Joel, you would likely get more information if you posted the make and model of the rifle you intend to use these loads in.
I'm saying this because I know of a local nimrod who blew the top of his M38 Swede receiver ring off his rifle last weekend.
He went onto a site which gave "HOT LOADS for the 6.5x55 Swede" and without reading any of the caveats, proceeded to load up ten rounds to take to the range for testing. First shot "Kaboom"
He didn't get hurt, other than his pride, especially when we went onto the site together and his rifle model/make was listed very clearly as one not to even consider shooting any of the loads listed.
His rifle is of course a paper weight as is the low end Leupold scope, which has a bit of a bend at the turret module.
Now that caveat aside, I'm going to assume you have a modern/strong action and give you a load I've recently been playing with, to see if I can find a decent accuracy node.
I did try Hornady #26110 GMX, but my Tikka T3, which normally isn't fussy, will not shoot them well, with any powder I tried.
So, I've moved onto the Barnes TTSX 120 grain bullets, which are very close in length, bearing surface to the Hornady SST 140 grain bullets.
In my T3, H4831 or IMR7828 gave me the best results with the 140 grain bullets, so IMHO they were an obvious choice for a bullet with similar bearing surface(friction) and length, even if it is lighter in weight.
51.0 grains of IMR7828 were about all I could squeeze into the case before compressing it too much, with the 120 TTSX bullet seated to fit in the magazine. Results have been good. 3000+fps, when comparing bullet drop from 100-300yds and 1moa accuracy is norm.
This is a good load with very consistent results so far.
H4831 results were OK but, velocities were slower and pressures showed before they could be brought up.
I haven't tried this load yet, but because I lucked into a shootable quantity of H100V which could be considered to be a "ball" type IMR4831 or RL19, it may work better. It will be 45.0 grains of H100V, over CCI250 primers, under TTSX 120 grain bullets, in Lapua cases. I'm hoping this will retain or exceed the 3000fps achieved above and with slightly better accuracy.
I can live with 1moa, without worry, but this rifle is capable of better, if I do my part and the load is consistent, with enough tweaking.
Even though it's been around for quite a while, I'm not familiar enough with H100V to be able to predict its parameters, without some more due diligence on my part, in my rifles. It's very similar all around to H450, long discontinued. Maybe a resurrection???
My 280 Remington, loves H100V, as does the 270 Winchester, both with 120 grain TTSX bullets.
I wasn't a fan of "monolithic" bullets, mostly because I was trying to apply rules for cup and core bullets into the equations. They're different, but similar and performance will vary greatly between rifles.
I have two each, 280 Rem/270 Winchesters, all in good quality receivers/stocks and excellent barrels as far as smoothness/consistent diameters/weight goes. Both of the 280 chambered rifles, shoot the TTSX bullets very well. The 270s, one is a custom, built by myself and it really likes the Barne's TTSX, the other is a Kimber 84L Mountain rifle with a light barrel and it won't shoot them nearly as well as the other three rifles.
So, no matter how fast you get your rifle to shoot these very good bullets, the specific rifle may not shoot them well, for reasons unto itself.
