Pellet at High Magnification

[Ricardo]

I recently took these images on a scanning electron microscope. It's an RWS Meisterkugeln out of a freshly opened box. Most images are at 30 X magnification.

[talladega]

really cool! got some of other pellet brands to compare?

[Ricardo as guest]

I want to optimize this so I can get a whole pellet in the field of view, then I'll take a peek at some H&N Match and RWS Hobby that I've got. I'll post pictures if they turn out.

[Thomas Monto]

The question is do these imperfections cause any decrease in accuracy?
Interesting photo's though

[JSBmatch]

Ricado, great pictures and a very interesting subject.
You will find that the 'high end' pellets such H+N Finale Match, RWS R-10, Vogel and JSB Match will not have a moulding seem as they are made from the extrusion method rather the moulding method.

JSB

[pilkguns]

Ricardo,

could you give me a call or e-mail Monday. I would like to talk with you about getting some other pics like this done.
scott at pilkguns dot com


931-924-3400

[Ricardo]

I doubt that the imperfections seen here have a significant effect on accuracy ON AVERAGE. For one thing, compare the size of the flaws with the curve between the head and skirt of the pellet: that indent is intended to maintain airflow over the surface of the projectile; that is, to keep the air making contact with the surface and thus avoid low-pressure areas that would increase drag. If so, a little crack on the order of microns is bound to be inconsequential, rather like the rivets on the surface of a WWII airplane. I also calculated that at a muzzle velocity of about 160 m/sec, with a quarter-turn rifling, the pellet is spinning at about 10,000 rpm and generating about 500-600 g at the outside edge. This is hardly enough to deform the little scraps that hang off. Think of the "flaws" produced by the rifling itself, for example. More important would be deviations from the axis of symmetry, such as a non-uniform skirt or an off-axis pellet face. That said, however, the random flaws might be part of the reason that the best barrels still produce ragged single holes from a vise. If the INDIVIDUAL pellets were IDENTICAL, perhaps single-hole accuracy would be cleaner. It also remains to be seen what lesser-quality pellets look like.

[Jack Milchanowski]

How about the affect of boundary layer separation in flight?

Just kidding. It was good to see you Tuesday night. It was an enjoyable time shooting. Kathy V. and I will be at Ft. Benning all next week. Looking forward to it.

Come see us in the woods.
Jack

[Thomas Monto]

We were using L cheapo pellets (whatever we could get at the lowest cost) for the begining juniors in Marksman Biathalon rifles with no problems. (They shoot at 15')

Switching some shooters over to Avanti air and CO2 using the same pellets caused problems with the head of the pellet seperating from the skirt. The head would strike the target much lower and not penetrate the paper. The skirt would stick to the plunger in the rifle. (still at 15') We have since switched to Vogel pellets in these rifles without any issues.

You get what you pay for.....
TM

[j-team]

Ricado, great pictures and a very interesting subject.
You will find that the 'high end' pellets such H+N Finale Match, RWS R-10, Vogel and JSB Match will not have a moulding seem as they are made from the extrusion method rather the moulding method.

JSB

High end pellets are not extruded, they are swaged in a 2 piece die. They will have a part line (seam) on them but the quality of the tooling makes it hard to see. As tooling wears, the line will become more visible and that set of tools will be used for lower grade pellets.

Low end pellets are often made by passing them between forming rollers, hence the knurling.

[Ricardo]

Comparisons between H&N Match and RWS Hobby. The former looks pretty nice, I think, while the latter looks like a lump of lead. Still, if it flies true, who cares?

[Philadelphia]

More important would be deviations from the axis of symmetry, . . .

FWIW, I agree that the real enemy of accuracy is a flaw in matching the center of the thing (pellet) with its true dynamic center of mass or gravity or however it's supposed to be expressed. I've seen studies of bullet paths showing some pretty wacky and surprising results coming from not having the bullet spin perfectly around its physical center. The bullets would travel along an irregular corkscrew type of path that would seem to make predicting the exact precise point of impact impossible.

Making bullets or pellets that are so perfectly symetrical and without internal flaws so that the things really do spin on their physical axis seems to be hard to do and thus expensive.