Bullet lead hardness...

Searching the internet,I find cast bullets from various makers at either BHN 12 or 18(mostly). I'm interested in low velocity bullseye loads. Please advise. Thank you.

Works for us..

What hardness bullet you use will largely depend on what works in your pistols.  I would encourage you to worry more about bullet fit, initially.  Structurally, Lead bullets are less strong, and as a practical matter are far less forgiving than jacketed bullets.  For autos, .001" over groove diameter usually works. Things are more complicated with revolvers.  

A website with a huge amount of information on Lead bullets and making them work:  
http://www.lasc.us/CastBulletNotes.htm

Bullet fit is King with Lead bullets.  If a bullet is smaller than needed, it is not likely to shoot well no matter what.  Some people claim to be able to get really soft bullets to "bump up" to a larger diameter on firing using really fast powders.  This is something that has never worked for me, but it may for you.  

Here is a lengthy thread on revolver accuracy, with many ideas important in autos:  
http://castboolits.gunloads.com/showthread.php?21598-A-beginner-s-guide-to-revolver-accuracy  

A lot of people believe in using softer bullets for lower pressure loads, and harder bullets for higher pressure.  This has never worked for me, but it may for you.  

I see less problems with Leading in some barrels with a harder bullet, so long as the bullet fits the barrel.  The harder one drives a Lead bullet, definitely the harder the bullet you need, and the better the bullet lubricant you need.  My impression of most commercial bullet lubricants is that they are usually fine with low velocity loads so long as the bullet fits the barrel, but they are used more because they stay in the lube grooves.  
  
Some more things to worry about with Lead that you do not worry about with Jacketed:  I have some pistols that the barrel requires a bullet a good bit larger than "the book" says it should.  All of my Beretta, Walther and FN 9mm barrels are slightly smaller than .358".  The book value is .356".  To complicate things more, the FN barrel's chamber will not admit a cartridge with a bullet larger than .356" diameter, so it gets only Jacketed bullets.  

Since you are talking target loads, and are probably using small charges of fast powder, after you have determined the bullet diameter you need, you might want to try soft bullets first.  After firing something like 50 rounds, examine your barrel for Leading.  Leading the whole length of your barrel says you probably have too small a bullet, and the gasses passing around it are cutting off large amounts of Lead and depositing it in the bore, but then again your barrel may just be accursed.  Leading at the muzzle can say that you have a lube problem.  Some barrels Lead some, no matter what.  If you are buying bullets and think you have a lubrication problem, you can try lubing over what is on them originally with the Lee Liquid Alox system.  

Some loads don't Lead, but don't shoot well.  That's another problem...

I use 12BGN for all my handgun shooting up to full power .44 Mag. I even use the same alloy, with gas checks, for rifles.
Fit and lubrication trumps alloy.

noylj wrote:I use 12BGN for all my handgun shooting up to full power .44 Mag. I even use the same alloy, with gas checks, for rifles.
Fit and lubrication trumps alloy.

Elmer used the same for his development of the 41 & 44 mags.  I always figured if it worked for him, it would probably work for me too.  Truth be told, most of mine are BNH of 9-10.
Al

To soft may case feeding problems, with the bullet nose dragging on the 45 acp  ramp. Having tested both  oven heat  treaded and  linotype bullets, to hard is not a problem. Bullet diameter should be same or + .0005" larger then the groove diameter.  Sizing to .452"  for Colt and .451" for  S&W.