I am interested in loading some reduced 458 Lott loads using cast bullets. Should there be any difficulty using the Lyman cast bullet handbook info for the 458 win mag assuming I use the same bullets? I notice that the 45/70 data recommends the use of 1/4" dacron wads with reduced loads, but the 458 Win Mag data does not for loads of similar velocities and bullet weight. I am a bit leery of position sensitivity with smaller powder charges in the big Lott case. Should I use 1/4" dacron wads with small charges of unique, 2400, or IMR 4227? I find it odd that the Lyman 458 Win Mag cast bullet data does not recommend them. With the Lott case being that much longer, I need some experienced big bore shooters to voice their opinions. I am shooting cast 385 g GC bullets, and cast 500 g PB bullets. Any thoughts?
elee

Have you looked into Accurate Powder's 5744? Made for use in reduced loads without the need for a filler. If you can't find data for the Lott, just send them a request for data, they have been very helpful in the past when I did so.

Welcom mr Lee,
485 gr LFP 13 gr Trail Boss 860 fps, max 19 gr for 962 fps. 27,200 CUP
300 gr LFP 19 gr for 1187 fps. max 23 gr for 1282 fps 13,200 CUP
You didn’t say what velocity you were shooting for. I plan on trying Trail Boss as it is made for cast bullet loading and is verrey bulky. I got these loads from Hodgdon’s web site. I don’t think there would be enough difference between the 458 and the lott to be noticed. Perhaps a slight reduction in velocity that you would need a coronagraph to tell.
Bill

Here is what I got from a Ruger 77 express using 430gr GC and 5744 powder. 215 primers were used w/ all loads. 41gr-5744 @ 1663f/s w/ extreme spreads of 32f/s and sd of13. 45gr-5744 @1768f/s,.extreme spread of 28f/s and sd of12. 47gr.-5744=1775f/s, es=25f/s and sd of 12. Really fun to shoot and very accurate. Dr.C

My plinking load:

405gr Rem SP
68.0gr IMR-4895
Fed 215 primer
Hornady brass
3.53" oal
2112fps/24" barrel

Keith