Daystate FT Diabolo in 4,53mm

Ich wusste schon daß Alfred ne menge Diabolos im Wagen hatte, aber daß es 4,53mm diabolos gibt wusste ich bisher nicht, von daher hab ich auch keine erfahrung mit dieser sorte.

Gruß
Para

Ich habe aus England nur gutes von diesem Kaliber gehört. Habe bei Holme angefragt, ob es die JSB auch in diesem Mass gibt. Sie fragen bei Schulz an.

moin,
ich hätte da mal gern eine frage, bei euch klingt es ja so als seien die 4,53 generel besser, hängt es nicht viel mehr von der jeweiligen waffe bzw. lauf ab ob man damit besserre ergebnise erziehlt ? so ist jedenfalls meien meinung.

Ich habe zwar keine Ahnung von FT, aber ich hab trotzdem mal versucht Infos über Diabolos in diesem speziellen Kaliber 4,53mm bzw 0.1785” zu finden. Vielleicht hilft euch das ja weiter (Ist aber leider Englisch)

[Edit]
Anscheinend kann man sich Diabolos in diesem und anderen ungewöhnlichen Formaten selber machen, indem man (so wie ich das verstanden habe) normale Diabolos mit einem Gerät das "Pell Size" heißt und von einer Firma namens Beeman hergestellt wir bearbeitet. In dieses lassen sich diverse "Dies" für die unterschiedliche Kaliber einsetzen. Ich glaube aber das Gerät ist nicht leicht zu beschaffen, denn es gibt im Inet sowenige Infos dazu, dass man sie an einer Hand abzählen kann. Ich hab auch keine Shops gefunden die das Teil haben. Wenn überhaupt ist es mit Sicherheit nur über den Hersteller zu bekommen. Ein Bild hab ich ganz unten in meinem Post eingefügt.

Hier jetzt erstma der oben genannte Text:

Zitat

Pellet "Fit"

Spring airguns encompass traditional metal spring and the newer "gas ram" springs. Pneumatics loosely include CO2, multi-pump and pre-charged compressed air guns. Spring guns are very different to pneumatics. In the spring gun, the air in the compression chamber is violently compressed by the spring driven piston when the trigger is pulled. Pneumatics release a blast of pre-compressed air or gas behind the pellet, which is a considerably more gentle process than that of the spring gun. Pneumatics have an air release valve; spring guns do not. This is perhaps the most significant difference between spring and pneumatic airguns when it comes to pellet selection because the pellet itself acts as a pressure release valve in the spring gun. When the air pressure behind it builds to a certain point, the pellet begins to move. As the pellet moves in the spring gun the compression volume behind it diminishes by the volume exposed in the barrel. If the pellet moves too soon, the piston pressure behind it will not reach it's full potential and energy in the system may be lost.

Pellet "fit" is a combination of several variables. Most notably the skirt diameter of the pellet.

For a .177" caliber airgun, the pellet head is usually 0.177", but may be 0.176" or 0.178" for different styles or brands of pellet. Ideally, the pellet head should be an exact fit in the bore or a little oversize so that the rifling cuts gently into the head. The pellet skirt on the other hand is deliberately oversized. The skirt is intended to be cut by the rifling so that a gas tight seal is produced in the barrel. Skirt diameters typically range from 0.184" to 0.188" for different styles and brands of pellet. There are pellet sizers available that reduce the skirt diameter to a precise and uniform diameter by pushing the pellet through a die. The Beeman "Pell Size" can size pellet skirts to: 0.1780", 0.1785", 0.1790" or 0.1800" for 0.177" caliber, depending upon the die used.
That's a bag load of size variables. Why so many size options? Several reasons:
In spring airguns, the breech of the barrel is reamed out a little to form a chamber that allows the pellet to be inserted so the breech can be closed. Spring airguns may be sensitive to the size of the pellet skirt. My first experiments with pellet sizing were actually inspired by a particular airgun that refused to accept a particular brand of pellet without the "thumb-nail push" or "skirt squish by closing breech" syndrome. Mangling the pellet skirt while forcing it into the gun does not inspire confidence in ones' hopes for accuracy! So a "Pell Size" was purchased and the cat was let out of the sizing bag.

If our rifle has a precise 0.177" bore diameter at the top of the rifling lands, then a pellet with a 0.188" skirt will either fit neatly into the bottom of the rifling lands, or be swaged down a little or a lot as it is forced down the barrel. The pellet skirt fit is most critical to the timing of our spring gun because the spring / piston system provides the force necessary to fit the pellet into the barrel. The tighter the skirt fit, the more force required. The precise instant when the piston has generated enough air pressure to move the pellet will affect the remaining piston travel and ultimate pressure achieved in the air chamber.

For want of a better term, "timing" in a spring gun means the exact instant that the pellet begins to move relative to piston in the air chamber. It is very analogous to "timing" in a an internal combustion engine for reasons that may be become clear in a while.

If the pellet head diameter is 0.178", then some energy will be required for the rifling to cut grooves into the head as well as the skirt; this also will affect the timing. The heavier the pellet, the more inertia (resistance to movement) it has, and that too will affect timing.

Why is timing so important? Well... sporting spring airguns burn oil!!!! They are oil burners. Oil will combust in a spring airgun.

This "combustion" behavior of sporting spring airguns is very well documented in the book: "The Airgun from Trigger to Target" by G .V. Cardew and G. M. Cardew, and makes most thought provoking and entertaining reading. Their experiments revealed that up to 45% of the energy yielded in a test gun was derived from combusting oils.

If you have a sporting spring gun, you should notice a slight burnt oil odor just after firing a pellet; or if you can safely look down the bore from the breech of the opened gun, a slight golden haze will usually be seen. Such are evidence of the traces of oil that have been burnt. (A very little oil is necessary for proper combustion. It is usually provided by the piston head wicking traces of oil or grease thrown from the spring in the air chamber behind the piston. NEVER inject any oil into the air chamber in front of the piston unless specifically advised to by the manufacturer (not to be confused with the distributor!!))

"Sporting" spring airguns need to combust. "Match" spring guns generally do not. Match air rifles usually yield less than 6 foot pounds of muzzle energy. Adult sporting spring rifles are intended to yield just under the UK FAC 12 foot pound limit, or non-FAC guns generally in the 20 to 30 foot pound class. They all burn oil. Sporting spring guns are tuned for power; Match guns are not. Match spring guns generally work in the "pop gun" phase (re: Cardew) and are not designed to burn any oil whatsoever. That is why Match guns often use steel piston rings that exclude oil from the air chamber.

Exactly when the oils combust depends upon the volatility of the lubricant, it's mix ratio with the air available and the pressure and temperature exerted upon it. If that sounds a little like a Diesel engine, it is, but with one major difference: the oils in the spring gun are meant to burn, NOT detonate! "Dieselling" in a spring gun is horrifically obvious; the gun fires with the noise of a firearm and sometimes with the smoke of a flintlock! Detonation in a spring gun is to be avoided at all costs; it can cause serious damage to the piston head, spring, and integrity of the gun and may be dangerous for the person holding same! The oil should combust in the transfer port or the breech; if it ignites in the air chamber, detonation may result.

To achieve the correct timing in our sporting spring gun the pellet is all important; it is the only variable besides lubricant that you can play with. Despite "common sense", fitting a more powerful spring to your gun usually does NOT produce more energy because the air is compressed too soon and the pellet is forced to move before the air pressure can reach the correct pressure and temperature for the oils to combust. Often fitting a less powerful spring will yield more energy. Refer to Cardews' experiments for some intriguing details.

Most pneumatic airguns have bolt actions that push the pellet into the barrel. Pneumatics do not burn oil and do not require the pressure relief valve timing properties of pellet fit as do spring air guns. For these reasons, pellet sizing for pneumatics is more concerned with consistent accuracy than energy efficiency. Pellet weight however becomes very important in pneumatics because it will affect the efficiency of energy transfer from the relatively large volume of compressed air and the pellet. The peak air pressure in a spring gun occurs before the pellet moves, whereas in a pneumatic, the peak pressure may not occur until the pellet is some way down the bore. Pneumatics usually exhaust air from the barrel at higher pressure and velocity than do spring airguns, that is why pneumatics are noisier.

Alles anzeigen

Hier noch der Link zu der Seite von der ich das habe: http://home.hiwaay.net/~ispellan/PelletTest01.html

Und ein Link zum Katalog des Herstellers dieses "Pell Size" Gerätes. Darin ist das Teil zu finden und auch kurz beschrieben.: http://www.beeman.com/beemancatalog.pdf

Hallo,

wie sind mittlerweile die Erfahrungen mit dem 4.53er Kopfmaß (Waffen? ? WBK?)
Gibt es dieses Maß nur in der Daystate-Ausgabe der Schulz-Dias oder auch von den originalen JSB?

Danke für die Info...

Viele Grüße,
acciaio

Hi acciaio,

die gibt es von Daystate oder JSB, und wer stellt die Dinger wohl her??
Laut Alfred de Vries sind die Daystate besser sortiert, was dann auch den Preis erklärt.

Erfahrungen:
HW 97K Custom -->gleiche Vnull wie bei 4,52ern, geringere Streuung.
Steyr LG 100 oder 16 --> geringere Vnull als bei 4,52.

Ich habe gerade eine neue Stange JSB 4,53er bestellt.

Gruß MOA

Wenn ich den Text über den Pell-Sizer richtig gedeutet habe, wird nicht das Kopfmass geändert, sondern nur der Kelch schmaler gemacht.

Aber trotzdem interessant!
Vor allem für Besitzer antiker schwacher Kinder-LGs, bei denen zu grosse Kelchmaße schon mal dazu führen, daß die Dias sich nicht mehr bewegen wollen.

Stefan

Zitat

Original von MOA

Ich habe gerade eine neue Stange JSB 4,53er bestellt.

Gruß MOA

Bei wenn denn? Ich würde das auch gerne ma ne kleine Testreihe mit schiessen?