Trimming 45acp?
- Thread starter willy
- Start date
Register to hide this ad
I can't remember the last time I had to trim a .45ACP case. I don't load anywhere near the upper edge of the envelope.
- Joined
- Aug 9, 2005
- Messages
- 9,021
- Reaction score
- 11,208
I've never trimmed .45 ACP even after many reloadings and have never heard of anyone doing so. Even hot loads in .45 ACP aren't very high pressure.
I never had to trim 45 acp.
SGT ROCK 11B
Member
Same here with 45 ACP.
Never trim 9mm for that matter either.
Never trim 9mm for that matter either.
Last edited:
Never in 40 years.
- Joined
- Apr 21, 2021
- Messages
- 5,007
- Reaction score
- 8,564
Have a case gauge and check length after vibratory cleaning during inspection. Never had to trim one in over 40 years. GI cases are very good.
I’ve seen people do long term tests of 45 ACP and they usually end up tossing rounds because they get too short. Each firing shortens the case a bit. I’m sure I have 45 ACP brass that has seen dozens of uses and I don’t really pay attention until they crack.
austintexas
Member
cases
Started loading 45 ACP in 1962, still reloading some .45 I picked up on the Range at Rota in '69. Never had to trim, when they crack I throw them away.
SWCA 892
Started loading 45 ACP in 1962, still reloading some .45 I picked up on the Range at Rota in '69. Never had to trim, when they crack I throw them away.
SWCA 892
There is one situation where trimming might make sense. Yesterday I loaded up 300 .45 Colt, 200 Starline brass and 100 Winchester. I measured a few cases before starting and found the Winchester averaged 4-5 thousandths longer, so I separated them. After running the Starline cases through my process, I switched to the Winchester and discovered that I had to back off the seating die a little and, especially, the expander die.
I considered trimming the Winchester cases before the next round but decided I’ll save them for after I’ve lost all of the Starline cases
I considered trimming the Winchester cases before the next round but decided I’ll save them for after I’ve lost all of the Starline cases
Straight walled cases tend to not stretch like bottleneck cases. Bottleneck cases stretch during resizing as the neck expander is pulled out through the neck of the case. I did trim a batch of about a thousand 45 ACP cases for USPSA match loads. Lost all of them in matches. Not really sure the trimming made a significant difference. I am more likely to trim revolver brass so that the roll crimp is consistent and my revolver brass is not going to be lost at the range.
Last edited:
ReloadforFun
Member
- Joined
- Feb 17, 2021
- Messages
- 282
- Reaction score
- 320
To expand on Stans post, bottler-neck cases see the gas pressure and flow through the case neck stretch the case. In extreme situations this is where you see bottle-neck cases separate slightly ahead of the extractor groove.
Cylindrical cases, such as 45 Auto shorten slightly upon firing. Resizing will grow them a bit, but since most are some 0.010" shorter than maximum, it is (extremely) rare you ever need to trim the typoical handgun, cylindrical case.
Cylindrical cases, such as 45 Auto shorten slightly upon firing. Resizing will grow them a bit, but since most are some 0.010" shorter than maximum, it is (extremely) rare you ever need to trim the typoical handgun, cylindrical case.
Hair Trigger
US Veteran
It was so rare I had a pistol case (or revolver) out of spec for length that it needed trimming, I don't even measure them any more.
Put me in the same boat. My pistol loads really don't work the brass that hard.
The hammer hits the case, pushing the shoulder forward in the chamber as far as it can go. The shoulder stays there (forward) as the powder ignites and expands the case to fill the chamber - especially pushing the case head backward into the bolt face. That’s a big part of why case head separation is the big concern. However, when you re-size, you push the shoulder back first and then pull the expander out of the case (forward if you will). That does stretch the neck a little and can pull the narrowest part of the shoulder forward also.
Last edited:
CMYSIX
Member
your wasting your time
- Joined
- Aug 9, 2005
- Messages
- 9,021
- Reaction score
- 11,208
I don't doubt what you said and certainly can't refute it because I've never tried it. I shoot Bullseye style at 25 and 50 yards. I have a thousand unfired Winchester .45 ACP cases. When I open these, I will trim 100. I'm curious as to an improvement in accuracy.
IIRC (and thats from a 77 year old mind) I did an experiment many years ago measurung 45 ACP and other semi-auto brass. Some actually shrunk in length after multiply reloadings/firings...
AManWearingAHat
Member
Life is too short to bother trimming pistol brass. Especially something as prolific as .45.
