Using 240 grain data for 245 grain?

[Pat73]

Good evening

I have found a cast bullets maket in Canada which sell 44 caliber flat base 245 grain Keith bullets.

I have the Lyman 4th edition cast bullets book, but i only have Blue dot, IMR 4227 and W296. I would like to use my other powder who are Winchester 244 and 572 which gave me excellent results with 240 grains swc bevel base.

The reason i want to try flat base is to prevent gas cutting and the light leading past the forcing cone.

I know you can swap heavier for lighter bullets, but can this be done for 5 grains difference?

I don't want to harme myself or other at the gun club.

Thank you.

 

[.308 Norma]

I know you can swap heavier for lighter bullets, but can this be done for 5 grains difference?

I don't want to harme myself or other at the gun club.

As always, "start low and work up."
I'd drop my powder charges back a little until I saw how the new bullets are going to work out. There might be more differences between the 240gr bullets you were using and the 245gr bullets you're planning on using than just "5 grains."
For one thing, the crimp grooves could be in different locations. So you might be seating the new bullets deeper into your cases, which could (would) increase pressures.
A 44 Mag, right? I use a lot of 245gr flat base "Keith" style cast bullets in my own 44 Mags.

 

[Pat73]

How low? Like 2% less than a starting load from 240 grains?

On the Hodgdon website, the starting load is 9.5 grain for 240 grain lswc.

I never attempted this and always had follow strict load data.

 

[N555]

Faster powder like unique, universal, HP38 might help too.

 

[CoalCrackerAl]

If you can find a copy of lymans 3rd. It has data the 4th don't have,

 

[.308 Norma]

How low? Like 2% less than a starting load from 240 grains?

On the Hodgdon website, the starting load is 9.5 grain for 240 grain lswc.

I never attempted this and always had follow strict load data.

Sorry, I didn't mean to confuse you. There's plenty of load data out there for 245gr Keith style SWCs.
Are the Lyman 4th edition cast bullets book and the Hodgdon website the only two places you've looked? My own Lyman 4th edition lists a lot of loads for the Lyman 429421 (a 245gr Keith style SWC) when used in the 44 Special and the 44 Magnum. But then again, you haven't stated what cartridge you're trying to load for yet.

 

[reddog81]

I wouldn’t worry about 5 grain difference for 240 vs 245 assuming similar bullets. The alloy used could be the difference. 5 grains in something like 32 ACP could matter.

As long as you aren’t using loads near max you’ll never notice the difference.

 

[GeoDudeFlorida]

Sorry, I didn't mean to confuse you. There's plenty of load data out there for 245gr Keith style SWCs.
Are the Lyman 4th edition cast bullets book and the Hodgdon website the only two places you've looked? My own Lyman 4th edition lists a lot of loads for the Lyman 429421 (a 245gr Keith style SWC) when used in the 44 Special and the 44 Magnum. But then again, you haven't stated what cartridge you're trying to load for yet.

In the screenshot he posted it shows a trim length of 1.280”. That makes it a .44Magnum.

 

[AJC1]

Start at start and no problem with using 240 data. The weight difference is less than allowed powder variation.

 

[Pat73]

Sorry, I didn't mean to confuse you. There's plenty of load data out there for 245gr Keith style SWCs.
Are the Lyman 4th edition cast bullets book and the Hodgdon website the only two places you've looked? My own Lyman 4th edition lists a lot of loads for the Lyman 429421 (a 245gr Keith style SWC) when used in the 44 Special and the 44 Magnum. But then again, you haven't stated what cartridge you're trying to load for yet.

I am sorry. I want t load 44 magnum using Starline brass with Winchester Large pistol primer. I would like to use this ammo for target and hunting.

 

[Pat73]

I am using .430 swc bb 240 grain right now. BHN is 19.

The bullet i want to try is 245 grain Keith bullet flat base sized .430 (but can be cast unsized). BHN 20

The more i read about cast bullet the more i realize fit is king. Bb bullets leave some light lead deposite. So thats why i want to try unsized flat base bullet. I hope it will solve gas cutting and help the bullet to obturate.

Chore boy wrap arround a brush help remove the lead, but if i can avoid this task and just clean the gun with just gun solvent that would be great.