Cast performance advertises that their gas checked bullets are good to 3100fps before leading occurs. How fast have you guys loaded your cast bullets? I ask because was thinking about loading some .475 cast gas checked bullets to around 2800 fps.

How fast a cast bullet can be driven before it leads is not as simple as at certain speed a bullet will start leading.

The factors that contribute to leading are bullet size vs throat, the twist rate of the barrel, the peak pressure of the charge and the bullet alloy/hardness all have an effect on how fast you can push a cast bullet without leading.

I'd say in general, once you get past 2200 fps in a rifle, everything as to be just right to prevent leading.

Leading and accuracy are two different matters. A guarantee of 3100 fps without leading is not a guarantee that the load will hit a washtub at 50 yards.

So, if we were talking about say... a 175 gr 7mm pushed to 2800 in a 1 in 9 twist at 57kpsi as compared to the 375gr .475 in a 1 in 20 twist at the same speed with 47kpsi, the 7mm theoretically would lead the barrel before the .475 did because of tighter twist and higher pressure? And of course accuracy is a whole other can of worms...

I don't like cleaning a leaded barrel, so I keep velocity to 1850 fps or less, usually less. Actually, I never clean my cast bullet barrels. You'll be cleaning yours at least daily.

quote:

Originally posted by gixxer:
So, if we were talking about say... a 175 gr 7mm pushed to 2800 in a 1 in 9 twist at 57kpsi as compared to the 375gr .475 in a 1 in 20 twist at the same speed with 47kpsi, the 7mm theoretically would lead the barrel before the .475 did because of tighter twist and higher pressure? And of course accuracy is a whole other can of worms...

Yes

I'd also say that there are only a few folks that claim to get good accuracy past 2200 fps in rifles. Ancedotal reports also seem to imply that performance on game with cast bullets is best at a max of 2000-2200 fps. This is mostly related to bullet alloys and hardness. A cast bullet hard enough to be driven past 2200 fps will either act as a solid, or shatter. If you keep around 2000 fps, you can use a much softer alloy, one that will expand on game.

If you want to drive 375 gr to 2800 fps for use on game, look at a monometal expanding bullet, ala X bullet, or a bonded soft point.

The novelty of driving 375 gr @ 2800 fps will wear off fast enough that the cost savings of cast bullets will be a moot point. Load cast bullets between 1100 and 2000 fps. You'll grin like a little kid when you drive them subsonic. I load a 470 gr cast to 1100 fps in my 500 Jeffrey, and it is a right fun load.

I dont have chronograph so I dont check them all. Even without the chronie I am sure my .243 is the fastest and I have chronographed that one. It's around 2900 fps--very accurate and no leading. This is using FWFBL. It aint worth a darn on deer I learned the hard way.

Hey Carpetman,
I guess the fastest load I've had great luck with is either H-335 or Win 748 with Lyman 311041 hardened w/w in my 94 Black Shadow. Sure is accurate.

Paul, yes, I was looking at getting the best of both worlds, cheap bullets and a rifle with a better drop rate than a 45-70. Not a serious issue, since there are other pistol bullets out there that I can try that are not that expensive. And yes, the Barnes TSX is hwat I was gonna load if other optionss did not work out. I was going to load them in a .470 Mbogo...

I've been mixing up some fairly hard alloy melt with ww's range scrap, 95% tin lead-free solder and a handfull of magnum shotgun shot. Around 17 1/2 bhn. Most of my calibers that use gas checked rifle bullets are pretty good to around 2000-2100fps without much leading and fairly good accuracy.

Bill