, but using the collet die, it's a superb handloader's cartridge. Neck tension with this cartridge seems particularly pertinent. The 300aac is economical, low recoiling, has excellent case life and runs cool.

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