Start working more from a crouch. I'm not saying you have to be as low as they are, but more of an MMA striking style posture. Second, work to establish inside control with your hands. Look for the thai plum, it's actually a fantastic way to prevent them from firing a shot.
Once you've silenced their gat, then you want to start thinking kizushi. Start checking your foot work for your Judo. Not knowing your experience levels in Judo, I'm going to assume you work primarily from a neutral stance, which is OK. Just not OK for good wrestlers. So let me give you a good example of some better footwork variations that I have found success with. Again, we're talking about having decent control of the inside, or having a nice thai plum with some of these. So if you're attacking O Uchi Gari with your right leg then break his posture, and start driving the school bus to your right. Remember, it's a school bus, it's big, it's yellow, and it's a bitch, so drop some muscle and manhandle her. Now, bring your left leg right, you want to place it so it is centered between your opponents left and right legs. You're not bringing it IN so much, just centering it between their legs but still maintaing the current distance away from his legs that it was already at. This is going to massively open up your attack with the right leg. Remember, you've already established inside control, applied kizushi by driving the school bus, now you've adjusted your left foot, allowing your right foot to really get a nice, deep penetrating Gari.
Ok so now that's one attack. Now let's say you don't feel comfortable attacking, but you've already established the inside control, and maybe even brought the left leg to center, from here, you can actually do a squat (yes a physical squat, so practice), drop your thai plum to their rib-cage (or attack a body-lock if you can wrap around enough), and then you can hit a ura nage. This level-change ura nage works especially well if they are pushing into you. Now here's a tricky part though, I want you to practice your footwork. Bring your left leg over, and then squat grabbing the ura nage, notice how you won't be able to go straight back with him. Because of how your feet are, you're going to need to really add a twist into your torso, do this by looking over your left shoulder while you throw. This will help you get enough rotational energy during the throw to make sure he lands to your side and not directly on top of you.
Now you can also use the same principle of that Ura Nage attack, and use it with a O Goshi. Bring the left leg center, when they start to push back, just change levels, dive that left hand nice and deep while you move into what is more or less a standard O Goshi just...lower. Of course, the Tai Otoshi is also an option if you prefer that to the O Gosh.
Now let's go back to the thai plum, because I really love the thai plum in nogi. So you're driving that school bus to the right, and what you're waiting for is for him to take a step with what would be his left leg. As soon as he does, go for an Uchi Mata, or a hane goshi which is actually made for this type of throw setup. The Uchi Mata may be stepped over, the Hane Goshi when done with the sharp angle we have just created, is going to be much harder for them to try and step over or for them to back their hips up away from. The Hane Goshi is kind of like Cee Lo Green, "Come On, Who Do You, Who Do You, Who Do You Think You Are", it's entire purpose is to shut them down for even THINKING they could step over your hip throw. Now let's say you force them to take that step or just before they take that step, but you don't feel comfortable with the Uchi Mata or Hane Goshi, from here, use the Sasae Tsurikomi attacking with your right leg blocking his left leg. You might have to turn it into a Sasae Halfway-stretched-out-on-the-floor, but as long as you block the forward motion, he's going to go flying with enough practice.
BUT Merciless, what if he doesn't give me inside control? You mean what if he's not a dumbass? Well, things are harder of course. But let's go over some options from here.
With us not controlling as much of the center as we'd like, we have to be more wary of the shot. He's a damn revolver right, he can fire off from mid-range, long-range, and way too close and probably without jamming. So what we want to do is start circling, fighting to keep our lead left leg to the outside of his lead right leg. Keeping him at the end of our range like this, and keeping him from sighting in on us, is going to allow us to get a good hard sprawl when he does shoot. Otherwise, we're going to have killer issues with being put on our back. Odds are, if you fight to keep that left lead leg outside, while working distance with your hands, he's going to have a hell of a time shooting in deep enough to blast you without your sprawl smashing and turning him down.
Once you've established ways to defeat a shot, then you can start working arm drags mixed with De Ashi Barai, Sasae's, O Uchi Gari's, O Guruma's, NoGi Sode Tsurikome Goshi's, and O Soto Gari's (takes a lot of turning and dragging to get in deep enough for the O Soto Gari, lots of rehearsed stepping practice). If they ever square up and come straight at you from the front, Tomoe Nage/Sumi Gaeshi.
Now if he's real stubborn and doesn't want us to arm-drag? Then let's add in an explosive, highly dynamic Russian Two on One Throw. As demonstrated here at the 1:00 minute mark.
https://www.youtube.com/watch?v=rvE9BtyF8DM
(I hate this guy's grip though, just grab the top of his wrist with your right hand, put his bicep into your left armpit, clamp down, take your left hand around his forearm like a snake, and monkey grip YOUR right wrist, so much easier).
If they do double leg you, check out Jose Aldo's work on fighting in reverse when being taken down. You need to start pushing down on the head and freeing the hips immediately, not waiting until you hit the mat.
This should give you some good stuff to play around with, mostly you just have to get them moving and keep their feet moving in circles. Once you do that, you'll see guillotine opportunities open up immensely also. Just don't let them set their feet up, setting their feet up is like them cocking the trigger.
A really, really good drill, is get some guys who know you want to practice arm-drags, and then just arm-drag them until you feel a throw, throw, then the next guy is right there in your face fighting arm-drags with you, no pause. If you have enough guys and trust each other with the right speed, you get all dizzy it is AWESOME.