Best hardware orientation to avoid loosening?

I've about concluded that the pictures are in need of a 90-deg rotation to the right to make sense. Then it would show the frame in upright position, and that LAGeek is holding the bolt toward the upper portion of the A-frame; and that angle gusset piece is between the top cross member and the vertical A-frame.

With that as a basis, the thing I would now suggest is the shaft of the eye-bolt should be vertical, so as to be in-line with the tension exerted on it by the swing. The upper cross member being set at a 45-deg angle complicates the problem since it presents a corner on the top edge, rather than a flat upper surface to bear the load of the bolts.

I'd consider doing one of these things:
I. cut a flat, horizontal. surface into the cross member , that is perpendicular to the bolt shaft. Make it large enough to accommodate a large flat washer under the nuts that hold the bolt.
II. cut a saddle that sits on top of the cross mender at the bolt hole zone, and provides the horizontal surface that is perpendicular to the bolt. Use the flat washer and nuts on top of that added saddle.

You could even combine these ideas:
Cut the notch in the beam edge to make the horizontal surface. Then add a spacer block of wood that is cut to fit that newly formed horizontal surface. The bolt then goes through the beam, and through that added block, and the washer and nuts combo sits on top of that. The spacer black could be replaced without compromising the beam, if the need arose.

(I hope there is at least a little chance that what I have written makes sense to at least a few readers. It's clear to me!)

I ve about concluded that the pictures are in need of a 90-deg rotation to the right to make sense. Then it would show the frame in upright position- jimintx

Click to expand...

OK. thanks, Jim. I think I get the concept now. Here's a sketch of what I think the OP has built. I agree that the eye bolt should be installed in the top beam, not the angled brace-even if the swing is a little too wide and the chain has to angle out a little to catch the swing.

Drilling into the corner of the beam should not be difficult with a V-block drill guide.

Thank you so much for the reply's everyone! I'm sorry I haven't been able to provide the requested photos or more clearly explain the situation. This is an insane week and I haven't had time to respond to you guys after throwing the post up as fast as I could.
You are correct about the photo rotation and reiterated my concern well. I was pretty sure that wouldn't be the best route, but was curious to see if it was possible to get away with it.
Moving the bolt to the top beam was my original plan, until real life didn't match perfectly with SketchUp. I found doing so allows the bench to move side to side too freely, as well as puts a lot of inward pulling stress on the frame, especially the armrests.
Cutting a flat cutout at a 45 to hold the bolt is what I've already done to counter sink all the carriage bolts that are in the frame so would be easy. I thought of putting the eye through both the top beam and brace as well, but I bought my hardware for going through just the top beam so it's too short. We only go into town once a month or less, so I'm stuck with these bolts.
Here's my SketchUp plan of the completed swing. Due to the size of my shop and the glue ups in progress, I can't have the A-frame and swing together yet.

Thank you all so much for your input, though I've been doing this for about 6 years now, I've always had to depend on asking those more knowledgeable than me for advice. I've never had anyone to teach me this wonderful craft, and really appreciate you all being so willing to share your experience.