There are a couple of points to remember about IM injections. Generally, the deeper, the better (especially with high volumes). There's more bloodflow to muscle tissue than subq tissue. That's the reason why absorption is always faster with IM than subq.
Depositing the liquid deep also helps prevent oil abcesses. While these might not be toxic, they're not helping us maintain even blood levels because subq oil is absorbed more slowly, which delays the de-esterification, binding, etc. Higher volumes of oil will increase the abcess risk because there's only so many cc's the site can handle especially if you're barely getting the pin into the muscle. Also, if the oil is not very thick, it tends to move around a bit once in the tissue.
I once shot some cheap Stens (2cc's) with a 1" pin and felt some of the oil drain out of my lateralis and pool at the top of my patella (there was a visible pool). Gravity works! The oil in Sten is very, very thin. That combined with the 2cc volume and the shallow depth caused the problem. The oil was eventually absorbed after about a week, but the point is the testosterones suspended in the oil were useless until the oil was absorbed.
With my quads, I've been shooting 1cc injects with 1" pins and I always bury them. Anything over 1cc, I always use a 1.5" pin and bury that as well.