Why weigh pellets?

by B.B. Pelletier

Well, this turned out to be pellet week, didn’t it? I thought I would share an accuracy secret with you, so we’re going to look at weighing pellets.

Weighing pellets is for the final edge!
You don’t have to weigh pellets. They will shoot just fine the way they come from the tin. But if you want to get the absolute last bit of accuracy from any pellet, weighing is about the best method I know. What I am talking about is the difference between a 1″ group and a 3/4″ group. The difference is perhaps 25 percent, though some pellets seem to need weighing while others don’t.

Why do we weigh?
Pellets today are remarkably uniform. Compared to what we shot back in the 1950s, today’s pellets are target-grade projectiles. But it isn’t perfect, and that’s where you can make a difference – by sorting your pellets into groups of the same weight. Irregularities in the weight of a lead pellet means there may be more lead – or less.

Weighing began with blackpowder shooters
A cast lead bullet can look fine on the outside while hiding a void (empty space) inside. When it is shot, the rifling spins it like a top. If it is unbalanced because of the void, the top will wobble. So shooters weighed their bullets and shot the ones that weighed the same, hoping that they were almost alike. It’s not a perfect method, but it’s about as good as you can get with affordable technology.

This was the old way of weighing bullets and pellets. This RCBS 1010 scale is magnetically dampened, but it still takes about ten times as long to weigh anything as an electronic scale.

When I got into both reloading and blackpowder shooting, the scales that were available weighed bullets to the nearest tenth of a grain, so that was what we used. Today’s scales still weigh that close, but they have an important advantage. The new electronic scales weigh things much faster than the old balance beam scales I once used. It might have taken 30 seconds to weigh a bullet on a balance beam scale, where today’s electronic scale does the same job in about three seconds. That difference means airgunners can quickly and accurately weigh all the pellets they need for a match or for a hunting trip.

Electronic scales are the way to go today. Incidentally, that’s a 10.5-grain Crosman Premier on the scale, which reads 10.7 grains!

Find the “peewees”
Crosman Premiers are among the finest pellets in the world, but a box of them can contain several undersized pellets that field target shooters call peewees. A peewee is so small that there’s no chance of it going where the other pellets have gone. You can usually feel the lack of resistance when loading a peewee, but in a match you can forget to check and the result will be a missed target. If you weigh all your pellets beforehand, this problem can’t occur.

What to look for
The thing to do is grab a box of your best pellets and start weighing them. You will be surprised at how much difference there is! A box of Crosman 10.5-grain Premiers used to yield 40 percent weighing 10.5 grains, 40 percent at 10.4 and the other 20 percent ranged from 9.9 to 10.7 grains! I would toss the bad 20 percent into a “dud” box and divide the two main groups into separate boxes, each clearly marked with the weight. I never entered a match with but one weight of pellet, and that’s the one I used for my final sight-in.

Weighing is the best way
I have tried washing pellets, numerous kinds of lubricants, and even moly-coating pellets and barrels – all with no discernable results. But simply sorting by weight has made a very clear difference. If you want to test for this, shoot several groups at 50 yards with weight-sorted pellets of any brand and other groups with the same pellets that fit into the dud category. I think the difference will amaze you.

Besides examining each pellet for visible deformities, sorting by weight offers the best accuracy advantage I know.

11 thoughts on “Why weigh pellets?”

  1. Yes i have just recently purchused the rws rm2003 and was wondering since it has both the .177 and the
    .22 barrel and i am looking to have some accuracy what do u sugest for scope wise so i can be accurt with the .177 and the .22

  2. I have a scale that is accurate to .1 grain. You really need one accurate to at least .05 grains but these are very expensive (in general). On the other hand, even though the scale may read 10.1 to 10.3 for the same pellet, all you really need do is look for the really off-weight pellets since +/-.1 grain is not going to show much of a difference in ballistics.

    Even with sorting, I have still seen enough fliers that I cannot explain by shape, skirt, or other visual feature. I had one tin of JSBEHs with about 10% fliers but that was very unusual. Most tins seem to have far fewer (maybe 1 out of 200 in the current tin, for instance). At that level, it could easily be brain-farts, too.



  3. To the person who owns the Mendoza RM 2003,

    I had a hard time finding your rifle, but I finally located it. I would try a BSA AR 4×32 if I were you. It has parallax adjustment down to7.5 yards and it is supposed to be tolerant of spring gun recoil.


  4. You know, that isn’t for me to say. Since you own it, why not tell us what you think?

    I know the Mendoza story a little, but there hasn’t been a spring rifle with interchangeable barrels on the market since the 1970s, I believe, when Webley sold their Hawk. According to the Blue Book of Airguns, it was last made in 1979. So what you have is very interesting.

    I would be interested in what sort of accuracy you get; in how easy it is to swap barrels and how close the velocity figures are (1,000 f.p.s. in .177 and 850 in .22).


  5. I just ordered it from Cabalas it should be here on monday or tuesday. So I am trying to find as much info on which pellets would be best before I get it. Maybe its a good thing cabalas backs up every sale with 100% customer satisfaction so if i dont like it it can always go back. what weight do u suggest i shoot with the fps being 1100fps .177 and 900fps .22?

  6. Mendoza guy,

    I would use a heavy pellet in both calibers to get the velocity down into the accurate category. Crosman Premiers in 10.5-grain weight would be fine for the .177, as would 10.6-grain Kodiaks.

    In .22 I’d try JSB Exact domed pellets and also Kodiaks.


  7. Just Google powder scales and you can find ones accurate to 1/10th of a grain for about $50 bucks. This is a good idea. I think I like tinkering/experimenting with things more than the hobby itself. Like R/C cars, old amplifiers and radios etc. I guess airguns is my hobby of the moment for now lol.


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