# 45acp hornady shell diameter



## WI45 (Mar 1, 2012)

ok, so on break in of a new cw45 we shot two mags of Hornady Critical Defense with no problems, along with 200 rounds of white box. well, i fill a mag with Hornady from another box, load, rack the slide and it won't close all the way, but it's stuck enough that it takes alot of pulling back to open up. try again with another round and same thing. i take out my micrometer and measure the hornady's at .474 and my chamber at .475, some remington jhp's at .470. does anyone know if this sounds normal? when i take the barrel out and drop a round in the hornady sticks at the base and the remington falls in and falls right out. anybody else have similar experiences???


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## Blade (Feb 23, 2012)

I had the exact same problem with my TP45.


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## Steve M1911A1 (Feb 6, 2008)

It seems as if maximum case tolerance is meeting minimum chamber tolerance.

I don't have the SAAMI specs memorized, but they're easy to look up.

You could always run the Hornady cartridges through a taper-crimp die, and see if it helps. For that matter, if you remove the decapping assembly, you could run loaded cartridges through a sizing die, too.

You'll have to be careful to run with a bright and shiny, clean chamber. Maybe it'd be worth doing a chamber-polish job, too. (PM me for instructions.)


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## WI45 (Mar 1, 2012)

Steve M1911A1 said:


> It seems as if maximum case tolerance is meeting minimum chamber tolerance.
> 
> I don't have the SAAMI specs memorized, but they're easy to look up.
> 
> ...


this is the kind of info i was hoping for, thank you.


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## Baldy (Jun 21, 2006)

The case mouth with a bullet in it should measure .470" to .473". That's for a .45ACP..

Here's one link to measurements. .45 ACP - Wikipedia, the free encyclopedia


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## WI45 (Mar 1, 2012)

Amazing, I found a piece of conduit that measured .465 and wrapped one layer of masking tape around it, then applied a little Maas polishing creme and carefully spun it in the chamber, checked it, and repeated a few times. this either brought me back to original or got me to an exceptable finish. although the Hornady bullets still stick, i think they are more likely to blame. the chamber looks much better, remington fmj and federal fmj fit fine, tulammo is a little tighter. i am going to the range today and will see how it cycles and cleans up. thanks for the input.:mrgreen:


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## WI45 (Mar 1, 2012)

thanks Steve for the instructions, i'm going to give this a try.


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## tomwalshco (Aug 20, 2009)

I have 5 different 45s, all different manufacturers including Glock & Colt. I can drop any 45 round in any barrel and there is plenty of room. Not snug at all. After discharge the case expands a little making it even tighter. Too tight - extraction issues.

Possible your chamber was one of the last few done after the reamer bit was worn down, meaning narrow, out of spec chamber. Have someone else measure inside diameter of their CW 45 chamber and you'll get an idea.

I have 3 Kahrs and none of them run worth a crap when dirty and that means 100/150+ in a sitting. I don't mind. Didn't buy them to fight an army, just one at a time. I always polish my chambers with a mild paste.


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## WI45 (Mar 1, 2012)

yea, dang it, i traded a very nice glock 30sf for this and it shot anything with no complaints, i only cleaned it for the the fun of it. well, i've been working on the chamber and its getting better, the tulammo fits now, and as long as i can shoot the remington hollow points i guess i'm good for the road. thanks for all the help gang.:smt1099


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