Load recommendations for 303 with cast boolit

[DaveC]

I have some gas checked 165g hard cast boolits ready to make up some 303 rounds, but I cant seem to find a load.

Any recommendations?

Dave

[TALL]

What powder you using?

[Spr826]

I have used cast in a .303 but mine were 215 gr., with them I was using 34gr of N140 ideally you want the bullet running at 1800-2000 fps, I also used 14 gr of N110 which is a nice mild 100yd plinking round.
These were safe in all of my rifles.
Have you tried asking on the cast boolit forum ?.

[DaveC]

I have Bullseye, IMR4064 and H414 in the cupboard, which I doubt will be any use so open to suggestions...

[DaveC]

I have used cast in a .303 but mine were 215 gr., with them I was using 34gr of N140 ideally you want the bullet running at 1800-2000 fps, I also used 14 gr of N110 which is a nice mild 100yd plinking round.
These were safe in all of my rifles.
Have you tried asking on the cast boolit forum ?.

when you use such small amounts of powder do you use any sort of filler?

Not asked on the cast boolit forum yet.

[amc577]

10 gns of GM3.....Unique.....10 gns Red Dot Green Dot....Or use the powder developed for the 303...3031...Make sure the cast are fat enough...the bore on the 303 is very variable......312 normal but can go to 315.

Lyman book for 150gn cast

Red Dot 10gns to 13 gns
Unique 11gns to15 gns
700x 10 gns to13 gns

Vit N110 will also work 14gns

Anything which shoots cast in the 308 will probably work with 303.

amc577

[lightning22]

I'm currently running 16g of Alliant 2400 behind a Lee 185gn powdercoated bullet. That's giving me somewhere around 1600fps and 4moa at 100m. Recoil is a lot more pleasant than factory FMJ loads with no mini fireball every time you pull the trigger either.

[Spr826]

when you use such small amounts of powder do you use any sort of filler?

Not asked on the cast boolit forum yet.

No I never used any fillers, no signs of pressure what so ever, I have also used black powder but that was for my martini Enfield

[amc577]

I rec the website "lever action performance studies"....the writers spent 10 years trialling light loads in big calibres..30-06 etc.
The technical stuff explains the different types of powder combustion ....what is safe and what is not safe.
Specifically aimed at cowboy action shooters using light loads in big cartridges. Anyone who downloads should read it.

amc577

[Marlin Mans Son]

Dave, I could suggest loads, but need to know a few things first.

A cast-bullet used in nitro loads, ideally needs to be 0.002" over the widest measurement of your bore, something traditionally found by 'slugging' - gently tapping a soft lead ball that is a a bit wider than your bore, using a brass or aluminium rod. When the ball pops out, take the widest measurement (not easy with odd number groove but try anyway) then add 0.002" - that's the sizing you should have on the cast bullet.

303's I cast for, have varied requiring depending on bore wear, from a 0.312" size up to 0.318" for some of the older, more worn bores (that really shine again with a well-fit cast bullet).

A hard cast bullet, however well made, if undersized, will just rattle down the bore and disappoint.