Cast Lead bullet question?

[win38-55]

Today I went shooting with some cast lead bullets that I reloaded.
I was shooting my Ruger Super Blackhawk at say 20 yds. The first 12-18 rounds were right on the money dead center.
After the barrel heated up my lead bullets seemed to turn into flyers. What would cause this to happen.
My thinking is the barrel just got to hot and was melting the lead, making the bullets inaccurate.
If any one else might have the answer please let me know. Maybee I should slow down my shooting
so the barrel does not heat up as much. The barrel was hot to the touch.
Thanks for the help.

[Griff]

A number of factors can lead to inaccuracy with lead bullets: hardness of lead, speed (velocity), lack or paucity of appropriate lube, rapidity of shooting (barrel heat retention). 1st symptom I'd look for was leading of the bore. If you're sloughin' off lead it will often stick in the corners of the grooves and will profoundly impact accuracy. If that's the case, you've found the culprit. Now comes the hard part; that of finding the cause.

[TedH]

Did you look in the bore to see if there was lead fouling built up?

[Griff]

Another factor I forgot ws bullet base shape. Bevel base bullets are great for low-speed rounds like the 45ACP, but when pushed faster they'll often melt at the corners faster than a plain base bullet and leave leading. But, hey... they are easier to load!

[Cimarron Red]

Griff's right about bevel base bullets potentially causing problems. They can be OK for revolvers, but I won't use them in a rifle.

[Chas.]

My guess would be what you suggested - heat, maybe with melting lead. For intense shooting, I have 2 identical .44Mag Super Blackhawks and rotate frequently. If any gun gets too hot to comfortably hold my hand on it, I quit shooting it until it cools.

[mikld]

One of the most important factors for shooting lead bullets is bullet diameter vs bore diameter. You need to know the diameter of the cylinder throats and the barrel grooves.Slug the barrel and cylinder throats and shoot bullets that are larger than bore, but the same or slightly smaller than cylinder throats. (My Super Blackhawk has a groove diameter of .429" to .430", depending on my measuring. The cylinder throats run .430" to .431". So, I shoot my lead bullets @ .431" and get very little or no leading).

http://www.lasc.us/Brennan_2-1_Measurin ... nsions.htm Good info for slugging/measuring...

[kimwcook]

If you do have leading make sure you get it all out before you go shooting again or you'll have trouble all over.

[Chuck 100 yd]

Mine the bore and then figure out why it happened in the first place.
Bore and bullet size? Bullet lube? Velocity? Alloy?
Lots of reasons to lead, and a leaded bore wont be accurate.

[gon2shoot]

Well, you;ve been given some good info, I'll only reinforce the fact that "fit" is king in cast. Alloy comes in second place in my opinion, as I have run cast (proper alloy of course) to 2100fps +. There is no one step answer for your problem, slug your barrel, check your alloy, and enjoy shooting.

[Charles]

The melting point of lead is over 600 degrees F. Do you think you barrel got that hot?

[Pisgah]

The heat of the barrel is nothing compared to the temp of the gases pushing on the base of that bullet. My guess is that lead fouling is building up shot by shot to the point that accuracy goes south. This may be a result of incorrect bullet hardness, too-small bullet diameter, insufficient lube, or any combination of these factors.

[Lefty Dude]

That bore most likely is a 40 caliber smooth bore.

I can just imagine what the forcing cone looks like.

[BAGTIC]

The lead bullet does not get hot enough "to melt'. A close inspection of a leaded bore or a fired bullet will not show any signs that the lead has ever been fluid.

The leading is often caused by a too small bullet. Also by poor bullet alignment. If the bullet is cocked in the bore the riflings will act like the teeth on a file and scrape metal off.