Just like with a real rifle, the only way to know for sure is to test your gun with the BB you want to use. Generally a heavier bb will require more hop up than a lighter one. Any change in bb, either brand or weight may require you to fine tune your hop up to get the most out of it.

That being said the differences in weight are pretty minor. .45's are 3/10s of a grain heavier and .36s are just under 1 grain lighter. If we look at the figures you have listed in your signature we can see that going from a .20 to a .43 bb only increases your energy by .2J. And that is more than doubling the weight. So increasing your weight by .02 grams probably isn't going to have a huge effect on anything. Providing those particular bb's fly well out of your particular set up. And the only way to know that is to actually test them.

 

All valid points, thanks. I have shot 0.4g at an earlier stage in the build and I recall them being pretty similar to the 0.43g in closer ranges. That's why I'd like access to somewhere where I can shoot between 60m-100m to really test them.

I was hoping for some theoretical or physical reason for one weight over another, and I appreciate that the differences will be subtle of negligible in some cases. I also thought that there is a good chance the real answer will be the same as yours; buy some and test them.

This is where I wish Geoff's weren't basically £20 a bag :nuts:

If the ranges and accuracy are likely to be similar, will they be similar in their behaviour against wind? Also, if there really is a negligible difference, should I use the lighter weight so as to decrease wear on the bucking?

 

Ah yes, the fiscal responsibilities of sniping...I know it well.

Personally, I slowed my rifle down (460fps with a .2) and have optimised it around a .36g BB. Readily available everywhere, relatively cheap to buy, and by the kilo, you simply get more. The terrain in this part of the world is heavily wooded so a shot past 300' won't happen, so why bother? If you can get an effective range of 285' here, you're golden and even then those opportunities do not come along very often if ever.

So, while you're contemplating your ammo, think of your objective.

Now, when it comes to the wind, the heavier BB will prevail. Also when punching through leaves or grass deflection is less likely. They simply carry more inertia for a longer period. That said there is a sweet spot where if you're firing too hot the flight path becomes unstable. Again, think of your objective and the game you play. Then build accordingly. Work with your surroundings and it'll be a piece of cake.

 

A fantastic reply, thank you.

The various sites I play offer many heavily wooded areas with lots of difficult shots through branches, bushes and grasses, and typically closer-range engagements, but some of the sites also offer clearings, tracks, valleys, overwatch positions and open areas where shots up to and over 300' are an very much an option for those with the range.

Whilst the sites offer opportunities for gameplay at those ranges, their shooting range does not, so testing results is hard.

 

With a Action Army + Maple Leaf setup you'll have no problems lifting any regular weight bb. Most likely, you can even lift .45s

I think the heavier, the better. Your gun seems to have some energy creep, so there's enough for whatever weight you'd like to. So yeah, probably .45s are the best option.

 

I'd also say the heavier, the better. That being said, .43 should be enough. .4 will also work well and so should .45, theoretically. But if .43 is on the limit of what your hopip can handle, then .45 will cause you issues, because you need more backspin, which requires more downforce on the bucking, which reduces fps, which means you need even more backspin, etc, which will either make your gun shoot with less energy, which will influence your range if you're already on the low end of the spectrum, or you will end up with a pinch jam.

I could probably use .43's in my setup just fine, but I generally use .4 since they're plenty good enough to basically outrange everyone except for other snipers.

Anything .4+ is good enough. As long as your velocity with that bb stays above 350 you'll be good. Heavier is always a tad better, but, the difference of .02 gram isn't going to change too much.

 

Now we're getting to the meat and potatoes of it!

Anything .4+ is good enough. As long as your velocity with that bb stays above 350 you'll be good. Heavier is always a tad better, but, the difference of .02 gram isn't going to change too much.

I'm shooting 355-360fps on 0.43g bbs, the fps with 0.45g is still north of 350, just. So I could use those heavier weights then...

330-370fps = 0.23-0.28gm
370-420fps = 0.28gm-0.30gm
420-450fps = 0.30gm-0.32gm
450-500fps = 0.32gm-0.36gm
500-540fps = 0.36gm-0.4gm
540fps upwards = 0.40gm-0.45gm
(This is an estimate and so you can go up or down a little in the weight but I would not change it too much)

But this suggests that, if I use your over-allowance, up to a 0.4g...

Also keep joule creep in mind when picking a bb weight. That will put your actual muzzle energy just a tad higher too :yup:

But yeah, I like really heavy bb's, they carry their momentum further and in theory get better range, but they do require a really good hopup if you want to use them at low fps.

And I can lift 0.45g fine, so does this mean that theoretically I can use 0.43g and should see similar range to the 0.4g?

I think, as there are opposing theories as to which would work best within the capabilities of my build, I will buy a bag of both 0.4g and 0.43g and try and do a decent range test if I can find somewhere suitable.

I find 1tonne's theory that an underpowered heavyweight bb will range worse than a lighter bb regardless of it's ability to be lifted interesting. I also like the idea that a lighter bb correctly matched will have the potential to fly straighter to its max range than a heavier bb.

Really appreciate all your help guys, I know this topic is discussed often but it is this difference in opinions that confuses me when trying to find the perfect weight for my setup.

 

I tend to think a little differently than others.
I would only use a 0.36-0.4gm bb at 500fps. So not the heaviest bb possible but it is still a heavy weight.
The reason for this is because you will not get the range you want for a sniper rifle that fires 500fps with an extra heavy bb. I would estimate the 0.45gm will get you about 60-70 meters while a 0.36-0.4gm bb will get you about 70-80 meters. A 0.45gm is too heavy for 500fps even though the rifle will fire it and it will be straight, it just won't have the range. The reason for this is because the heavier bb will take longer to get to it's long distance target and by the time it reaches the target, the back spin would have run out. So then you would need to apply more backspin and this will then create more of an ark which is not really optimal. We want trajectory that is as straight as possible. (By the way, it will never be perfectly straight)
So I like to use a bb that can make it to the target within the shortest time possible. Different rifles will have different energy rates and different optimum bb weights to get the bb to the target the fastest. The lower the energy rate, the lower the bb weight while the higher the energy rate, the heavier the bb. This is opposite to what a lot of technicians say, which is, "just use the heaviest bb possible". Try firing a 0.45gm out of a 300fps gun and see how short it goes.
In saying this, the heavier the bb, the longer it will keep it's energy and backspin. But if a bb is too heavy for the energy that the rifle produces, then the backspin will run out before the bb reaches the long distance target while the middle weight bb will be pushed faster over the average of the distance. Now if a bb gets too light, then yes, it will be very fast initially but it will not keep the energy needed and it will fall short. So you need to match the bb weight to the energy that the rifle can produce as well make sure you can create good backspin.

I know I repeat this a lot but these are the bb weights I use with different fps rates. (NOTE: It does not matter what the rifle is, AEG, pistol or sniper, I still use these bb weights.)

330-370fps = 0.23-0.28gm
370-420fps = 0.28gm-0.30gm
420-450fps = 0.30gm-0.32gm
450-500fps = 0.32gm-0.36gm
500-540fps = 0.36gm-0.4gm
540fps upwards = 0.40gm-0.45gm
(This is an estimate and so you can go up or down a little in the weight but I would not change it too much)

So overall, the higher the fps/energy of your rifle, the heavier the bb you can use and the more the bb will be able to keep it's energy and backspin making it shoot further. High fps rifles are awesome.

 

I know I repeat this a lot but these are the bb weights I use with different fps rates. (NOTE: It does not matter what the rifle is, AEG, pistol or sniper, I still use these bb weights.)

330-370fps = 0.23-0.28gm
370-420fps = 0.28gm-0.30gm
420-450fps = 0.30gm-0.32gm
450-500fps = 0.32gm-0.36gm
500-540fps = 0.36gm-0.4gm
540fps upwards = 0.40gm-0.45gm
(This is an estimate and so you can go up or down a little in the weight but I would not change it too much)

I have been doing this for a while now. Though my own scale is a little different, its close enough.

 

You able to let us know what your scale is? I would be interested. Cheers

 

Also keep joule creep in mind when picking a bb weight. That will put your actual muzzle energy just a tad higher too :yup:

But yeah, I like really heavy bb's, they carry their momentum further and in theory get better range, but they do require a really good hopup if you want to use them at low fps. Example: I've used .3 at 295 fps (with .2) in conjunction with an R-hop, and with some overhold, this reaches out and hits people at up to 200' (60 meters). Which is crazy for a system shooting around 0.8 J. This was done without joule creep by the way.

That being said, the system performed very similarly with .28, because the R-hop really struggles to lift the heavy bb and actually slows the bb down when applying that much backspin.

 

AEG (stock)
300-350 .25g
350-400 .28g
400-420 .30g
420-450 .32g

Gas (Stock)
300-360 .28g
360-420 .32g
420-500 .36g-.4g
500+ .43 and heavier.

Spring(stock)
330-370 -.28
370-450 .28- .32
450-510 .32-.36
510-550 .36-.43
550+ .43 and up

Modified guns have a different scale based on the barrel, but that is only small changes.

If you want to know what guns I used to test all of this I can post that too.

 

Now hold yer wagon, man...I think those numbers that Plazmaburn put up are if the rifle is shooting those figures with a .2g, then it will lift the corresponding weights. For example, my L96 fires 460 and change on a .2g BB, and I use .36's on the field (now firing in the mid 300 zone). Which makes his numbers spot on. For example, my aeg's all fire between 405 and 415 on a .2, and yes I do use 30's with great success.

Did I get this right Plazmaburn?

 

Now hold yer wagon, man...I think those numbers that Plazmaburn put up are if the rifle is shooting those figures with a .2g, then it will lift the corresponding weights. For example, my L96 fires 460 and change on a .2g BB, and I use .36's on the field (now firing in the mid 300 zone). Which makes his numbers spot on. For example, my aeg's all fire between 405 and 415 on a .2, and yes I do use 30's with great success.

Did I get this right Plazmaburn?

Pretty much. Lately I have been running nothing but field rental guns, primarily the new version Valken Battle Machines, ASG Proline Armalite M15 (some version of it), and G&G Combat machines.

Now look at the power levels of those rifles. I ran .28g on all of those with great success. People need to get on board with using heavier weight bbs that are high quality. Your gun will thank you for it.

 

The CM was well past new. Last leg to be precise, I killed it during the last game. Wrecked something, dunno yet have not had a chance to open it to fix it.

 

You gotta love a Combat Machine! They get no respect, but boy do they go and go. In fact, I think my next build will be the trusty CM16. Why not...I built one a couple of years ago and tagging guys at 250' with a CM was such a hoot. It weighed nothing, took piles of abuse, in fact, I miss that little guy...

 

You gotta love a Combat Machine! They get no love, but boy do they go and go. In fact, I think my next build will be the trusty CM16. Why not...I built one a couple of years ago and tagging guys at 250' with a CM was such a hoot. It weighed nothing, took piles of abuse, in fact, I miss that little guy...

Yeah, they can for sure take some abuse. This one is one of the first field rentals. As far as I know, no one has ever opened it. So I am fairly confident a nightmare-ish sight is awaiting me once I open it up. Judging by how it was acting during the day, I am sure its the trigger contacts.

 

And I can lift 0.45g fine, so does this mean that theoretically I can use 0.43g and should see similar range to the 0.4g?

I use as a rule of thumb:

If you can overhop it, then you can lift it well enough to use it effectively.

This has so far checked out for everything I've built :hehe:

 

I use as a rule of thumb:
If you can overhop it, then you can lift it well enough to use it effectively.

I go by the same rule and in the case of my BAR10 also how loud/quiet it is.

Ive also been succesful running .32s in a second hand G&G CM with very little modding (regular flat-hop and with a shortened inner/outter barrel), its not a great distance but the bb goes where i want it to go with very little deviation to roughly the same distance it would go with a lighter weight.

 

.43 at 250 fps?

What setup are you running???

What's the muzzle velocity with the .43 then? Way too low I reckon. How can you overhop it at such low velocity? The backspin required would be crazy!

Unless you mean 250 fps measured with said .43 bb. I've never tried that, but I have tried 280 fps with .4 (roughly 1.5 J), and this still reached out to 80 meters with a little lobbing. The same amount of lobbing you'd use to get .4 out to 90 meters at 2.5 J.

I've also tried .3 at 295 fps (with .2, so 0.83 J, 244 fps with .3), which reached out to 60 meters with a little overhold.

The rule of thumb I just described has always held up for me so far. Because even though the heavier bb travels slower at first, it eventually overtakes the lighter bb because it doesn't lose as much velocity over time. Because of this, it flies for a longer amount of time, because the magnus force stays more constant. And since it loses less velocity, its average velocity is very similar (because the lighter bb always decellerates quicker because it has less inertia). This means, compared to the lighter bb, its total distance travelled is greater because its velocity is about the same but its travel time is longer.

That's the theory, and in all my builds so far it has checked out. Assuming there is no reverse joule creep, of course :yup:

 

Sorry, not sure what the setup for the M4 was. I did it a couple of years back but I am pretty sure the bucking would have been a maple
In saying this is was only just over hopping enough so that I could lessen it a notch and the bb was flying reasonably straight. So I could not massively overhop and it did not get range.

even though the heavier bb travels slower at first, it eventually overtakes the lighter bb because it doesn't lose as much velocity over time.

This is the important factor. At what point does a heavy bb become too slow that it does not make it to the target because it runs out of backspin?

 

Well, this is kind of trying to take the sniping out of sniping.

Each ammo has it's pros and cons, and the ideal bb weight depends on each gun setup... and the mission of the day.

Heavier bbs will generally carry a little more energy (creep) and conserve it a little better. So as long as your gun is able to hop it, they will fly further.

Lighter bbs are faster to hit the target (until certain distances, when they get overtaken by the extra energy of heavier bbs). So there's less chance of people dodging your shots (intentionally or not) at somewhat shorter distances. They are also more susceptible to wind, but every bb is.

So the ideal weight depends on the situation. Playing in a MOUT environment? lighter might help to take out those peekers and runners. Windy out there? heavier will do. Got a really cold day and your gun is not hopping quite right? the lighter might be better. A somewhat static game with long range shots? go heavier.

You might find that anything between .32 and .45 will work great with your 500 FPS setup, as long as your gun is able to hop them. But you should take the time to practice with each one, both in test firing as in-game, to gain enough experience. As I said, don't take the sniping out of sniping.

 

Sorry, not sure what the setup for the M4 was. I did it a couple of years back but I am pretty sure the bucking would have been a maple
In saying this is was only just over hopping enough so that I could lessen it a notch and the bb was flying reasonably straight. So I could not massively overhop and it did not get range

That's the explanation then, when I said overhop, I really meant sending it sky-high. If you can only barely get it to go up, then you're applying so much force that the bb's energy is severely lessened, almost to the point of a pinch jam. This will indeed reduce range.

Temperature is also a thing like Dimitri says. I've had cold days, with a very worn and weak spring down to 420 fps, and it just wouldn't lift a .4 quite enough. So I switched to .36 and I was able to lift those properly, which increased the muzzle energy of the bb, which allowed them to shoot further.

So yes, different cases require different bb's, but I mostly tune a gun to a certain bb that the hopup can handle comfortably, which means it can also handle in cold days. .4 is a good weight in my opinion because it is easier to lift than .45 so you can use it at 500 fps comfortably but also easily outranges 1 J AEGs.

This is the important factor. At what point does a heavy bb become too slow that it does not make it to the target because it runs out of backspin?

For snipers (2+ J), I use another rule of thumb: 350+ fps with that bb weight is good enough. If it drops below 350 with the heavyweight of choice, add more joule creep or switch to one class lighter (e.g. .4 instead of .43).

Also works well for me

For sub-1J builds, you can go lower of course because the velocity is already lower anyway. 250+ fps is good there generally. A .3 at 250 fps (300 with .2) will still reach out to 60 meters with some lobbing

 

Question- with .40 I get 2.98J 400fps, on 510mm barrel, autobot bucking. With .46 i get 3.07J and like 375fps. Is it better to use 40? Or is there better to switch to .36 weight, and get little more on fps. J limit we have for spring sniper is 3.3j. Hop lifts 46 with no problem, and there is still room left on hop dial. Spring is stock, I know that with .02 I get around 600fps.

 

Bit of a necro, I'd check the dates before you post.

FPS doesn't really matter for time to target, as usually heavy BBs gets there faster due to wind resistance. Def use .46g, but if you can get .48g or .50g I'd do that

 

Duh, didn't even notice the date 🤦‍♂️ hm, interesting, I'm using 46. Regularly, but man, these 46. It looks like they need a day to get there to the target through the scope..