Platoon Weapons

[JonathanF]

Hi all - just a layman (museum worker) here really, but from everything I've read the small PDW calibres are woefully inadequate both anecdotally, and in ballistic gel. So I was confused to read William Owen's RUSI article suggesting adoption of 4.6 or 5.7mm weapons, and his comments here regarding the NATO data.

Can I confirm Wilf (if I may) that you saw the post by DocGKR on the Lightfighter forum link you were given earlier in this thread?

http://lightfighter.net/eve/forums/a...102#4131082102

How do you reconcile that data with what you have (and I admit that I have seen none of your data - I'm genuinely interested in how two so different assessments of the same round (5.7mm) can emerge, bearing in mind that you do support the validity of ballistic gel tests.

Look forward to your reply, but quite understand if you're too preoccupied (and also that this isn't really the thrust of your RUSI article - but it's an aspect that stuck out for me.)

[William F. Owen]

How do you reconcile that data with what you have (and I admit that I have seen none of your data - I'm genuinely interested in how two so different assessments of the same round (5.7mm) can emerge, bearing in mind that you do support the validity of ballistic gel tests.

Look forward to your reply, but quite understand if you're too preoccupied (and also that this isn't really the thrust of your RUSI article - but it's an aspect that stuck out for me.)

Hey Jonathan F! Very happy to take time to reply.

No, I haven't been able to access the link, but its most likely immaterial.
There is a massive hoplophile inspired bug fight over PDWs and small calibre rounds, that has nothing to do with operational reality - in my view - and has not been tested in that regard.

Testing the rounds is easy. We can measure their terminal effect on targets. The problem is that no one can agree on the most desirable effects. My contention is that we are missing the point. (I also speak direct to both FN and Heckler Koch's - so I ignore most of what is on the net)

What my RUSI article was suggesting was that we trade IW weight for sensors, support weapon, and projected HE weight. EG- The things we know create greatest benefit in dismounted operations. The article was intended to be provocative, but has sparked little useful debate, except here!

[JonathanF]

Let me firstly say thanks for your reply, and I'm sorry the article didn't raise the discussion in the professional or academic circles you were hoping for. The overarching argument seemed to me to be a good one, although I agree with the caveat above that the military will simply plug all weight gaps with other equipment as and when they come available. If you could ensure the made-up weight consisted of the sort of kit you talk about (MP7s and P90s notwithstanding for a moment) then it seems a perfectly sensible approach to current conflicts. Of course, what goes on in the future is a different matter. But if a greater degree of flexibility comes out of suggestions like yours, that can only be a good thing.

On to the terminal ballistics. Hoplophile is a new one on me, and a good one too, but unfair in this case I think. "DocGKR" is Gary Roberts, a recognised wound ballistics expert. Dr Martin Fackler (who I think you must have heard of) is also down on these rounds. Neither, as far as I can tell, qualifies as a gun nut, cultural bias aside.

Both men point to a very small permanent wound channel and little to no secondary effect, which to me (and I stress I am not an expert by any means) makes a lot of sense. The only reliable way to cause incapacitating wounds aside from shot placement is to use weapons and ammunition that create large permanent wounds that, to put it bluntly, will bleed a lot.

Ironically enough, at 4-500m, this would be less of an issue. Any 10"+ perforating gunshot wound is going to cause a fighter enough difficulty at that range to put them out of the fight. But at the <300m range you're talking about, rapid incapacitation becomes pretty crucial as I see it, and not just from anecdotes that may relate to unusually resilient individuals (such stories can be rustled up for just about any calibre).

If you acknowledge the utility of gel tests, I wonder how you square the following with what you've seen, and would ask how the test methodology and results compare (assuming you have access to the articles cited)?

(Edited quote from the lightfighter link - I'd urge you to read the whole thing in situ)

Other than being able to perforate soft body armor, the 5.7 x 28 mm used in the FN P90, as well as the 4.6 x 30 mm fired from the HK MP7 cause wounds less incapacitating than those made by 9 mm FMJ fired from a pistol...

Several papers have described the incredibly poor terminal performance of projectiles fired by the FN P90.
--Dahlstrom D, Powley K, and Gordon C: “Wound Profile of the FN Cartridge (SS 190) Fired from the FN P90 Submachine Gun". Wound Ballistic Review. 4(3):21-26; Spring 2000.
--Fackler M: "Errors & Omissions", Wound Ballistic Review. 1(1):46; Winter 1991.
--Fackler M: "More on the Bizarre Fabrique National P-90", Wound Ballistic Review. 3(1):44-45; 1997.
--FBI Academy Firearms Training Unit. FBI Handgun Ammunition Tests 1989-1995. Quantico, U.S. Department of Justice--Federal Bureau of Investigation.
--Hayes C: “Personal Defense Weapons—Answer in Search of a Question”, Wound Ballistic Review. 5(1):30-36; Spring 2001.
--Roberts G: “Preliminary Evaluation of the Terminal Performance of the 5.7 x 28 mm 23 Grain FMJ Bullet Fired by the New FN P-90 , Using 10% Ordnance Gelatin as a Tissue Simulant”, AFTE Journal. 30(2):326-329, Spring 1998.
--Roberts G: “Terminal Performance of the 5.7 x 28 mm 31 Grain SS-190 FMJ Bullet Fired by the FN P-90 in 10% Ordnance Gelatin.”, AFTE Journal. In Press.

It is all basic physics and physiology. Look at the surface areas in contact with tissue for 9 mm FMJ and JHP compared to 5.7 mm. When both are point forward, the 9 mm FMJ crushes more tissue than the 5.7 mm; for the short time that the 5.7 mm is at FULL yaw, it crushes a bit more tissue than the 9 mm FMJ. At no time does the 5.7 mm crush more tissue than the expanded 9 mm JHP--even when the 5.7 mm FMJ is at full yaw, an expanded 9 mm JHP crushes more tissue. The relatively small temporary cavities produced by both the 9 mm and 5.7 mm projectiles are not likely to cause significant injury to the majority of elastic structures of the body. As with any penetrating projectile, if either a 9 mm or 5.7 mm bullet is ideally placed to cause significant damage to the CNS or major cardiovascular organs, a fatal result is likely.

[William F. Owen]

If you acknowledge the utility of gel tests, I wonder how you square the following with what you've seen, and would ask how the test methodology and results compare (assuming you have access to the articles cited)?

I am extremely familiar with Gel tests and the wounding literature to which you refer. Gel tests are excellent for comparison data, (as is CRISAT) but you can't use Police Firearms criteria for judging these rounds.

1. Military rounds are not just about what they do to humans. The ability to perforate cover is absolutely critical.

2. As I say in the article, no one ever says, "c'mon lads. They're only using 4.85mm. let's go!" Any round can suppress.

3. PDW rounds have very low dispersion and good accuracy at <200m. Very few tests take this into account.

Hoplophile = Lover of Weapons, or "gun nuts".

[JonathanF]

Thanks Wilf.

I am extremely familiar with Gel tests and the wounding literature to which you refer. Gel tests are excellent for comparison data, (as is CRISAT) but you can't use Police Firearms criteria for judging these rounds.

1. Military rounds are not just about what they do to humans.

I realise that, but it's increasingly a factor in weapon design and procurement, at least in the US. So what are your thoughts on the gel testing that shows a smaller permanent wound channel and neglible secondary "tissue stretch" effect?

The ability to perforate cover is absolutely critical.

I appreciate there's a difference in military and law enforcement requirements. Again I would suggest that attitudes in this respect are changing and I'd also ask why not consider wound ballistics? If it's important to a policeman to quickly incapacitate his target, why not a soldier?

I also accept that historically, armies have been happy simply to suppress and to score penetrating hits at range. But to equip infantrymen with what are basically less ballistically effective sub-machineguns, seems like a case of baby+bathwater to me. I realise you're proposing that GPMGs, MLGs and sniper weapons can take up the slack, but I just don't see the PDWs cutting the mustard even at the <300m range.

2. As I say in the article, no one ever says, "c'mon lads. They're only using 4.85mm. let's go!" Any round can suppress.

Yes, but not any round can incapacitate, nor make it through cover (see below). I concede that my suggestion that insurgents might adapt to take advantage of platoons armed primarily with short-range weapons was exaggeration to try to make a point.

3. PDW rounds have very low dispersion and good accuracy at <200m. Very few tests take this into account.

True, though of course so does 5.56, which can also work to mid-long range and (with the right ammo) cause reliably incapacitating wounds). Much heavier weapons, of course, which I recognise is really your point in the article - reducing carried weight.

So are you thinking along Project Salvo lines? Lots of grouped small-calibre rounds to increase hit probability, at the sacrifice of terminal performance?

Hoplophile = Lover of Weapons, or "gun nuts".

I did gather (after a google, admittedly) which is why I said it was a good line, didn't apply to the experts I cited, and used the term "gun nuts" myself. Just because a lot of gun nuts support something, doesn't lend it either credibility, or a lack of it.

In the expanded version of what I posted, Roberts (as does 120mm above) states that the 5.7mm round is NOT good at making it through cover, I presume in terms of maintaining velocity and vector (since it can do the CRISAT and soft armour no problem). This is because of its low mass/momentum - AP 9mm is (he says) better at this. So I wonder why you feel PDW rounds do meet this military criterion.

I'm still not sure how you can say that "4.6mm and even 5.7mm weapons are generally more effective in terms of measurable criteria (CRISAT performance and PERMANENT wound channel) than 9mm SMGs." Everything I've seen, and simple physics as Roberts says, strongly suggests otherwise. So whilst I'm not saying terminal effects in bodies should be the be-all and end-all of a military round and weapon, what I am saying is that the current 5.7 and 4.6mm rounds are not the compromise that you're looking for to save weight.

Now, once again, I realise that all I've read has all been online, whereas you have access to some real data that might totally trump the Fackler/Roberts tests. But if you could just clarify why you think those cited articles show a lesser gel result than 9mm ball, where other tests (presumably) contradict that, that would address my main concern (if for the sake of argument I concede that sub-carbine weapons are appropriate IWs). If you can point me to anything online or accessible via say, JSTOR, that would be a bonus for which I'd be most grateful.

[William F. Owen]

JonathanF

I am not sure I would advocate the issuing of small calibre PDWs until I had done all the testing I feel necessary to provide the data. UK Infantry Thinking is incredibly conservative and equipment focussed, so I merely advocate it, to create discussion.

Be very careful of using the word "incapacitate." It's meaningless unless applied to a specific time frame and capability which you seek to defeat.

A .22 long rifle round can incapacitate just as well as a .50 if it hits in the right place. I know I use it as wildly as a lot of folks, but that's the frame of the argument right now.

[slapout9]

JonathanF
A .22 long rifle round can incapacitate just as well as a .50 if it hits in the right place. I know I use it as wildly as a lot of folks, but that's the frame of the argument right now.

That is very true Wif. One of the worst Officer Survival films I have seen involved a South Carolins State trooper who was killed by a .22 fired from what we used to call a mouse gun (small handgun). It entered his armpit just above his body armor and just nicked the top of his heart causing him to bleed to death. Also the trooper fired his .357 magnum at point blank range at his attacker hitting him 3 time I believe. The attacker survived. the trooper didn't.

[JonathanF]

JonathanF

I am not sure I would advocate the issuing of small calibre PDWs until I had done all the testing I feel necessary to provide the data. UK Infantry Thinking is incredibly conservative and equipment focussed, so I merely advocate it, to create discussion.

Understood, thanks.

Be very careful of using the word "incapacitate." It's meaningless unless applied to a specific time frame and capability which you seek to defeat.

Incapacitate in my mind means that the enemy is unable to return aimed fire. Timeframe = the sooner the better, surely? From what I'm seeing, even 9mm is sooner and better than 5.7mm, by virtue of a larger permanent wound channel. Plus it's supposedly better at defeating cover without deflection. Bearing this in mind, for your purposes, I would argue that you'd be better off proposing a different weapon. I also note the post above about the comparative weight of the 10" barrelled Colt carbine.

A .22 long rifle round can incapacitate just as well as a .50 if it hits in the right place. I know I use it as wildly as a lot of folks, but that's the frame of the argument right now.

Yes, of course -shot placement, whether by luck, judgement, or a mixture of both, is key. That's a given - why further reduce the effectiveness of your fire by choosing rounds that are shown relatively to be less damaging to the human body and less able to deal with interfering barriers.

I see now that you were poking the hornet's nest, and agree that it's one that needed poking. But needless to say you still have to be able to back up what you say. You don't need to prove anything to me, but if you can show me the evidence that counters what I've pointed to myself, I'd love to see it. I have no horse in any race here, I've ended up studying this area as an offshoot of an offshoot of my real job (historical stuff). And as a paid-up member of the sceptic's club, I try to assess everything from that perspective. The weight of evidence seems to me to be against PDWs, which were designed for a specific role, being capable of serving effectively as a main IW.

Playing devil's advocate to myself for a moment, and being optimistic about the tumbling claimed for the 5.7mm round + the capabilities of the P90 itself, you could see it as a fairly close parallel to the 7.62x39 and the AK family. With the advantages of being lighter, higher capacity, more accurate and better able to defeat soft armour. Viewed in those terms (and in the context of your other proposed changes), it's an option. But in terms of wound ballistics, I still think you'd be sacrificing quite a lot even compared to the "clean wounding" 7.62x39 round. A case would need to be made that the pros outweigh the apparent con of the lacking wound ballistics, and I don't think, on balance, that it has been (if it has, great! I hope to read about it one day.).

Anyway, a bit of a distraction from the real point of the article - my apologies for this. I did find it interesting and thought provoking.

[120mm]

I am extremely familiar with Gel tests and the wounding literature to which you refer. Gel tests are excellent for comparison data, (as is CRISAT) but you can't use Police Firearms criteria for judging these rounds.

1. Military rounds are not just about what they do to humans. The ability to perforate cover is absolutely critical.

I say again, the ONLY "cover" that PDW rounds can perforate reliably is CRISAT. And none of our current or foreseeable enemies is stupid enough to wear body armor to the battlefield. PDW rounds against "real" cover are worse than useless. Light, fast bullets just don't penetrate very well.

One more point on PDWs and "itty-bitty bullets" IOT save weight. I guaran-freaking-tee you, that a lightweight "bullet-hose" PDW will go through ammo fast enough, that will more than neutralize the alleged "weight-savings" versus a "real" rifle.

[William F. Owen]

I say again, the ONLY "cover" that PDW rounds can perforate reliably is CRISAT. And none of our current or foreseeable enemies is stupid enough to wear body armor to the battlefield. PDW rounds against "real" cover are worse than useless. Light, fast bullets just don't penetrate very well.

One more point on PDWs and "itty-bitty bullets" IOT save weight. I guaran-freaking-tee you, that a lightweight "bullet-hose" PDW will go through ammo fast enough, that will more than neutralize the alleged "weight-savings" versus a "real" rifle.

...and these would be reasons not to adopt a PDW, but as no one has really done the testing versus tactical applications, I would want to see some evidence. The MP-7A1 and P-90s are both being used on operations by various folks, but hard data is very hard to come by.

[120mm]

...and these would be reasons not to adopt a PDW, but as no one has really done the testing versus tactical applications, I would want to see some evidence. The MP-7A1 and P-90s are both being used on operations by various folks, but hard data is very hard to come by.

Don't "get" the "no one has really done the testing" thing. I think there is plenty of evidence that shows that light, fast bullets don't penetrate, and don't produce secondary effects anywhere near as well as heavier, slower projectiles.

There is at least one decent study on suppression effects out there, of various types of ammunition and weapons. (BTW - I think the study I saw post-WWII, indicated that even a bolt action rifle can "suppress" with occasional rounds, rather than "beating up" the target with fully auto fire.

Since this thread has started, I've developed one additional objection to PDWs: In combat, very few people will put themselves in a position where they can put their weapon "in play" effectively. The great majority are incapable, or unwilling to put effective fire onto the enemy. Therefore, why sell out to the lowest common denominator at all in your selection of a shoulder arm?

With the assumption that MGs and arty are truly the biggest battlefield killers, why not go to a 16" carbine that shoots the rounds common to your machineguns? (Which would be an excellent reason to change to a single, common caliber, around the 7mm x 45mm range...) If suppression is your goal, accuracy becomes unimportant, and the bigger bullets will have a great effect downrange in ricochets, barrier penetration and splinter effects. Heck, just give everyone a SAGL... (Semi-Auto Grenade Launcher...)