Just modified C309-170-F to plain base How fast should I push

[zomby woof]

I just modified a mold I had lying around and never used. I made it a plain base from a GC. I just cast a test lot of 60/40 WW/Lino + 1% Tin and WQ. They came out very hard. How fast should I push these through my '03 Springfield? I will be lubing with LLA. I have 2400, 4198. red dot, 4895 around. Thanks.

[Leftoverdj]

Your mileage may vary, but I find easy to get accuracy with plain base bullets at 1200 fps, possible to 1400 fps, and a pipe dream past 1600 fps.

[lifeon2]

I think it would depend on how hard you cast the boolit, water dropped , air cooled, etc
harder = faster

[Bret4207]

I think it would depend on how hard you cast the boolit, water dropped , air cooled, etc
harder = faster

No, no, no, no, no, no, a thousand times NO! First rule of castboolit shooting- hardness means NOTHING without proper fit and even then hardness is relative and the "hardness" varies with alloy composition. You can have 3 different boolit alloys all measuring 15 Bhn, for instance, and all 3 will have different limitations. Same for fit, only more so. The first thing you need to do if FORGET THE AD HYPE!!! Hardness means NOTHING wiithout fit. What does your barrel slug? What do your boolits measure? What does the nose measure? Have you cleaned the barrel of all fouling? What kind of throat do you have? Is this a pitted or worn barrel or a fresh one?

As a general rule I'd see what my boolits dropped at straight from the mould, IOW- without sizing. If they look "fat enough" you can simply try tumble lubing in Mule Snot or JPW and try something around 10 gr Red Dot and work up from there, or 12 gr 2400 and work up.

I don't mean to be raining on anyone's parade, but if you read the posts and stickies here and are still clinging to the "hard boolits are always better" mindset then you aren't getting the idea. Straight WW alloy with maybe a little tin and a clean mould are all you need, even with plain base, up to maybe 1400 fps depending on what your rifle likes. A nice smooth barrel may take you to 16-1700 and a GC can take you past 2200 fps with straight WW in some cartridges. The big thing isn't "hardness", it's fit. If you want a sure recipe for a leaded barrel shoot those HARD boolits in a barrel that needs boolits .002 fatter, and push them hard! Fit comes first guys. Get a boolit that fits and start working up from there.

[Ben]

I too am interested in shooting plain based .30 cal bullets.
I've plain based the same Lee .30 cal 170 gr. mold.
Ditto on everything that Bret4207 has said above about fit and hardness ! !

Have you read this thread :

http://castboolits.gunloads.com/showthread.php?t=55235

[jrayborn]

Would you be willing to explain how you modified the mold to make a plain base? I suspect you must have bored the gas check portion larger to make it a driving band, correct? An other method I can see would be milling the mold shorter to remove that portion that has the gas check.

Please share!!

Jon

[zomby woof]

We machined out the GC to .309".

[Ben]

jrayborn:

If that question is directed to me ? ?, Here are photos showing how I did mine in the link below .

Ben

http://castboolits.gunloads.com/showthread.php?t=22102

Here is a group that I fired at 50 yards with the Lee 200 gr. RN in a 308 Win. , 1903-A3 target rifle. Lyman 48 rear, 17 -A front sight :

http://img.photobucket.com/albums/v494/haysb/12%2018%2007%20Range%20trip/PICT0007.jpg