9mm oal differences

[Trevordc]

Hey everyone,

I'm new to the forum and somewhat new to reloading. I reloaded a lot in college on a friend's press--he had it all set up and all I did was pull the lever and make sure everything went where it should.

Now, I'm starting out on my own and have a question about overall length for 9mm.

I shoot an xdm 5.25 in 9mm. I bought Missouri Bullet Co. 115 grain lrn bullets. I always used Titegroup in college so that's what I bought this time. Brass is a mixture of once-fired and 2-3 times fired.

Minimum oal is 1.100 by the book. The problem is, my reloaded rounds won't chamber until they're 1.080, and the gun prefers 1.075-1.078.

I loaded 20 rounds with 4.0 grains Titegroup and shot them, checking for signs that anything was wrong. The bullets grouped far superior to factory rounds. One primer did come out of the primer pocket as the case was ejected and hit the cement. I don't know if that's due to high pressure or just an older, slightly loose primer pocket that I didn't notice when I loaded it.

I just don't like being this new to reloading and already being off the charts--using an oal below minimum. I've checked my powder measure 100 times and I'm right in the middle of the range for Titegroup (my Lee Pro Auto Disk measure won't get me lower without going below the minimum). At 4.0 grains, I'm actually at the lower end of the range.

Do you think I'm safe to drop the oal by this much and use 4.0 grains titegroup, or should I try something else?

Sorry for the long post, and thank you for your advice.

[g.willikers]

When you say the rounds won't chamber at lengths over 1.08", do you mean they won't fit the barrel chamber, or won't run through the gun?

[PA-Joe]

I believe that Missouri Bullets are lead or plated lead. They should be reloaded using lead bullet data. Each bullet maker uses a different shape bullet so you cannot interchange OALs. You should start with teh manufacturer's recommended OAL.

[jepp2]

Minimum oal is 1.100 by the book.

Keep in mind, that unless you are using exactly the same bullet as the load was developed with, even though you seat to the same OAL, your bullet seating depth is probably going to be different. Bullet seating depth determine peak pressure, not OAL.

TG is a fine powder, but like any of the other fast burning powders, it has a smaller margin for error. Using a mid burn rate powder can be more forgiving and might be a better choice for a newer reloader.

If you increase bullet seating depth (which would reduce OAL), the pressure is going to higher. How qualified are you to read pressure signs? How much setback are you getting? Setback further increases peak pressure. If you aren't checking how do you know?

I load for many different 9mm. I don't have my max OAL for MB 125 gr. LRN, but I have it for SNS equivalent bullet. As you can see, my max length for a wide variety of pistols is the SAAMI max of 1.169". So I also have to question why your OAL max is so short?

[Trevordc]

When I said lengths greater than 1.08 would not chamber, I was describing two tests:
First, with the barrel removed, I compared a factory round with a hand loaded round at different OAL's. No length greater than 1.08 would compare to a factory round.
Second, I have made many dummy rounds of various lengths and ran them through the magazine into the chamber. No length greater than 1.08 would chamber. I thought that would be the ultimate test of whether a round would chamber or not.

Jepp2, I wish I knew why my max OAL was so short. But 1.08 is my maximum OAL with this bullet, and now I need help figuring out how to load them for that OAL. Any longer than that and they simply won't chamber.
I know now that TG isn't the best for beginners, but I've got several pounds of it, so I'm sure there's a way to get this figured out.

As for checking signs of pressure, I checked the primers on the ejected cases--they may be very slightly flattened, so I'm thinking the pressure was a little high.

Missouri Bullet Co. doesn't publish load recommendations, so I have to go with what the Lee manual and others tell me to do. I won't buy Missouri Bullets again after I use up this 1000 unless I can confidently get this figured out. I've seen in other places that other people have found their OAL needs to be a little lower than minimum with bullets from this company.

So, any help would be appreciated so I can safely load this 1000 and use them up so I can buy a better bullet.

If anyone else has had this problem and has successfully adjusted their charge to account for a below-minimum OAL, please let me know.

[GJSchulze]

I have the XDm 9mm 5.25 also and have no such problem. I load 147 gr FMJ-TC from Precision Delta anywhere from 1.12 to 1.14 with no feed problems.

I suggest that you find someone else to confirm your measurements with different methods. I would be more concerned about the gun not feeding right than I would be trying to get that particular round to work.

[g.willikers]

Is it possible that the OAL is not the reason the rounds won't fit the chamber?
Like maybe the mouth of the cases are too wide, with still too much flare that hasn't been removed by the crimp die?
Can you provide pictures of your reloads?
In the end, though, the best approach is to check the loads with a chrony, for whatever OAL works best for that combination of components.
Otherwise it's just a guesstimate as to what is an acceptable load.
They don't have to be expensive; some start at under $100.
Well worth it.

[Trevordc]

It's possible that OAL isn't the cause, but I've spent hours playing with the dies. I barely flare the mouth at all--just enough to barely hold the bullet. My crimp is light but definite. I purposefully over crimped one as far as it would go and it didn't change the problem. I'll use the range chrono tomorrow and see what it tells me.

I'll try to figure out how to post pictures when I get home tonight.

[g.willikers]

Well, it's indeed possible that the barrel does have a weird chamber.
It wouldn't be the first.
If so, then the rounds will have to be assembled accordingly.
No big deal, though.
Just go about it as if it's a wildcat round.
Or buy another barrel.
Or you can measure the chamber with CerroSafe:
https://www.youtube.com/watch?v=2d5DA4_OcuE

[serf 'rett]

I have a stock XDm 9mm which has the same "limited" distance it appears you are describing. Three of the “wider” nosed bullets I use will come in contact with the lands before the case mouth headspaces in the chamber.

My overall lengths are less than that shown in some of the manuals. OAL is 1.070”, with a jump of 0.015, with Berry’s 124 grain HBFP. My MBC 124 grain Smallball rounds are loaded to 1.100” but that particular length has the lead bullet touching the lands. With a MO Bullet Company 115 grain Smallball, I loaded at 1.090” with around 0.010” set back off lands.

I don’t know if the MO Bullet Company 115 grain Smallball is the same as the current 115 grain round nose.

I don’t use Titegroup so I’m unable to help you there.

[GJSchulze]

I have the same gun, so PM me your address and I'll send you one of my 147 gr rounds with OAL around 1.135. I'll remove powder so it will only be a sizing tool. If it doesn't fit, then you have a chamber problem. Otherwise your measuring is wrong or the bullets you use are odd.

[serf 'rett]

or the bullets you use are odd.

That was the main point of my previous post. In my Springfield XDm, bullets with a wider nose profile would come in contact with the lands when I tried to load at some of the lengths given in manuals. In that pistol:

Ball shaped profiles = shortened OAL.

Cone shaped profiles = no OAL problems.

Example: 124 gr HBRNTP Berry's are loaded at 1.150” (conic profile)

[boostedtt91]

when first starting out with setting up your dies and loading the first rounds, i usually take the barrel out of the gun and load one up and you should be able to drop the loaded round into the chamber and it should fall out if you turn it upside down.

[Trevordc]

Hopefully I figured out how to attach photos...we'll see here...

One photo should show my reloaded round not passing the barrel drop test at the stated minimum OAL of 1.100". The don't pass the test until they reach a minimum OAL of 1.080".

The other photo should show a reloaded round next to a factory round, albeit not a similar lrn round. photo(23).jpg

photo(24).jpg


I don't mind having a shorter OAL than minimum as long as I can verify that the powder charge is subsequently adjusted. I haven't found a chrono yet so it might be a little while before I get one and make it 50 miles up to the range.

It's good to see that other folks are somewhat familiar with the issue I'm having and have adjusted to it.

[GJSchulze]

Treverdc, please try this:

Make a resized case with no primer
Cut four slots in the mouth at 3, 6, 9, and 12 o'clock. I used a dremmel.
Push a bullet into it just enough to hold. Made this way you will have enough tension to firmly hold the bullet and yet it slide with some pressure.
Push it all the way into the chamber until the mouth hits the end of the chamber.
Measure and repeat two more times. You should get the same results within a .002 or so.
This is your maximum OAL for that bullet.

When I first tried this method, I used an unresized case with no slots. The results varied too much, probably because the bullet moved as I pulled it out. With the resized case and slots I got consistent results.

[g.willikers]

The factory rounds have a less blunt bullet profile.
The nose of the bullet can probably extend into the rifling somewhat.
Your reload bullets are too fat to do that.
So they have to be loaded shorter to fit the chamber.