Strut there certainly is 10 Rem HeviShot available. I kept a customer from buyinga box of it the other day, he picked up 10ga #6 HeviShot thinkin it was 12ga 3.5". We used to shoot the HeviShot before we got introed too the Nitro. The key too the HeviShot is it is REALLY prone to being easily overchoked. Most guys will tell you that 3" HeviShot patterns better than 3.5" that is true with tight tubes. But it's really a sign of overchoking. Drop back too a .665 or even better, something in the .670-.680 range and try that 3.5" HeviShot. HS is bad to donut ring when constricted to much. That is a sign of poor buffering and shotcup design. That is where Nitro Ray has them beat, he uses Winchester cups and special, small buffer. My father-in-law retired after 31 years from a U.S. contractor arsenal so he knows the ins and outs of loading and methods. He looked into Rays portable cement mixer that he uses to coat the HeviShot once he gets it. Ray wouldn't tell us what it was (proprietary mixture) but my father-in-law said he could tell it was a mixture with ALOT of graphite in it.

We also found that you should try both size loads offered in the Rem HeviShot. I believe they offer two weights in each load and our testing typically got better patterns with the lighter (like a 1 5/8 vs 17/8 oz offerings of the otherwise same load). Again I believe that to be a sign of choke restriction. Just make sure your tubes are approved for HeviShot. And if you aren't shooting very restrictive tubes (under .670) you shouldn't have a problem with just about any tube out there. Alot of guys are still hung up on the tightest of tight tubes right now, there are several .640s out now. Those are STRICTLY for lead loads. I haven't tried the new Federal or Winchester HeviShot copies but have heard from several that they REALLY liked the Winchester offerings.I have'nt heard of any Federal testers yet.

Good luck,
RA

ps
The last lead loads I shot were several years ago and after all my testing I found the Winchester Supreme copper plated 2oz # 5s were the best in the majority of my guns. But lead just "gives up" at around 50-55yds. The heavier materails like HeviShot and similar metals retain better energy plus you can drop down in pellet size to not only equal larger lead knockdown but also increase your pellet count. Pellet count and density is the real key IMHO. But getting all those pellets on target takes a lil time and testing. Several years ago I would've laughed in your face if you told me that someone could consistently use 7.5 size shot for turkeys. With Nitro you can. In fact the fellow who got me into all this shot stuff actually bought a 10g BPS and had Ray load him some all 7.5size 3oz (yep 3 OZs!!!) which just look like a swarm of mosquitos inside of 75 yds. I would'nt believe it if I had'nt seen it for my own eyes. AMAZING!!! And the pellet count is unbelievable with that load! Yet because it it made of HeviShot those 7.5s have the energy and knockdown of lead 6s.

pss
BPS yes you CAN get HeviShot in 10ga, just not in the new High Velocity HeviShot but I wouldn't let that stop me. Regular HeviShot has it all over lead and I recommend it heartily to those who aren't willing to pay for Nitros.