Bullet Tumble out of PX4

[Kingsoverqueens 10]

I've been having tumble issues out of my Beretta's, primarily the PX4.

 

Someone suggested that the bullets I use (Extreme 124 gr rn) aren't wide enough at .355 dia and suggested that I use .356 dia like Berry's.

 

Anyone have a small supply of Berry's to trade for an equal supply of extreme's?  Say 100 count?

 

I need to experiment.

[Blacksmythe 71]

What happens when you use commercially produced 9mm?

[Kingsoverqueens 10]

You mean factory?

 

Couldn't say.  I don't think I've ever fired factory ammo from the PX4.

 

I never had an issue when fired out of the 92.  I have 2 Beretta's...a 92FS and the PX4.  I get a rare tumble out of the 92 but have had multiple out of the PX4 and from what I'm told on the Beretta forum .356 dia bullets perform better.

 

I considered picking up a box of factory ammo for testing purpose, but it makes me feel dirty to buy ammo now that I reload.

[diamondd817 827]

Rarely hear about any problems with the PX4, on any level. I would try some factory 9mm (speer, Winchester, federal, etc) and see what happens. I willing to bet it's the ammo.

[Respect2A 0]

Too much crimp

Too slow velocity wise

Need a .356 projectile

 

Could be any of those.

[Kingsoverqueens 10]

Don't think it's velocity because I'm making power factor, and in same cases the faster (hotter) rounds are tumbling and the softer ones don't.  There is no direct pattern.

 

Too much crimp is a possibility but I'm leaning towards the the projectile or the coal being too short.

[raz-0 1,259]

Higher velocity is causing tumble with plated?

 

Check your crimp, you may be compromising the plating. Usually it just results in worse accuracy and gives you lead spirals on the target. But if you really push it and/or you rifling is tight or sharp, you cans do some asymmetric damage and get tumbling and key holing.

 

Plated likes lots of belling and a gentle taper crimp.

[T Bill 649]

I agree here. 

Read this: http://www.tannersbrass.com/crimping.aspx

FYI I would seat the 124RN to 1.150 COAL

[Respect2A 0]

Pull some bullets and inspect the bullet. Is the plating damaged? Is the bullet the same shape it was when you placed it on top prior to the seating die? If not, you are probably overcrimping.

 

Also take some finished rounds, measure at the case mouth. The measurement should be the size of the bullet plus the thickness of 2 case walls. Or pretty damn close.

[Kingsoverqueens 10]

I'm all but positive its not my crimp.

 

I measured at the case mouth and it was at around .373.  I had a few rounds of factory ammo on hand and it measured .377.  Anyway, I tweaked the crimp up to mirror .377 anyway.

 

I pressed out 50 rounds recording the powder measure for each (between 4.2 and 4.4 GR 231) and then measured every round after setting the die to 1.150 coal.  I'm using mixed range brass so it's plus/minus that number.

 

Then I ran off another 50 but didn't record the measure of powder this time (powder check was in place) but did measure the coal.  For some reason they measured out as long as 1.155....1.158....1.162.  I even had one at 1.168.  I need to check that when I press out more in the future but for now I'll just see how they perform.  

 

Everything is on a grid on a piece of paper.  Now all I have to do is remember to load the magazines in the correct order and I'm ready to record the results. 

[NJKen 23]

All of this is sound advice.  The only thing I would add is to try some FMJ bullets of the same diameter and see if the problem persists.  It could be as simple as your rifling does not like those bullets.  I have an AR that wont shoot a vmax bullet strait at all.  I think its because the rifling is too sharp for the vmax thin jacket.  It could be that simple with your load as well.

Ken

[Kingsoverqueens 10]

Well, I had a few minutes on Saturday to chrono some rounds.

 

The press was modified to +/- 1.150 COAL and 4.2 to 4.4 gr of 231.  I weighed each measure of powder and recorded the results.  The crimp is at .377.

 

Using Extreme 124 gr rn.  10 rounds test for each gun.

 

The results are at home, but I'm sure that everything out of the M&P Pro was clean (no tumble) and all rounds made power factor.

 

I had one minor tumble out of the PX4 and some results around 975 FPS, give or take.

 

I had 4 tumble/keyholes out of the 92FS and similar FPS results.

 

These two Beretta's are going to be bane on my existence. lol

 

I'll post the actual results and photo's of the suspected tumbles tomorrow.

[noylj 5]

What is making you think the bullets are tumbling? Is there a full outline of bullet cross-section on the target? I have had people confuse tumbling with the target not having a firm backer and the bullets leaving oval holes in the target from the target moving (either from the wind or, maybe, being pushed back by the bullet?)

What is the actual diameter of the bullets? Plated are all too often small. I have heard of plated bullets being as much as 0.003" too small in diameter.

What is the actual groove diameter of the barrel? It used to be that a 9x19 barrel could have a groove diameter of 0.354-0.362". Slug your barrel and match bullet diameter to actual groove diameter. I use 0.355-0.357" jacketed bullets and 0.356-0.358" lead bullets, with the larger bullets often being more accurate.

Did you pull any seated and crimped bullets and see any "damage?" There should be NO change in bullet appearance (note from the URL above—that bullet was WAY OVER crimped). Adding the effect of a very thin plating and a very soft lead alloy, damage is very easy. Maybe, if you need to use plated, you should look into "heavily plated" bullets.

Of all the cartridges in the world, I would say that, except for some milsurp rifles, all the complaints about keyholing bullets has been 9x19 and most of those are with plated bullets. There should be thousands of results for a Google search on 9mm and tumbling bullets.

I would go to Powder Valley and buy some 9mm Zero bullets 124 grain FMJ for $57/500 or $299/3000 (or Roze Distribution for $110.60/1000 or $105.85/1000 for 2000+). If your gun has a problem with Zeros, it will have a problem with just about any bullet. Zero and Montana Gold are my go-to jacketed bullets.

[raz-0 1,259]

I'm all but positive its not my crimp.

 

I measured at the case mouth and it was at around .373.  I had a few rounds of factory ammo on hand and it measured .377.  Anyway, I tweaked the crimp up to mirror .377 anyway.

 

I pressed out 50 rounds recording the powder measure for each (between 4.2 and 4.4 GR 231) and then measured every round after setting the die to 1.150 coal.  I'm using mixed range brass so it's plus/minus that number.

 

Then I ran off another 50 but didn't record the measure of powder this time (powder check was in place) but did measure the coal.  For some reason they measured out as long as 1.155....1.158....1.162.  I even had one at 1.168.  I need to check that when I press out more in the future but for now I'll just see how they perform.  

 

Everything is on a grid on a piece of paper.  Now all I have to do is remember to load the magazines in the correct order and I'm ready to record the results. 

 

 

You can be positive all you want. Pull the bullets and mic them. Brass is springy, lead is not. There's a reason why I said PULL the bullets and check them. preferably both visual and mic them. Pulling them will more than likely be a PITA. You will need a hammer type puller, and quite possibly need a spare. 

 

I will also be specific, and if they are micing smaller than they are out of the box, and you are using a lee factory crimp die, change to something else like a dillon taper crimp. something without the sizing ring at the base. 

 

I've shot a LOT of plated. I get good performance out of them. I don't know why people having problems so often dismiss the specifics of what I say and insist I'm wrong. 

[Kingsoverqueens 10]

In your learned opinion what is more likely to cause tumble?

 

1) crimp at .373

2) coal between 1.012 and 1.121

3) .355 dia bullet in a barrel (Beretta) that apparently prefers .356 dia bullets?

 

Moving forward.

 

How many bullets would you like me to pull to inspect and which ones in particular?  

 

According to just about everyone else I've asked the crimp issue is least likely to be the culprit when compared to the other issues and making the correction to the coal has already given me much improved results on the PX4, so at least I can start to record a trend.

 

But you seem to feel strongly about your theory so guide me.  Which bullets should I pull?  

[raz-0 1,259]

I'd pick either the best or the worst performer. Pull one and mic it and visually inspect it.

 

Tumbling is most likely caused by one of two things: undersized bullet or asymmetric damage to the bullet. With plated, the latter can lead to the rifling trying to pull the plating in the damaged area off the bullet.

 

Undersized from the factory can bite you, but you can undersize during crimp for all or part of the bearing surface with a crimp set up that works dandy for jacketed. The case mouth won't show it because it springs back. Jacketed doesn't care because the jacket springs back and covers up most of the problem. Plated and coated can have severe degradation of performance with a setup that loads jacketed happily all day.

 

One thing I forgot, less pita than pulling is take a qtip and swab your seating die. If you have copper flakes, your odds of finding damage when pulling is higher.

 

But pulling a plated bullet is less of a pita than slugging a barrel, so I'd still pull and mic. I'd mic out of the box bullets first of course.

 

 

As for oal, in 9mm most factory isn't saami max oal. It's something like 1.120 iirc I got my best combo of reliability and accuracy in 9mm with 1.125.

 

 

[noylj 5]

Kingsoverqueens

So, any pictures of the holes from tumble bullets so we know we are talking about tumble bullets?

Have you slugged the barrel yet? Are the bullets at least groove diameter or larger?

Have you pulled any rounds and inspected the bullets for crimp damage or having been swaged down in diameter?

We can all "hand wave" for weeks, but it would be nice to get some answers back.

Thanks.