Sturgeon Posted July 4, 2015 Report Share Posted July 4, 2015 The above is the working title for an article I decided today I would write. The article will discuss the effect requirements have on small arms ammunition, specifically how they might affect the development of a universal round. I will be looking in particular about two assumptions that are commonly made about the General Purpose Cartridge concept promoted by Anthony Williams - barrel length and ballistic coefficient of the projectile.To illustrate the effect this might have, I did some figuring and came up with the size of 6.5mm cartridge needed to generate the same retained energy as M80 as fired from 16" barrels, the 6.5mm round fired from a 16.7" barrel, and with a bullet having a .96 i7 FF (note that this is 8% poorer than the Balle D, a projectile Williams promotes as being optimum, but still 15% superior to the form factor of M80 Ball). Due to material constraints, the bullet must weigh 7 grams (108grs). I found that such a bullet has a .231 G7 BC, and requires 2,952 ft/s (900 m/s) muzzle velocity to reach 1,000m with equivalent energy to .308 Winchester. This means the cartridge case required to fire it must generate 2,833 Joules. We can assume that 25 ft/s will be gained for every inch of barrel added after 16.7", which means we need a rifle round that can produce 3,135 ft/s muzzle velocity from a 24" test barrel. Perusing Hodgdon showed that the 6.5-284 was one round that approximated this performance. Note the large size of the 6.5-284: The 6.5-284 on the left is wider than .30-06 on the right, and almost as long. Not a light, svelte round. This dramatic increase in size results from adding the likely requirement of terminal performance from shorter, carbine-length barrels, and a mild increase in bullet drag over the ideal. This does not necessarily represent what will happen if a universal round is pursued, but what can happen if requirements are laden upon the round without the correct oversight.This kind of requirements spiral typifies Army and more generally military programs. From SPIW, to the MBT-70 tank, to the ACUs and their Universal Camouflage Pattern, to the F-35 and A-12, these requirements have a way of creeping up on these sorts of "elegant" ideas. 7.62 NATO is an excellent example of this, as well. Not a bad round, but not a universal round, either.I want to convey this to my readers, and communicate the great risk the universal cartridge concept presents to military procurement programs. I want to specifically target the universal cartridge idea in general without calling out Anthony Williams, and to do this I am going to avoid explicitly mentioning the "general purpose cartridge". Williams and other GPC advocates will of course know what I am talking about, but I don't want to alienate audiences who may be familiar with the universal cartridge idea in general but not specifically familiar with Williams' writing on the subject.I'm opening this thread to help refine the post and communicate to a wide audience my thoughts on a subject that is pretty esoteric and technical. I will be, like I have in the OP, experimenting with arguments and writing segments, and would appreciate the feedback of the members on the forum. Quote Link to comment Share on other sites More sharing options...
Meplat Posted July 4, 2015 Report Share Posted July 4, 2015 Having it use a different case head diameter than '06/7,62NATO is going to result in a stillborn concept, for a variety of reasons.. But not before oodles of "free" money is consumed in the pursuit of the concept. The more I hear of "suggestions" like this, the less I think it's to improve the lethality of the issued firearms, and more to tap into that sweet, sweet government money. Quote Link to comment Share on other sites More sharing options...
Sturgeon Posted July 4, 2015 Author Report Share Posted July 4, 2015 Meplat, I don't know how much of my stuff you've read. To say that I'm "not a big general purpose cartridge fan" is pretty euphemistic. Once on Anthony Williams' forum, I was dubbed his "nemesis" by one of the other posters, for the writing I've done criticizing the concept. Now I want to convey how risky the concept is, and how it could lead to another product that didn't live up to expectations, like the 7.62 NATO, or even how it could collapse altogether. Quote Link to comment Share on other sites More sharing options...
Meplat Posted July 4, 2015 Report Share Posted July 4, 2015 Yeah, I'm agreeing with you that the whole concept is a dead goldfish looking for a toilet-bowl. I'm just pointing out why this example is not going to succeed from a manufacturing and engineering angle. There is a reason it's going to be very very difficult to get away from anything of the nominal case head and body diameters of the 7,62NATO, for anything larger than 5.56NATO. Quote Link to comment Share on other sites More sharing options...
Khand-e Posted July 4, 2015 Report Share Posted July 4, 2015 Meplat, I don't know how much of my stuff you've read. To say that I'm "not a big general purpose cartridge fan" is pretty euphemistic. Once on Anthony Williams' forum, I was dubbed his "nemesis" by one of the other posters, for the writing I've done criticizing the concept. Now I want to convey how risky the concept is, and how it could lead to another product that didn't live up to expectations, like the 7.62 NATO, or even how it could collapse altogether. No, you were dubbed his "Nemis", Yeah, you're a designer clothing company, get it right. Quote Link to comment Share on other sites More sharing options...
Toxn Posted July 4, 2015 Report Share Posted July 4, 2015 I think you might have to have a pretty substantial lead-in explaining things, as well as generally adding in simplified explanations for the slow kids. For the smart ones, you might want to dig into your methodology a bit (what programs you used and why you expect them to be accurate, what assumptions you made and so on) to preempt people simply labelling you a shill. Include a head-to-head with existing cartridges to illustrate specific factors. Good luck getting the balance right. Quote Link to comment Share on other sites More sharing options...
Toxn Posted July 4, 2015 Report Share Posted July 4, 2015 Thinking about it some more, this actually sounds like a two-parter: 1- setup. Start by referencing pentagon wars. Use as analogy to explain real tendency in any bureaucracy. Explain how big projects tend to get funded more than a bunch of little ones. Now introduce your role players. Explain what strands of thought were smushed together to get gpc, then finish by spelling out all the requirements that have been shoved in. 2- payoff. Reiterate the requirements, then go step by step through the process of designing a cartridge to meet them. Then reveal the thing, do comparisons and demonstrate how you end up with a bloated mess instead of a one-size-fits-all solution. Reference other projects that have failed due to this issue, cap off with 'perfect is the enemy of good'. LoooSeR, Belesarius and Sturgeon 3 Quote Link to comment Share on other sites More sharing options...
Sturgeon Posted July 4, 2015 Author Report Share Posted July 4, 2015 No, you were dubbed his "Nemis", Yeah, you're a designer clothing company, get it right. Right, well, if I actually said that it would sound like I was suggesting the good folks of Tony's forum were stupid or something. Quote Link to comment Share on other sites More sharing options...
Sturgeon Posted July 4, 2015 Author Report Share Posted July 4, 2015 I think you might have to have a pretty substantial lead-in explaining things, as well as generally adding in simplified explanations for the slow kids. For the smart ones, you might want to dig into your methodology a bit (what programs you used and why you expect them to be accurate, what assumptions you made and so on) to preempt people simply labelling you a shill. Include a head-to-head with existing cartridges to illustrate specific factors. Good luck getting the balance right. Thinking about it some more, this actually sounds like a two-parter: 1- setup. Start by referencing pentagon wars. Use as analogy to explain real tendency in any bureaucracy. Explain how big projects tend to get funded more than a bunch of little ones. Now introduce your role players. Explain what strands of thought were smushed together to get gpc, then finish by spelling out all the requirements that have been shoved in. 2- payoff. Reiterate the requirements, then go step by step through the process of designing a cartridge to meet them. Then reveal the thing, do comparisons and demonstrate how you end up with a bloated mess instead of a one-size-fits-all solution. Reference other projects that have failed due to this issue, cap off with 'perfect is the enemy of good'. Good suggestions, Tox. I agree this is going to be really tricky. I am trying to create an easily-crossed bridge between a highly technical understanding and a general audience. That is why I've started this thread, so if you have any more great suggestions like those for me, please post them! Quote Link to comment Share on other sites More sharing options...
Toxn Posted July 5, 2015 Report Share Posted July 5, 2015 Good suggestions, Tox. I agree this is going to be really tricky. I am trying to create an easily-crossed bridge between a highly technical understanding and a general audience. That is why I've started this thread, so if you have any more great suggestions like those for me, please post them! Thanks, hope it helps Quote Link to comment Share on other sites More sharing options...
Tied Posted July 5, 2015 Report Share Posted July 5, 2015 Thinking about it some more, this actually sounds like a two-parter: 1- setup. Start by referencing pentagon wars. Use as analogy to explain real tendency in any bureaucracy. Explain how big projects tend to get funded more than a bunch of little ones. Now introduce your role players. Explain what strands of thought were smushed together to get gpc, then finish by spelling out all the requirements that have been shoved in. 2- payoff. Reiterate the requirements, then go step by step through the process of designing a cartridge to meet them. Then reveal the thing, do comparisons and demonstrate how you end up with a bloated mess instead of a one-size-fits-all solution. Reference other projects that have failed due to this issue, cap off with 'perfect is the enemy of good'. An error occurredYou have reached your quota of positive votes for the day Quote Link to comment Share on other sites More sharing options...
Toxn Posted July 6, 2015 Report Share Posted July 6, 2015 Something a bit more... gimmicky to add. One way of compressing a debate is to personify the relevant trends involved. In this case, you could draw an analogy by using fictional avatars to represent the real-life camps and cliques which will weigh in on the matter: Gen. Metraje - represents the Afghanistan/range overmatch camp. Is very concerned that infantry have a rifle which can outrange the enemy and still deliver a lethal blow. Gen. Voet - represents the weight-savings camp. Is very concerned about soldier injury rates and wants to 'lighten the load' by tweaking equipment instead of doctrine. Gen. Comptable - represents the bean counters. Is convinced that rationalising supply lines by minimising the number of ammunition types will make everything run better. Gen Glänzend - represents the whiz-bang crowd. Wants every bullet design to be barrier-blind, capable of accommodating tracer and incendiary, accuratised and Geneva-compliant. Gen. Powers - represents the big rock brigade. Is convinced that knock-down power and one-stop shots, rather than casualties, should be the primary focus of development. Gen. Greene - represents the lead-free camp. Is determined to prevent training ranges from turning into superfund sites while polishing armed forces PR with an 'increasingly environmentally aware' public. Tied and Sturgeon 2 Quote Link to comment Share on other sites More sharing options...
Toxn Posted July 6, 2015 Report Share Posted July 6, 2015 Generals Porke and Bedryf will, of course, be overseeing the entire process. Quote Link to comment Share on other sites More sharing options...
Sturgeon Posted July 6, 2015 Author Report Share Posted July 6, 2015 One small problem. We're talking small arms, so they'd be Colonels or lower. Quote Link to comment Share on other sites More sharing options...
Khand-e Posted July 6, 2015 Report Share Posted July 6, 2015 *General purpose arms. Quote Link to comment Share on other sites More sharing options...
Khand-e Posted July 6, 2015 Report Share Posted July 6, 2015 Actually fuck that, can we have a "Col. Purpose Cartridge"? Quote Link to comment Share on other sites More sharing options...
xthetenth Posted July 6, 2015 Report Share Posted July 6, 2015 Actually fuck that, can we have a "Col. Purpose Cartridge"? Isn't that decided by how spiffy the pistol firing it looks? Quote Link to comment Share on other sites More sharing options...
Tied Posted July 8, 2015 Report Share Posted July 8, 2015 Marshal Tied= the Russia stronk camp, believes that 5.45 is the only round for human knockers, 7.62 only round for door knockers, and 14.5mm KVPTs the best solution for Afghan knockers Quote Link to comment Share on other sites More sharing options...
Donward Posted July 9, 2015 Report Share Posted July 9, 2015 Marshal Tied= the Russia stronk camp, believes that 5.45 is the only round for human knockers, 7.62 only round for door knockers, and 14.5mm KVPTs the best solution for Afghan knockers 7.62X25 for "morale" building. Quote Link to comment Share on other sites More sharing options...
Sturgeon Posted July 9, 2015 Author Report Share Posted July 9, 2015 I gave an example of how shorter barrels can dramatically affect the GPC here. Quote Link to comment Share on other sites More sharing options...
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