TargetTalk

I'd like to understand more about pellet weights and the importance [or not] of the pellet weight - plus the relevance [meaning?] of "g" and "gr".
Why I ask is that I notice the RWS match 10 plus are 0.45g and 7.0gr. Then there's the Meisterkugein R10 (light) at 0.50g and 7.7gr. The RWS Match are 0.45g and 7.0gr - yet the RWS R10 are 0.50g and 7.7gr. All recommended for AP.
From all this I'm deducting that the optimium weight for AP is somewhere between 7.0gr and 7.7gr. I'm not sure that the difference [meaning] of 0.45g as oppossed to 0.50g.
What I do know is that I put an RWS Club 10 (0.45g,7.0gr) through my chrono [pistol IZH-46M] and it was consistent at 469ft/sec - 472ft/sec. The only other pellet I had access to was the RWS Match 10 for air rifle (0.53g,8.2gr) and this registered consistantly around 412ft/sec.
Given that I'm not reading too much into all of this - am I right in presuming that the heavier the pellet the slower the velocity? Most importantly - could you recommend what the "optimium" velocity is for AP competition.

g = grams
gr = grains, there being 7000 grains to the pound (I think...)

The heavier the pellet the slower it goes.

For absolute accuracy there will be different optimums for bullet weight and velocity for a given pistol. Generally people believe heavier = more stable and more accurate.

Slower = more time in the barrel, so the effect of flinch is greater.

Heavier pellet also = more recoil (Not sure about the physics but seems to hold true)

I guess this is why rifle shooters like heavier pellets, pistol shooters lighter ones.

Personally my technique has never been that great, so I found lighter pellets gave better results in pistols. If you never blink or flinch then heavy pellets will be fine.

John Harvey wrote: What I do know is that I put an RWS Club 10 (0.45g,7.0gr) through my chrono [pistol IZH-46M] and it was consistent at 469ft/sec - 472ft/sec. The only other pellet I had access to was the RWS Match 10 for air rifle (0.53g,8.2gr) and this registered consistantly around 412ft/sec.
Given that I'm not reading too much into all of this - am I right in presuming that the heavier the pellet the slower the velocity? Most importantly - could you recommend what the "optimium" velocity is for AP competition.

What were the pellet diameters (usually marked somewhere on the packaging in the range 4.48 to 4.52). This might affect velocity as well.

Spencer

The pellet diameter in all cases was .45mm

I'll confirm that there are 7000 grains to the pound. Also, recoil won't change in force, but it can change in character. Since the same charge is used every time, the heavier pellet might give heavier recoil due to the long barrel time.

H.

The one weight is in grams, abbreviated as 'g', so that 0.50g is half a gram. Shooters also use a different unit of measurement, called "grain" and sometimes abbreviate this as "gr". So that the pellet that weighs half a gram, is 7grain. Grain is usefull, because such small weight are being measured and you get nicer numbers with fewer decimals.

As for what is best, while some companies (like RWS) call their pellets "light" and "heavy", H&N (who also have a light and heavy match pellet) actually calls the lighter one "pistol" and the heavier one "rifle" with little pictures on the tins to match. See their site for info and pics:
http://www.natermann.de/sport/uk/frameset.html

The top 3/4 pellet companies (Besides RWS/H&N also JSB and Vogel) all have a pellet specifically for Air Pistol and one of Air Rifle and the weight ranges tend to be similar:

RWS light 7.7 grain
RWS heavy 8.3 grain

H&N Match Pistol 7.6 grain (0.49g)
H&N Match Rifle 8.2 grain (0.53g)

Best thing to do is stick to the pistol type from whichever brand and play around with the different head size if you are getting one that is sorted in head size (4.48 / 4.49 / 4.50 / 4.51 / 4.52 mm). All companies also have a cheaper line, which are the same pellets, but with unsorted head size usually called "practice" or "sport" (JSB calls it "shak") as opposed to "match" (or R10 in RWS' case).

JSB actually sell a tin with a selection of pellets to try out different head sizes.
http://web.telecom.cz/schulz/main_e.htm

In the end all of it might not make THAT big a difference, but since you have access to RWS stick to their pistol pellets.

Thank you for the feedback. I've now come to the conclusion that the pellet's weigh is stated in grams and grains - given there are 7000 grains to a pound.
I know (ds) states that half a gram (.50g) is 7grain - but ds also mentioned that H&N Match have a pellet which is 0.49g - 7.6grain. That part confused me. I'm now taking this to be that the weight is both the gram and the grain?
I guess my confusion was using the RWS brand which is the only one available to me [residing in Indonesia] and when searching the web, RWS make two "weights" of Match 10 for pistol - both being 0.45g but one at 7.0gr and the other at 7.7gr. That being so I was wondering if there was a weight preference for air pistol.
I think I'm reading too much into this weight thing!!

John Harvey wrote: I know (ds) states that half a gram (.50g) is 7grain - but ds also mentioned that H&N Match have a pellet which is 0.49g - 7.6grain. That part confused me.

Apologies for that, I was speaking in rough terms first (half a gram = 7 grain) and then quoted some figures from H&N (0.49g=7.6gr). The latter will be rounded too and most sites/sources are a little casual with their conversion. I quick 'net search lists the following conversion factor:
grain x 0.0648 = gram

Where pellets are concerned most people use "grains" so don't worry about grams.

John Harvey wrote: RWS make two "weights" of Match 10 for pistol - both being 0.45g but one at 7.0gr and the other at 7.7gr.

Yes, sadly some sources don't list everything accurately, even the offical RWS site has some mistakes, but the clearly state that the "R10 Light" is better for pistol and the "R10 Heavy" for rifle. Quote from the site:

Two versions [of R10] are made. For the rifle shooter, we recommend the slightly heavier 8.3 grain and for the pistol shooter the 7.7 gram

Even that sentence is incorrect, the last word should also read "grain"... perhaps someone should point out their mistake and maybe "score" some free pellets for their trouble :-)

Have a look at their site:
http://www.dnrws.com/r10_pellets.html

In case your local supplier/store stocks more options, you will notice that apart from the R10, RWS also list RWS MEISTERKUGELN PISTOL. The would be the same weight as the R10 light (7.7grain), but just not sorted according to head size (so you can't specify 4.49mm or 4.52mm) and therefor it should be a little cheaper, but to start out with perfectly adequate.

John Harvey is right,
RWS R10's are available in 3 weights.

8.2 grains (.53 grams)
7.7 grains (.50 grams)
7.0 grains (.45 grams)

They don't seem to mention the .45 gram ones on the website. May be a new product?

John,
I am surprised that more members haven't jumped in on this thread. This subject has been discussed many times before, however, and some may be tired of repeating themselves. Depending upon the air gun you are shooting, pellet weight may be a non-issue. When I have ordered pellets from our host Pilkguns, they recommend light pellets only for older single stroke pneumatic air pistols with lower velocity, and heavy pellets for all others, such as precharged pneumatic (compressed air) and CO2 air pistols. I have used both light and heavy pellets in my IZH-46M, which is a high velocity SSP, and saw no difference in performance. I now shoot an Anschutz LP Junior PCP and use heavy pellets per Pilkguns recommendation.

Thank you all. Much appreciated all the info. I have a IZH-46 too and was surprised when I compared an 8.2 grain pellet with a 6.9 pellet using the chrono - the 8.2 being noticably slower.
Now I'm using a compressed air (LP-10) and will run with the advice that by selecting a "light" or "heavy" pellet should not make a great difference if any at all.

John,

You may not find any difference in accuracy between the weights you mention.
BUT you will still find a big difference in velocity, 40-50 fps approx.

why would you be surprised that a heavier pellet shot slower?

Also, recoil won't change in force, but it can change in character

Actually it will, using the figures quoted earlier.

In terms of momentum:

7gr@470fps = 7x470 = 3290 gr.fps (that must be a new unit!)
8.2gr@412fps = 8.2x412 = 3378 gr.fps

Only 2% difference, could be within experimental error I guess.

If you skim through reloading data, generally for a given pressure a heavier bullet will carry more momentum, and hence recoil, than a lighter one