It is interesting how opinions vary so much here is my .02
I have been shooting the Swift longer than any other varmint caliber that I own, on my first swift I tried about every powder on the market in the approximate burn rate. From bbassi's powder list I would have never tried IMR4198,H335 or H332 for that reason, from his list the only powder I really had success with was IMR4831. it has shot very accurate over the years in several of my swifts with 55gr BT's or BK's not the fastest velocity but good accuracy. one powder that some on this thread love is H380 ????????????????? this boggles my mind, in my testing it proved to be the most temp sensitive powder I have ever used, I have since given it away or used it in the garden with the last of my H335.
Over the years one powder has stood out in my rifles.....H414/W760 some say that it is temp sensitive, it may be but not in the realm of H380. the only time it would be a factor is if I were shooting it in 100 degree weather, in 100 degrees I will shoot a 222 or something that will create less barrel heat.
I will never use Winchester brass in my swift again, The Norma brass in this chambering is night and day better and will last the life of the barrel.
My pet load for several rifles is 55gr Ballistic Tips, Norma brass, Fed210 primers and H414/W760.
One thing that TOM mentioned is bullet seating depth, In every swift I have ever owned they love to have the bullet slightly jammed in the rifling or slightly off, you seat your bullets OAL to what the reloading books say and your accuracy will go away significantly .
