So apparently these things exist: 762 SLAP (saboted tungsten for extra penetration), used by Sweden in their AI sniper rifles.
Conventionally, saboted .30 cals like the EABCO stuff tend to be quite inaccurate. What's the trick to getting them to be accurate enough for sniping/sharpshooting? Articles out there mention that these extend effective range from 800 to 1000 meters, so for an 18 inch (shoulder width) target that means just under 2 MOA at least (probably less). Apparently it's a 3.4 gram projectile at 1340m/s, that translates to 52 grains @ 4400FPS.
Rumor has it that those are also inaccurate. I mean, they're accurate when they work, but ~10% of the time the sabot doesn't come off right, and you won't be able to hit the broad side of a barn.
This is why the US Military tends to use M993 rather than M948.
>Rumor has it that those are also inaccurate.
Why use them in a sniper rifle if they're inaccurate then?
Probably around .22/5.56 size.
Any source on that?
>Why use them in a sniper rifle if they're inaccurate then?
is this your first day on the board and your military knowledge is derived from Call of Duty?
>Any source on that?
Literally any source on SLAP rounds ever.
I'm sorry but at this point I can't tell if this is bait or not
It literally says on the box ''only for use in PSG 90'', their version of the AI.
>Literally any source on SLAP rounds ever.
And yet the Swede used them. I'm not an idiot, I'm just wondering if the Swedes are, since I can't really find test data on these rounds as used in an AI.
Nope, just simple pointy projectiles. Firing finned projectiles in a rifled barrel is counterproductive iirc.
Sweden are not idiots when it comes to military equipment generally. Can't speak about the accuracy of these though.
>Nope, just simple pointy projectiles. Firing finned projectiles in a rifled barrel is counterproductive iirc.
Nope, the sabot spins independently of the projectile which "floats" inside the sabot. When the sabot separates it doesn't impart spin to the projectile.
That's wierd. When I designed sabots and analysed the high speed footage I could have sworn the projectiles were spinning.
Then how does it remain stable and properly oriented in flight? I think it would backflip and present its base towards the direction of travel
>Why use them in a sniper rifle if they're inaccurate then?
Real snipers use .338 AP
A non discarding plastic jacket would probably work better.
Would nuke the BC, an the projectile would decelerate to very low velocities within a very short range
Not very short range, the Dagny Dagger worked alright and it had a smaller, lighter core proportional to the mass of Tungsten this would have.
Sure, it would give up some range over a saboted bullet, but it would be totally fine within normal rifle ranges.
The point isn’t really giving up range or trajectory, it’s that the velocity must be retained for armor penetration. Going from 224->308 without increasing weight drops the BC by 1.9x
A plastic shell holding a tungsten Penetrator moving at 4000fps would penetrate effectively identically to that same Penetrator moving alone at the same speed, the only loss would be the tiny amount of energy used to deform the plastic jacket out of the way.
Anybody know why the penetrators are shaped like that? I can see that cone is a good shape for penetration, but would something like a secant ogive not be better? If it’s slipperier in the air, doesn’t that also make it slipperier in every other medium, including armor?
But for it to be moving at 4000fps, unless it’s extremely close range, the projectile would have to leave the barrel at significantly higher velocities than it would need if the sabot discards. It’s gonna lose a ton of velocity in flight.
>If it’s slipperier in the air, doesn’t that also make it slipperier in every other medium, including armor?
Not really, every medium has a particular shape that would be more slippery. Against hard materials, you want a strong shape that does not break apart, and cones teend to be strong in compression.
>But for it to be moving at 4000fps, unless it’s extremely close range, the projectile would have to leave the barrel at significantly higher velocities than it would need if the sabot discards.
This has not been true of the Dagny Dagger, various semi-plastic shotgun shells, or any real world example I can name. Yes, a plastic shelled bullet loses velocity faster, but it is nowhere near the extreme you're implying.
A more ogival shape would be more aerodynamic but more brittle when penetrating hard materials. The typical steel penetrators are shaped more bluntly than the actual bullet profile they fit inside. The biggest factor here is that tungsten is difficult to machine and having a simpler shape would drastically cut on tool and material wear and time, resulting in much improved price. That's why tungsten cores in normal AP have only a cone shaped tip, or double cone tip at most. The shape of the tip SLAP projectiles is quite long, similar to how it would be if it was ogival but without the price tag and with most of the benefits of it.
you can always make it lighter. it's adding weight that can be a problem.
>you can always make it lighter. it's adding weight that can be a problem
What? You said my idea was the same as a normal AP round, and I pointed out it's faster, but it will have the same theoretical Penetrator weight, thus better penetration.
>Anybody know why the penetrators are shaped like that?
Compromise bettwen production difficulty and aerodynamics.
Tungsten carbide is very hard and difficult to grind so it used simple shape for ease of production and for performance that shape is not great but not terrible.
that's what basic tungsten core rounds like m993 are
Except this would be much faster.
What's the diameter of the projectile?
dam bruh that SLAP shit slaps fr
Sweden came thru on god fa.m
Failed design, they aren't accurate at all.
How is a twist even imparted on the tungsten penetrator? Ok the plastic discarding bit engraves and follows the rifling, but it transfers that violent spike in RPM to the tungsten how?
this is exactly what i was thinking
how can it grip the tungsten hard enough to impart spin reliably
Aren't you that gay furry.
Probably uses fins like tank rounds to stabilise in the air.
Easy. Compression force. You have no idea how hard even plastic can grip if its compressed massively. Just think how strong plastic dowels can get even with their soft material.
The plastic compressing against the bullet and imparting spin by friction? Then how do they separate reliably if they are compressed that hard together ?
Because the sabots have grooves cut on the ID that allow air in to umbrella the 'petals' of the sabot out
>The plastic compressing against the bullet and imparting spin by friction?
Yes. Friction force is a function of friction coefficient times normal force (in this case the pressure between bullet and barrel). With a really tight fit comes more normal force and thus more friction. Some of these sabot designs have a little gap behind the bullet: once the cartridge ignites, the sabot goes forward and the projectile stays stationary, meaning it moves rearward relative to the sabot. This movement is used with a sloped surface to push the petals of the sabot further against the barrel.
>Then how do they separate reliably if they are compressed that hard together ?
Once the bullet exists the barrel, the normal force instantly disappears since there is no more barrel. This means there is no resistance between the two anymore.
Negative, the grooves are there to allow petal motion. If it was one continuous ring, without grooves, it would stay attached even after exiting the barrel. It's not so much about letting air in, but rather about reducing friction between the two so the air that is always going to be there drags the sabot more than the projectile.
>What's the trick to getting them to be accurate enough for sniping/sharpshooting?
Teixk is not giving a frick. Swedish belive that inaccuracy of sabit is more than compensated it flatter trajectory and wind ressistnce compring to match sniper ball. Mind you their tests and calculations were for sniper rifles with optical sights and mildot calculations in mind. No laser rangefinders, ballistics calculators and weather meters .
Do you have any evidence that Sweden actually used these in their snipers? Because I can't imagine why they would, they give practically no advantage whatsoever.
There are a bunch of Swedish sources. They were chosen because they gave a higher first hit probability for non-expert marksmen due to flat trajectory and wind insensitivity. Saw some combat use in Afghanistan.
Swegay here. A guy I did my conscription with went to Afghanistan and killed a few Afghanis with a PSG90. He said he didn't feel anything doing it and it fricked him up mentally because he was worried he might be some kind of psycho for not feeling bad about it. This is off topic but I just wanted to share.
See:
These aren't for long range precision use, rather for squad DM to provide flat trajectory and enhanced armor penetration at normal rifle engagement ranges.
>These aren't for long range precision use
Yes they are, all the Swedish souces explictly mention these extending out effective range from 800 to 1000 (so definitely long range), and only to be used in the PSG90, their precision rifle (pryckskittegevär, literally: (pin) prick shooting rifle).
>prick shooting rifle
Why are they like this bros
>all the Swedish souces explictly mention these extending out effective range from 800 to 1000 (so definitely long range)
I sure wonder what these sources are, because the official documentations feature no such numbers, and AFAIK engagement at 800m+ isn't even covered in training other than on the AG90 (Barrett .50).
It's however entirely possible that specific SF units do so, the rifle is certainly capable in good conditions.
My perspective come from the platoon level infantry/jägare (recon/sabotage) and home guard perspective in the mid 2000s.
These rounds weren't considered very accurate past 500m, as has already been touched on previously the advantage considered was first round hit probability in a mixed range target environment, moving targets and armor penetration.
The dedicated snipers used AP (Pansarprojektil, black tip steel core) for long range.
>their precision rifle (pryckskittegevär, literally: (pin) prick shooting rifle).
That is, or at least was in the early-mid 2000s, also used as a squad level DM rifle in some units.
makes guns explode in your face
> sabot
> accuracy
Can they hit the wide side of a barn from 500 yards with that shit?
I mean it would certainly reach the target faster, especially out of something like a 22 inch barrel. Do they have semi autos like AR 10's/ G3's or just bolt actions for snipers, because in something like a AR 10 I can see it used to frick up the side of a BTR 80
It will punch through 15mm of steel at 100m so sure it will, have to wonder how much good it would do on the other side though.
Also these rounds are dedicated to the PSG90 only, and only with the muzzle break removed, saboted rounds in general do not play well with muzzle devices.
They were a pain in the ass to be issued during training since every single round has to be accounted for and either returned or proven fired by empty casing.
15mm of steel pen will indeed screw up a BTR or MT-LB, but it's sad to hear it's only issued to pure sniper units. Give it to guys with DMR's for anti armor, and let them screw up a apc if it rolls around
Somebody send some to Kentucky Buttlipsticks to test accuracy.
One day we will have good apfsds on civilian small calibre shotguns and all will be well in the world. There is nothing wrong with the materials and design of the penetrator. But the plastic sabot is what is limiting this technology in civilian uses.