It is a lot of factors to take into consideration, JCBgm had the basics covered. When you get into 15y sizes then it starts to be very important of how strong the steel is and how they build the bucket. It's better to have a bucket that is 1y too small instead of maybe on the spot or even 1y too big. That really hurt production and put a lot of stress on the machine.
At work we have an old 15y bucket that where built for our old Volvo L160, we had a hard time using it's full capacity, only when we had light woodchips we could fill it all the way. Then we stepped up a size to a new L180, and it handled the bucket great. Just ram into the pile and tilt back, full bucket each time. When we got our first L220 we got a new 17y with it. Bucket was from the same company, but even it was 2y more it was also a lot lighter. It was also close to a foot more narrow, but deeper and higher. We asked them how it could be bigger and lighter. Better steel was their answer. Well, after a month we saw the first cracks. To make it short, it was back to the factory twice and the result from them was to reinforce the whole back of the bucket. It ended up with that we cut off a foot in the front of the bucket, and after that it have worked great. We don't loose much capacity either because we always manage to fill it all the way up, it could even be a foot higher without hurting it much. It's the break out force that kills the bottom of the bucket.
We used our old L180 with the new 17y also, it handled it OK but we where back to the old issues with the L160. It had a hard time using the bucket to the max.
In the first video you can see how he uses a lot of time when he have trouble breaking out the chips on the barge. He was not a very experienced operator either. When you load from a high pile like that it's much easier to work from the sides of the pile and then cut down the high part in the middle with a quick stab with the bucket. Important to back up fast so the chips won't fall on the machine. This way you will always load out from loose material, and production will go up maybe 40%.
