PDWs...and other small arms.

[LR1955]

I think the NATO CRISAT target is badly outdated. As best I can tell from the limited research I've done, the CRISAT target was created to simulate Soviet-era body armor.

Protection level of Russian body armor has reportedly been improved several times since the 1980s. The latest 6B43 and 6B45 vests have ceramic inserts that reportedly provide protection comparable to Western hard armor. http://www.armyrecognition.com/weapons_d...05162.html

Below: 6B43 body armor shot with 7.62x54R SVD sniper rifle @ 10 meters.

[video=youtube;SXvgDfE8g2w]https://www.youtube.com/watch?v=SXvgDfE8g2w[/video]
https://www.youtube.com/watch?v=SXvgDfE8g2w



If it is desired to prepare for possible future war against the Russians, will any proposed PDW round be adequate to defeat their latest body armor?

Or will it be necessary to use the standard rifle/machine gun caliber?

Stan:

You probably won't penetrate it with any single shot from any small arms. Multiple shots and who knows but from guys I know who did get shot in chest plates, the impact knocked them down pretty hard.

May be able to cleave it with your tomahawk or perhaps stab through with your knife.

Why a PDW anyway if the best way to prevent fratricide (when being over run) is to discard your firearm and use 'cold steel'?

LR55

[stanc]

Stan: You probably won't penetrate it with any single shot from any small arms. Multiple shots and who knows but from guys I know who did get shot in chest plates, the impact knocked them down pretty hard.

Yeah, that can sure be seen in these videos. One soldier described it as like being hit with a sledgehammer.

[video=youtube;JxeP9SjJt68]https://www.youtube.com/watch?v=JxeP9SjJt68[/video]
https://www.youtube.com/watch?v=JxeP9SjJt68

[video=youtube;tMMSA3opBk4]https://www.youtube.com/watch?v=tMMSA3opBk4[/video]
https://www.youtube.com/watch?v=tMMSA3opBk4

May be able to cleave it with your tomahawk or perhaps stab through with your knife.

Why a PDW anyway if the best way to prevent fratricide (when being over run) is to discard your firearm and use 'cold steel'?

LOL. Now you're just being mean.

But seriously, if it should be deemed necessary for small arms to be able to defeat modern hard armor, it looks to me like the only way to possibly achieve that is to go the route that the Russians started down three decades ago: Intermediate caliber, ultra-high velocity.

Developed for machine gun and sniper rifle, the 6x49 Unified (below, center) had a 77-gr steel-core bullet @ nearly 3800 fps.

[Sticks]

...May be able to cleave it with your tomahawk or perhaps stab through with your knife.

Why a PDW anyway if the best way to prevent fratricide (when being over run) is to discard your firearm and use 'cold steel'?

LR55

That's not going away any time soon, is it? Flashbacks of Gecko45.

[LR1955]

Yeah, that can sure be seen in these videos. One soldier described it as like being hit with a sledgehammer.

[video=youtube;JxeP9SjJt68]https://www.youtube.com/watch?v=JxeP9SjJt68[/video]
https://www.youtube.com/watch?v=JxeP9SjJt68

[video=youtube;tMMSA3opBk4]https://www.youtube.com/watch?v=tMMSA3opBk4[/video]
https://www.youtube.com/watch?v=tMMSA3opBk4



LOL. Now you're just being mean.

But seriously, if it should be deemed necessary for small arms to be able to defeat modern hard armor, it looks to me like the only way to possibly achieve that is to go the route that the Russians started down three decades ago: Intermediate caliber, ultra-high velocity.

Developed for machine gun and sniper rifle, the 6x49 Unified (below, center) had a 77-gr steel-core bullet @ nearly 3800 fps.

Stan:

Once again you come through. Living lexicon of small arms and ammunition. I could look on the internet for days and not find this.

I can imagine that this 6 X 49 Russkie cartridge could go through our ceramic body armor.

Must be ten years ago when one of our guys got hold of a new chest plate that we shot with various NATO cartridges. The one that penetrated the most was M-855. Then M-118 Special Ball. Neither went through but both dimpled the back side of the plate. The 855 more so than the 118. I still have the plate somewhere.

And what you have continually demonstrated the entire time on this forum is that every practical combination of bullet and cartridge probably has already been developed and tested. The ones that worked the best were the ones that became issued. Most likely that Russian 6 mm went through about everything but went through barrels faster so it wasn't put into production.

Thats why I get a kick out of guys who come on screaming about how much better a 6.5 Grendel is than X, Y or Z cartridge or combination of bullet and cartridge. I am sure a Grendel could be selected to replace the issued 5.56, providing the Grendel met what ever requirements were developed by DoD and did so by a great enough margin to warrant the billions it would cost. Same with that Russian 6 X 49. Or anything else for that matter.

LR55

[stanc]

I can imagine that this 6 X 49 Russkie cartridge could go through our ceramic body armor.

And what you have continually demonstrated the entire time on this forum is that every practical combination of bullet and cartridge probably has already been developed and tested. The ones that worked the best were the ones that became issued. Most likely that Russian 6 mm went through about everything but went through barrels faster so it wasn't put into production.

That does seem likely. Although there are other issues which could be contributing factors:

- Development began in the late 1980s, just before the Soviet Union collapsed. The resulting budget cutbacks could have caused the program to be dropped, just as the Germans cancelled adoption of the G11 caseless ammo rifle.

- In that time period, the standard body armor for US troops was the PASGT Kevlar vest, which is easily penetrated by ordinary ball ammo, especially the steel-core stuff the Russkis use.

But, if barrel wear is the determining factor, isn't that what quick-change barrels are for?

Design the new rifle like the Steyr AUG, and issue a spare barrel with every rifle. Problem solved.

[video=youtube;A3Gzn7XxBaQ]https://www.youtube.com/watch?v=A3Gzn7XxBaQ[/video]
https://www.youtube.com/watch?v=A3Gzn7XxBaQ

Thats why I get a kick out of guys who come on screaming about how much better a 6.5 Grendel is than X, Y or Z cartridge or combination of bullet and cartridge. I am sure a Grendel could be selected to replace the issued 5.56, providing the Grendel met what ever requirements were developed by DoD and did so by a great enough margin to warrant the billions it would cost. Same with that Russian 6 X 49. Or anything else for that matter.

Yup.

[LRRPF52]

6.5 Grendel with an M855A1 projectile does have arms defeat advantage over M855A1 5.56, and will perforate the CRISAT test at 400m from a 14.5" barrel.

Sectional density and length of projectile to depth of armor shows significant advantage to 6.5mm, as well as BC and retained impact speed or momentum at distance.

Not saying 6.5 Grendel should be a 5.56 replacement, just something to consider.



If one of the main objections to a new PDW cartridge is adding an additional DODIC to the system, then we really should be looking at letting 9mm and 7.62 NATO being left in the 20th Century, and maybe even 5.56 NATO.

A smart move would be to develop a PDW cartridge that is also suitable for a good portion of the Combat Arms Duty positions that are not specifically tasked with engaging the enemy with their primary weapon unless in the defense or in an overrun scenario. Guys like key leaders, RTOs, Ammo Bearers, Assistant Machine Gunners, Forward Observers, JTACs, TAC-Ps, Stinger Gunners, Javelin Gunners, Carl Gustav Gunners, etc.

None of them should be carrying a 9mm pistol. All of them should be carrying a small PDW that is effective out to 300m, but fits in a smaller package than 5.56 NATO, like the 6x35 KAC PDW updated with a better projectile in the form of M855A1.

If that 6x35 PDW was dusted off with engineered propellant, a higher BC, and copper core with steel penetrator construction, you could have something that would do as well as 5.56 NATO M855A1 by making up for MV with BC, while allowing many more magazines to be carried than is currently feasible. Even 5.56 mags become more difficult to carry with out armor. I used to be able to carry a double basic load before Interceptor IOTV and SAAPI plates. Now you have man units who go with an SOP that is less than the older 210 rounds basic load for the M16/M4.

With an improved 6x35 PDW, you could carry 1.5x as many mags as with NATO 5.56 STANAG mags, and have better terminal performance than M855, with higher hit probability than M855A1 5.56 by going with much higher BC.

Have a dismounted cartridge mix of:

PDW/Enhanced Infantry Rifle Cartridge for most soldiers
DM/Light SASS 6.5mm cartridge
6.5mm LSAT (which exceeds 7.62x54R performance)

These would replace the aging 9mm, 5.56 NATO, and 7.62 NATO systems and all their penalties and limitations. 9mm has no place outside the wire, 7.62 NATO is too heavy with not enough juice for the squeeze, and 5.56 suffers from too long of a case with no room for ogive length to increase BC like 5.45x39 has.

[Texas]

6.5 Grendel with an M855A1 projectile does have arms defeat advantage over M855A1 5.56, and will perforate the CRISAT test at 400m from a 14.5" barrel.

Sectional density and length of projectile to depth of armor shows significant advantage to 6.5mm, as well as BC and retained impact speed or momentum at distance.

Not saying 6.5 Grendel should be a 5.56 replacement, just something to consider.



If one of the main objections to a new PDW cartridge is adding an additional DODIC to the system, then we really should be looking at letting 9mm and 7.62 NATO being left in the 20th Century, and maybe even 5.56 NATO.

A smart move would be to develop a PDW cartridge that is also suitable for a good portion of the Combat Arms Duty positions that are not specifically tasked with engaging the enemy with their primary weapon unless in the defense or in an overrun scenario. Guys like key leaders, RTOs, Ammo Bearers, Assistant Machine Gunners, Forward Observers, JTACs, TAC-Ps, Stinger Gunners, Javelin Gunners, Carl Gustav Gunners, etc.

None of them should be carrying a 9mm pistol. All of them should be carrying a small PDW that is effective out to 300m, but fits in a smaller package than 5.56 NATO, like the 6x35 KAC PDW updated with a better projectile in the form of M855A1.

If that 6x35 PDW was dusted off with engineered propellant, a higher BC, and copper core with steel penetrator construction, you could have something that would do as well as 5.56 NATO M855A1 by making up for MV with BC, while allowing many more magazines to be carried than is currently feasible. Even 5.56 mags become more difficult to carry with out armor. I used to be able to carry a double basic load before Interceptor IOTV and SAAPI plates. Now you have man units who go with an SOP that is less than the older 210 rounds basic load for the M16/M4.

With an improved 6x35 PDW, you could carry 1.5x as many mags as with NATO 5.56 STANAG mags, and have better terminal performance than M855, with higher hit probability than M855A1 5.56 by going with much higher BC.

Have a dismounted cartridge mix of:

PDW/Enhanced Infantry Rifle Cartridge for most soldiers
DM/Light SASS 6.5mm cartridge
6.5mm LSAT (which exceeds 7.62x54R performance)

These would replace the aging 9mm, 5.56 NATO, and 7.62 NATO systems and all their penalties and limitations. 9mm has no place outside the wire, 7.62 NATO is too heavy with not enough juice for the squeeze, and 5.56 suffers from too long of a case with no room for ogive length to increase BC like 5.45x39 has.

WE ARE IN VIOLENT AGREEMENT! Keeping the same demensions in the joining of the M16 upper and lower, the diameter to the upper could be increased to provide stronger webbing to the bolt/barrel lockup which would allow for higher pressures/velocities and REPLACE THE 5.56 and 7.62 which would simplify the supply chain significantly.

[LRRPF52]

I like the lower working pressure of 6.5 Grendel and see it as a major advantage over higher pressure systems, especially in a military context looking at critical component life.

You could still engineer a rifle around it from the start, but don't chase pressure when you have BC already. They have pushed 5.56 way too hard from the start, always wanting more, more, more, when a better case design with longer ogive length could have solved their retained momentum desires.

BC gives you a lot of room to work with on the back end, rather than trying to milk performance out of the front.

[stanc]

6.5 Grendel with an M855A1 projectile does have arms defeat advantage over M855A1 5.56, and will perforate the CRISAT test at 400m from a 14.5" barrel.

That would be great if it was 30 years ago and we were planning to defeat the thin metal plate armor then in use by the Soviets.

But, how does it perform against current Russian ceramic armor?

A smart move would be to develop a PDW cartridge that is also suitable for a good portion of the Combat Arms Duty positions that are not specifically tasked with engaging the enemy with their primary weapon unless in the defense or in an overrun scenario. Guys like key leaders, RTOs, Ammo Bearers, Assistant Machine Gunners, Forward Observers, JTACs, TAC-Ps, Stinger Gunners, Javelin Gunners, Carl Gustav Gunners, etc.

None of them should be carrying a 9mm pistol. All of them should be carrying a small PDW that is effective out to 300m, but fits in a smaller package than 5.56 NATO, like the 6x35 KAC PDW updated with a better projectile in the form of M855A1.

If that 6x35 PDW was dusted off with engineered propellant, a higher BC, and copper core with steel penetrator construction, you could have something that would do as well as 5.56 NATO M855A1 by making up for MV with BC, while allowing many more magazines to be carried than is currently feasible. Even 5.56 mags become more difficult to carry with out armor. I used to be able to carry a double basic load before Interceptor IOTV and SAAPI plates. Now you have man units who go with an SOP that is less than the older 210 rounds basic load for the M16/M4.

With an improved 6x35 PDW, you could carry 1.5x as many mags as with NATO 5.56 STANAG mags, and have better terminal performance than M855, with higher hit probability than M855A1 5.56 by going with much higher BC.

Unfortunately, there appears to be a number of problems with your proposal.



1. The 6mm 65gr bullet has a lower BC than 5.56mm 62gr.

2. If the 6mm bullet construction is changed to steel tip/copper slug, projectile weight will decrease, and BC will be even lower.

3. In order to get your "much higher BC," it will be necessary to use a long-ogive bullet, a la 6.5 Grendel, which will increase cartridge OAL to that of 5.56 NATO, thereby permitting no reduction in magazine dimensions, or increase in number of magazines that can be carried. (Since OAL of the 6x35 TSWG cartridge is only 20% less than that of 5.56x45 NATO, I'm not sure how you figure it would be possible to fit 50% more magazines in the same area on a soldier's chest, anyway.)



4. Such a long, streamlined projectile would also be much heavier*, which would significantly reduce muzzle velocity, adversely affecting effective range and armor penetration.

*Steel core bullets for the 6mm Unified (below) were 77gr; for the 6mm SAW, 90gr.

Have a dismounted cartridge mix of:

PDW/Enhanced Infantry Rifle Cartridge for most soldiers
DM/Light SASS 6.5mm cartridge
6.5mm LSAT (which exceeds 7.62x54R performance)

These would replace the aging 9mm, 5.56 NATO, and 7.62 NATO systems and all their penalties and limitations. 9mm has no place outside the wire, 7.62 NATO is too heavy with not enough juice for the squeeze, and 5.56 suffers from too long of a case with no room for ogive length to increase BC like 5.45x39 has.

IMO, the optimum choice depends upon whether or not the capability to defeat modern hard body armor is wanted.

If it is, then I think it'll be necessary to use a cartridge which combines a high BC (hardened steel or tungsten core) projectile and very high muzzle velocity.

The velocity requirement pretty much calls for a return to long barrels. And the operational need for short weapons effectively mandates adoption of the bullpup concept.

[Texas]

And so now we can see why there is not a fielded PDW

[ahillock]

[video=youtube;_HfwUO-iWH4]https://www.youtube.com/watch?v=_HfwUO-iWH4[/video]


SFC Gregory Wilson @ Fort Benning regarding training of combat soldier:

"More and more soldiers now a days are using pistols than in past. So now they are carrying it as a secondary weapon in case their primary weapon goes hard down, or there is a malfunction that they can not clear themselves. They still have a pistol to go to to fight their way to a secure position or to where another rifle is, that they can get to use."

[stanc]

Any straight-walled pistol cartridge simply doesn't have the speed/projectile weight to do the job. Any legacy 20th Century pistol cartridge should be excluded on that basis alone, in addition to the fact that they all have terrible effective ranges due to low mv and poor projectile shaping.

When you look at things like the 7.62x25 and other small, bottle-necked cartridges, things start to shift towards rifle performance. 9x25 Dillon is another example of a pistol cartridge that can spit a decent weight projectile at 2000fps or more.

7.5x27 FK







https://www.fkbrno.com/cartridge-7-5

[yoni]

The original question was about the military adopting a PDW for support troops.

I have an Israeli perspective.

I have never been in a support position, however I was in a position where I was issued a full sized M16 that I set up for urban sniping, a Colt Commando, mini Uzi and depending on the time frame a Hi Power and later a Glock.

I also own a micro Uzi in Israel.

In the IDF during my time the support weapon could have been a full sized Uzi in the old days, or today we are seeing Galils and M16 in the hands of support troops. A full sized M16 does not fit the idea of a PDW of most people here, but a lot of terrorist in Israeli cities have been killed by a full sized M16 in the hands of support troops travel between their duty station and home.

We operated in either uniform or in civilian clothing in a covert manor. When covert a lot of us would carry in a bag a mini Uzi and I would a lot of times do the same thing off duty with my micro Uzi.

I did have shootings off duty with the micro and was glad I had it plus a pistol with me.

I will note that the micro was used when I had to go to social events such as wedding or bar mitsvah, etc. I would carry it in a back pack and it went on the floor at my feet. Much better than sitting a Colt Commando on the floor at a social event.

When off duty I usually had the Colt commando with me and my pistol.

I remember talking with my good friend Eugene Sockut who was twice the Chief Shooting Instructor for the IDF and he had a habit of training support troops to really shoot. He told me they never complained about what gun they were issued and were very happy to be taught to shoot better.

In the civilian police they have used M1 Carbines and even micro Galils inthe same caliber. I remember hearing that with proper ammo the M1 carbine round has a good record over the military ball.

In closing we tried the P90 in a trial and that round was a joke. 9mm ball put terrorist down better.

So I think something like the B&T poly framed 9mm with proper training would be easy for the troops to carry and would do the job for 90% plus of what a support troop might need.

[VASCAR2]

Thanks for posting your perspective yoni, it's always good to hear from people with first hand experience!

[stanc]

PEO Soldier wants a 9mm PDW? RFI issued: http://www.thefirearmblog.com/blog/2018/...t-weapons/

[LRRPF52]

Stan, I think I'm going to be more disgruntled and cynical than you if I ever reach your years...

This is madness.

[stanc]

Stan, I think I'm going to be more disgruntled and cynical than you if I ever reach your years...