357mag and 357 max chambers

[bajabill]

This topic developed out of another thread so I wanted to give it a home of its own.
 
I am going to do a chamber cast of my home reamed 357max, but it is not from the reamer that is currently being used by the members here.  I am currious what the factory 357mag and the few factory 357max throats looked like.
 

[quickdtoo]

This is an old topic, here's one of em with a typical 357Mag Handi chamber cast, I haven't done a chamber cast since I Maxd mine, it shot terrible with the one load I tried in it before tho, it shoots good as a Maxi, so I never cast it, so do the hundreds of barrels that have been maxed with the same reamer since. 

Tim

http://www.gboreloaded.com/forums/index.php/topic,125780.msg1098446320.html#msg1098446320

[bajabill]

Just did a chamber cast, and I have 1.86" from the base to the start of the rifling, the "cone" region (not an abrupt step beyond the chamber) is .082" long. 

[Tioal]

I have been looking at this same issue.I bought the 357 Handi so I can shoot cheap.I wanted to use 357SWC lead bullets I cast for my hand guns.The first time out was sad.The bullets spread over 4 to 6 inches at 40 yards and 5 or 6 keyholed.The chamber is way long the bullet is totaly out off the case then hits the bevel to the rifling maybe stright maybe off center. my next try was a truncated cone lead bullet hoping it would self center after the free jump.I also cut back on the velosity.This worked much better with groups closer to 1 to 2 inchesat 40 yards,but I get 1 or 2 flyers per 10 that show a oval hole .My next try was 357 Max brass I can trim to fit the long chamber.It seems the chamber has a taper to it. A resized max case has a chamber length of 1.420 but when the bullet is seated the case expands at the mouth and chamber depth drops to about 1.340.That is only .050 over 357 mag and still does not allow the bullet to hit the rifling before leaving the case.If I try to use a longer case then 1.340 the brass can not open to release the bullet and pressure will go up ??. I am at the point the only real choice seems to be ream the chamber to Max with a better profile,shoot cooper jacket bullets,or sell it as not doing what I want it to do.The last choice is looking best to me now. I am going to shoot some more of the low speed truncated cone too see if it grows on me.