Short Colt .45 brass

C

cdoc42

New member
I measured 50 fired Colt .45 cases and all were less than 1.270 inches, the minimum SAAMI length. These have all been fired and resized at least 3 times.

Here’s 10, pre- and post- sized:

Winchester
Pre- post-
1.249 1.256
1.254 1.258
1.257 1.268
1.265 1.272
1.264 1.273

R-P
1.263 1.268
1.262 1.269
1.260 1.266
1.258 1.267
1.259 1.268

I recall Unclenick advising that pistol brass gets shorter with firing, but is that also true of revolver brass?
 
cdoc42 said:
I recall Unclenick advising that pistol brass gets shorter with firing, but is that also true of revolver brass?
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From what I recall the shortening was from the case headspacing off the mouth, bringing the case head away from the breech face. Upon firing, the brass slams against the breech and shrinks. In a revolver that headspaces off the rim, the rim holds the case head against the breech face, so there really isn't space for the case head to slam against the breech face, nor is there the extractor groove, which is where the 45acp shortened.

That's just me remembering that post and thinking through the differences.

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In a revolver that headspaces off the rim, the rim holds the case head against the breech face, so there really isn't space for the case head to slam against the breech face...
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There has to be space between the case head and breech face, otherwise cylinder rotation would be difficult.

Don
 
USSR said:
There has to be space between the case head and breech face, otherwise cylinder rotation would be difficult.

Don
Click to expand...
Right, and I am aware of that. Hmmm... I'm going to measure some 454 casull. See if I can fire a single piece and measure if it shrinks it grows. There will be a hell of a slam of that case head against the breech, bit I think with straight wall there isn't that extractor groove that acts as a crumple zone

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After I posted this I recalled we had a discussion like this in the past and I hoped I didn't annoy anyone with a repeat.
 
Consider this,

The firing pin strike drives the case into the chamber, the rim stops any forward movement. The case expands, sealing to the cylinder walls, under several thousand psi pressure, briefly. This counteracts some of the rearward thrust, so the case base doesn't "slam" into the recoil shield as hard as it might, with a normal pressure load.

It does contact the shield, but "bounces back" a bit when the pressure drops as the bullet leaves the barrel, allowing the cylinder to turn.

Straight wall cases don't act exactly like bottleneck cases, which, due to their shape, provide a shoulder for the pressure to push against, which results in more force applied to the base of the case than a straight case (or very slightly tapered one).

The revolver design doesn't handle bottleneck cases very well. Other designs do.

Revolvers are also very tolerant of "shorter than spec" rimmed cases. If you have revolver brass shorter than SAAMI spec, just use it. The gun won't care. Adjust your dies to flare, seat and crimp for the length of brass you have, and remember to change things when you get different length brass.
 
Thanks, 44 and nhyrum, great and useful advice.

This is probably pushing the envelope of useful interest, but from the measurements I made, the Winchester cases grew anywhere from 0.004 to 0.011 inches while Remington cases grew 0.005-0.009." The average of both groups, however, was 0.0076 for Winchester and 0.0072 for R-P. I surmise the difference is due to manufacturing procedures similar to those that produce rifle cases with thicker walls, etc. Of course, this only involved 10 cases.

I suppose I should trim all cases to the same length and reassess the rate of growth between manufacturers, if any, but since, so far, I have not seen any problem with accuracy from 10-15 yards shooting at water-filled plastic containers, I should look for something more useful to do.....
 
For a case not to grow the way a rifle case grows, it simply needs to have pressure too low to stick the case walls to the chamber walls (usually given as being in the vicinity of 30,000 psi, but it is higher for straight wall cases than for bottleneck case which have some forward pressure against the inside of the shoulder). Then stretching where the brass gets thick near the head does not occur and you get no pressure ring stretch adding length to the case as it does with a rifle.

But other things can create stretch, even at lower pressures. Significant factors with pistol brass shrinking are that the cases are short and the crimps used are lighter and release the bullet at lower pressure than heavy roll crimps do. If you have a long case and a strong roll crimp and a heavy bullet, and especially if you have a fairly wide chamber, the case can swell to chamber diameter while pressure forward against the bullet and crimp and the bullet's inertia help maintain the case's length. These mitigate how far the lateral expansion can pull the case mouth to the rear as far as it would otherwise try do upon expansion. The result is the brass yields laterally to thin the sides of the case. A long case means a long diametrically swollen piece of brass that will subsequently be narrowed and squeezed forward by the resizing die. The longer that swollen part is, the more growth you will get from that squeeze. For example, despite the SAAMI standard pressure being too low for pressure ring stretch, the 45-70 grows to need trimming.

My .357 brass simply doesn't change length appreciably before case mouths start to split from all the roll crimping and the brass has to be retired. I have some I've used for wadcutter loads that lasts longer because it gets taper-crimped, but the light loads don't swell the case much on firing so it doesn't seem to change length, either. I don't recall noting what my 44 Magnum brass does, but I wouldn't be surprised if it grew a bit. I would expect it to grow less in my Encore barrel than in the revolvers.
 
Noting above that I said I should look for something more useful to do, I migrated to the following, and although it might be considered by some to be "busy work," at least I learned one cannot simply measure 10 cases, as I originally reported, to obtain any meaningful information.

I had 129 fired cases; I resized and flared the mouths, then measured all of them.

As previously mentioned, the SAAMI range for a .45 Colt case is 1.270-1.280 inches, with a target being 1.275.

Cases less than 1.270 = 15%
1.270-1.273 = 15%
1.274 -1.276 =50%
1.277-1.280 = 20% (only one case was 1.280")

So I had 20 cases shorter than 1.270.

I reloaded 18 cases that measured 1.275" and fired them. They all measured 1.270 to 1.272"so they did get shorter. When I resized them, they all measured 1.275 or 1.276.

What did I learn? I have 109 out of 129 cases with sizes that I really don't have to worry about. I should trash the 20 cases shorter than 1.270" (one is 1.258") unless I want to take the time to change the crimp setting.

Of the other 109, only 1 - the 1.280" - should be trimmed to 1.275". The only time I might need to measure the remainder after resizing is when I expand the case mouth, I feel less resistance (shorter case)or more resistance (longer case), but it appears this group of cases will shorten with firing, then lengthen with resizing, and remain in the SAAMI range of 1.270 to 1.280".

Thoughts?
 
What did I learn? I have 109 out of 129 cases with sizes that I really don't have to worry about. I should trash the 20 cases shorter than 1.270" (one is 1.258") unless I want to take the time to change the crimp setting.
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Trash perfectly good .45 Colt brass? Sacre Bleu! You're making a mountain out of a mole hill. Unless you are shooting in competition with your .45 Colt (highly unlikely), you will simply have a hair less of a crimp with the slightly short brass. Nothing of any consequence.

Don
 
No need to trash them, and I wouldn't change crimp for them either. Keep em, shoot em and load em with the rest

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You have 20; that's a good start. Just set them aside. When the case mouths crack on your "good" brass, add those to the pile. At some point, trim them all down to .45 Schofield length. You have a new life for your worn out brass and can keep adding to it.

Some cowboy action shooters trim their brass even shorter. I think they call it a ".45 Cowboy Special"
 
Some cowboy action shooters trim their brass even shorter. I think they call it a ".45 Cowboy Special"
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Actually, the .45 Cowboy Special is a case all on it's own that is sold by Starline, with a length identical to a .45 ACP case. That's a whole lot of trimming to bring a .45 Colt case down that short.

Don
 
As previously mentioned, the SAAMI range for a .45 Colt case is 1.270-1.280 inches, with a target being 1.275.
Click to expand...

I wonder where the 0.005" went??

My old Lyman manual (1970) says max length for .45 Colt is 1.285" Trim to length is 1.280".

So do my books from the 80s, 90s, and 2012 and 2016. All say 1.285".

WIKIPEDIA says 1.285".

so, where does this "SAAMI says 1.280" come from?

Typo?? or some other mistake??

If you've got brass too short, and don't want to adjust your dies just for them, toss them in a baggie (labled with length) and when you get other cases too short (and you will...) add them to the bag. Eventually you'll have a box worth or more, where it will be worth your time to adjust to load them. Or sell/trade them as excess to need. All you get throwing them out is throwing away some money for no good reason.
 
I took this off the SAAMI web site just a few minutes ago:

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In a previous discussion on this subject, I recall that Unclenick had given the SAAMI dimensions and ended with the recommendation that 1.275" was a reasonable targeted length. That's what I recalled and I assumed that would be the middle of the both extremes. Maybe I misunderstood him and he said a target "trim to" would be 1.275"

But if the real max length is 1.285, trim to 1.280, that really screws my load of brass up. I have 20 unfired, new, Winchester .45 Colt brass that all measure 1.276". Not to mention only one fired and resized case out of 129 was 1.280" and 53% were under 1.275." They would probably NEVER get to 1.285"-?

But, from what everyone added thus far it seems like this much to do about nothing. When I first started to load for the Thomas/Uberti model 1873 I did have a round where the bullet advanced from recoil to block the cylinder rotation. Most likely that was a short case with an insufficient crimp. So as advised, if I cull the real shorties out and put them aside until I need to change the crimp, that makes sense.

Sorry for all the confusion. I'm getting to be one of those more mature members of our society that experience more frequent brain farts.
 
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There are times when I get frustrated with "SAAMI specs" or "SAAMI says..." though it probably not so much SAAMI but people's interpretation of what they see written.

One factor is that SAAMI dimension specs include the tolerances. If you look at the document Uncle Nick downloaded, you find the case length to be
"1.285 - .020"

Now, as I understand it (and, PLEASE correct me if I am wrong) this indicates a maximum length of 1.285" with cases up to .020" shorter being allowable.

And these are specs for ammo and gun MAKERS.

Our loading manuals take a slightly simpler approach, giving the listed max length, only.

Adding to the confusion is the fact that you will almost never get new brass or loaded ammo that reaches the listed max lengths. It is almost always shorter than the industry max spec. And, this is intentional. By being under listed max dimensions it helps ensure their round will fit into all the chambers it may likely encounter.

It is not a flaw, its a "feature" and along with chambering, it also helps ensure that any case stretch during firing will not create an immediately dangerous situation.

When working with straight case rimmed rounds the exact case length (below listed max length) is only a critical measurement when you are loading the brass, not when chambering or firing. A little short makes a difference when flaring, seating and crimping, but not once its in the gun.

Think .38 Special and .357 Magnum, for a common example. There are several combinations of cartridges where they are essentially the same size, other than length. Most are revolver rounds, but not all.

.22 Short, .22 Long, and .22LR are another example. ALL guns chambered for the LR will chamber and fire the shorter rounds. Many will also FEED the shorter rounds, but some will not due to the design of their feed systems.

You are entirely right to ask the question, as it seems like something isn't right. But it is, and of no concern USING short cased ammo in your guns. It is only a concern when you are reloading the brass, and there are ways to deal with that, which I've already mentioned.

Hope this helps, make things clear as mud now right? :D
 
No, that clears it up spectacularly! That means the SAAMI lower limit can be 1.265" and the middle of that and the high end of 1.285 is.......drum roll......1.275" which is what I recalled from Unclenick's post.

So, therefore, cases between 1.265 and 1.285 are ok to use; the only concern being will a satisfactory crimp at 1.275 or above hold those bullets in place in shorter cases?

No apparent danger to the user, just inconvenience if the cylinder won't turn. Is that it, in a nutshell?
 
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