Looking at a Hay Van Megaliner, but only because it's for sale nearby. I have a RAM 3500 SRW (Aisin transmission/6.7 HO).

Currently making 1,200lb, 5/5.5 round bales.

Looking mainly for moving out of the pastures (not for road hauls).

My knee jerk instinct is to go big (14 bales, dual), but I'm guessing it may be more efficient for a smaller 5-12 bale size for what I'm doing).

Any tips?

My preference is a 36' or 42' single line dump. I've considered the dual that would hold 14 big bales but I didn't think I would be gaining anything by the time I hauled multiple loads and had to use the skid steer or tractor to move hay from the dump site to keep dumping. With the single dump I can dump 260+ bales without having to move any hay out of my way to keep dumping. If I had a dual dump I don't think I could do more than 70-80 before I ran out of room. Other places I couldn't even do a fraction of that. If I need to haul 14 bales, I'll use my tandem dual flatbed.

I did quite a bit of research on this topic few years back and I contacted a fella I know that hauls a lot of hay each year and that is basically what he told me also. He said for moving out of the field single line dump all day. If he was hauling over 25 miles he used a flatbed trailer. I'm sure the dual line dump would be just as effective over 25 miles but he and I already both owned a tandem dual flatbed for hauling equipment.

I ended up buying a 36' Hay Toter brand trailer in 2023 only because I couldn't find a 42' in stock. One of these days I may trade up to the 42' but for now the 36' has worked pretty dang well even at only moving 7 big bales at a time. So easy to load quickly and keep moving. Wish I would've broke down and bought one sooner.

We run 5x6 bales on a single row hay trailer. It improved our efficiency by 6x getting hay out of the field. We usually bale 5-6k bales per year. The double row hay trailer is nice but some efficiency is lost when dumping them since they have to be re stacked.

Our trailer is probably the best purchase we've made in the last 5 years.

We pull ours with either an f350 or a Kodiak c4500.

The 4500 makes it a little easier to get turned to a good angle so we don't push too hard against the transmission.

How is the dual dump problematic? Can't you just dump one side, then turn around and dump in the same direction?

The dual dumps I've been around both dump at the same time. There is not a single side option that I've been around. Not saying it doesn't exist, I've just never seen one.

We have the dual dump, double cradle with 10k axles and the cradles are 40 feet long so with our 4x bales, we can haul 20 bales. Using our 3/4 ton gas pickups, we only load 16 bales, leaving the front of the trailer empty which balances the vast majority of the weight over the tandem dual trailer axles. We feed hay and sell the remainder and in our area, almost everyone sells 4x5 round bales as they are Much easier to load on big trailers.
We occasionally use a bigger truck or a row crop tractor with the dump trailer to haul 20 bales.

I think the brand is pride of the Prarie. A local neighbor bought one in 2008 and I helped him move hay with it. Called the next morning to the welding shop in N Kansas and had ours built that week. By far the dump trailers have been the best innovation since the first round baler arrived at our ranch in the 70s. Multiple companies make them now and I saw a new one on the yard at the Gooseneck factory in Bryan last month. I would recommend getting the 40 foot cradle, dual dump model as it hauls so much more and is much easier on your truck if you don't load the very front. We try to move all the hay baled the prior day the next morning before baling again around noon. Not needing a loader on the barn end of the haul is great and the hay we sell locally we just dump in front of the buyers barn. It usually rolls far enough that the second load can be dumped inside the first load.