9mm OAL not consistent

[gifbohane]

I sort brass by headlamp. It makes the OAL very consistent

I do the same but I still notice what I consider significant differences. When I flare them they rarely are all the same width usually vary from .382 to .385 ( for a 9mm.)

Maybe the lot # is different or the pistol that shot it. But I refuse to trim pistol brass.

 

[murf]

your stem is hitting two places on that "sharpie" bullet. can you modify that stem to hit one place?

luck,

murf

 

[Bill M.]

I have to ask. Is there any chance you are hitting the bullet and moving it with the crimper die?

 

[FROGO207]

Take a handfull of bullets and line them up on a flat surface. Then with a light behind them set a straight edge on them. Any light at the tops? If the bullets are not all the same they will seat differently.
As for me, I gave up trying to get my 9MM all the same and they still shoot better than I can.

 

[LiveLife]

your stem is hitting two places on that "sharpie" bullet. can you modify that stem to hit one place?

Bullet seating stem hitting two places on bullet nose/ogive could indicate bullet is tilting during seating, which can result in inconsistent OAL.

9mm OAL not consistent ... I have kept my single stage press because I strive for accuracy.

I've been seriously considering a press upgrade. Any thoughts or input would greatly be appreciated.

Upgrade from a single stage press?

If you are looking for OAL consistency, you cannot do any better than a single stage press. Think about it, ram goes up and down and limits of travel are determined by the shell holder and dies, specifically bullet seating stem and how the bullet nose/ogive engage the stem.

So what are the variables that affect OAL?

• Bullet nose profile/ogive consistency as typical RN seating plug does not push on tip, rather further down from the tip (see below pictures)

• Bullet tilting while seating - Does your finished rounds have even bulging around the case neck where the bottom of bullet base is? If not and you have one sided bulging, you are likely tilting the bullet during seating and this will affect OAL consistency - https://www.thehighroad.org/index.php?threads/bulges-on-9mm-case.848008/#post-11059827

• Brass - I believe we busted this myth for single stage press but could be a factor for progressive press where different sizing effort may tilt/deflect the shell plate with different amounts - https://www.thehighroad.org/index.p...progressive-press.833604/page-2#post-10779806

Lee 9mm bullet seating stem showing hole in the center where the RN tip would go so if nose profile/ogive of bullet is inconsistent, OAL will vary even though bullet length is consistent and seated straight.

Comparison picture showing bullet seating stems contacting mid way down from tip of FMJ/JHP bullets

 

[Waterboy3313]

I don't think I'm bumping the bullet between the seating and crimping process. I guess I could try to cleaning up the stem and see if anything improves.

I've been reloading for about a year now. Maybe being relatively new has me a little bit on edge with the tolerances. I try to work up a load and when I find what works best I try to replicate that is exact as I can with the equipment I have. 9mm is the only thing I load gives me problems like this.

I haven't seen any lopsided bulging. I flare the case mouth to the minimum, set the bullet on the case to get it as straight as possible and rotate 2-3 times before the bullet is fully seated. Sometimes I will randomly take 4-5 completed rounds and roll them on a smooth flat table just to see if any of them look like they were seated crooked.

Maybe the question I should be asking is what amount of OAL difference should be considered acceptable?

 

[JFrank]

I think you’re doing a great job.
J

 

[LiveLife]

Maybe the question I should be asking is what amount of OAL difference should be considered acceptable?

While .001" OAL variance is possible with match grade bullets with consistent nose profile/ogive and single stage press (And some progressive presses using pre-resized brass to factor out shell plate tilt/deflection), I have found with typical bulk bullets and unsized mixed brass on progressive press to vary OAL by a few thousands.

To me OAL variance of less than .005" is OK provided your rounds do not experience significant bullet setback of more than .005" (when fed from the magazine) and why I post my reference 9mm load using 115 gr FMJ OAL range to be 1.130"-1.135".

I think you’re doing a great job.

Yes, keep in mind that if OAL variance of several thousandths you are seeing is from inconsistency of bullet nose profile/ogive, there's not much you can do other than change to bullets with more consistent nose profile/ogive.

 

[kmw1954]

Waterboy3313 about 2 years ago I was loading some 9mm 115gr RN Xtreme and my lengths were going all over the place from right on my set point to -.006" and it was driving me nuts, just as it is you now. As a last straw effort with nothing left to try I opened another box of the same bullets and started loading.. With just a change of bullet lots I went from 0 to -.006 to o to -.002. Honestly all I did was change lots. Same Xtreme weight and profile but different lot. Never made a single adjustment to the press or dies.

At times I see the same results with Berry's bullets too but not like I had seen with the Xtreme.

 

[LiveLife]

if OAL variance of several thousandths you are seeing is from inconsistency of bullet nose profile/ogive, there's not much you can do other than change to bullets with more consistent nose profile/ogive.

9mm 115gr RN Xtreme and my lengths were going all over the place from right on my set point to -.006" ... another box of the same bullets ... went from 0 to -.006 to o to -.002 ... Never made a single adjustment to the press or dies.

Larger bullet manufacturers may have several machines making bullets and depending on the age/wear of forming dies and machines, consistency of nose profile/ogive could vary by machine/lot.

When RMR started manufacturing their own in-house jacketed bullets, Jake pointed this out and since his forming dies were all new, he anticipated more consistent nose profile/ogive to produce more consistent OAL and said he would work to maintain the consistency of his bullets in terms of nose profile/ogive and weight variance. And since, has made several improvements to make bullets more consistent like increasing bullet base copper foldover amount.

I have noticed RMR jacketed bullets are more consistent in weight variance and produce tighter OAL variance than other bullets, even match grade bullets and perhaps reason why ELEY chose them for their line of centerfire match ammunition.

ELEY match ammunition (with RMR 124 gr FMJ) showing .001" OAL variance - https://www.thehighroad.org/index.p...-match-ammunition.854750/page-3#post-11282439

GunsAmerica Digest evaluated RMR 124 gr JHP/MPR and 20 bullet sample showed spread of only .3 gr weight variance which is quite impressive (In comparison, many jacketed bullets have up to around 1.0 gr weight variance and some plated/lead bullets have weight variance of several grains) - https://www.gunsamerica.com/digest/rmr-9mm-124-jhp-mpr-review/?utm_source=email&utm_medium=20190708_BlogDigest_336&utm_campaign=/digest/rmr-9mm-124-jhp-mpr-review/&fbclid=IwAR0px_E2pxIBTpEGsu3J1xLvk86kfwopr2zmXyU2jlAL_2Ij3-hskEk4PtI

 

[murf]

too bad hornady or sinclair don't make a handgun bullet comparator. you could size a case and slip it over a loaded round then measure the length of this combo, i guess. anything to get a measurement off the bullet ogive.

luck,

murf

 

[tcoz]

It depends a lot on the particular bullet that you’re loading. You’ll find a greater variance if it’s a bulk inexpensive bullet. Measure the CBTO (cartridge base to ogive) and you’ll find that it’s likely to be much more consistent. That’s really the measurement that’s you’re most interested in anyway.

 

[azrocks]

I don't think I'm bumping the bullet between the seating and crimping process. I guess I could try to cleaning up the stem and see if anything improves.

I've been reloading for about a year now. Maybe being relatively new has me a little bit on edge with the tolerances. I try to work up a load and when I find what works best I try to replicate that is exact as I can with the equipment I have. 9mm is the only thing I load gives me problems like this.

I haven't seen any lopsided bulging. I flare the case mouth to the minimum, set the bullet on the case to get it as straight as possible and rotate 2-3 times before the bullet is fully seated. Sometimes I will randomly take 4-5 completed rounds and roll them on a smooth flat table just to see if any of them look like they were seated crooked.

Maybe the question I should be asking is what amount of OAL difference should be considered acceptable?

I just got through asking the same question (acceptable OAL) regarding my 300AAC rounds, which like you were coming out with very inconsistent OALs. And I received excellent answers here. The problem in my case was the inconsistency of the bullets from the ogive forward. The effect was much more pronounced than I'd expect from 9mm, simply due to the shape/dimensions of these specific rifle bullets, but from what you've posted so far it looks like you're most likely suffering from the same issue. That's why I suggested - & hoped you'd experiment with - flat-nose bullets with a flat-nose contact point on your seating die (sorry, there are probably terms for these parts, but I don't know them. Think you know what I mean). I realized you've said you've used many bullets in the past, but past memory doesn't really count here. If you do an experiment now - using flat-nose bullets and a flat-nose die interface that takes the ogive out of the equation - while making everything else the same (new brass, or at the very least all the same headstamp in all the same condition), you should be able to either eliminate this possibility or confirm it is indeed the problem.

Whether the problem is a problem is another matter. Referencing again my issues w/ 300, what I found ultimately (using the seating stem from my die along w/ calipers to measure from the bullet base) was that though the bullets were inconsistent from the point where the seating stem made contact to the tip, they were very consistent from the point where the stem made contact to the base. So the things that really mattered - seating depth, the resultant case volume, and distance to the lands - were all very consistent. I'd guess this is likely the case here as well - and maybe if they shoot to your expectations there's no need for further inquiry - but you sound like me wanting to get to the bottom of things.

Here's a link to the thread I was talking about. Lots of good info that's likely applicable to your situation was well:

https://www.thehighroad.org/index.php?threads/whats-a-reasonable-oal-spread-308-hornady-150g.872221/

 

[Waterboy3313]

I went out to the range this morning. I think the loads were better than any other 9mm I have loaded. I only took my shield and shot it the best ever.

 

[Otto]

too bad hornady or sinclair don't make a handgun bullet comparator. you could size a case and slip it over a loaded round then measure the length of this combo, i guess. anything to get a measurement off the bullet ogive.

They do of sorts.....this is how I measure OAL variances. These are RMR match winners, mixed brass, Redding Competition seating die.
Tolerances of +/- 0.010 won't cause me to lose sleep as long as the finished rounds shoot one ragged hole.

 

[340PD]

Out of a handgun or a AR9 will it matter? I mean honestly is 010-.015 going to make a difference? What kind of shooting are you doing that its going to matter? Just asking.

I am sitting here thinking the same thing. For a good 50 years I have picked up any mixed brass I could get my hands on, left them all unsorted, cleaned, deprimed, and using all four dies in my RCBS set, a ran a few test rounds based on specs from a Lyman reloading guide.
Once I knew they would run I never touch them again. I cannot remember when I have given a second thought to OAL or readjusted any of my dies as the rounds have continued to run through every 9mm handgun I own for years.
Note, I do not load to higher pressures, just 4.0 Titegroup under a 124gr. plated or FMJ bullet.

 

[LiveLife]

I went out to the range this morning. I think the loads were better than any other 9mm I have loaded. I only took my shield and shot it the best ever.

Great.

I love happy endings.

Out of a handgun or a AR9 will it matter? I mean honestly is 010-.015 going to make a difference? What kind of shooting are you doing that its going to matter? Just asking.

OP posed the question why 9mm OAL was inconsistent by .010"-.015" and I believe THR members provided sufficient reloading variables and causes why.

As to whether .010" - .015" OAL variance can show a difference on target shot from a pistol or PCC, that's for another thread discussion.

BTW, I did do limited myth busting with RMR 115 gr FMJ using 4.2-4.3 gr of Target with 1.155" OAL vs 1.130" OAL and got the following 25 yard groups out of my JR Carbine (sorry for the dirty, dark target as it was raining hard that day) - https://www.thehighroad.org/index.p...g-oal-col-long-vs-short.819257/#post-10511700

 

[Waterboy3313]

I'm not the smartest guy out there when it comes to learning by reading. I do feel that if I'm going to do something or anything for that matter I do it right. I can read a book all day but sometimes having it explained in a different way really helps. Like I also said I have been reloading for almost a year now. When I see Data that's says X I try to replicate that consistently. I'm not the best pistol shooter by any means but I try to be the best I can and improve as I go. Thanks to all of you and your helpful comments,tips and suggestions I appreciate it.

 

[rfwobbly]

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Your third photo with the Sharpie mark-up clearly shows that the Seating Stem does not accurately fit the bullet. Therefore you are "seating off the ogive" while you are taking your OAL measurements off the bullet's extreme tip. This is like getting the height of a flag pole by measuring where the flag is. If you want tight OALs, then you're going to need to start pushing on the surface you'll measure from.

Each FMJ will have a slightly different shape. Pick one brand, and then apply a dab of JB Weld to the seating stem as was previously suggested.