Overall cartridge length

[Denny4kids]

I check all my pistol reloads before and after they are loaded. I use a single gauge for my 10mm and a 20 hole for my 9mm. I can check 300 rounds of 9mm real fast. Here is a link so you can see what the 20 hole looks like. Denny

http://www.dawsonprecision.com/ProductDetail.jsp?LISTID=80000FE9-1304967670

 

[bigdogdaddy]

Thanks for the link Denny. As for the trim you mention millsriver, I am assuming that you are referring to trimming the length of the brass case. Not sure if it is because of the low pressure of a .45 acp round or something else, but my .45 brass never has needed trimmed. In fact, some measures a hair under the specific length measurement.

 

[bigdogdaddy]

BTW Denny, the link reminded me of a lucky deal I just ran into. I own a business where I sell & install invisible type fencing for dogs. I sell a lot of batteries for my collars, probably close to 1000 every year. Well just recently my battery source started sending my batteries in these nice little blue plastic boxes with a snap lid. Upon closer inspection I realized they are actually ammo boxes. Imagine how happy I was when I looked at the writing and it said 10mm or .45 acp! So I will not be using my recycled cardboard ammo boxes much longer. ;D

 

[Denny4kids]

Bigdog that’s a good score on the box's. I got my 10mm/45 box's the hard way, I thought they were 9mm when I bought them. It's all good.
I'm pretty new to reloading and I have never had to trim a pistol case. The reason that I run each cartridge through a gauge is to check for a deformed case like a bulge or a rolled over neck where the bullet is seated and of course the case length.
I had a Winchester white box round fail to chamber in a match one time and it took two racks of the slide and two wasted rounds to clear. After we scored my stage, a bud came to me a said good save! At first I wasn't sure what he meant and then realized I cleared a jam without thinking or taking my eyes off the targets. Besides being fun, this competition stuff is training me very well. Denny

 

[Herk]

I thought it would be better to bump an old thread than to create a new one on a topic that's already been covered:

Yesterday I went to the range before work and tested some handloads. I'd made up six different loads. The difference between them was powder charge and overall length of the cartridge (COAL). I did a "plunk test" to determine my max COAL:

Going by the advice in this guy's vid, my max COAL was 1.14", which I loaded three of the loads to. After looking at them, I thought they just didn't look right: the bullet's wax groove was sticking way out the end of the case and that didn't seem right so I made the three loads again but with a COAL of 1.06", which placed the wax ring just inside the case mouth.

The longer COAL rounds were a) unreliable (had to smack the slide shut after almost every round), b) inaccurate (all loads printed high, some rounds going over the top of the paper), and c) inconsistent (groups ranged from 4-7", not counting the rounds that went over top of the paper, which I can't measure, of course).

By contrast, the shorter rounds were a) 100% reliable, b) shooting to POA, and c) giving me groups of about 2.5".

The recoil of the shorter rounds was quite nice and there were no obvious signs of high pressure.

Is that Plunk Test a bunch of voodoo? After doing it I learned how long of a cartridge I could load, but the stuff I made up was worse in every way than the ammo whose COAL I came up with by seating the bullet deeper and deeper until I thought to myself "Yep, that looks about right." There's lots of info online about rifle COAL but not so much for pistol. Is there any scientific reason to pick a COAL/seating depth with pistol rounds or is what I did (i.e.: throw spaghetti at the wall and see if it sticks) as good a method as any? I could see being more cautious if you were using a max powder charge, but I wasn't even close.

 

[dial1911]

I didn't watch the video.

But you've got to be careful with smokeless powder. It has a funny characteristic in that the higher the pressure, the faster it burns.

So reduced volume inside the case, i.e. deeper seating depth, can cause powder to be consumed faster and create even higher pressures (like over the top pressure).

A reloading recipe for a specific bullet should list the COAL for the loaded round. That is about as important as how much powder you put in the case.

 

[dial1911]

Fucking youtube experts.... he kind of touched on it when he says "more space makes a shower round"... well, he should have said with emphasis that you don't load then short with out the opposite effect. And i would have said very clearly that if you're going to load shorter than the recipe, start low on the powder charge and work your way up.

Someone loading hot rounds that followed his advice might not be happy. These are pistol rounds, so they are generally fairly low pressure. Well, at least not the same as a rifle round.

 

[Herk]

Is there a way to measure pressure? I know you can measure velocity with a chronograph but I assume that doesn't necessarily tell you anything about pressure. I've also seen flattened primers as a sign of high pressure; is that a good indicator? Isn't loading too long also potentially a pressure issue? If the bullet starts out pressed against the rifling then there's more resistance to get moving and so pressure spikes, right?

 

[dial1911]

Is there a way to measure pressure? I know you can measure velocity with a chronograph but I assume that doesn't necessarily tell you anything about pressure. I've also seen flattened primers as a sign of high pressure; is that a good indicator? Isn't loading too long also potentially a pressure issue? If the bullet starts out pressed against the rifling then there's more resistance to get moving and so pressure spikes, right?

Yes, too long can be a problem too. Although i have not tested this, I'm not sure you could get rounds that long into a standard mag. I've seen long rounds be a problem in bolt actions though.

Cratered primers, flattened primers, blown out primers, shiny spots in the back of the brass (almost exclusive to rotary actions), split brass, bulged brass at the base, etc. are all high pressure signs.

Edit- can't test pressure without a special rig. Chrono speed is a very good indicator that you are in the good pressure range.

 

[Herk]

I think a friend of mine has a chrono but he's in the process of moving so it's probably packed up right now. Once he's completed the move I'll bug him to let me use it. In the mean time, I'm happy to say that my brass looks fine; none of the signs that you listed.

Another thing I thought of: what about recoil impulse? I've loaded some +P/max loads before and the muzzle flip was A LOT more than what I'm used to. These current loads are about what I'm used to from factory ammo, so is that an indicator that the pressure is *probably* fine? Not measurable or objective, I know, but it's something...

 

[Herk]

Today I was loading up some 10mm Auto and I made about 100 rounds with Federal brass, no problem. The COAL stayed consistent and all seemed to be going well. I had a bit of Remington brass lying around and so I thought I'd load some of that too. With the die still in the press at the same settings as I loaded the Federal brass with, I tried loading the Remington brass and the bullet just fell into the case, about as far as it could. I made three rounds that way and then gave up.

What would make the bullet just fall in like that? Does Remington brass just suck or something? I've loaded plenty of 9mm Remington brass with no issues, so what gives?

 

[Herk]

Also, I learned that my Hornady 9mm dies have a crimp feature built into the seating die but the 10mm dies, also Hornady, do not. Is the lack of crimp feature perhaps to blame for the bullet-falls-in-case problem? It's just odd that the problem only arises with one kind of brass.

 

[Miles]

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[Herk]

I did some reading online it people were saying that some Hornady dies have the crimp feature and some don't. They also said that the die sets that have the crimp feature will say "Taper Crimp" on the box; my 9mm Hornady dies say that but the 10mm dies don't. Also, I followed the instructions (which totally suck, BTW; Hornady needs to redo those) and didn't get a crimp on my 10mm loads like I get on the 9mm. All I really got was the die being screwed farther in without any real effect that I could see or feel on the cases. On the 9mm, I can feel slight resistance when pulling the case out of the crimp die, like the round has been lightly "grabbed". On the 10mm, it just seems to hit a wall and then it comes back out with no resistance.

As for changing the the expander die, I didn't change it from the Federal brass to the Remington. The bell was so slight that I wondered if I had gone too light on it, but it allowed a bullet to just barely start in the case, which I was told is all the expander is supposed to do. If anything, the resistance that I felt with the Remington brass in the expander die was less than with the Federal and the "bell" was less too.

 

[Miles]

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[Herk]

I haven't weighed the empty cases so that something I could try. I haven't kept track of how much each of the cases has been reloaded but I haven't reloaded all that much 10mm yet so I'm not sure that I've even loaded any case more than once (I think the most I would have done would be twice).
The sizing die and settings for that die were the same though.

I thought that straight-walled pistol brass didn't stretch in length? I thought that was just a bottle-neck rifle thing.

 

[lesptr]

The Dillon carbide die set has a seating die and a crimping die (taper).
Dillon seating dies don’t crimp.

 

[lesptr]

I haven't weighed the empty cases so that something I could try. I haven't kept track of how much each of the cases has been reloaded but I haven't reloaded all that much 10mm yet so I'm not sure that I've even loaded any case more than once (I think the most I would have done would be twice).
The sizing die and settings for that die were the same though.

I thought that straight-walled pistol brass didn't stretch in length? I thought that was just a bottle-neck rifle thing.

I have never had to trim pistol brass to length. But I only load 9, 45, 357, 38, and 32s&w long. I wouldn’t think 10mm would need trimming either.

 

[Herk]

A couple of follow-ups here:

First, I weighed a selection of brass by brand. I weighed ten cases from Armscor, CORBON, Starline, Federal, Winchester, Top Brass, and PPU. The Remington, which caused me seating problems, I couldn't find any more of in my stash but the PPU exhibited very similar tension issues in the past.



As you can see, the Armscor was the most consistent in terms of weight by far and the Federal the least consistent. Both of these brands of brass have been fine in terms of seating correctly for me in the past. Federal also turned in the heaviest single piece of brass as well as the fourth lightest! Again, not consistent in terms of weight.

The PPU, which has had seating issues for me, turned in the lightest average brass, which might indeed be an indication of something. It also had the second highest extreme spread, though it was still nearly half that of Federal's.

My second bit of news is that I got a Lee crimp die and used it on my current batch of loads. The Remington and PPU stuff, with which I could previously press the bullet into the case with my finger, is now crimped tight enough to prevent that while still leaving a "ledge" on the case mouth for headspacing. I will have to see if these rounds can withstand the force of getting chambered before deciding for sure that my crimp is appropriate.