Schwing said:
I think Lawyers is the key word here.
There are many Kaboom threads where the OP posted the loads used were within published max limits ... I wonder which load data they were using?
Call me overly cautious but keep in mind that all the chamber pressure testings were most likely done using
NEW brass and not mixed
RANGE BRASS that may have been reloaded several times. Especially with brass that were overly stretched (can you say thinned case walls?) and "fixed" multiple times with push-through dies like Lee FCD/Redding G-Rx, you run the risk of case wall failure/rupture at weakened part of the cases.
Before FCD/G-Rx dies, these overly expanded cases were not reused and reloaders tossed/culled them so other reloaders did not get to use them unknowingly. Now they get "fixed" and become part of the mixed range brass we pick up and/or buy. Also, many match shooters use 9mm Major loads (124 gr bullets at 1450+ fps) beyond SAAMI +P pressures and these cases are left on the range floor after the match because match shooters do not want to reuse them for obvious safety concerns of case wall failure on subsequent reloadings. Guess what happens to those overly expanded cases? They get collected and sold as mixed range brass and we get to reload them unknowingly.
Recently, there have been some threads where reloaders were having difficulty properly resizing their 9mm cases. Perhaps 9mm Major cases shot in looser factory barrels may explain why. Over the years, there have been known issues with various headstamp cases and many reloaders factored culling of these cases as part of their reloading routine. There are many variables to reloading and unfortunately overly expanded/fixed cases are one of them. You can choose to reload without factoring them in but it's simply the new reality of reloading unless you use verified once-fired brass.
So if you are reloading with new brass, you may consider using the higher published load data. If you are using mixed range brass, especially if the cases were work hardened and experience significant bullet setback from case wall spring back, I would suggest you consider using more conservative load data, just in case you are using weakened cases with reduced neck tension.
Many may post recent years' reductions in powder max charges as simply driven by corporate lawyers and older higher max charges should still be used. I like my fingers and hands just the way they are and use more conservative load data whenever I have doubt. But it's your life and your body parts. As always, YMMV
BTW, Hodgdon load data and other powder manufacturers' load data now carry warnings for 40S&W similar to:
This data is intended for use in firearms with barrels that fully support the cartridge in the chamber. Use of this data in firearms that do not fully support the cartridge may result in bulged cases, ruptured cases, case-head separation or other condition that may result in damage to the firearm and/or result in injury or death of the shooter and/or bystanders.
Instruction for Lee Bulge Buster kits that use the FCD carries the following warning -
http://leeprecision.com/cgi-data/instruct/1855.pdf
Do not use the Bulge Buster Kit to reload for the 40 S&W Glock or similar guns with chambers that do not fully support the cartridge due to the intrusion of the feed ramp
How many of the reloaders using the FCD/Bulge Buster kits follow this warning and not repeatedly "fix" their Glocked brass? Many won't.
Many people ask me why I use 40S&W Lone Wolf barrels with tighter chamber issues for my Glocks instead of factory barrels. For above mentioned reasons, I like to have my 40S&W cases supported all the way down the case base and tighter the chamber the better. I use mixed range brass and consider LW barrels cheap insurance. Besides, the spent cases from LW barrels hardly take any effort to resize.
I have a feeling that we haven't seen the last of 40S&W Kaboom threads ...