Reloading For The Thompson
Posted 18 September 2005 - 08:16 PM
The loading manuals call for a min length of .898" and a max length of .898" Tight tolerances!
Using once fired factory brass, I'm coming up with measurements all over the place. All being under the suggested length.
I'm getting a range from .852" up to .895" after resizing. At this point I do not plan on trimming any of the cases seeing that they are all under sized.
Too short of a case could cause a misfire, due to a light or no primer strike, too long and the bolt may not close quite far enough.
Then there is the OAL to deal with. I guess I'll seat the bullets to the cannelure irregardless of case length. With shorter cases there may be a slightly higher pressure.
Any suggestions, tips?
Posted 19 September 2005 - 09:37 AM
Case= .898 - .010
LOA= 1.200 to 1.275
Posted 19 September 2005 - 09:50 AM
That is the nature of straight wall cases... Sizing doesn't involve much reshaping of the case if any and the crimp is pretty much a little squeeze....
Posted 20 September 2005 - 10:01 AM
Yes, I was referring to the cannelure on the bullet. I haven't loaded for over 15 years, and probably 25 for straight wall cases. LOL, I've owned .45 dies for about 7 years and just this Sunday 9/18/05 started setting them up.
In my reloading books there is no listing for OAL, thanks PK!
I have .357 and .38 casings that have been reloaded many times without any signs of fatigue. Although its a different story with those casings, as a roll crimp is used and placed on the cannelure for a more secure grip.
I haven't had the opportunity to observe any fatigue in the straight wall cases due to parting with my Colt Commander 9 mm, many years ago.
I'm not one to pick up brass of unknown origin and history. I guess I follow the manuals perhaps a little close. But then of course they want you to buy more casings.
Most likely I'll get 1k of hard cast bullets, and a few hundred of plated to use as chasers to scrub the lead out if any. From the 1911 boards its thought that plated bullets are not as accurate as FMJ or cast. The Jury is still out on that one, at least in this household.
My goal is to simply get more bang for the buck, and still maintain a good group.
Thanks for the tips and feedback!
Posted 22 September 2005 - 11:53 AM
Posted 23 September 2005 - 01:52 PM
I am currently using the RCBS three die set with carbide resizer die. According to the RCBS site the third die is bullet seater / taper crimp die.
Although the part numbers no longer match. I have Group B, part 18912
Their site lists it as Group B, part 18915.
Gun show this weekend, hopefully with a lot of luck I can get a deal on bullets.