Richmond Carbine

[luckychessie]

Have a cut down armisport richmond. First three shots group very well after that the barrel heats up and throws shots everywhere some also keyhole. Any suggestions would be appreciated.

[Walt Magee]

Is it a smoothbore or rifled?
Walt

[luckychessie]

It is rifled and I am shooting a lee .575 500 grain minie.

[Jim Brake 3587]

Sounds like hard lead to me but I would check the bore size of the barrel and make sure the bullet is .001 to .002 under bore size, made with pure virgin lead and topped off with Len's Lube. Send this projectile down range with 40 to 42 grains Goex 3F powder and all your problems will go away unless you have a bad barrel. If the barrel is bad , it can be lined by Bobby Hoyt. That's my 2 cents worth....Jim Brake