gatnerd

Military Guns and Ammunition

Hosted by gatnerd

This is intended for people interested in the subject of military guns and their ammunition, with emphasis on automatic weapons.

  • 3360
    MEMBERS
  • 191213
    MESSAGES
  • 4
    POSTS TODAY

Discussions

FN SCAR Mk 2 and Evolys   Small Arms <20mm

Started 14/4/22 by Guardsman26; 8345 views.
schnuersi

From: schnuersi

28/5/22

stancrist said:

Granted. However -- as with the BAR -- the reason for the RPK's inadequate firepower was due to being mag-fed, not the non-QC barrel. Like the RPK, the current squad automatic weapon -- the PKP -- has a non-QC barrel. The difference is that the PKP is a belt-fed weapon.

That is a very limited view.
The first in line has been the RPD which is belt fed but without QCB. Resulting in common overheating. The replacement was the RPD, mag fed without QCB. No overheating but lackluster performance. So they went back full circle to the PKM, belt fed, QCB and full power cartidge. Which evolved into the PKP wich dispenses with the QCB and replaces it by a forced cooling apperature. This apperature increses the weight of the gun allmost to the point where it weights as much as a PKM plus one spare.
So its not true that the Russian just dispensed with the QCB in the same way as the automatic rifles did. They modified the design of the LMG so that the gun can handle the additonal heat. Which is not the case with the RPD, PKM or M24. Its also not the case with a M249 whos gunner decided to leave the QCB behind.

gatnerd

From: gatnerd

28/5/22

schnuersi said:

Why is this a problem.

Well, its adding another 5lbs to the already heavily burdened SAW gunners loadout, and then the basic mechanics of a 16-20" metal tube that needs to be carried in some type of pouch, plus asbestos oven mitt. 

Its not a huge surprise that not carrying a spare barrel would prove popular. 

Whether thats sustainable across the board, I dont know. We'd have to look at the expected ammo loudout of the saw gunner and his squad, and then see how quickly that load could be expended without overheating the gun catastrophically. 

In the case of the M249 gunner, we saw in the Afghan vid him firing ~800rd in ~10 minutes with no ill effect, essentially the squads entire load of belted 5.56 in the time it takes to smoke a cigarette. In that example, it's easy to see why the M249 gunner doesnt feel the need for a spare barrel. 

However the question will be how heavy duty the barrel is on the EVOLYS, and whether its comparably heat resistant / tolerant as the M249. 

If the barrel is the same ~5lbs as the M249/MK48, then it should be fine. However if its more in the 2.5-3.5lb range like a heavy rifle barrel, then...

  • Edited 28 May 2022 9:11  by  gatnerd
schnuersi

From: schnuersi

28/5/22

gatnerd said:

that needs to be carried in some type of pouch, plus asbestos oven mitt.

I am not sure about the barrel change procedure of the M249 but isn't the carrying handle use to handle the barrel so gloves are not needed?

We used to change the hot MG3 barrels just with the standard issue leather gloves. You need to be quick yes but it can be done. Also there is a standard issue container for spare barrels. The hot barrels also go in there and can cool down. The container can be carried with a hot barrel inside without risk of burning.

gatnerd said:

Well, its adding another 5lbs to the already heavily burdened SAW gunners loadout,

This is why the ammo load is distributed over the squad.

gatnerd said:

In the case of the M249 gunner, we saw in the Afghan vid him firing ~800rd in ~10 minutes with no ill effect,

Well i am very sceptical. Just because the gun doesn't jam or blew up in his face doesn't mean there are no ill effects. Accuracy could be degraded. Actually the barrel could be worn out. Which propably isn't a problem when it can be easily replaced in short notice but if not the gun is now useless.
800 rds in 10 min is just 80 rds per minute on average. That is a rather tame ROF for a machine gun.

gatnerd said:

essentially the squads entire load of belted 5.56 in the time it takes to smoke a cigarette

A rather long or slow smoked cigarette ;)
800 rds is the entire loadoad... that sounds very few to me.
 

mpopenker

From: mpopenker

28/5/22

PKM got down to the squad level only relatively recently, after Afghan and Chechen campaigns were mountainous terrain dictated longer ranges. Originally it was used at platoon and company levels.

before that RPK-74 was the SAW, and in fact it was in many ways superior to PKM at short to medium ranges, being much lighter, with noticeably bigger ammo load and better accuracy

the PKP still retains QCB feature (after all, it's just a PKM receiver fitted with new barrel), only it is issued with one barrel and no readily available spares

However, some complain that it's too heavy for the SAW role and it's rarely required for the SAW to fire 500-600 rds in a sustained fire mode

stancrist

From: stancrist

28/5/22

schnuersi said:

       stancrist said: Granted. However -- as with the BAR -- the reason for the RPK's inadequate firepower was due to being mag-fed, not the non-QC barrel. Like the RPK, the current squad automatic weapon -- the PKP -- has a non-QC barrel. The difference is that the PKP is a belt-fed weapon.

That is a very limited view. The first in line has been the RPD which is belt fed but without QCB. Resulting in common overheating. The replacement was the RPK, mag fed without QCB. No overheating but lackluster performance.

So they went back full circle to the PKM, belt fed, QCB and full power cartidge. Which evolved into the PKP wich dispenses with the QCB...

So its not true that the Russian just dispensed with the QCB in the same way as the automatic rifles did.

You just confirmed what I said.

schnuersi

From: schnuersi

28/5/22

stancrist said:

You just confirmed what I said.

Where did I gave the impression that I disagree?
I just put it into the broader context.

BTW apparently we have both been wrong since the PKP still has the QCB option and the force cooled is just a special type of barrel.

schnuersi

From: schnuersi

28/5/22

mpopenker said:

with noticeably bigger ammo load

How so?
How many spare mags does the gunner carry? How many spares for the RPG do the other squadmembers carry?
What is the standard load of 7,62x54R for a squad (if equiped with a LMG)?

If the RPK gunner carries 6 spares his loadout would be 7 x 45 = 315 rds. That doesn't seem impressive for me.
A single full size beltbox 7,62 is 250 rounds.
The clip on, one use plastic boxes, pre loaded with disintegrating belts come with 120 rds. One loaded and two spares on the gunner, one spare on each squad member, 8 men squad 3+7=10 boxes=1200 rds. Which is about a usefull minimum loadout for an LMG.
A more traditional loadout would give most squad members a 250 rd box instead.

stancrist

From: stancrist

28/5/22

schnuersi said:

BTW apparently we have both been wrong since the PKP still has the QCB option and the force cooled is just a special type of barrel.

Yes, I noticed that.  Although since Max says the PKP is not issued with a spare barrel, the effect is the same as if it did not have a QCB.

In reply toRe: msg 62
dobrodan

From: dobrodan

29/5/22

There are in my opinion three ways to keep pasively air-cooled machineguns from overheating:

1: Keep the rate of fire down: 


+ Allows for a relatively large load of MG-ammunition to be carried by the squad, while saving the weight and bulk of the spare-barrel.


- Low rate of fire, or risk ruining the barrel, or even leaving the MG-unoperable.
 

2: Have one or more spare barrels:

+ Allows for a high continous rate of fire.

- Adds bulk and weight, reducing the amount of ammo available, and is not disposable.
 

3: Have more machineguns available:

+ Allows for the highest rate of fire from the squad, both instantaneous and continous, higher ammunition load than alt#2, but lower than alt#1  and also being able to fire at more targets at the same time, or fire at the same target from different angles.

Adds redundancy.

Allows lighter machineguns, and even magazine-fed machineguns)

- Doctrine has to be changed to utilize them effectively.

mpopenker

From: mpopenker

29/5/22

200 and 250 round boxes are used only for PKMS or vehicle-mounted PKP

Note that they do not have a clip to attach it to the gun

In LMG role it's almost exclusively 100-rd boxes that are clipped on to the gun

TOP