I just shot my third deer of the season. It was a nice hunt. The weather was bearable, I saw several deer, the RUT is on

and I made a clean kill on a doe.
My question is regarding my arrow penetration. I have a G5 bow that's set between 50 and 55 lbs. It's not a very quick bow, but it shoots well. I'm shooting Maxima Hunter 250's with 100 gr 3-blade Muzzys.
The first deer I shot with it, a buck last fall, was quartering away from me at about 20 yards. I shot him behind the shoulder up high and the arrow made it out on the far side in front of his leg, but didn't pass completely through. It was a very clean kill and he didn't go more than 50 yards.
The second deer that I shot this season was a doe, and I hit it a bit high. I didn't get hardly any penetration. I watched her run off with my arrow, and there was no blood to be found. The woods is open enough that we were able to walk the whole thing and we found nothing.
The deer I shot tonight was only about 7 yards from my stand. She was quartering away and I shot her just behind the shoulder up high. She jumped and kicked, and there was blood spraying before she hit the ground. She didn't go far, but this time too my arrow didn't pass clear through. It punctured the chest down low on the far side up in front of front shoulder. She was crashing before she'd gone more than 30 yards.
I want to stick my arrows in the ground on the other side of the deer. It's nice to be able to look at the blood on them to know what kind of shot I made, and they are a lot less likely to get broken off against trees when they aren't hanging out of the deer. I'm just wondering if I should drop down to a 90- or 75-grain Muzzy? Or should I keep shooting what I've got?
rw