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Old 10-10-2009, 20:30   #16
fredj338
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Quote:
Originally Posted by nytehawk View Post
Thanks guys very much for the quick replies! Based on your responses, three quick follow-up questions:

1) fredj338 noted that the 40S&W is a high-pressure round. But looking at load data, the .40 pressures appear to be generally in the same ballpark as many 9mm loads -- low 30,000 psi range. So why is this pressure more of a problem in the 40 than the 9? Is it because the 40 brass has more surface area on which that pressure can act (due to slightly larger case size)?
I suspect brass thickness & chamber support. Add to that the heavier bullets used w/ limited OAL resitrictions. Bullet setbacks are rare w/ the slightly tapered 9mm, but can happen easily w/ the 40.
2) You also recommended using med to med/slow powders when reloading .40. Is TiteGroup acceptable? According to Hodgdon's website, TiteGroup is the 10th fastest of 117 powders listed. (http://www.hodgdon.com/burn-rate.html)
I would not use TG, but many do. That is just my prejudice against powders that have such a narrow load range & steep pressure curves for a high pressure round like the 40. Something like WSF gives broader load range, less rpessure for any given vel. than TG & great accuracy. The only downside is you use slightly more powder, big deal. Powder is the cheapest part of any pistol load.
3) Would it ever be advisable to use less powder than the recommended starting load in order to further avoid possible overpressuring? Or could that also be dangerous as the under-pressure condition could result in incomplete powder burn, etc.?
I would NOT. Starting loads in semiautos often won't give relaible feeding. Going lower only makes this worse. I NEVER shoot low recoiling "mousefart" loads. It is diff. for a newb shooter to realize he has had a squib load if there is no recoil. Use starting data & workup in small batches in 0.1gr increments until you get accuracy & reliable feeding w/ complete pwoder burn (too low in pressure loads of med. powder will often leave unburned powder behind)You want low recoil, shoot a 22lr.

As always, JMO.
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Last edited by fredj338; 10-10-2009 at 20:33..
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