C.O.L. question on .45 auto


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Rescue6
June 15, 2013, 08:02 PM
So I have two reloading manuals and one gives cartridge overall length for the loads and the other gives a length and then says that overall length may need to be changed for the re-loaders pistol. the first book lists length at 1.210 and says can be adjusted for pistol, the other just gives max length at 1.275 I am using 6gr of unique powder and a 230gr plated round nose projectile to start.

How much will the overall length make to pressures?
What length do most of you start with?

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steve4102
June 15, 2013, 08:27 PM
OAL is bullet a firearm specific, not manual specific. Find the longest OAL that fits-feed -fires in your pistol, then start low and work up. After all if it doesn't fit, feed and fire, there is no need to worry about pressure.

rcmodel
June 15, 2013, 08:27 PM
It all depends on the bullet shape.

230 grain U.S.GI issue RN-FMJ ammo was loaded to an OAL of 1.265" - 1.271".

Your 1.275" measurement is the SAAMI MAx length that will fit in any magazine with that bullet shape.

You run into problems when you change the bullet shape or ogive profile.
Even a little bit.

JHP and flat points have to be seated shorter to miss hitting the rifling leade when chambered.

Some 230 JRN use a different more rounded ogive shape then the G.I. bullet and have to be seated shorter too.

You need to do the 'Plunk Test' in your barrel, with it out of the gun, to figure out how long you can seat the bullet shape you have.

Your load needs to drop in your chamber to full depth with a 'Plunk' and stop with the case rim even or flush with the back of the barrel hood.

Then, it needs to fall out on the bench of it's own weight with a 'Plunk' when you turn the barrel chamber down.

Seat as long as you can below 1.275" for best feeding in most guns with RN bullets.

Your 6.0 Unique / 230 JRN load will not be effected pressure wise at any normal seating depth that still looks halfway right to a discerning eye that ever looked at a .230 grain .45 ACP load before..

rc

James2
June 15, 2013, 08:31 PM
I would choose a load from the middle of the chart and load one at the long length, then see if it is going to work in the magazine and if it will feed. If it will I would load up a clip full and go shoot them and see if they function and if they feed. Look for signs of pressure.

If you need the shorter length, I would pick a load from near the low end. I really have no idea how much a little difference in seating depth changes the pressures, but don't think you will have any problems unless you are going for the top velocity loads.

As usual, start low and work up. My manual suggests 5.4 gr Unique with that bullet. (mid load 1.30 length) 6.1 max. I don't think I would start at 6.

Lj1941
June 15, 2013, 08:33 PM
I would start at 1.27 and use the barrel as a length guage.As long as it goes in the barrel OK and goes in your magazines without binding, you should be good to go. The 230 RN is what the cartridge was designed for and should feed in most any pistol.:evil:

Reefinmike
June 15, 2013, 08:37 PM
It all varies between each manufacturers bullets and bullet profiles. For example, the 230gr lead truncated cone 45's I load are seated to 1.170, 185 grain Montana gold JHP are loaded to 1.230 and a factory 230gr federal ball round I found at the range is loaded to 1.262. Proper bullet seating depth varies with both the gun and bullets you are using. For example, rainier plated 230 gr 45's may need to be seated deeper than berrys 230 gr plated. Tailor the round to your gun such that the bullet is seated just deep enough that the bullet does not come into contact with the rifling when chambered.

when loading you first round, seat it long, pull the barrel out of your gun and do the classic plunk test. As long as its seated long enough, the first time you drop it in the barrel, it wont make a plunk noise nor will it freely drop out when the barrel is tilted. little by little, seat the bullet deeper while checking them in the barrel inbetween. once you hear it drop freely in the barrel and make a plunk noise and freely drop out when you tilt the barrel, you are at the right spot for your gun. load a few more and check them to ensure that you arent right at the very max OAL as your rounds will tend to vary .003-.005 in OAL.

Reloadron
June 15, 2013, 08:49 PM
1.275" (32.39mm) is the SAAMI specification Maximum Cartridge Overall Length for the .45 ACP cartridge. The dimensions can be found here. (http://en.wikipedia.org/wiki/.45_ACP) That maximum is regardless of bullet weight. Loading manuals generally show the COL the particular bullet was tested at. For example the Speer #12 shows COL Tested At for a 230 Grain TMJ bullet as 1.260" for their loading data. My Lyman manual shows a COL of 1.275 for their loading data for the same bullet.

Unique in the Speer #12 manual ranges from 5.5 to 6.5 grains with their COL tested at 1.260". Unique in the Lyman manual ranges from 5.9 to 6.6 grains with their COL tested at 1.275". This makes sense as while the Lyman maximum load exceeds the Speer load by .1 grain for the same bullet the Lyman load with a COL of .015" greater would have slightly more case volume.

This is only an example. You would work up your loads based on the bullets and cases you have.

<EDIT> Started typing with 0 replies, took a phone call and posted 6 replies later. You guys are quick! :) </EDIT>

Ron

Rescue6
June 15, 2013, 10:59 PM
Thanks for the help everyone. I will do the barrel drop tests in all of my .45's I want to load so that the rounds work in all of my Glocks and 1911's. I am just starting out so all of the help is appreciated

mljdeckard
June 15, 2013, 11:07 PM
What I had to do was find out (THE HARD WAY) which of my .45s was the most finicky. between me and my friends we have about 5 .45s that might taste my handloads, and I got it right in my carry gun, but when I went to try the same loads in a couple of other guns, it didn't work. They would fail to go into battery, and sometimes stick, and I had to force it open by holding the slide and pounding the butt against something solid. (Once I even yanked out the bullet, left it stuck in the end of the barrel, and powder spilled all over the place. Yeah.) I tried various tricks and asked for help in here, and I finally got it right, and they functioned well in all pistols except one. (My commemorative Para SF-45A.) For that one, I had to get a Lee Factory Crimp Die. Not for better crimping or OAL problems, but because it does a final stage re-shaping.

Then I had to cycle out all of the old loads, to make sure I didn't try to shoot them in that gun AGAIN. By the way, the worst ones were 230 gr plated lead flat nose bullets, which as RC said, have a longer stretch to the ogive.

JDGray
June 16, 2013, 08:19 AM
I have found 1.250" to work with RN bullets, never ever a problem. Trying to stretch it out, with a less pointy round nose, will get you an out of battery problem for sure. Its all in the profile of the bullet.;)

Twmaster
June 20, 2013, 08:41 PM
(My commemorative Para SF-45A.) For that one, I had to get a Lee Factory Crimp Die. Not for better crimping or OAL problems, but because it does a final stage re-shaping.

(Sorry if this is a thread hijack..)

What sort of issues were you having with that Para? I've got a P14.45 that is more finicky than Morris The Cat. So if you could shed some insight I'd appreciate it.

RainDodger
June 21, 2013, 07:58 PM
Yeah, listen to rcmodel. My standard 230 gr FMJ hand loads were originally 1.271" long and function absolutely flawlessly in my custom Springfield that has a Wilson comp barrel in it. I worked it up and used the longest OAL I could and it is 100% reliable in that pistol.

Fast forward to the last 6 months in which I have added 2 more 1911s to my small-but-growing arsenal. That Wilson chamber is longer than the 2 I just got, so I had to literally re-seat thousands of bullets just a few thousandths of an inch shorter. (or more likely the lands don't taper as much into the chamber as the Wilson barrel, etc.)

Moral of the story: If you own more than one 1911, be sure and do the plunk test in both barrels. It could save you a few evenings at the press.

Magnum Shooter
June 22, 2013, 05:04 AM
I have found 1.250" to work with RN bullets, never ever a problem.


Me too

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