The short barrel tests show how the lead tin alloys turn to putty, a direct relationship to nose slump and the accordion affect. It is discussed in more detail in Boats Twist Rate thread.

J.Louis

That I don't recall and my book is currently out on loan, but what I find interesting is 1-25 and 1-30 are still very popular alloys and still being used to this date. Sometimes even softer than the 1-30 at 1-40. It is also interesting knowing Mann's findings that the trend has not moved to the harder lead and tin alloys. As stated earlier I currently use a 1-16 alloy as I have proven to my self the increased benefits by doing so. When I share this with others the typical response is the concern for the added costs of the tin and they opt to save money in lieu of improving their accuracy as well as thier day in and day out consistency. I think this due to the mindset that the little things cannot make that much of a difference, when the opposite holds true and that being the difference is substantial. The name of Schuetzen game is to pickup points and not to loss them, yet due to the minor additional costs of tin and match primers of which can also follow suit, there are those that just won't spend the money to get that little extra out of their rifles to take them to the top. 

J.Louis

I hope this conversation continues and only wish I had my book in hand. It is discussions like this that take competitors to a higher level as it is about the most important part of the accuracy puzzle, the bullet and the bullet is the component that is ignored the most.

J.Louis

Frank,

I do think the same happens with pistol bullets. When testing magnum handgun loads, I have recovered heavy jacketed bullets whose bases started out flat but were quite cupped after the shot. I did not measure to see if the base had expanded over groove dia as I was concentrating on nose expansion.

I might as well join the party, I think most of what everyone has written is correct in some way, after using QuickLoad for 9+years I have some thoughts about the expanded bases on the bullets in very short barrel/no barrel rifles and the handgun, especially revolvers with very short barrels.
Compare the 357 magnum, bullet is 18.75” down the barrel for a almost max load of AA#9 to powder to al-burnt 95% in a 20” barrel with a muzzle pressure of about 1550psi and 1596fps, the same load same cartridge out of a 2” revolver barrel produces 21,500psi muzzle pressure at 830fps.
 
Switching to Bullseye Powder and almost max load in the 20” barrel produces 890psi and 1385fps and the 95% powder al-burnt distance in the barrel is just less than 2 inches. Muzzle pressure being 17,890psi with the 2 inch barrel and 795fps these figures are all using a 168gr cast bullet if you change to a 4” barrel everything else the same muzzle pressure drops to 6900psi.
 
So has anyone here shot max loads with soft cast bullets in a 2” barreled 357 Mag. I have not. 

But I have a S&W M36 with 3” barrel and adjustable J-fame sights I installed, tried to hot rod into a strong defense gun in the late 70’s, it was not accurate with heavy loads of Unique and a soft bullet alloy I used of mostly free smelted down shot, the carbine actually shot pretty well and did not lead, cannot say the same for the 36, leaded bore and muzzle, sprayed bullets all over at 50ft.

Let’s look at that load from the QuickLoad side of pressures and muzzle velocities.
Near max 16,500psi 38 special load of Unique in 18” carbine barrel (had a converted M92 for a while) muzzle velocity 1130fps, muzzle pressure 700psi, 95% powder all-burnt distance is 6.5” down the barrel, same load 3 inch barrel velocity 740fps, muzzle pressure 7426psi.

Mike,

Interesting info, and an indication to try fast burning powders (relative to the application) to keep the muzzle pressures lower. 

Were you using the 358429 Keith bullet with Unique in your 3" J-frame?

Mike provided very interesting information while trying to address Franks confusion. Lets keep the original discussion going, it has allot of value in it and I don't think we want to see it morph into a discussion about pistols and loads.

J.Louis