My very first 45 ACP hand load was 5g of Red Dot behind a 225g cast RN. I shot that load for a couple years before switching to the H&G #68, 200g SWC and 5.2g of Red Dot. Both made major in early IPSC (would you believe on a Ballistic Pendulum).
Yes, the 4.0 Red Dot/200 H&G 68 cycle reliably in a very smooth cycling 80's vintage Wilson/Colt Master Grade. I don't know the overall length measurement - I just set the load to match WW Hardball Length.
I believe the 230gr LRN and 4.7 Red Dot load was mentioned in an article about training loads used at Jeff Cooper's Gunsite training facility - again back in the 80's.
The main bonus to using the H&G 68 for practice loads and the H&G 34 style bullets is load identification. Even if I dumped all my loaded ammo out in one pile, the loads could be sorted out without a doubt as to the load used.
That these two loads shoot to the same POA in my gun with my hold is just happy coincidence.
Frankly, I started using Red Dot back in the 80's when a local shop went out of business and I bought two eight pound kegs very cheaply. It worked out very well and I have stayed with Red Dot since for .45 Acp, .38 Special, and 12 bore target loads.