Bullet length issue, determining correct OAL

[DarkSoul]

So I have only been reloading now for a few months, I purchased a used setup (Dillion 550) with 20 or so die sets and tons of bullets, brass, primers and so on. The equipment was in excellent shape, and used by a guy that knew what he was doing.

So, the issue I am have come across is actual bullet size and how it effects the OAL, for example, with 9mm, in the Lymans book, it states the following-

100 gr. FMJ - OAL - 1.105
125 gr. Jacketed SP - OAL - 1.120
130 gr. FMJ - OAL - 1.160

So here is my question, what if I have a 125 gr. FMJ , the book does not give an OAL for said bullet. Is it safe to say that based on weight, and the shape of the bullet, that I set the bullet depth to give me an OAL the same as the 125 gr jacketed SP ?

If not, then how does one determine the OAL for a bullet that is not listed in the loading guides? I have run across this for several bullets in several calibers, and it has be pretty confused.

So as a blanket question, what is the possible dangers/issues, if any of having a bullet seated to far down in the case? Or too far out, aside from the OAL being to great, and creating issues with smooth loading in an auto.

I know this probably does not have a simple answer, but any light any of you can shed on the above questions would be very helpful.

[joelogic]

Too short and pressure can be dangerous.
Too long and they wont fit in the mag.

OAL for pistol is kind of a balancing game. You want the round to chamber and fit in the mag. Plus you can shorten the OAL and use less powder.

For 125gr RN FMJ 9mm I think I am at 1.125" for my glock.

Tip: Make sure they work in all your guns otherwise you will have to note which loading is for which gun.

[bruceflinch]

That Joe is so so so Logical!

[Bill Steele]

So I have only been reloading now for a few months, I purchased a used setup (Dillion 550) with 20 or so die sets and tons of bullets, brass, primers and so on. The equipment was in excellent shape, and used by a guy that knew what he was doing.

So, the issue I am have come across is actual bullet size and how it effects the OAL, for example, with 9mm, in the Lymans book, it states the following-

100 gr. FMJ - OAL - 1.105
125 gr. Jacketed SP - OAL - 1.120
130 gr. FMJ - OAL - 1.160

So here is my question, what if I have a 125 gr. FMJ , the book does not give an OAL for said bullet. Is it safe to say that based on weight, and the shape of the bullet, that I set the bullet depth to give me an OAL the same as the 125 gr jacketed SP ?

If not, then how does one determine the OAL for a bullet that is not listed in the loading guides? I have run across this for several bullets in several calibers, and it has be pretty confused.

So as a blanket question, what is the possible dangers/issues, if any of having a bullet seated to far down in the case? Or too far out, aside from the OAL being to great, and creating issues with smooth loading in an auto.

I know this probably does not have a simple answer, but any light any of you can shed on the above questions would be very helpful.

In your examples, you don't have a given powder and amount, that is an important part of the load spec and effects what a safe OAL will be. Saying I am going to load all my 125gr bullets to 1.120" might get you into trouble.

For instance, if you loaded one of my favorite powders for 9MM, VV-3N37 with a 125gr FMJ using 6.2grs of the powder and loaded to 1.120", you would have a very compressed load and may or may not be looking at an over pressure situation. The reason is VV's load spec for this bullet calls out a Minimum OAL of 1.142". That doesn't guarentee you will be over pressure for the load at 1.120" it just means VV never tested it.

On the other hand, I load a number of different powders for my 125gr LRN bullets. The max load spec I use on any powders I load call out a minimum OAL of 1.142" (the VV's). 1.142" will feed in all my 9's I own, so I just load all my powders to 1.142" and I am good (as all the other powders I load, in the amounts I load them with the 125gr LRN's, call out a shorter minimum OAL than 1.142").

Hope that made some sense.

Have fun and good luck.

[erik_26]

The other thing you can try is to reload one long with no primer or powder to make sure it fits in the magazine and the gun will feed it without issues.

And try looking at other reloading books. As I have learned some books offer way more load data than others. You will probably ending up buying a couple more books to give you more coverage.

[rsrocket1]

Here's an example of three 180g .40 cal flat nose solid bullets:

L to R: eXtreme plated 180g 0.557", Bear Creek 180g 0.595", my cast Lee 401-175-TC 0.563" which also weighs in at 180g

If you loaded them up equally with the same COL, the difference in peak pressure could be 5-6,000 psi, but you would only see about 40 fps difference.

As said earlier, seating depth (and powder charge) is what controls the peak pressure in the cartridge, COL plays a more important role in feeding, chambering and magazine fit.

If you load low to mid range of the recommended charge, you would probably be safe, but always look for pressure signs and if you see any, back off quite a bit because once you get there, you are probably way over pressure.

[Bill Steele]

Man, a picture really is worth a thousand words.

[DarkSoul]

So I think I may understand.... or maybe not, so let me ask another way (excuse me for just using random numbers here, all my loading books are down at the shop)

If I have 3 different bullets that are all the same weight (180 g), but we will use the .40 cal weights mentioned by rsrocket1, but we have different bullet lengths -

Bullet X = .557
Bullet Y = .595
Bullet Z = .563

And the powder call out is for (just example) 6.5 g , so I understand that loading all of these to the same OAL can get me in trouble, but this is the issue, I have two Lymans books, and both of them give only one OAL for a specific bullet shape/style (like an FMJ flat point). So lacking information about seating depth (which does not seem to be mentioned), how does one sort this out? Or is it really just loading on the safe side, seeing how it does at the range (chronograph), and go from there?

If I understand you correctly Bill Steele, you just load all of them to the greater OAL for a given bullet, and just error to the safe side then, correct? If I understood that correctly, have you had any issues using this method, i.e. noticeably underpowered rounds, failure of action to properly cycle, etc?

I love reloading, and I have had no issues so far (loaded lots of 9mm 124g FMJ, and 230 g , .45 FMJ), but I have LOTS of misc. bullets from the purchase, and some of them leave these questions to be answered.

So in advance, thanks to all that have offered help on this.

[Bill Steele]

So I think I may understand.... or maybe not, so let me ask another way (excuse me for just using random numbers here, all my loading books are down at the shop)

If I have 3 different bullets that are all the same weight (180 g), but we will use the .40 cal weights mentioned by rsrocket1, but we have different bullet lengths -

Bullet X = .557
Bullet Y = .595
Bullet Z = .563

And the powder call out is for (just example) 6.5 g , so I understand that loading all of these to the same OAL can get me in trouble, but this is the issue, I have two Lymans books, and both of them give only one OAL for a specific bullet shape/style (like an FMJ flat point). So lacking information about seating depth (which does not seem to be mentioned), how does one sort this out? Or is it really just loading on the safe side, seeing how it does at the range (chronograph), and go from there?

If I understand you correctly Bill Steele, you just load all of them to the greater OAL for a given bullet, and just error to the safe side then, correct? If I understood that correctly, have you had any issues using this method, i.e. noticeably underpowered rounds, failure of action to properly cycle, etc?

I love reloading, and I have had no issues so far (loaded lots of 9mm 124g FMJ, and 230 g , .45 FMJ), but I have LOTS of misc. bullets from the purchase, and some of them leave these questions to be answered.

So in advance, thanks to all that have offered help on this.

Yes, you have it down very well.

In my example, I load to the longest OAL for the powder loads I use for convenience and safety sake. This length also happens to fit in my mags, feed reliably and chamber in all my guns. Most of my rounds I load in a year are target loads, so I am loading more for consistency than max power. It happens that my HD loads are also my longest OAL spec loads, so again it just happens to work out that way in my 9's. My various .45ACP loads use pretty different OAL's to get the results I want.

Most of the load references I use rarely specify the bullet profile, I think mainly because the weight and construction (lead vs FMJ, etc.) are the big factors relative to the powder type and charge used. I think it is more of a rarity that you might run into problems with OAL if you are loading to a given weight and type (lead vs jacketed) spec. But then again, with things that go bang, being on the safe side and working up slowly is always a good idea. The exception to the above is when loading an all copper bullet, which can be pretty different for a given weight bullet due to the difference in material density (copper versus lead).

In general, the OAL (and the resultant seating depth) only becomes something you really have to pay close attention to is when you are using max loads. If you use a load spec for a given weight, type (lead vs FMJ), powder and charge level, and you use the specificed start load level (or say something like -10% if only one charge is specificed), then you probably don't have to worry much about the difference in bullet profiles the OAL spec will yield in seating depth.

The above is one reason I don't like Alliant's load spec data, as they only give one recommended powder amount for a given bullet. If I only have Alliant's data to go on for a load I want to try, I always back off 10% from their recommended load and start there.

If you use a load spec and are not sure what the profile of the bullet used in the load development, like any other type of load development, start in the safe zone of charge (like -10% powder) and work up slowly.

Jeez, sorry to run on and on, I am not good at explaining simple concepts that have a lot of variables.

[DarkSoul]

Thats great info Bill, I really appreciate you taking the time to explain this. As I said, I have been loading a lot, and the pistol rounds for the most part have been a snap, with of course aforementioned issues with a few odd ball bullets.

I shoot a .45, and have had zero issues with that (and good thing since I am shooting about 500-1000 per month). I have now just started in on .223, and am quickly learning that I really hate the cylindrical powders (pencil lead type) it loads for ***** through the powder feed, and again.... bullets, seems that what I purchased are very inconsistent, but I have a handful that I will test out tomorrow, and hope I have no issues (fingers crossed).

Thanks again for the help

[J-cat]

What I do is set the OAL to max, say 1.169" and use the starting load. I then load five at that OAL, then five at an OAL .010" shorter and so forth until I get the function and accuracy I want. If that particular powder charge just isn't doing it for me, I go back to max OAL and increase the powder charge. Then I do over, decrease OAL in .010" increments. The 9mm is very flexible. You can load a 125gr FMJ RN from 1.100" to 1.169" which allows you alot of wiggle room. Fine tuning is easy and the 9mm responds well to it.

TC profile bullets have to be loaded a little shorter. I have loaded them from 1.050" to 1.125" where they ususlly start hitting the rifling.

[SoCal AJ]

I have been using Hornady's 7th edt Handbook and they specify the OAL per bullet but how do I know the minimum safe length? Do I need to also get a book like Lymans or some other brand that might have more data?

I definitely don't want to get into a safety situation with pressure.

[J-cat]

You can do a couple of things:

Get QuickLoad software. It will show you how a change in OAL affects pressure with a particular powder.

Measure case expansion at the casehead. Most 9mm's will expand a case to .391" in factory loads. +P sometimes go to .392" and +P+ to .394"+. I stop at .391", but as you can see, even .394" is safe. Most of my loads expand the case to under .390".

Stick to middle of the road loads and medium burning rate powders. You will not blow anything up that way at any OAL. People get in trouble with ultrafast powders like Clays and heavy bullets. Avoiding this extreme combination will keep you from worrying.