Reloading 9mm Luger problem

[mehavey]

...thickness of the rim?

Uuuhh... make the case rimless?

That said, I do have to check/accommodate different bullet shapes/ogives
with both cast and "non-traditional" 9mm bullets (like some of Berry's)

No big deal, I just record that bullet's req'd OAL in "The Book"

As to powder charge differences, that's where calipers/QuickLoad/chronograph come
into play along w/ judgement to stay within bounds/reasonable expectations.

 

[HighValleyRanch]

Some of you are making a mountain out of molehill.
Perhaps I should have said the thickness of the base of the case on the "rimless 9mm,.....but I guess you couldn't figure it out, so....
According to Wikipedia, that little rim that the extractor catches onto on the "rimless" 9mm is actually by anyone's definition a RIM.


Wikipedia states:
A rim is an external flange that is machined, cast, molded, stamped, or pressed around the bottom of a firearms cartridge. Thus, rimmed cartridges are sometimes called "flanged" cartridges. Almost all cartridges feature an extractor or headspacing rim, in spite of the fact that some cartridges are known as "rimless cartridges". The rim may serve a number of purposes, including providing a lip for the extractor to engage, and sometimes serving to headspace the cartridge.

Also note #4, the RIM

 

[44 AMP]

Perhaps I should have said the thickness of the base of the case...

Perhaps you should have.

because what you seem to be asking about is the case web forming the bottom of the powder space. Rim sent me in an entirely different direction.

In common use, cases are described as rimmed, semi rimmed, rimless, and rebated rim. Flanged is the British term for a rimmed case.

"rimless" cases do have a rim, and are called rimless because the rim is either the same diameter as the case head or very slightly larger. Many rounds called "rimless" have rims spec'd at 0.003" larger than case head diameter.

Semi rimmed cases have small projecting rim that is approx 0.1" larger in diameter than the case head. The only ones I know of in production these days are the .25ACP, .32ACP and .38 Super /.38ACP.

Browning designed the cases before he was convinced that headspacing on the case mouth would work reliably, so he included a small projecting rim. After the 9mm Luger proved headspacing on the case mouth was reliable, Browning's later designs, the .380 ACP and the .45ACP were "rimless" designs.

Rebated rim cases use a case rim diameter that is actually smaller than the case head diameter.

And rimmed cases are obvious due to the larger diameter rims.

None of this has anything to do with the internal powder capacity of a case. Rims are external features.

 

[jetinteriorguy]

Good advice, but how do you determine the powder level using what measurement methods?
Marking the case with a permanent marker would not be fine enough, IMHO because of the width and variance of the magic marker.
And how do you account for the thickness of the rim?

Or do you simple use a depth gauge from the top of the case to the powder level?

I drop a wood dowel in the empty case and mark where the rim of the case sits with a very sharp pencil. Then using this ‘rough’ measurement with a caliper I just do the math using the case length,Bullet OAL and the seating depth of the bullet. I do realize this isn’t an exact method, but that’s why I usually load to 90% of this space to allow for variances in bullets and differing brands of brass. So far after around 100,000 rounds loaded and shot using this method I haven’t had any issues with excessive pressure. As far as accuracy, in pistols if I can rapid fire a full mag/cylinder into a six inch circle at up to 15 yds it meets my pistol requirements. Although I have shot a torso sized steel target at 100yds with my LC9s with about a 50% hit ratio, but that was an exceptional day where I was fortunate enough to impress my nephew with my ability. Those days don’t come around very often anymore.

 

[HighValleyRanch]

^^^^^'
Thank you for answering my question without bitching about the terms I used!
I think I will use the depth gauge on my micrometer to measure the inside depth and then subtract the bullet length from the OAL, or is it COAL or C.O.A.L. or O.A.L

 

[mehavey]

- delete -

 

[Unclenick]

I drop a wood dowel in the empty case and mark where the rim of the case sits with a very sharp pencil.

Might you mean you mark the dowel at the level of the case mouth? Though, I suppose, technically, the case mouth has a rim, too, just not a flanged one.

HighValleyRanch:

A simple computation:

Seating Depth = Case Length + Bullet Length - COL

Determine your seating depth, as above, and open your caliper jaws to that number. Park the back of the beam on the edge of the case mouth and add powder until it is level with the beam. Weigh the charge, and you will know how much you can put in before you start compressing the load.

Note that the above will change with cases, so you want to find a range. Sample some of your heaviest and lightest cases to get some idea of what difference you are dealing with. There is no commercial case capacity specification; just exterior dimension limits.

Note that powder density varies some by lot. Western Powders, before Hodgdon bought them, used to publish bulk density and its lot-to-lot tolerance, and ±5.6% (a span of 11.2%) was the largest one, and ±2.2% (4.4% span) was the smallest. So, you will have to make this determination again when you buy more powder.


AlanWK,

Do your resized and untrimmed but not yet expanded cases plunk into but protrude from the back end of the barrel? If so, take a caliper to them. If they do not exceed the SAAMI maximum case length of 0.745" but are sticking out and are plunking in without dragging on the sides of your chamber, the chamber is too short and out of spec. A gunsmith can fix that. But if they are longer than 0.745" at that point, it may be you have a tight (small base) resizing die, and it is squeezing the brass out too long, requiring you to trim. Still, you should only need to trim once with 9mm Luger cases, and they should be good to go using that resizing die after that.

 

[HighValleyRanch]

I can see this calculation working with a flat base bullet, but if it is hollow base, then how does this calculate into factoring how much powder before it is too compressed?

Some hollow base bullets are longer than the same grain flat base as the void mandates a longer bullet to achieve the same grain. So would one still just use the bullet length in the calculation?

 

[44 AMP]

how does this calculate into factoring how much powder before it is too compressed?

Other than you own standards, absent a manufacturer's specs, how do you figure a powder charge is "too compressed" without actually shooting it and seeing the results, good or bad??

 

[74A95]

Why the concern with whether the powder is compressed?

 

[rc]

Something like Blue Dot is compressed in 9mm but something like 231 tends to have a lot more room in the case. As long as I'm within book specs for powder charge I've never had a problem.

 

[jetinteriorguy]

Might you mean you mark the dowel at the level of the case mouth? Though, I suppose, technically, the case mouth has a rim, too, just not a flanged one.

HighValleyRanch:

A simple computation:

Seating Depth = Case Length + Bullet Length - COL

Determine your seating depth, as above, and open your caliper jaws to that number. Park the back of the beam on the edge of the case mouth and add powder until it is level with the beam. Weigh the charge, and you will know how much you can put in before you start compressing the load.

Note that the above will change with cases, so you want to find a range. Sample some of your heaviest and lightest cases to get some idea of what difference you are dealing with. There is no commercial case capacity specification; just exterior dimension limits.

Note that powder density varies some by lot. Western Powders, before Hodgdon bought them, used to publish bulk density and its lot-to-lot tolerance, and ±5.6% (a span of 11.2%) was the largest one, and ±2.2% (4.4% span) was the smallest. So, you will have to make this determination again when you buy more powder.


AlanWK,

Do your resized and untrimmed but not yet expanded cases plunk into but protrude from the back end of the barrel? If so, take a caliper to them. If they do not exceed the SAAMI maximum case length of 0.745" but are sticking out and are plunking in without dragging on the sides of your chamber, the chamber is too short and out of spec. A gunsmith can fix that. But if they are longer than 0.745" at that point, it may be you have a tight (small base) resizing die, and it is squeezing the brass out too long, requiring you to trim. Still, you should only need to trim once with 9mm Luger cases, and they should be good to go using that resizing die after that.

Of course, silly me, I should have said case mouth.

 

[jetinteriorguy]

Why the concern with whether the powder is compressed?

I’m just going by the Lyman 50th edition, bottom of page 40 and top of page 41. Now that being said I have played around with compressed charges in 9mm before with no problems. But, I’m not going to suggest someone else do this in a public forum that’s probably being read by a novice reloader who hasn’t quite learned how to judge signs of over pressure.

 

[74A95]

I’m just going by the Lyman 50th edition, bottom of page 40 and top of page 41. Now that being said I have played around with compressed charges in 9mm before with no problems. But, I’m not going to suggest someone else do this in a public forum that’s probably being read by a novice reloader who hasn’t quite learned how to judge signs of over pressure.

I'm surprised to see that in Lyman's guide. Some powder charges are normally compressed in handgun loads, and I have not seen that warning anywhere else in other guides.

Here is what Hodgdon says about compressed loads:

COMPRESSED LOADS
Normally a pistol or rifle shellcase is considered full, or 100% loading density, when the powder charge sits at the base of the bullet when the bullet is fully seated. It is possible with some powders and cartridges to increase the powder charge slightly above this point, such that when the bullet is seated it actually compresses the powder charge slightly. This condition is known as a compressed load.

Hodgdon notes in its reloading data if the subject charge is a compressed load. A full case, or lightly compressed charge is an ideal condition for creating loads with the most uniform velocities and pressures, and oftentimes, producing top accuracy.

https://www.hodgdonreloading.com/compressed-loads

Lyman also uses the term "overly" compressed loads, and that might be an issue with some powders. But compressed is not usually a problem, and it does not happen that often when following published load data. Generally, with most powders, the charge weight will reach maximum SAAMI pressure limits before the powder gets compressed anyway.

 

[44 AMP]

Generally, with most powders, the charge weight will reach maximum SAAMI pressure limits before the powder gets compressed anyway.

With most handguns cartridges and their powders, perhaps.

There are lots of rifle rounds where compressed loads are standard with certain powders.

 

[jetinteriorguy]

Compressing a load in a small case such as 9mm using some powders can be very touchy as well, Titegroup comes to mind with me since at a certain level of pressure it can get very spikey very fast and is quite unpredictable. Especially if someone is using range brass with mixed head stamps and varying degrees of interior space. Add in a new hand loader that is maybe a little overzealous with a crimp and boom.

 

[74A95]

Compressing a load in a small case such as 9mm using some powders can be very touchy as well, Titegroup comes to mind with me since at a certain level of pressure it can get very spikey very fast and is quite unpredictable. Especially if someone is using range brass with mixed head stamps and varying degrees of interior space. Add in a new hand loader that is maybe a little overzealous with a crimp and boom.

What's required here is actual pressure data. We can 'imagine' any scenario we want, but it has to be backed up with pressure test data. Is there data on how much crimp affects pressure with Titegroup?

 

[mehavey]

...how much crimp affects pressure with Titegroup?

As noted before, one does not crimp 9mm

 

[Recycled bullet]

Which one does not crimp 9 mm?

This one most assuredly does.

My crimps most definitely roll into the ogive of the projectile.

 

[tangolima]

Which one does not crimp 9 mm?

This one most assuredly does.

My crimps most definitely roll into the ogive of the projectile.

This doesn't sound kosher. 9mm headspaces on mouth. Roll crimp on to ogive ... This one is loading for revolver?

-TL

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