View Single Post
Old January 14, 2012, 02:35 PM   #43
SL1
Senior Member
 
Join Date: November 8, 2007
Posts: 2,001
JohnSKa,

I'm not sure who is really the one shooting at a moving target. And, I am not trying to pick an argument.

But, I stand-by my comments that SAAMI has seriously down-graded the .357 and .44 magnum rounds with their new psi standard, as compared to their older CUP standard. And, I stand by my comments that has invited people who have strong guns to try to exceed the lower velocities of the newer standard. That is why I pointed the OP to pressure tested data from the old CUP standard, because I think that is a safe way to up the performance, and still stay within SAAMI standards, because CUP is STILL an accepted standard. I want to discourage "winging it" without pressure tested data as a guide.

Trying to compare apples to apples, the new Speer manual (#14) lists the maximum load of 296 as 14.7 grains to comply with the 35,000 psi standard, and says that achieves 1185 fps. It also lists 15.5 grains of (supposedly identical) H-110 as max and say that gives 1217 psi. Both velocities are from a S&W M19 with a six inch barrel. Compare that to Winchester's original load of 16.6 grains of 296 that produced only about 40,000 CUP, or Speer, Hodgdon, Hornady and Sierra pressure-tested loads from the 1980's that range all the way up to 17.8 grains and were supposed to be within the 46,000 CUP limit. OBVIOUSLY, the psi standard produces a much lower actual pressure than the CUP standard. Don't you agree with that?

Now, comparing velocities is more of a problem keeping apples to apples, because of the wide range of velocities that can occur with different guns shooting the same load and the same gun shooting the same amount of the same powder under the same bullet, but with different powder, primer and case lot numbers.

I don't have any velocity measurements from .357 ammo manufactured in the 1930s/40s and shot in any 8-3/8" barreled revolvers. But, I do have some fired cases with LARGE pistol primers from that era. So, I expect that things were probably pretty hot in those days. But, I do not really have a way of knowing just how close some of the original factory ammo got to their advertized velocities in real guns.

I do know that MODERN 10" test barrel data EXCEEDED that advertized velocity at pressures that are probably considerably lower than the old factory ammo. And, I see that there is still a Lyman load for a CAST LEAD 158 grain bullet that gets 1450 to 1460 fps with pressures around 42,000 CUP from a 4" VENTED test barrel. So even going to 46,000 CUP and an 8-3/8" vented test barrel seems to put 1500 fps within plausible reach. And, if you go here http://www.buffalobore.com/index.php...t_detail&p=100 you will see that Buffalo Bore lists velocities of 1485 and 1457 fps for their 158 grain JHP from revolvers with a 4" and 5" barrel, respectively. So, again, I don't see that the pre-WWII ammo had to surely be less than 1500 fps with LEAD bullets. If there is really an apples to oranges problem with the comparison of the old advertizing to the new manual velocities, it is partly that the original loads were lead, while most of todays manuals are giving data for jacketed bullets.

But, getting back to whether we are arguing or not, you seem to have picked on a minor detail in what I said about the design velocity of the original cartridge as a way of disagreeing with or changing the subject from my main point that the SAAMI psi standard has seriously downgraded the older magnum rounds from what they were under the CUP standard. You and some of the other posters also seem to be ignoring my secondary point that some of the old advertizing (and possibly old testing results) have been incorporated into regulations on the use of handguns that we must still obey, today, if we intend to use the .357 magnum cartridge for the uses that those regulations INTENDED it to be used for.

I think those points explain why we see so many people wanting to push .357 Magnum loads instead of going out to buy newer, heavier guns chambered in newer cartridges. And, I don't think posts that say the answer is to never shoot maximum loads in your .357 Magnum are going to be effective in stopping those people from seeking hot loads. I think our answers are better directed at getting that type of poster to look for hot PRESSURE-TESTED data and stay within that, with some warnings about what people should ALWAYS think about whenever they are approaching max loads. (As an aside, some of the max load data for the .357 magnum seems to use more powder than I have found will even fit into the case under the bullet used in the data, so there are obviously some issues to consider when trying to use that data.)

Respectfully,
SL1
SL1 is offline  
 
Page generated in 0.04472 seconds with 7 queries