External Ballistics Experiment

[crazyhorse]

Interesting conversation for sure! I think of a lot of weird things that could affect speed/accuracy but Ill admit, I've never got this far off in the weeds!
Maybe an over simplified observation, but wouldn't a balloon with enough helium to maintain an o2 free environment by purging the barrel as it leaks out of the chamber obscure your line of sight? Not to mention make you talk funny after every shot?

 

[Radman]

Been think the same thing. Since the He would purge all O I'm thinking that you may lose the follow-up "push" down the barrel after the initial internal bullet explosion. May be a negligible factor. (I still cant figure out how a translucent plastic pulley, that I can twist with my hand, can handle steel cables bearing 350 tons AND swing around!)

Of course....if we had a few spare billions lying around we could let an astronaut shoot it in the vacuum of space. (Something I think they've already done with a shotgun) My local chemistry/physics tech-head assures me that the powder inside a shell generates it's own O2 for the explosion, (which is evidenced by using bang sticks u/w). DEEP thoughts.....

 

[Its204fast]

Been think the same thing. Since the He would purge all O I'm thinking that you may lose the follow-up "push" down the barrel after the initial internal bullet explosion. May be a negligible factor. (I still cant figure out how a translucent plastic pulley, that I can twist with my hand, can handle steel cables bearing 350 tons AND swing around!)

I read an article about firing a gun in space, it stated the powder creates its own O2, I wouldn't think there is any gain after the initial ignition. responding to the pulley analogy, I imagine if you were to turn that pulley on its side and load it, it would fail at a fraction of its designed load. Have you ever looked at how a G rated carabiner is rated? the most strength is along the spine(36-45kN) it also shows the rating for the short side usually >1/2 the long side, and with the gate open it usually around half.

 

[Its204fast]

Interesting conversation for sure! I think of a lot of weird things that could affect speed/accuracy but Ill admit, I've never got this far off in the weeds!
Maybe an over simplified observation, but wouldn't a balloon with enough helium to maintain an o2 free environment by purging the barrel as it leaks out of the chamber obscure your line of sight? Not to mention make you talk funny after every shot?

LOL!! I figured that out already, stick the balloon over the barrel and tape it down below the line of sight. Might get me high and relax me more

 

[JustMe2]

You'd be much further ahead by developing a sabot for a high velocity rifle or a rocket assisted bullet.

Also any velocity gain would probably be negated by the friction of breaking and then going through your balloon probably destabilizing the bullet causing the bullet to wobble.

 

[John Klingenberg]

Besides the OP talking funny during the experiment, do you think the rifle report will sound like a cartoon squirrel yelling "bang"?

 

[Radman]

Besides the OP talking funny during the experiment, do you think the rifle report will sound like a cartoon squirrel yelling "bang"?

This report, just in: Shooters all over America target shooting with balloons on their guns! All talking in strange tongues.
Now liberals want to outlaw balloons saying it's some sort of attempt at making suppressors. Now this........
(Just joking of course....but)

 

[jimisbell]

Working to get more velocity at the barrel is good. but I have been thinking about tthe other end of the path. Design a bullet to make the transision from super-sonic to sub-sonic without destabalizing.

 

[J E Custom]

This has been a thought I've had for a while.

How much does the density of the air in front of the bullet affect velocity, trajectory, and accuracy?

If you could reduce the air density in the barrel in front of the bullet would it make a measurable difference? I feel it would.

I want to work up a load, get the SD as low as possible, fire a group at a target at 100 yards for the control, then another group with a Helium balloon over the barrel purging Helium down the barrel. The idea is that Helium is lighter than air and will reduce pressure in front of the bullet theoretically allowing the bullet to move faster.

I plan to start with 100 rounds of virgin Hornady brass, CCI BR-4 Primers, Benchmark Powder, 26Gr Barnes Varmint Grenade.
Rem 700 chambered in .204 Ruger with apx. 1000 rounds through it.

Is this something someone has attempted or or does anyone have any thoughts on this not working?

Some questions and concerns I have are:
Is my reloading ability and equipment capable of making loads as consistent as necessary for best results? I Full length size (as opposed to neck sizing) and I don't have the ability to turn necks.
Is my gun up to the task?
Could the Helium cause a catastrophic event with the gun?
Is 100 yards enough to see a change in POI due to the (likely) minor change in velocity

Before all the gadgets and computers, the rule for most rifles was 1 MOA per 10 degrees up or down and 1 MOA for every 10 % change in humidity. It was far from perfect but at the time a 600 yard shot was considered a long shot and it seemed to work well.

It will be tough for you to get good information for the differences unless you make many outings. Historical data for many years would help if anyone has any. Hunt at sea level and then going to 8,000 to 11,000 feet with much lower humidity, we generally made our changes and then proofed them By shooting a target at the expected distance to see if adjustments needed to be made.

I would suggest that you establish a bench mark for testing under one set of conditions and then test the same loads at the longest distance you feel comfortable with and shoot at least 5 shots and use the center of these groups to establish the measurement center point.

The heavy air (humidity) and the lowest altitude always lowered trajectory from any other location.
so we had to adjust no mater where we went with different conditions. you will have to look for every change to get good results. More than once, one change canceled the effect of another so good data is the only way to get meaningful data.

Interested in your results.

J E CUSTOM

 

[judgebill]

Go for it. If this is an area of exploration that calls you, go for it. If nothing else you learn negative information. Maybe you're on to something, balloon shooting or whatever. At least you're thinking, which these days is important.

 

[Radman]

Working to get more velocity at the barrel is good. but I have been thinking about tthe other end of the path. Design a bullet to make the transision from super-sonic to sub-sonic without destabalizing.

Darn good point. I've been looking at this most of this year & have about decided that we can't do it. While it's easy to calculate when/where a bullet becomes transonic I have no idea what can ge done about it. Okay, now we get way out there...The guys at the desks who work on defense against alien races, where to locate doomsday machines, etc, say that UFO's can travel as much as 500 mph underwater because they obviously (?) enclose themselves in an air bubble. I'm just saying... (Not saying that I buy in to any of this...)

 

[Calamity]

Its204fast: This is a fun experiment, and I would like to hear the findings. One thing not mentioned in the responses so far is compression. Gas has inertia, and the denser the gas, the greater the inertia. As the bullet moves down the barrel, the gas resident in the barrel will compress, and resistance will spike. This will have greater effect than the mass of the gas that must be moved. Helium will change the sonic velocity of the compression wave, and the accuracy node of your barrel. Also, rather than using a balloon, tap the gas safety port in the breech and install a threaded check valve (one-way valve) fitting, attach a soft plastic feed line from a helium cylinder and flow regulator, and send a low flow (<5 ltr/min) of helium down the barrel to displace the air. Do not put anything over the muzzle, just let the helium flow through. The flow regulator, fittings, hose and check valve will set you back about $120.

https://www.amazon.com/dp/B001C11BP4/?tag=lrhmag19-20

https://www.amazon.com/dp/B07RXLLVSQ/?tag=lrhmag19-20

I strongly recommend you tie a string to the trigger and fire the gun remotely, until you see what the effects are. I do not think this is particularly dangerous, but anytime you try something new, you get unexpected results or side-effects. In all cases, wear eye protection and use moderate loads. Good luck!

 

[Calamity]

Its204fast: I inadvertently copied and pasted the wrong links for the components I suggested. Here are the correct links:

Cost is more like $200 for everything you will need: i.e., cylinder gas, hose, fittings, etc.

https://www.amazon.com/dp/B07RXLLVSQ/?tag=lrhmag19-20

https://www.amazon.com/dp/B001C11BP4/?tag=lrhmag19-20

 

[Calamity]

For some reason, the links I sent Its204fast will not copy in the post. Posting changes the links. For the correct links, email me at [email protected].