Just an Idea...

[pmulcahy11b]

If an automatic weapon has a ROF of 800 RPM, should it have a game ROF of 8?
It it has a ROF of 550-600, maybe a game ROF of 6?
450 RPM, game ROF of 5?

?

Pros and Cons.

[Legbreaker]

Seems reasonable at first glance. Obviously burst limiters and recoil would be factors, but you already know that.
Without me having to dredge up the formula myself, what's the current way of calculating burst size?
How would you model reduction of dice for the non-standard burst sizes?

[StainlessSteelCynic]

I believe someone actually used that idea for their own house rules although I can't recall where I saw it.
I have a recollection that part of the reason for adopting the idea was the difference that it made to the various small arms (i.e. most select-fire rifles in the vanilla rules have almost the same stats but this idea showed the difference between various weapons).

[Legbreaker]

One point sticking in my mind is you've got high cyclic rate of fire with many lighter weapons. Like I touched on before though, recoil will likely deal with any players wanting to use assault rifles for example as automatic support weapons, so that's probably a bit of a non-issue.

[Legbreaker]

Another semi-related point which just popped into my head is heat build up. I can't recall any rule system that adequately, or even vaguely touches on the need for barrel changes, water cooling, etc. They all just assume you can simply squeeze off a few thousand rounds in a couple of minutes and not have the barrel melt.

[Vespers War]

Originally Posted by Legbreaker

Seems reasonable at first glance. Obviously burst limiters and recoil would be factors, but you already know that.
Without me having to dredge up the formula myself, what's the current way of calculating burst size?

According to IWotW, anything under 700 RPM cyclic is ROF 5 (or 3 if it has a limiter), between 701 and 1000 is ROF 10, 1001 to 5000 is 50, and 5001+ is 100.

[StainlessSteelCynic]

Originally Posted by Legbreaker

Another semi-related point which just popped into my head is heat build up. I can't recall any rule system that adequately, or even vaguely touches on the need for barrel changes, water cooling, etc. They all just assume you can simply squeeze off a few thousand rounds in a couple of minutes and not have the barrel melt.

I believe Palladium's Recon or Advanced Recon paid some attention to heat build-up on machine guns. I haven't played either of those two or even seen the rules so I can only go on what some old gaming mates told me in the 1990s and I believe they had interpreted the rules far too literally - like, "you have to change the barrel on the M60 every 200 rounds or the barrel will melt" literally.

They were straight up civvies so they had no idea about how rate of fire effects heat build up and how the 200-rd limit is a procedure to prolong the life span & accuracy of the barrel and not a limitation of the barrels abilities etc. etc.

[swaghauler]

Originally Posted by pmulcahy11b

If an automatic weapon has a ROF of 800 RPM, should it have a game ROF of 8?
It it has a ROF of 550-600, maybe a game ROF of 6?
450 RPM, game ROF of 5?

?

Pros and Cons.

That's my houserule. I adopted it because it was the easiest way to do bursts around one-half of a second in duration (it's actually 6/10ths of a second for such a burst rate in reality). The half-second burst rate is the most accurate rate of fire in NFA/Class III matches and produces reasonable accuracy at short range. I always round cyclic rates DOWN to take into account dirty weapons, poor quality ammo, and more time spent in target acquisition and trigger control.

In Twilight2000, it also allows the GM to manage autofire at ONE BURST per one-second Initiative Step. This reduces the lethality of 6 Initiative characters by interspersing their bursts/shots (at one per Initiative Step) among the slower combatants. It also makes the number of D20s the Player must roll a more reasonable number (per burst/second).
I do change RECOIL to that calculated by burst or shot in a one-second round. Thus, a MAC-10 (ROF12, RCL 2?... I don't have my book handy) would be generating a Recoil of 12 per one-second burst. I use excess recoil to reduce the number of rounds on target (dice rolled) these days.

RCL and ROF can interact in unique ways. Let's look at battle rifles. A G3 will have an average Cyclic rate of 550rpm. If RCL is 3 (roller-locking is smooth) you get a RCL of 8 (rounding up as I do) for a full burst. The FAL is also fairly smooth with a RCL of 3 but has a 600rpm ROF. This gives the FAL a RCL of 9 and a ROF of 6. The M14 is notoriously hard to handle in recoil even in single fire mode. It's 700rpm was nearly uncontrollable even in "experienced hands." The rifle will "climb like a monkey" and the sights will bounce all over the place (unlike the FAL or G3). The lack of a pistol grip doesn't help but is more problematic than in older designs like the BAR (which is actually more controllable than the M14 in autofire). This gives the M14 a RCL of 4 with a ROF of 7. The RCL of a burst becomes 14, essentially uncontrollable for a STR of 5 or less. I find that the interaction between Recoil and Rate of Fire produce unique characteristics that help "define" how a given weapon will be used during play. I have NEVER had any real issues with the variable ROF system. It works quite well.

[pmulcahy11b]

As a side note, with the M60s low ROF (about 550 RPM), I found out when I was in the ARNG and when we were using MILES than you can use the M60 as a sniper rifle, if a somewhat inaccurate one, because it is easy to squeeze off single shots with one without having to jerk the trigger.

[pmulcahy11b]

Originally Posted by StainlessSteelCynic

I believe Palladium's Recon or Advanced Recon paid some attention to heat build-up on machine guns. I haven't played either of those two or even seen the rules so I can only go on what some old gaming mates told me in the 1990s and I believe they had interpreted the rules far too literally - like, "you have to change the barrel on the M60 every 200 rounds or the barrel will melt" literally.

Now that a good idea, tell us how you implemented it in T2000!

[Legbreaker]

Originally Posted by pmulcahy11b

As a side note, with the M60s low ROF (about 550 RPM), I found out when I was in the ARNG and when we were using MILES than you can use the M60 as a sniper rifle, if a somewhat inaccurate one, because it is easy to squeeze off single shots with one without having to jerk the trigger.

I always found it hard to fire off the required 5-10 round bursts from the '60. Just felt like I was burning through too much ammo at a time. Personally I MUCH preferred 3-5 round bursts at a more rapid rate even though that's not what the official policy was at the time.
Interesting to see that a few years later the Minimi bursts were supposed to be the smaller 2-3 rounds I believe....

[Legbreaker]

Originally Posted by StainlessSteelCynic

I believe Palladium's Recon or Advanced Recon paid some attention to heat build-up on machine guns.

From what I can see it's little more than lip service. Found this (and only this) in "The Compendium of Contemporary Weapons" in the "Light Machineguns" section:

The gunner only has to release a latch or lock and he can change a hot barrel for a cool one in approximately 20 to 30 seconds.

Nothing in Advanced Recon, and don't have a copy of the original ruleset to check.

[pmulcahy11b]

Originally Posted by Legbreaker

I always found it hard to fire off the required 5-10 round bursts from the '60.

We were taught in Basic that when firing the M60, you say in your head, "fire a burst of six" and you end up with the required burst of 6-9. Remember, you're supposed to be firing somewhat long bursts -- it's a support weapon, not a rifle (regardless of the way I tended to use it).

[Legbreaker]

Speaking of machineguns as rifles, it's uncanny how closely an M60 resembles a rifle when you remove the bipod. Even at relatively close range most people mistake it for a lighter weapon.

The other issue with burst size is I almost always operated without a No2 that was any use, so I ended up carrying all the ammo.
ALL the ammo.
Could never rely on getting a new belt when and where I needed it.

[Legbreaker]

Just remembered the only time I fired off large bursts.
The trigger group retaining pin clip went missing so, naturally, the pin was free to slide out and trigger group fall off (not my fault, all the M60s in the battalion where recalled by the local armourer the following day and completely overhauled - our unit armourer was utterly incompetent).
We had an attack planned later that day (we using blanks, while Vickers fired live rounds about ten metres over us on fixed lines as "battlefield simulation"), and of course as one of the three machinegunners in the attacking platoon, I couldn't exactly go in unarmed.
So, twenty round belts were prepared and when I needed to fire, it was a case of load, pull back the cocking handle and...
Attachment 4272

[StainlessSteelCynic]

And I reckon Leg, that at the time you and I got our hands on the M60 they were probably 20 years old at least. They had been well and truly used & abused.
I twice had a -60 go runaway on me due to wearing down of the notch on the operating rod that was supposed to engage the safety sear. The first experience was "What The Hell! OMGWTF!!!!!!!" - fortunately only had about 8-12 rounds left on the belt.
The second experience was "Oh, this again'. Had about 20-25 rounds on the belt and no Number Two so I decided to ride that one long burst just for the hell of it (rather than try to break such a short belt with one hand).

Both times happened in the early 1990s so those guns were pushing 30 years old by then.
I found out that later builds of the M60 (i.e. the M60E3 & E4) featured two or three notches on the operating rod, I think to prevent that particular problem.
Ah ha! Found an image of what I mean and I see that there were rods made with two notches and rods made with three. I have no idea if that correlates to the E3 and E4 versions respectively but I wouldn't be surprised as it can be seen on the image below, the two-notch rod has some wear on the first safety notch.
Seems to me that the extra notches are a decent way to avoid throwing out an entirely still usable operating rod plus they'd give a minor decrease in overall weight for a much better safety factor.



Image from here http://beltfeds.com/m60-operating-rod-assembly/

I felt the same way as you Leg, 3-5 round bursts were my preferred choice but part of that was also to do with doctrine. When I was first being trained as a section gunner, we were taught the normal rate of fire was "bursts of 3-5 rounds, as required". I can't recall the specifics without digging out my old notebooks but I believe that fixed lines was the only rate of fire that required a burst of 10 or so rounds.
When I did my Sustained Fire Machine Gun course, the highest normal rate of fire we would employ was I think Double Rapid which was bursts of 10-20 rounds.
(Not to mention the anti-aircraft ROF which was taught officially as being the weapons cyclic rate and unofficially as "hold down the trigger until you shoot that bastard out of the sky")

As an aside, because I had the experience with the -60 and if I was feeling a bit cheeky (or perhaps smug is a better description!) when we had new guys being trained at the range, I'd deliberately squeeze off one round every second or so and smirk at their lack of ability to get a burst lower than 8-10 rounds.

[StainlessSteelCynic]

Originally Posted by pmulcahy11b

Now that a good idea, tell us how you implemented it in T2000!

As mentioned, I never saw the rules for Recon or Advanced Recon and I was going on what people told me at the time and me having been trained on the M60 I thought that they had misunderstood the rules.
So from that perspective, there was nothing to try and incorporate from Recon into T2k.

From what Leg has found out, it seems more likely that whoever was running Recon/Advanced Recon at the time had some vague knowledge of barrel heating and barrel changes and applied his misunderstanding to the game, as it appears there are no real rules at all in the Recon games to deal with barrel changes.

[pmulcahy11b]

Originally Posted by StainlessSteelCynic

As mentioned, I never saw the rules for Recon or Advanced Recon and I was going on what people told me at the time and me having been trained on the M60 I thought that they had misunderstood the rules.
So from that perspective, there was nothing to try and incorporate from Recon into T2k.

From what Leg has found out, it seems more likely that whoever was running Recon/Advanced Recon at the time had some vague knowledge of barrel heating and barrel changes and applied his misunderstanding to the game, as it appears there are no real rules at all in the Recon games to deal with barrel changes.

I think I can take a look. I believe I have copies of those games as PDFs -- maybe. Let me see.

[swaghauler]

Originally Posted by pmulcahy11b

Now that a good idea, tell us how you implemented it in T2000!

I tie the machinegun's heat to BOTH the weapon's Reliability and the number of belts of an average round count for that gun (ie 100 for most GPMGs and 200 for most SAWs) fired. This number [which I call Dependability] ranges from 1 (for older .50 Caliber MGs) to as many as 10 (for a liquid-cooled Maxim) and represents the number of belts you can fire before problems begin.

RELIABILITY:

This is the weapon's normal reliability and determines when a jam might occur. It is an "evolution" of my earlier houserule.

Good Reliability: The weapon will only jam on a roll of 20 IF the user rolls EQUAL TO OR UNDER the weapon's WEAR VALUE.

Average Reliability: The weapon automatically jams on a roll of 20 but the user can roll OVER the weapon's current WEAR VALUE to shoot a burst BEFORE the weapon jams. On a roll of 19, the weapon jams IF the user rolls EQUAL TO OR UNDER the weapon's WEAR VALUE. A burst is considered fired before the jam.

Poor Reliability: The weapon automatically jams on a roll of 20. NO burst is fired too. On a roll of 19, The weapon jams BUT a burst/shot may be fired IF the user rolls OVER the weapon's WEAR VALUE. On a roll of 18, a burst is fired BUT the weapon jams.

Reliability goes hand-in-hand with the machinegun's Dependability ratings.

The Dependability Rating:

As previously mentioned, the Dependability rating is the number of BELTS/MAGS (of a typical round-count) that can be fired BEFORE issues arise. Once the "belt count" has been exceeded without a barrel change, the user rolls against the weapon's WEAR VALUE. IF they roll EQUAL TO OR UNDER the weapon's WEAR VALUE, reduce the base range by 5m (hand-held/shoulder-fired) and decrease reliability by one number (ie a 19 or 20 average reliability becomes poor, while poor reliability weapons will now jam on a roll of 17 too). IF the user rolls 5 or more under the WEAR VALUE'S THRESHOLD number, a Catastrophic event like a "blown/melted barrel" or a "runaway gun" occurs! This roll is made for each new belt without a barrel change.

I found this to be the best balance between a "user-friendly" houserule and "gritty realism."

[CDAT]

Originally Posted by swaghauler

I tie the machinegun's heat to BOTH the weapon's Reliability and the number of belts of an average round count for that gun (ie 100 for most GPMGs and 200 for most SAWs) fired. This number [which I call Dependability] ranges from 1 (for older .50 Caliber MGs) to as many as 10 (for a liquid-cooled Maxim) and represents the number of belts you can fire before problems begin.

RELIABILITY:

This is the weapon's normal reliability and determines when a jam might occur. It is an "evolution" of my earlier houserule.

Good Reliability: The weapon will only jam on a roll of 20 IF the user rolls EQUAL TO OR UNDER the weapon's WEAR VALUE.

Average Reliability: The weapon automatically jams on a roll of 20 but the user can roll OVER the weapon's current WEAR VALUE to shoot a burst BEFORE the weapon jams. On a roll of 19, the weapon jams IF the user rolls EQUAL TO OR UNDER the weapon's WEAR VALUE. A burst is considered fired before the jam.

Poor Reliability: The weapon automatically jams on a roll of 20. NO burst is fired too. On a roll of 19, The weapon jams BUT a burst/shot may be fired IF the user rolls OVER the weapon's WEAR VALUE. On a roll of 18, a burst is fired BUT the weapon jams.

Reliability goes hand-in-hand with the machinegun's Dependability ratings.

The Dependability Rating:

As previously mentioned, the Dependability rating is the number of BELTS/MAGS (of a typical round-count) that can be fired BEFORE issues arise. Once the "belt count" has been exceeded without a barrel change, the user rolls against the weapon's WEAR VALUE. IF they roll EQUAL TO OR UNDER the weapon's WEAR VALUE, reduce the base range by 5m (hand-held/shoulder-fired) and decrease reliability by one number (ie a 19 or 20 average reliability becomes poor, while poor reliability weapons will now jam on a roll of 17 too). IF the user rolls 5 or more under the WEAR VALUE'S THRESHOLD number, a Catastrophic event like a "blown/melted barrel" or a "runaway gun" occurs! This roll is made for each new belt without a barrel change.

I found this to be the best balance between a "user-friendly" houserule and "gritty realism."

A question, just to make sure I am understanding. You are saying that the M2 has a dependability of 1? So after firing one belt it runs the chance of jamming?

[Legbreaker]

Originally Posted by CDAT

A question, just to make sure I am understanding. You are saying that the M2 has a dependability of 1? So after firing one belt it runs the chance of jamming?

Looks that way. I'm guessing he's referring to the nearly 70 year old, badly worn ones.

[swaghauler]

Originally Posted by Legbreaker

Looks that way. I'm guessing he's referring to the nearly 70 year old, badly worn ones.

YEP!

[swaghauler]

Originally Posted by CDAT

A question, just to make sure I am understanding. You are saying that the M2 has a dependability of 1? So after firing one belt it runs the chance of jamming?

The rating of 1 would be for older M2HB guns like the one on my HEMTT that was built in 1942 and still being used in 1993. Those guns have a ROF of 4 and require the gun to be manually headspaced and timed with EACH barrel change. If you shoot more than a belt or two in rapid succession, the gun would begin to lose its timing as the barrel heated up. In my experience, you can usually get through a 100-round belt with no issues but after the second belt, things begin to get "interesting." The M2 is certainly not as bad as the MK19, but the older guns can be very unreliable.

The older AN/M2-M3 air-cooled aircraft-mounted guns have a ROF of 8 and a rating of 3. The airflow these guns receive greatly reduces their heat buildup (despite their rate of fire).

The new Army M2A1 and Navy mod1(?) .50 Caliber Machineguns built by Ohio Ordinance with the non-reciprocating barrel (the action and barrel actually reciprocate together) with fixed headspace and timing and the Quick-Change Barrel (QCB) would have a rating of 5 and their ROF increases to 6.

Also, remember that the Dependability rating only tells you WHEN to check for a performance reduction during a firefight. The weapon's WEAR VALUE actually determines what the outcome of that check is, AND changing the barrel resets the rating back to "0."

[Legbreaker]

Originally Posted by swaghauler

...changing the barrel resets the rating back to "0."

Of course if you're firing a lot of rounds in a relatively short period, that spare barrel may not have had much time to loose all the heat previously built up...

[swaghauler]

Originally Posted by Legbreaker

Of course if you're firing a lot of rounds in a relatively short period, that spare barrel may not have had much time to loose all the heat previously built up...

If your belt-fed is getting that kind of a workout, you're lucky you're still alive to change that barrel.

[Legbreaker]

Originally Posted by swaghauler

If your belt-fed is getting that kind of a workout, you're lucky you're still alive to change that barrel.

It's been known to happen. Thinking specifically of the Battle of Long Tan.
My understanding from reading a number of accounts, and actually talking with a couple of the men who were on the ground, was that out of the 9 M60's, most had seized up by the end of it. This was due almost entirely because of the massively high rate of fire required to fend off the thousands (estimated at somewhere between 2,500 and 3,000) of Vietnamese coming in waves at the Company.

[StainlessSteelCynic]

Originally Posted by Legbreaker

It's been known to happen. Thinking specifically of the Battle of Long Tan.
My understanding from reading a number of accounts, and actually talking with a couple of the men who were on the ground, was that out of the 9 M60's, most had seized up by the end of it. This was due almost entirely because of the massively high rate of fire required to fend off the thousands (estimated at somewhere between 2,500 and 3,000) of Vietnamese coming in waves at the Company.

From personal experience I know that you can fire a hell of a lot of rounds through a GPMG but at some point you cross a line of no return and it becomes a "keep firing or come to a complete stop" situation.
I did a Sustained Fire Machine Gun (SFMG) course in 1991 (if I remember the year correctly) and we had a live fire exercise from late afternoon to mid-evening where the guys doing the mortar course were firing Illum for us.
Quick & dirty explanation of SFMG for those not in British Commonwealth countries (because it seems to only be British Commonwealth armies that still use SFMG) - essentially it's a line of machine guns on tripods using mortar sighting systems so as to be used in the same manner as artillery or mortars except that instead of explosive shells, you're filling a grid with 7.62 (or whatever calibre of gun you're using).
For this reason, it's nicknamed poor man's artillery or the infantryman's artillery.

We had a gun line of six guns but because all the guns we had were M60s with at least 25 years of use & abuse on them, all of them except mine broke down due to wear & tear issues. I had just swapped from No1 Gunner to No2 so my No2 could get his time as No1 when two of the other guns went offline and we got the order to fire Double Rapid. Then the other guns started to fail and we were told to keep firing, non-stop.
The other gun crews started delivering their link to us because we were the only gun firing.

We put about 3000 rounds through the gun without the luxury of a barrel change. The barrel was glowing white-orange and the gun continued to function fine, so long as we never stopped firing.
As soon as we did, we broke the gun. My No2 who was pulling the trigger just sat back after the last round and didn't think to pull the bolt back after the last round was gone and the bolt welded itself to the barrel. The receiver had one significant crack just in front of the bolt handle and if I recall, the gas piston was jammed from all the fouling.

Now okay, it was a training exercise but we were using the guns assigned to SFMG Platoons at the time and at the time, these were all well used M60s. If we had deployed as SFMG to East Timor for sake of argument, we could have faced the same situation of guns breaking down while in operational use.
The one benefit we would have had as SFMG, is that the gun line, like arty or mortars is normally located behind the frontline, typically a klick (because SFMG with 7.62 has an indirect fire range of 3000m if I remember correctly - was 25+ years ago so my memory ain't what it used to be!) so immediate risk of death by enemy action isn't as much of a concern as someone on the frontline!

[Legbreaker]

Originally Posted by StainlessSteelCynic

We put about 3000 rounds through the gun without the luxury of a barrel change. The barrel was glowing white-orange and the gun continued to function fine, so long as we never stopped firing.

Given the M60's at Long Tan were only a couple of years old, goes to show just how heavy the fire was in both directions....

Originally Posted by StainlessSteelCynic

...(because SFMG with 7.62 has an indirect fire range of 3000m if I remember correctly - was 25+ years ago so my memory ain't what it used to be!) so immediate risk of death by enemy action isn't as much of a concern as someone on the frontline!

I recall from my reading of the PAM (25 years ago) the ranges of 2000 and 3000 metres (effective and harassing I think). Did the theory lessons for SFMG, but we never got the chance to do the practical component.

[StainlessSteelCynic]

I believe the M60 had only been in Australian service for about five years by the time of Long Tan so they were still quite new in that sense. They're a pretty tough gun when they aren't old and worn out (like most GPMGs from that era) and I'd be willing to argue that sustained, direct fire from those guns made the difference between life and death at Long Tan.
To me, it makes plenty of sense that they ignored the 200-rd barrel change and only did it when they had the luxury of time. The gun could take the abuse and there were plenty of reasons (about 2,500 to 3,000 of them) to ignore the barrel change every 200-rds.

[Legbreaker]

Totally agree with that. Given the attacks were coming in waves, provided the No2 could get the spare barrel to the gun, I think they may have had a few moments here and there to switch it over - maybe. Of course the torrential downpour probably helped with cooling too.
Still, to have 7 of the 9 (I think) utterly US at the end of it...