Rimfire bullet design, something to think about

Bill Wynne

Bill Wynne

Active member
I must have too much time on my hands. I was just wondering if anyone in the world has ever tried to change the basic shape of a 22 rimfire bullet to a streamlined pointed design. There is no doubt in my mind that the best 22 centerfire target rifle with a benchrest bullet can group better at any range than the best 22 rimfire with the best target ammo that money can buy.

I realize that no one tries to load their own rimfire bullets and that it is not legal by the rules in most, if not all, organized and sanctioned competitive events.

The type of bullets that we use today are probably easier to make and keep uniform. I am not at all sure that what the factories make are the very best for accuracy.

Concho Bill
 
Streamlining the nose won't do much except shift the CG, CP or both. Subsonic bullet drag is mainly base drag and the only way to address this is with a boattail.
As for the accuracy, rimfire, at 1060 is below the start of what is a plateau in elevation differences with variations in velocity. That plateau starts around 1140 and extends up to 1300 fps. This is where you could have a larger ES and still have little elevation on your shots. BUT, then you are going through the sonic barrier twice on the way to the target, and this brings forth new problems with accuracy, and wind drift. Centerfire is way above this problem, plus you load your own so you can match it to your rifle.

All you can do is tune it, and get some good ammo, and yes, it is a case of 'chicken or egg'.
I personally believe there is more good ammo out there, but everyone believes (wants to) in the 'once tuned' theory.
That theory only works when you get to test multiple lots and pick what shoots with your given tune, JUST LIKE you do with a sporter!

But hey, what do I know, I ain't never won a big match, and never slept at a Holiday Inn....
 
Given the Eley EPS bullet vs the more traditional parabolic shapes, it does look like there has been some attempt to change bullet shapes. But I believe there may be a lot more to be gained in some cases. Given that most .22 target shooting is only 50 yds, there is not going to be a big premium on bullet shapes in my opinion. If 200+ yds competitions ever get more popular, I think bullet shape could really be improved. There have been a lot of folks toying with bullet shapes in bpcr competitions and they have been making some significant progress with lead bullets that are running at similar velocities.
 
Experimental Eley 22 long rifle with 42 grain simi-pointed boattail design bullets (1050 fps) for $10.25 per box.

Even if you haven't spend the night at a Holiday Inn would you care to try a box?

Concho Bill
 
Bill Wynne said:
I was just wondering if anyone in the world has ever tried to change the basic shape of a 22 rimfire bullet to a streamlined pointed design.
Click to expand...
Bill,

When Federal Ammunition was in the planning stages for producing Ultra Match .22 ammo (1980s or 1990s, I think?), they ran such a study. Conclusion: the present shape of the .22 bullet was as close to ideal (subsonic or transsonic .22 LR bullet as modeled by computer) as they could come.

I believe the statement above was printed in either the "American Rifleman" or "Precision Shooting" sometime in the mid- to late- 1990s.

Hope this helps.

Asa
 
interesting thing i ran into i'm sure alot have noticed, if you shoot eley match then cheap ammo the cheap stuff shoots a whole
lot better even federal 510s the 1.50 a box stuff, so i've come to a couple of conclusions,
1. eley has great lube
2. the eps bullet does a good job of shedding it in front of the bullet.
3. the eps bullets seems to buck the wind better than the regular shape.
the federal study was done in late 80's i believe, it's possible for slower speed
rimfire the eps shape is better for what we do and for lube dispersement.
i've got some ultramatch, i need to get a paco tool to reform the bullet shape
steal some eley lube from their bullets and see what these jewels could really do.
the ultramatch is the most consistant stuff i've shot, it's just not good in the wind.
and it does lead up the barrel.
 
I gotta wonder about that "buck the wind" comment. Have you measured a ballistic coefficient on that bullet relative to any others? I would guess it has a somewhat higher BC and that would have it tending to "buck the wind" much more poorly.

One of these days, I'm going to measure the BC on that bullet and compare it to a nonEPS Eley bullet.

Brent
 
no i haven't brent, just seems to move less in the wind, and ask the guys from
this weekend if the wind isn't blowing here you're not at fairchance. i get plenty
of practice in the wind. unless i go to the range at dawn or dusk it seems like
it's always blowing. to be truthful i wouldn't have a clue how to measure the b.c.
of a bullet. i take it that's more your field of expertise? if you can explain i'll try to
understand.
 
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Asa Yam said:
Bill,

When Federal Ammunition was in the planning stages for producing Ultra Match .22 ammo (1980s or 1990s, I think?), they ran such a study. Conclusion: the present shape of the .22 bullet was as close to ideal (subsonic or transsonic .22 LR bullet as modeled by computer) as they could come.

I believe the statement above was printed in either the "American Rifleman" or "Precision Shooting" sometime in the mid- to late- 1990s.

Hope this helps.

Asa
Click to expand...

Asa,

You could be correct about Federal running their own testing, but the only definitive testing I’m currently aware of was done by the BRL using the Ultra Match, RWS R-50, Eley SA, and a couple of prototypes.

A quote from page 1 of BRL document MR-3877:

“In July 1989, a meeting was held at the U.S. Army Ballistic Research Laboratory
(BRL), Aberdeen Proving Ground, Maryland, to discuss possible BRL technical assistance to the U.S. Olympic Shooting Team. In attendance were Dr. John Frasier, Director of BRL, Mr. R, L. McCoy of the Launch and Flight Division, BRL, Dr. Henry D. Cross, III, Chairman of the U.S. Shooting Team, Mr. Ray P. Carter of the U.S. Shooting Team, and Ms. Marsha Beasley, National Women's Champion smallbore shooter. Dr. Cross requested assistance from the BRL in defining the effect of wind on the performance of caliber .22 Long Rifle match ammunition used in Olympic competition. The result of the meeting was a decision to conduct a limited firing program of caliber .22 match ammunition in the BRL Aerodynamics Range.”

The conclusions that “might” be inferred from that document and the extensive study I’ve done over the last 5 or 6 years (mostly from JPL’s wind tunnel experiments for transonic velocities) would tend to make me agree that the current bullet shape leaves little room for improvement.

Landy
 
BrentD said:
I gotta wonder about that "buck the wind" comment. Have you measured a ballistic coefficient on that bullet relative to any others? I would guess it has a somewhat higher BC and that would have it tending to "buck the wind" much more poorly.

One of these days, I'm going to measure the BC on that bullet and compare it to a nonEPS Eley bullet.

Brent
Click to expand...

Brent,

Been there....done that!

After a very careful and tedious calibration of my 2 Chronographs:
http://benchrest.com/entry.php?62-Chrono-Calibration-for-the-Tunnel-(Part-1)
http://benchrest.com/entry.php?71-Chrono-Calibration-for-the-Tunnel-(Part-2)

I did a test firing of two lots of SA and Flat Point Eley ammo. There was no statistically significant difference between the two for a 50 yd range with the screen spacing and accuracy of my Chronos included in the data.
Sometime in the future I plan on increasing screen spacing and test firing at 100 yds but I don’t plan on seeing a very big difference in the results. I have to admit I was a little surprised because some of the testing done at JPL (Jet Propulsion Lab) showed transonic probes benefiting aerodynamically from the placement of protuberances on the nose, as is the case for the Eley Flat Point bullet.

Landy
 
I did the following test at 7000 feet and used only one CED MII chronograph. I fired 20 rounds of SA and 20 of the EPS bullet with the screens at 10 feet and the 20 of each at 148 feet and used an online BC calculator and the average velocity of the 20 rounds at each distance. I got .15 for the SA and .17 for the EPS bullet. I don't doubt that the numbers may not be accurate but I would believe that the difference is close to reality. As I remember the test you could see a difference between the velocity loss for the SA that was more than the EPS. Yes this was done with different rounds as I only have one chronograph.
 
MKnarr, that is exactly how I would do the experiment, but I am surprised that you got the EPS to have the higher BC. I believe you though. Just goes to show that intuition is not very accurate sometimes.

Now, if I get time tonight I want to see how much difference 0.02 BC makes in wind drift at 50 and 200 yds.

BTW, what exactly is SA? I know I should recognize what you are acronyming, but it is escaping me.
 
Sorry for budding in BUt...
I would worrry more about the assembly of the amunition then the bullet shape.
The ammo is loaded in gang presses. the bullets are not handled gently either. Nicks are often on the bullet noses, ad base. the powder charges vary. so does the case and the priming . Theres a lot of things to consider.
Its not hand loaded with constant attention to detail. Once in a while all of it comes together and you get outstanding ammo. What your looking for is handloaded ammo. then and only then you would have olympic grade ammo to shoot
Sometimes you get a great lot that is only close'
 
blvedere said:
Bill, Is this a legit offer, or are you pulling my chain ?
Click to expand...

Sad to say, I was only kidding.

If someone offered some experimental pills from an ammo company with a pedigree, I would be willing to try them out. That is the only way I will really know.

What if we had some Ammo made by Eley or Lapua that had a lead bullet in the shape of Hornady V-max? The bullet could be lead and have the little plastic thing on the front.

www.hornady.com/store/22-Cal-.224-40-gr-V-MAX/

Concho Bill
 
At the speed of .22 lr, a bit less point is probably better. I lean towards a prolate shape (true ellipse in 3d) with a nose that is about 1/2 as long as the overall bullet and a tangent ogive. I call it a 411 prolate and that shape works well across the sound barrier. It will probably require faster twists than we see now.
 
You can never separate the manufacturing process from the design of the projectile. Have a few flyers every box from deformed bullets and you lose no matter how good the performance is on the rest of the rounds in the box.
 
"Have a few flyers every box from deformed bullets and you lose no matter how good the performance is on the rest of the rounds in the box."

Good point, no pun intended.

Why not a scaled down hollow based wadcutter design?



Too much jump to the rifling? Kiff makes reamers everyday.
 
The real problem is that w/o a supply of primed cases, the amateur experimenter cannot make any progress, unlike centerfire lead bullet shooters. So, the point is really moot. I believe the companies that make quality ammo do have quality bullet shapes, but I wonder if a host of different shapes might better serve a greater diversity of shooting than what we have today. Fun to speculate about, but that's as far as it goes.

Brent
 
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