Beginner 9mm - Stressing about min OAL

[Mobuck]

"Too short of a OAL could very well cause the bullet to key hole ( tumble thru the air hitting the target sideways) because its seated so deep that the bullet is too far from the start of the rifling grooves in the "
Never heard that one in relation to handgun reloading. The smaller, high pressure cases (like 9mm) are very sensitive to OAL when loading at the top end. Moderate loads won't make so much difference but inconsistent OAL will affect accuracy-.03" is a fairly big difference. A lot of the cheap bullets showing up right now have significant variances in the nose profile causing the inconsistent contact with the seating plug and variable OAL. The plated bullets are the worst I've seen in this area.
I also found MG to be quite variable in the point(hollow point) but the ogive was consistent so the actual contact surfaces were good. The slightly misshaped points were causing the apparent differences in OAL and this can be overlooked.

[Grandpa45]

Thanks MrApathy, I was thinking that sorting the brass might help.

One thing I noticed is I get a different OAL with the press loaded in all station, than if I try one round at a time in the seating station. I have read about this on other forums as well, specifically on the loadmaster press. That tells me that what's in the other stations affects "to some degree" the seating depth. So it seems logical if I had the same kind of case in every station it would help to keep things consistent.... or at least not make it worse.

Right now I have the following dies:
1. universal deprimer
2. deprimer / resizer with the depriming pin out (also prime in this station)
3. powder
4. bullet seat
5. factory crimp

It seems like station 2 (resizer) is the one that take the most force, and it varies from stroke to stroke. I'm guessing it varies because of mixed brass, some being thicker, etc.

So far I haven't been lubing the cases, I was wondering if that might help station 2 go a little smoother. The reason I mentioned this is I think the cases that are really hard to reshape might be causing me to use a lot more force and could be flexing something or in some other way contributing to the inconsistent seating depth.

[Grandpa45]

A lot of the cheap bullets showing up right now have significant variances in the nose profile causing the inconsistent contact with the seating plug and variable OAL.

Mobuck, Just for the heck of it I measured a handful of my MG FMJ RN bullets. I got a range of .559 to .568 with an average of .5629.

So that's a +/- .009 variance in the bullet length, which I was thinking might be close to a third of the .030 OAL variance I was seeing.... so then I checked one of Brian's suggestions.

You can verify #1 by removing the seating plug and zeroing your calipers on it. Then use it in the calipers to measure 10 or so bullets. Whatever variance you get there will be impossible for you to eliminate unless you drill out the seating plug so that it touches a more consistent part of the bullet

The seating plug has a hole in it already, I'm guessing that's normal, at least for this particular die. I measured another handful of the same bullets while seated in the plug and I got a pretty consistent 1.598 - 1.599.

So, even though the bullets vary up to .009, the actual seating plug/bullet together only vary .001 which is good, right?

What I didn't understand before and just realized is, if everything else was perfect, even though the bullets vary .009, I could be seating them to within .001 because the die hits the more consistent part of the bullet instead of the tip. But the finished round could vary as much as .009 even though they are seated to almost the same depth. I think I'm starting to understand some of this better.

Thanks again for everyone's comments and suggestions!

[serf 'rett]

A lot of the cheap bullets showing up right now have significant variances in the nose profile causing the inconsistent contact with the seating plug and variable OAL. The plated bullets are the worst I've seen in this area.

Mobuck, I'm interested in which particular plated bullets are guilty. I'm not seeing this in the Berry's I normally load and want to avoid purchasing "cheap bullets" with this problem.

What I didn't understand before and just realized is, if everything else was perfect, even though the bullets vary .009, I could be seating them to within .001 because the die hits the more consistent part of the bullet instead of the tip. But the finished round could vary as much as .009 even though they are seated to almost the same depth. I think I'm starting to understand some of this better.

From your measurements, it appears the 0.009" difference in coming from a variance in the tip or nose of the bullet; whereas, the contact between the seater and bullet ogive gives a consistent length to the bottom of the bullet. I'd say you are progressing in understanding.

[Don P]

Grandpa45, Brian has some solid advice in his post. All I will add is get yourself the Lee Reloading book. A lot of information on reloading besides the load data. Could very well answer many of the questions you have. I found it to be a very in dept interesting read.

[Wyoredman]

Here is a thought. Tell me if I am all wet.

If gramps has a bullet that doesn't have a listed/suggested OAL, why can't he just begin seating a dummy round on the long side and doing a "plunk test" in his chamber. Repeat, seating shorter until the dummy cartridge fits in his chamber correctly. He will know for sure this is the longest OAL with that bullet that will chamber in his gun, and also be the safest OAL for pressure.

Anyway, that is what I would do. Tell me where I am wrong!

[Brian Pfleuger]

There'd be two small issues with that method, as described.

1)There's a good chance that the longest round that will chamber will be too long to fit properly in the magazine, so you'd have to check that.

2)The longest round that will chamber is going to be touching the rifling (or very close). That actually RAISES pressure rather than lowering it. If you took that longest round that would chamber and shortened it a couple hundredths, you'd be golden.

I don't have a lot of handguns to compare but I have loaded for a 10mm 1911 and a Glock 357sig. In both cases, the chamber would handle a round considerably longer than would the magazine.

[serf 'rett]

Wyoredman - I basically use the same idea but a different method. Starting with five fired cases, I tension the case mouth enough to slightly grip the particular bullet I will be loading. The cases and bullet are inserted into the pistol chamber and pushed forward until the bullet contacts the lands and the case headspaces in the chamber. The bullet will get pushed into the case. The case and bullet are removed and the length is measured. This process is repeated until I'm confident I have a good OAL. For jacketed bullets I use finished OAL 0.015 shorter to get achieve the setback I want. For lead bullets, I may actually seat at the lands, but that's a different animal.

[RC20]

I go with Brian on the let them run long.

I have the same issue, I think they tend to run variations of .005 rather than .030.

I just checked my land distance and it was way in excess of what my variation was (never cross check to the magazine).

That may vary from gun to gun so you should try it in yours and see what length pushed the case up.

The one post was not right in that its not the dies or equipment, its the bullet variations that cause (or should) the COAL difference.

If its a last bullet then the length is the cause, if its round of any type then its the shoulder where the seater connects (or the length if you have a flat seater which I am not even sure is available).

Your mild loads should not be an issue with the 115s. 147s get far dicier and worse as you hit the max pressure areas.

The 9mm case is so small that very lintel variation can cause a nasty pressure spike, ergo, got long not short.

May not be an issue with what you are doing but good to get it established as the baseline.

I also crimp in a separate (last!) step and only do a mild one, enough to take the flare out.

[57K]

Wyoredman - I basically use the same idea but a different method. Starting with five fired cases, I tension the case mouth enough to slightly grip the particular bullet I will be loading. The cases and bullet are inserted into the pistol chamber and pushed forward until the bullet contacts the lands and the case headspaces in the chamber. The bullet will get pushed into the case. The case and bullet are removed and the length is measured. This process is repeated until I'm confident I have a good OAL. For jacketed bullets I use finished OAL 0.015 shorter to get achieve the setback I want. For lead bullets, I may actually seat at the lands, but that's a different animal.

Grandpa45, the information I'm quoting is something ALL handloaders should know. The method I use and recommend is very similar to what serf 'rett is recommending. With 9mm jacketed bullets that have the correct diameter of .355", I use Winchester cases where there is enough tension between the bullet and case that you probably won't have to add additional tension. Just start the bullet into the fired case and place the "dummy" into the chamber and push on the rim until the case stops. That's where the case-mouth is contacting the forward ledge in the chamber and the barrel's leade/throat is seating the bullet to give you the MAX. allowable OACL. Obviously, the round has to be short enough to function in the mags. Make up 5 "dummies" so that you can compare the consistency in OACL between the 5 "dummies". In situations where the bullet is slightly over-sized, you may need to tap very lightly on the case-rim with a plastic mallet or a block of wood to fully seat the case. Depending on the OACL tolerances of your handloads, controlled by your press and dies, your loaded cartridges should be .005 - .010" shorter than the Max. allowable you got from the average of the 5 "dummies".

Naturally, there are exceptions. In your case, your press/dies are varying too much in OACL to use even the .010" shorter recommendation. Having loaded a lot of 9mm over the years, I have used my fair share of European powders where OACL recommendations will sometimes be in millimeters, sometimes both inches and millimeters. What I do today after finding the MAX. allowable OACL is to shorten my handloads by .5mm. I load my own defense loads and maintain very close tolerances in OACL because the majority of my loads are +P, at least in terms of the velocity they'll achieve. The majority of these loads get loaded on a single-stage REDDING Boss with REDDING dies. The Boss has a feature called Top-Dead-Center that helps with OACL consistency. The only real OACL variations I get come from the bullets themselves, but typically with the JHPs I use for my defense loads I can hold a tolerance of +/- .002". For my 9mm pistols and those of my shooting partner whom I also load for. I load JHPs to 1.142"/29mm. There are a good number of 9mm pistols that have throats that are too short for this OACL. In that case I drop down to 1.122"/28.5mm. There are very few 9mm pistols that won't accept and function with that OACL. In the case of a particular bullet's design or a very short barrel throat, 1.102"/28mm will work. For 147 gr. JHPs as well as various weights of FMJ, a longer OACL is often desirable. Again, after confirming the MAX. allowable OACL, I load long at 1.161"/29.5mm. That may be too long for some 9mm pistols so you can see the necessity of determining the proper OACL for an individual bullet to be fired from an individual pistol.

The 1.155" you lengthened to is pretty typical for 115 & 124 gr. FMJs, but that should be at least confirmed by a "plunk test" or better still, by making up 5 "dummies to determine MAX. allowable OACL for that particular bullet.

serf 'rett caused me to consider an example of where adding a little tension to the "dummies" could be very useful. I have some Montana Gold 124 gr. JHPs and they are slightly under-diameter with a good many of them measuring .354" in diameter, so adding some additional tension may be necessary to hold the bullets in place firmly enough for measuring purposes. There is also a reverse condition that can occur with pistol barrels that have tight chambers. If the case-mouth diameter on your "dummies" run higher than the SAAMI Max. spec of .380", the cases will not easily seat and too much force from tapping will be required. This will often result in the bullet becoming lodged where you'll need to use a dowel rod from the muzzle to tap the bullet out and that's gonna result in the bullet being seated deeper into the case. To avoid this occurrence, taper crimp the "dummies" just enough to get the case-mouth under .380". So long as you don't over-do it with adding taper crimp, your pulled bullets from the "dummies" should still be in pristine condition for reloading.

I didn't see it stated so I'm surprised this wasn't mentioned. To maintain somewhat of an equivalent pressure between 2 bullets of the same weight but with different lengths, you could have added the extra bullet length of the longer bullet to the OACL recommendation of 1.125". Determining the exact length for the bullet you're using is still preferable and would have given you a longer OACL than adding the additional bullet length to the 1.125" OACL. In 9mm, all I load are JHPs, but the OACLs most often recommended for safe and accurate FMJ loads are around 1.150" give or take so I'm guessing that someone recommended the 1.155" OACL you lengthened to.