Quote - tirpassion,
Agn bhaisaheb, the mystic success of your Mastershot Yellow and the failure of your R10s in your AP might have a relation to the above phenomenon.
Would any metal expert enlighten us on this matter?
best regards
tirpassion
Hi Guys,
> Since
tirpassion has thrown the gauntlet - here's my take
An Over-view
The metallurgical composition of a barrel & the physics and mechanics of the pitch and landing of the grooves (rifling) within it + the proportion of metals such as lead, antimony and tin in a pellet and not to mention its shape (Diablo) have been subjects that have been discussed and debated since the introduction of air weapons without any conclusive findings with respect to ‘an ideal combination’ that would result in a ‘perfect’ match score!!!
Any air arm is an ‘enigma’ and the ‘idiosyncrasy’ of their behavior is a well known fact. Even the most respected of manufacturers opine that ‘no two air arm behaves similarly’ even though they come from the same batch, something beyond the comprehension of shooters the world over.
Thus the discussions & debates on the gun and pellet and their unified performance will go on till kingdom come followed by thesis after thesis being written on it…
Like the experts keep repeating – Only exhaustive trials can determine the ideal match between the barrel & pellet that deliver consistent match winning groupings. And when you strike the perfect match – stay with it and enjoy your shooting.
COMPOSITION OF PELLETS:
Almost all air-gun pellets are made of soft lead. No other material seems to offer such an excellent combination of weight and density, workability, rifling engagement, air seal, inertia, expansion upon impact, and resistance to ricochet.
Small amounts of antimony and/or tin are sometimes alloyed into pellet lead to increase in its hardness. Harder pellets resist handling and loading damage better, but they also may resist proper engagement by the rifling, and reduce velocity through increased friction and lesser air compression.
Penetration is increased, but expansion is reduced. A hard pellet may appear more effective in tests because of its greater penetration, but in use on game it probably would be less effective than an expanding pellet.
A typical analysis on the perfect pellet composition by British Standard No. 602: 1956 II
•Lead – Should not be less than 99.25% and not more than 99.80%
•Antimony – Should not be more than 0.10%
•Zinc – Should not be more than 0.005%
•Copper – Should not be more than 0.07%
•Tin – Should not be more than 0.50%
•Other elements - not more than 0.075%.
BEEMAN / H&N pellets are 99.9% lead and 0.05% antimony. The addition of antimony has three noteworthy purposes:
1.To improve the swaging process.
2.To protect the pellets against transportation damages.
3.To improve resistance to corrosion.
So in the final analysis ‘there’s more than that meets the eye’ regarding a perfect match between barrel & pellet. While Germans & the British conform to stringent standards in manufacturing pellets, it remains to be seen what other manufacturers do.
Briha
Then the "outsiders" might simply read us as "TOPS HOT" and try to start "dostana" here !!! naheeeeee.... my quill simply has retreated into the cover, err, the pot, err, never mind ! 
. Amazing, I am not being able to get good groupings with them and they are my usual pellets. On the contrary, the JSB pellets have turned out to be amazingly accurate. 
Switched back to the JSBs to be very happy again 
BTW more out of curiosity & ignorance, what is a dummy gun ?