I started shooting the cast bullet loads, I loaded 160 grain cast bullet from Penn Bullets with 13 grains of Green Dot, estimated MV of 1600fps. Accuracy was terrible, almost shotgun like and it was getting worse progressively. There was no leading when I looked through the back end but when I took it home to clean it, I found severe leading at the muzzle end.

I wonder what could be the problem? I'm not using a gas check (the bullet isn't designed for one) and the bullet was rated for 2000fps so I thought I was safe. Plus I always thought most leading happened from the chamber end.

I'm going to try again reducing the velocity to 1300 fps or less, maybe that will help.

Bullet was sized to .310 and the bore is .308

Did you clean the bore  of any and all copper fouling before using lead bullets?  Copper fouling can cause excessive leading.

Are you sure their was no lead anywhere else in the bore?  It's long and dark in their may have been hiding.

See here, notice how difficult leading can be to see.

http://www.reloadingtips.com/pages/leading-degrees.htm

How did you "Clean it"?  Removing lead is a bit different than remove powder and copper fouling.

When I shoot lead I clean with a bore brush wrapped in Chore-Boy all copper scrubber.  I usually point the muzzle at a clean piece of paper or paper towel to catch all the lead particles, this is the way I determine the amount (if Any) leading has built up.

If there was truly no leading anywhere but the muzzle, then my first guess would be that your bullet ran out of lube, or the lube failed as it traveled down the bore.

Leading at the muzzle usually indicates running out of lube.

Where did you get your load data from?

How long is your barrel?

I was using Quickload to develop a data, as well as using "the load" as a guide when using green dot.

I cleaned the leading out with chore boy wrapped in a jag, it got the fouling out fairly quickly but I may need to go back and clean it some more, I think there's some leftover.

what bullet lube are you using and is it rated for the speed your trying to hit?

The bullet had no lube, it was moly coated (Penn Bullet said it needed no lube since the moly was the lube). The barrel is 16" long.

They said the bullet is rated to 2000fps.

This is what I am using

http://www.pennbullets.com/30/30150.html

1600 is pushing it for a plain based bullet, sorry to say.

Try and dial it back a touch.

Failing that, give some gc'd bullets a try and load some red dot loads with the ones you have for close in practice.

Also ensure you aren't shaving the bullet when loading. Although if you were you would probably have leading in places other than just the end of the barrel.

I personally wouldn't try to push most boolits over 1400fps unless they met certain criteria.  Not too small a diameter.  Lube/coating that will hold up (gas check dependent on lube).  That said, I've only pushed some PC boolits fast, and had no leading without gas checks (BB tumble method of PC).  Of course you can always paper patch, but that is a whole different road to travel down.

The guy at Penn bullet said it could be the powder... he said Green dot isn't such a good powder and suggested IMR single based rifle powder rather than pistol powders. Problem with rifle powder is at low loading they don't burn very efficiently at all...

I think I'll just try adding actual lube to the groove. Any suggestions as to what lube to use?

For a plain base bullet in a rifle, Trail Boss has worked for me with no leading.

IMR 4895  as a reduced loading.   Leading near muzzle is running out of lube or the gas port venting is cutting the base of the bullets.  You need a gas check. Imo. Lube- 50/50  bees wax/alox in the bullet grooves, but I think u will be wasting your time.  Hodgdon reduced loads with H4895 may work.    http://www.hodgdon.com/PDF/H4895%20Reduced%20Rifle%20Loads.pdf     I used 27.5gr IMR 4895 in 30-30 with 173 gr cast gas checked .310"  bullets. Worked well.  Use a Lyman "M" die to open the case mouth so you dont shave lead on bullet seating.     Do  not use the starting load for jacketed bullets in the 308 Winchester.    
 

 

Sorry, but the Penn bullet you linked is NOT Molly coated and is NOT 160gr.

http://www.pennbullets.com/30/30150.html

The bullet link you provided is a 150Gr 30-30 bullet with two(2) lube groves and has NO Moly.

What bullet are you actually using?

That's the bullet I'm using... I don't know why I kept thinking it was 160 grains, I guess it said it on the side bar (rather than the top page). I weighted it and it's 155 grains, actually fairly consistent too (Hornady jacketed 150 grain bullet has more variation than this).

I asked the guy to moly coat it for 15 dollars, thinking it would eliminate leading, but it didn't. I am thinking part of it is the fact that he didn't put any lubes in the groove (said moly is the lube) so it must have failed at the last 4" of the barrel.

I got some plain base gas checks from Sage Outdoors, and LEE push through sizer (309 size), going to try this again with gas checks, hopefully it means no more leading.

Or I can just paper patch the thing and use it in a .311 bored rifle.