Ammo Upgrades?

[UmarexOctane]

With every introduction of "New And Improved" Break-Barrel air gun that comes on the market I begin to wonder more and more,  "What's the use?"  I think the most significant advance in Break-Barrel Air guns lately has been the introduction of the Gas-Spring power plant.  Beyond that it's just the same old thing dressed in a new outer skin.

Don't get me wrong; I think todays Break-Barrel air rifles in general are a whole lot better than most of the oldies but goodies but, for the most part they are all built basically using the same principles as our granddaddy's air guns.

They've been made to shoot faster but not necessarily more accurately.  This is due mainly to the fact that most shooters of even the most cutting edge air rifles are still relegated to shooting some variation of the first generation pellet designs; and these pellet designs were mainly designed to be shot at sub-sonic velocities.  If you shoot them to fast they tend to loose their in-flight stability and accuracy.

My air rifle shoots these first-generation pellets real well as long as I stay within the limits that these wasp-waisted, shuttle-cock designs were made for but I'm wondering,  why haven't the pellet designers kept up with the pellet-gun designers in terms of making pellets that shoot accurately at super sonic velocities?  It seems to me that the pellet designer that comes up with such a design will immediately find himself with a majority of the pellet market-share. 

If I go to a lighter massed produced pellet I can achieve super sonic velocity but this also ushers in super-krappy accuracy.

A while back I undertook a project where I was able to come up with a home made pellet design that would allow me to never have to buy any more store-bought pellets again.  I succeeded by coming up with a two stage process of making my own pellets that are equally as accurate as store-bought pellets and at the same velocities but, while I was engrossed in this home made pellet project I wondered, "If a do it yourself goober like me can come up with a way to make myself free pellets as needed,  why can't the pellet manufactures come up with a small bore pellet (.17-22 caliber)  that can be consistently shot accurately out of the higher velocity Break-Barrel air rifles on the market?

In terms of performance,  it seems to me that the antiquated pellet designs we're shooting have now become the weak link in the air gunning world.  An analogy of what I'm getting at is having a cutting edge stealth fighter jet being kept aloft by a propeller driven engine.  It just doesn't make any sense.  We need better pellet designs.

Tim M.

[Kailua]

I think spring or piston airguns are limited to fpe.  When the power is increased the cocking and the recoil make them more of a challenge to shoot accurately.  So pellets tend to be produced with in these limits of power.
Now if you look into PCP airguns the projectiles are being designed and produced to match the growing development of power being produced.  Check the GTA Darkside Gate a lot to be said on this is happening there.  JMO

[UmarexOctane]

In some countries, like England, there is a "Foot-Pounds-Of-Energy" limit in place.  If I'm not mistaken, beyond the FPE the air rifle then comes under firearms rules and regulations.

I've seen and heard and Read about PCP air gun shooters slowly gravitating toward more traditional cast bullet designs in order to overcome the short comings of classic pellet designs.  This is as it should be if they want to evolve toward higher performance.  My original post is talking mainly about Break-Barrel air guns; rifles in particular.

There are many newer models that are well able to reach super-sonic velocities with the lighter weight pellets but, those particular pellets are generally not designed  to remain stable in flight at super-sonic velocities.  This is where we are needing  better pellet designs that can enhance the performance of the newer Break-Barrel air guns on the market.  What good is an ultra cutting edge break barrel that has loads of potential if it's being held back by the fact the the ammo available for it won't allow it to reach its potential?

In the image I uploaded above, the tin of pellets on the left are my home made pellets.  I made them with a sleeker profile in hopes of allowing them to remain stable at higher velocities.  Unfortunately it didn't work out; at least not at the highest velocities that my air rifle can achieve when shooting the lightest weight 22 caliber pellets.  They'll shoot out of the barrel with no problem but the accuracy is just not there unless I keep them below 860 fps or so. 

In this case I believe its a rifling twist issue and not a pellet design problem.  I use a cast bullet-type of mold to cast little cylindrical slug of lead.  I can increase or decrease the weight of these little lead slugs from about 12 grains up to 30 grains.  From there I swage them into their final shape.  Like conventional pellets, the lighter I make them, the faster they fly.  The faster they fly, the poorer the accuracy. 

Maybe one day I'll break down and make myself a replacement barrel in .22 caliber with a slightly tighter rifling twist; just to test my theory.

Tim M.

[Kailua]

You may need to a search on past post on subjects like this.  Your best bet is to search with anything that was written by rsterne.  It beyond me to explain the physics  on the subject.  But anything shooting over 950 fps will lose accuracy.  Anything shooting supersonic will almost immediately slow down a few feet after leaving the barrel.  Anyways I hope I got that somewhat right.

[UmarexOctane]

You may need to a search on past post on subjects like this.  Your best bet is to search with anything that was written by rsterne.  It beyond me to explain the physics  on the subject.  But anything shooting over 950 fps will lose accuracy.  Anything shooting supersonic will almost immediately slow down a few feet after leaving the barrel.  Anyways I hope I got that somewhat right.

I'm familiar with rsterne.  I believe he's a member over at the Cast Boolits forum where I'm a member as well.  When you state that anything over 950 fps will lose accuracy and will almost immediately slow down, I know this is a generally accepted truth.  I think it's correct; and because it's correct I'm thinking that  better pellet designs are in order to overcome this deficiency.

This facts also apply regardless of its starting velocity and regardless of the efficiency of the projectile design.   What I'm hoping to do by ^*%$#@ and moaning about the poor performance of conventional pellets is to get someone to design a pellet with more efficient exterior ballistics; one that will remain stable at conventional air rifle velocities and at the higher velocities that even PCP air guns can achieve.

Generally speaking,  when a pellet of conventional design is shot at supersonic velocity, it will (just like you've pointed out) start to loose velocity right out of the gate.  The point where it goes from supersonic to sub-sonic is the point where accuracy really takes a nose dive.  I think this can be overcome by possibly scaling down a conventional firearms bullet design in some way.  Unfortunately, when using heavy metals like lead to make your projectiles we end up with overly-heavy projectiles for use in a Break-Barrel air rifle.  However, they will work in PCP air guns.

Tim M.

[UmarexOctane]

These are some concept drawings I came up with several years ago when I first started thinking about improving the ballistics of Break-Barrel air rifle ammo.   These drawings are intended for use in an air rifle with a true .223"-.224" bore diameter with a 1 in 14 twist barrel.

At that same time I had figured out a way to increase the volume of my air gun's exiting pressure-chamber so even with the heavier weight of this pellet design I might still be able to launch them at velocities above the 860 fps range and retain the accuracy I've been getting with conventional pellets fired at or below the 860 fps levels.

Tim M.

[Kailua]

Seems like you have done a lot of work on the subject.  You might want to go to the GTA Machine Shop Talk & AG Parts Machining  gate and then to the Engineering- Research & Development sub gate.  I hope there this will be all figured out. 

[UmarexOctane]

Seems like you have done a lot of work on the subject.  You might want to go to the GTA Machine Shop Talk & AG Parts Machining  gate and then to the Engineering- Research & Development sub gate.  I hope there this will be all figured out.

I'm kind of reluctant to post my ideas in a realm where I'm the new guy; even though the members of such a group of guys  are most likely very capable people.   In the past when I've done so with other projects and ideas I've been met with alot of condescension; to put it mildly.
Nearly all of my previous posts involving my projects and ideas were interpreted as if I'd posted to ask their permission to undertake these projects.  Maybe it was the manner in which I described the projects in question that brought about this kind of unwarranted feedback; I don't really know.  It's just that ever since then I've tried to finish my project before posting them to any of the forums I belong to.  That way the "Nay-Sayers" and the "Well-Meaning-Dream-Killers" cant' deter me from completing my projects.   

I'll just keep plucking away at it myself as time permits; in between other project.   I'd like to have this particular pellet upgrade project completed and working before I go in search of input on how to make it better.

Tim M.

[Airgun.Sniper]

 For spring power air rifles break barrels side levers etc...they dont benefit of an increase weight like pcp's...i believe they only have a max amount of energy. Accuracy is gonna be played on the shooter..I take what every one says in accuracy for a grain of salt...

[UmarexOctane]

For spring power air rifles break barrels side levers etc...they dont benefit of an increase weight like pcp's...i believe they only have a max amount of energy. Accuracy is gonna be played on the shooter..I take what every one says in accuracy for a grain of salt...

I tend to agree with you on this.  It's the generally accepted line of reasoning when it comes to break-barrel air rifles.  My original post was meant to address the inefficiency of design of the first generation pellets being fired from most air rifles.  As they are, these first generation pellet designs make it pointless for the manufactures of air rifles to come up with air-rifle designs that shoot faster.  If antiquated pellet design only allow those pellets to be fired accurately within a certain low velocity window, spending a fortune on R&D to design a faster shooting break-barrel air rifle doesn't make any sense.

Right now, the only reason to manufacture a faster shooting break-barrel air rifle would be for bragging rights and marketing hype.  It's not likely that the accuracy out of such an air rifle would be anything to brag about unless a more efficient pellet were designed along with it.  Such a pellet could, in theory be a cross platform air rifle projectile that could be shot accurately out of both sub-sonic and supersonic velocity break-barrel and PCP guns.

At least that's how I see it.  Not everyone will agree.  This is generally due to the fact air gunning has alot of tradition behind it.  When we speak of pellets, traditionally, the shuttle-cock, wasp-waisted pellets of yesteryear come to mind.  This is because pellet design has not kept pace with pellet gun design.

I believe that by changing the rifling twist to a slightly faster twist a pellet with a more streamlined bullet-like profile can be made to work.  As an example of a low velocity gun shooting a more efficiently designed projectile accurately,  note the 300 Blackout cartridge.  It can shoot a 200-plus grain projectile at subsonic speeds very accurately.  I know that to some, this analogy is like comparing apples to oranges but I'm not trying to compare a powder burner to an air gun.  I'm not trying to compare anything to anything.   This is just an analogy to make my point.

In order for the 300 Blackout to shoot a heavy bullet accurately at subsonic velocities, a tight rifling twist is needed.  In a similar manner, in order for an air rifle to be able to shoot a more efficient pellet design accurately, it would require a tighter rifling twisted barrel to stabilize that projectile.  It would also require a little more power/velocity to overcome the additional drag that the tighter twist would impart to the Upgraded Ammo.  I'm certain that designing such an upgrade in air gun ammo for break barrel air rifles is within the realm of possibility.   I'm perplexed by the fact that none of the pellet manufactures have done it yet.

Perhaps they fear the plethora of potential legal liabilities that such an ammo upgrade could bring about; who knows.

Tim M.