boyd@mailer.cc.fsu.edu (Mickey Boyd) (06/14/91)
In article <35569@mimsy.umd.edu>, nstar!bluemoon!jamaass@iuvax.cs.indiana.edu (Jeffrey A. Maass) writes:
#
#Is it necessary to trim 9mm/.45ACP brass? I'd been told that
#the non-rifle cases won't need trimmed.
Most auto pistol brass is really short. It is unlikely that you will ever
need to trim them, and if you do it is likely that the brass is really
stretched and should be discarded. I occasionally check with my calipers,
but I have never found a long .45ACP case (not even close), even after
being loaded 5 or 6 times.
By the way, this brings up an interesting point. If the 9mm/.45ACP is
supposed to headspace on the case mouth, and if the vast majority of the
brass made in these calibers is too short to make this possible, what is the
primary force that holds the case against the slide face? I personally
believe it is the extractor (since lots of other really smart folks do :-).
However, this may also imply that by using "correctly" sized and lengthed
brass you may get more consistancy (ie accuracy, never mind where you would
get this brass). Anybody tried this?
--
Mickey R. Boyd | "God is a comedian playing to an
FSU Computer Science | audience too afraid to laugh."
Technical Support Group |
email: boyd@fsucs.cs.fsu.edu | - Voltaire bercov@bevsun.bev.lbl.gov (John Bercovitz) (06/15/91)
In article <35600@mimsy.umd.edu> boyd@mailer.cc.fsu.edu (Mickey Boyd) writes:
#However, this may also imply that by using "correctly" sized and lengthed
#brass you may get more consistency (ie accuracy, never mind where you would
#get this brass). Anybody tried this?
I've tried it - with 45 Win Mag brass. The only trouble with using this
case as a starting point is that you have to thin out the neck walls where
the bullet goes because after you shorten the brass, the bullet will seat
in the thick-neck area of the case. You may not have this problem if you
start with Detonics cases because they're only a little bit longer than
45ACP brass. I've never tried Detonics cases fearing that they're probably
expensive and hard to come by. Do remember that case capacities will vary
with different constructions.
As far as getting a more accurate load by using this brass - well, I haven't
been able to detect it. That's what I wanted, but I didn't get it. I have
a very tight Gold Cup and it didn't know the difference out of the Ransom Rest.
I do sort my brass by length though. This way I get a consistent taper
crimp. I believe that that helps though I've never done a rigorous test.
JHBercovitz@lbl.gov (John Bercovitz)petert@uunet.UU.NET (Peter Toth) (06/15/91)
In article <35600@mimsy.umd.edu> boyd@mailer.cc.fsu.edu (Mickey Boyd) writes:
#[...]
#By the way, this brings up an interesting point. If the 9mm/.45ACP is
#supposed to headspace on the case mouth, and if the vast majority of the
#brass made in these calibers is too short to make this possible, what is the
#primary force that holds the case against the slide face? I personally
#believe it is the extractor (since lots of other really smart folks do :-).
#However, this may also imply that by using "correctly" sized and lengthed
#brass you may get more consistency (ie accuracy, never mind where you would
#get this brass). Anybody tried this?
Not me, but it sounds good.
Match barrels have shorter ("tighter") chambers, so that the case
does headspace on the forward end. This is one of the reasons for the
decrease in their reliability. (Tight frame-to-slide is another, etc).
"Field" barrels are expected to have crud in them, so there is room left for it.
You could lengthen brass by firing it with an high pressure load from a chamber
that can take it. For example there are inserts available for the 30-30,
30-06, 308 that'll fit a 30 carbine or 32ACP case. I know of no sleeves in
the .35 caliber (38/357/380/9) but i'd love to hear about one.
If the 444 Marlin is rated higher than the 44Sp and 44Mag, it could be used
for them.
Peter Toth