Grendel as a Universal Infantry Cartridge

[Tony Williams]

The Grendel and 6.8 are much closer to 5.56 controllability, but not the same, however, I still think they are suitable assault rifle or carbine cartridges, although I prefer the 5.56 personally. The 7x46 UIC would be a bit too much for space utilization, weight, and recoil for the common assault rifle. It would make a great cartridge in the no man's land, but you simply can't mitigate the requirements for a close-in weapon and an LMG with the same loading. It is an interesting option for replacement of 7.62x51 in LMG's and maybe a DMR, but should not be considered for use in a carbine or standard service rifle.

Don't forget that the recent ARDEC calibre tests, which were aimed at assessing the optimum cartridge for a new carbine not a general-purpose round, took into account recoil and ammunition weight in reaching their conclusions that the optimum calibre using the latest service-type bullets is between 6.5mm and 7mm (although there is some inconsistency in the figures which raises doubt as whether these are bore or bullet diameters - if the latter, the optimum bore calibre would be 6.35-6.8mm). Furthermore, I have heard that the loadings they tested in these calibres were fairly "hot" - more than a Grendel, for instance.

As far as Mk12's and M14 EBR's being more and more popular, they are becoming less and less popular from what I understand, although MK12's are seeing more service with the USMC. Guys in Sniper duty positions are quite happy with a regular M4 with a drop-in match trigger and Mk.262, preferring that over an 18" SPR, since your job as a rifleman is more common than performing precision marksmanship functions at distance.

I didn't comment on MK12 popularity, merely noted it as yet another gun in service. I expect that the popularity of 7.62mm heavy rifles will vary depending on the circumstances - if many of the engagements are at long range they become extremely popular, but if the job is mostly house-clearing then a 5.56mm carbine clearly has appeal.

Certainly all of the feedback I've had about the L129A1 in British service is highly positive. I am also told that the Royal Marines (who ran a detailed study on the calibre question, including consultations with troops) would prefer an intermediate round but, faced with the choice between 5.56mm and 7.62mm, most of the combat-experienced troops would drop 5.56mm altogether and go back to 7.62mm for everything.

Also, from very reliable sources in the UK, I'm told that the 7.62 bolt guns have been binned in favor of the .338 LM AI's, which are mostly used in a static position in the defense, although there have been some rare exceptions with much fanfare. There is no reason to have a manual bolt operated 7.62 weapon, in my opinion, having carried them and suffering under their impracticality. They make great range queens, but have negative net effect in a maneuver war.

Yes, the BA's 7.62mm L96 bolt-action sniper rifles have all been replaced by .338 L115 because of its much superior long-range performance. The US Army is of course doing something similar with its bolt guns, rebarrelling them from 7.62mm to .300 Win Mag, for the same reason.

I wasn't suggesting that carrying 7.62mm bolt guns on patrol was a good idea - it was only done in the BA because they were desperate for something with a better long-range performance than 5.56mm, and the L96 was all they had to hand. I am told that when on foot patrol in areas where the engagagement distances are likely to be long, it is not unusual for an L115-armed sniper to accompany the patrol. This is not of course the way in which snipers are normally used, but it indicates the importance given to effective long-range small-arms fire.

We could eliminate some of the logistics and over-diversification issue with a universal LMG, that fills the role of the SAW and the 240 without losing the 240's downrange effectiveness. 6.5mm can do that with the right projectile and loading. A friend of mine is getting 2700fps with 139gr Scenars out of a Cz527 bolt action, so an LMG with no requirement to baby brass could get significant velocity with a load heavier than 120gr easily. 6.5mm bullets will always out-gas 7mm from smaller cartridges. You need significantly more powder to make even a 6.8 VLD match a 6.6 for trajectory, and you still lose the wind deflection contest.

A couple of years ago I would have agreed with you but, as Stan points out, it's the lead-free ammo requirement which changes the traditional equations. I really don't know what the optimum calibre will turn out to be, it is very dependent on just how aerodynamic the bullet shape can be made for mass production.

Even if we put a larger, heavier-recoiling rifle or carbine in Joe tentpeg's hands, it will not equal an increased hit probability passed the maximum effective range he can engage targets under stress from a hasty position while under fire. It will guarantee a logistics stress on his load, and less ability to recover shot-to-shot. There's no way around that which is practical.

We have to set some practical expectations that factor the soldier into the dismounted land component system from a holistic perspective, which the weapon is actually not much of a determining factor, in my opinion and experience. An extensive training and maturity curve in the mind and heart of a professional infantryman is what makes a difference in bringing about higher hit probability ballistic solutions with small arms, driven by an intensely focused trigger towards extreme violence to overwhelm an enemy.

It takes a lot of quality training to achieve that, which is almost impossible to achieve with a leadership climate that will never understand that dynamic until they have a demand for it downrange when it's too late.

Once the training solution code is cracked, guys who have stepped past it into a continuous cycle of maintaining proficiency love 5.56, and use it effectively from contact ranges out to 700m, some even making intentional 1st-round head shots as evidenced in one of the videos I linked previously, but the training cycle code has to be cracked first to make effective infantrymen, and practical marksmanship is just one individual skillset that comes together in a series of collective tasks that are necessary to make a unit effective in the dismounted game.

All good points and I entirely agree that training is by far the most important element in soldier performance, and that not enough training in long-range marksmanship has been provided in the past (although I understand that this has changed recently).

I am only interested in seeing that the soldiers get a gun+ammo combo which meets their needs and overmatches whatever the likely enemy has. The view from just about every UK and US military source I've heard is that 400m is the maximum range for effective 5.56mm fire - maybe 500m if you really push it, but then you can run into serious wind-drift problems - and that the standard infantry rifle needs to shoot further than this in the future (something which becomes feasible with the new sights coming down the track).

The most favourable comment I've heard about 5.56mm is that it's tolerable within its range limitations as long as it's backed up by 7.62mm weapons for longer range fire. Which takes us right back to the situation I started my article with!