what size should I make my boolit??

[Marlin Hunter]

I am casting for a %#@$ Taurus 454 Casull. The barrel slugs .4535. The throat of the cylinder is .4528 to .4535. What size should I make the boolit. I assume that anything over .4528 will get fire sized by the cylinder throat. Should I try to put some lapping compound on each round and fire lap the opening of the cylinder?

I hate Taurus.

[rob45]

You could have the cylinder throats reamed. Not only would this rectify the problem of undersized throats, but it could also make the throats more uniform.

[Bret4207]

If the throats are small you'll have problems getting max accuracy.

[MtGun44]

Try .454, but expect fliers from the undersize cyl. Consider reaming to .001 or .002 over
bore diam for best accy. HOWEVER, with a large bore like yours, you could start getting into
the place where you need a custom mold to fit the even larger throats. Say you want .001
over bore size for throats. This is .4545, call it .455. You can probably get a mold that
casts .455 pretty easily and size your boolits to that size. If you were to ream .002 larger
(.456) you'd be getting into more difficult territory.

If you have yours reamed to .455 and match your boolits, you should be good to go.

OTOH - how does the gun shoot NOW?? I do not think that fire lapping is going to be good
for this, no experience with that application of firelapping. Most use it to smooth the bore
and open up a constriction where the bbl is screwed into the frame.

Bill

[runfiverun]

i'd shoot for 454 on the boolit side and try lapping out the small cylinders or have them cut out.
the 454is bbl could then be dealt with through alloy composition.
cylinders don't need to be bigger than the bbl same size is okay. smaller ain't.
same size gives you a levergun like throat. and the gap can be dealt with through the alloy.

[stephen perry]

Take the gun to a pistol smith and have him hone all the cylinders to the size of the largest one. Lapping wouldn't take enough off and chances are all your cylinders would be different when you got done.

As far as sizing size to the size of your cylinders to the next thousand up, .454. This way you are lubing only and looking for round bullets with no change to diameter if that is possible.

Stephen Perry
Angeles BR :brokenima