AR Sponsor
Posted: 4/29/2003 6:28:53 AM EDT
|
I know that there have been some tests of gun/cartridge designs that feature a rocket propelled bullet, but I wonder about using rocekt propulsion as an assist rather than the primary accellerant. For example, if you designed the bullet to have a low thrust rocket that burns for, say, 1.5 seconds, the MV might be no greater but the velocity fall off would be less. As I see it the value to the rocket propulsion would be two fold: first, the thrust from the rocket would help to retain velocity and energy for obvious reasons, and second, the low pressure region behind the bullet which normally adds to the total drag would be reduced by the gasses expelled from the rocket. Does anyone have any pointers to work done on this subject? Thanks, |
|
No expert here , but here is my opinion: In the size of bullets we typically fire out of smallarms, the amount of space that is available for rocket propellant is not sufficient (with current technology) to have any noticable effect, i.e. maintain velocity. In artillery shells there are rocket assist and base bleed (reduce wake drag) shells that used at the expense of payload. Tracers only carry a few grams of pyrotechnic material. I don't believe a few grams of rocket fuel would be suficient for your stated purposes. Kent |
|
Quoted: No expert here , but here is my opinion: In the size of bullets we typically fire out of smallarms, the amount of space that is available for rocket propellant is not sufficient (with current technology) to have any noticable effect, i.e. maintain velocity. In artillery shells there are rocket assist and base bleed (reduce wake drag) shells that used at the expense of payload. Tracers only carry a few grams of pyrotechnic material. I don't believe a few grams of rocket fuel would be suficient for your stated purposes. Kent Good info - thanks... I was thinking more along the "base blead" lines as the amount of volume available for rocket propellant is indeed limited. I can think of another potential problem with RA: greater velocity variation at the longer distances due to variations in the quantity and burn rate of the propellant. But, as I said earlier, if there are some pointers to data on the subject (preferably spam/popup free) I'd be happy... Thanks, |
|
Quoted: Lame. You can't take a single freakin popup. I gave you one of the best resources on the web for the gyrojet. If you can't stomach a single popup, then do your own search. Single popup -- I spent about 5 minutes closing literly dozens of popups -- it just wouldn't stop! Sorry, no offense, it's one thing to work for info, that's ok, but working and getting no place just sucks! Anyway, |
|
Well I did a Google on "Gyrojet" and found some useful info (without the popups). It was/is an interesting concept but not exactly what I was thinking about. The Gyrojet, as I read it, is a pure rocket propelled bullet that is very inaccurate due, at least in part, to its very low MV. The only advantages I can think of for it are a lighter gun and reduced sound footprint. What I AM thnking about is using rocket propullsion to ASSIST a bullet that is accellerated using a conventional gun/cartridge/propellant setup. For example: suppose you took a 5.56mm round of about 80gr weight and replaced 20gr of that weight for rocket propellant. If you could come up with the correct combination of fuels and orifice diameters the burn time might be controlled to last, say, 1.5 seconds. The burn would produce some thrust which would improve long range velocity/energy, and the bleading of gasses begind the bullet would reduce bullet drag, also inproving long range velociy/energy. It might be possible for a relatively small amount of fuel to have a greater net effect due to the combined thrust and lower drag. This is kind of an efficiency thing... This is something I'm just playing with in my head, but when an idea comes to me I can get little sleep until I know the 'ballpark' a little better. Thanks, |
|
Quoted: Quoted: Already been done The Gyrojet. [url]http://pub80.ezboard.com/bmbassociatesgyrojetpage[/url] Well I just took a tour of the link you posted and was HAMERED by an unending sequence of unwanted popups! So, I learned nothing from that unpleasant trip... Later, Go to [url]www.webwasher.com[/url] and download the free personal use software. This is one of the best free software products that prevents the annoying pop-ups. If you are really interested in securing your system, install Kerio Personal Firewall (free) with it. |
|
Quoted: Quoted: Quoted: Already been done The Gyrojet. [url]http://pub80.ezboard.com/bmbassociatesgyrojetpage[/url] Well I just took a tour of the link you posted and was HAMERED by an unending sequence of unwanted popups! So, I learned nothing from that unpleasant trip... Later, Go to [url]www.webwasher.com[/url] and download the free personal use software. This is one of the best free software products that prevents the annoying pop-ups. If you are really interested in securing your system, install Kerio Personal Firewall (free) with it. Unfortunately since this is my companies computer and the internet connection is running in an NT terminal server window I have no control over the tools. As to the topic at hand ... I poked arround some more and think I have a chance that this might just work. I need to see learn a bit more about the various solid rocket fuels and the possibility of configuring it to run at higher than normal pressure as this should improve the effeciency and thus permit a smaller amount of fuel to do the job. Again, what I'm looking to do is conjure up a new bullet design that can be used in a standard rifle that will permit retaining much greater energy at 1000y. If I've figured correctly I could just about insure a velocity of more than 1500'/sec at 1000y from a 55gr-60gr 5.56mm bullet. I'll report back when my confidence is greater on this... Later, |
AR Sponsor