Been reloading 200gr. plated flat points from various mfg. for years without a problem in 3 1911's and a SIG P220, always to a 1.200 overall length. Not long ago I purchased a CZ97B whose throat is so short I needed to go 1.965 in order to pass the plunk test. Just figured it was the way CZ makes them but then a couple weeks ago a good friend purchased a new Ruger commander 1911 that exhibits the same problem. Are shorter .45 ACP throats becoming a standard?
.45 ACP throats
- Thread starter Brutus
- Start date
Don't know. All of them need to meet SAAMI specifications.
Were these the same bullet you had previously loaded longer?
I load almost all L-RNFP at 1.241".
The only times I load short are:
H&G 130 L-SWC (with a "button" nose) at 1.152"
and ,
200gn Sierra Match FPJ at 1.155".
So, at least you didn't load them at your standard COL of 1.240" for RNFP and find you needed 1.150"...
Were these the same bullet you had previously loaded longer?
I load almost all L-RNFP at 1.241".
The only times I load short are:
H&G 130 L-SWC (with a "button" nose) at 1.152"
and ,
200gn Sierra Match FPJ at 1.155".
So, at least you didn't load them at your standard COL of 1.240" for RNFP and find you needed 1.150"...
chris in va
New member
The 97b has a notoriously short leade, almost nonexistent. You have to load just below plunk test for them to chamber properly.
I had a heck of a time when first casting for my 75bd. I was using a RNFP style 9mm and it wouldn't pass until 1.04. Yikes.
I had a heck of a time when first casting for my 75bd. I was using a RNFP style 9mm and it wouldn't pass until 1.04. Yikes.
I have a Clymer 45 Auto throating reamer. It used to be common for bull's eye shooters to have one run into military barrels before fitting them up in order to be rid of the short throat. A tiny bit of added freebore lets the bullet shoulder center in the throat, which increases accuracy.
I am not a great fan of the plunk test. It works out that after the barrel fit slop allowed for barrel interchangeability is included, many 1911's and other 45 Autos have excess headspace clearance such that during firing the extractor hook actually stops the rim of the cartridge from being driven forward by the firing pin before the case reaches the end of the chamber. So, by making sure your cartridges will "plunk" their case mouths at the end of the chamber, in these guns you are merely guaranteeing you will be headspacing off the extractor hook. This does not seem to affect jacketed bullet performance measurably in the 45 Auto, though it may in higher pressure rounds and it increases the risk of having an extractor hook breakage at some point. Lead bullets, though, wind up swaging into the bore at a slight tilt because the extractor pulls the cartridge alignment to the side if the bullet shoulder isn't already in the throat to align it with the bore axis. This also shaves bullet lead off against the edge of the throat and unbalances lead bullets just enough to open groups up significantly.
Back in the 80's I was using my share of a bulk purchase of swaged 185 grain Star bullets for conventional pistol gallery matches (50 ft, indoors). From my accurized Goldcup, these soft, stubby bullets grouped 10 shots into about 1.8" C.T.C. at 50 feet off bench bags. When I hit on seating out to headspace on the bullets, 10-shot groups dropped to about 1.1" C.T.C. off the bags. These bullets were not nearly as accurate as the 200 grain H&G 68 cast bullet design, which would group 10 shots into about 2.5" at 50 yards when seated to headspace on the bullet, but more like 3.5" when seated to "plunk".
The only things you have to be careful about are that your throat is not so long that loading to headspace on the bullet causes magazine fit problems or feed failures. (See third image from left.)
I am not a great fan of the plunk test. It works out that after the barrel fit slop allowed for barrel interchangeability is included, many 1911's and other 45 Autos have excess headspace clearance such that during firing the extractor hook actually stops the rim of the cartridge from being driven forward by the firing pin before the case reaches the end of the chamber. So, by making sure your cartridges will "plunk" their case mouths at the end of the chamber, in these guns you are merely guaranteeing you will be headspacing off the extractor hook. This does not seem to affect jacketed bullet performance measurably in the 45 Auto, though it may in higher pressure rounds and it increases the risk of having an extractor hook breakage at some point. Lead bullets, though, wind up swaging into the bore at a slight tilt because the extractor pulls the cartridge alignment to the side if the bullet shoulder isn't already in the throat to align it with the bore axis. This also shaves bullet lead off against the edge of the throat and unbalances lead bullets just enough to open groups up significantly.
Back in the 80's I was using my share of a bulk purchase of swaged 185 grain Star bullets for conventional pistol gallery matches (50 ft, indoors). From my accurized Goldcup, these soft, stubby bullets grouped 10 shots into about 1.8" C.T.C. at 50 feet off bench bags. When I hit on seating out to headspace on the bullets, 10-shot groups dropped to about 1.1" C.T.C. off the bags. These bullets were not nearly as accurate as the 200 grain H&G 68 cast bullet design, which would group 10 shots into about 2.5" at 50 yards when seated to headspace on the bullet, but more like 3.5" when seated to "plunk".
The only things you have to be careful about are that your throat is not so long that loading to headspace on the bullet causes magazine fit problems or feed failures. (See third image from left.)