Keyholing - 115gr Rainier + Clays 3.8 - why?

[editingfx]

Did my 1st IDPA Classifier today, and noticed in about 3-4 hits that the bullets had keyholed (tumbled in flight so it wasn't a clean hole). Rainier 115gr plated bullets, 3.8gr Clays and Win mag primers. (I know that Clays and mag primers aren't optimal, but it's what I've got at the moment. Have an order of HP38 & reg primers going in this week.) Showed my crimp (using Lee Factory Crimp) to an old-hand reloader, and he pronounced it just right. I'd worked up to 3.8 as the lighter throw from the Lee disc wouldn't reliably cycle my M&P Pro 9. (Lighter does cycle my XD9sc, though.) Hodgdon load data says 3.0 - 3.4 for LRN, and 3.7 - 3.9 for SPR GDHP. So though it's hot for lead, 3.8 is right in the middle of GDHP. (Rainier suggests using lead data.)

Thoughts on why there were keyholes?

 

[rcmodel]

Did the bullets hit the target going sideways?

If the hole is just a little oblong, it is cause by the paper target moving when the slow moving, light load bullet goes through it.

Put the target on a cardboard backer and it will stop.

rc

 

[editingfx]

Nope, these were IDPA cardboard targets. The bullet had obviously tumbled.

This was 3 or 4 out of 90.

 

[D. Manley]

Take an actual measurement of both the bullets and your crimp. If your FCD is over-doing it a tad, you might be shooting bullets resized down enough to cause the tumbling. Plated bullets are fairly soft and while the crimp may "look good", can be overdone...check pulled ones for cut plating or a crimp ring you can both see and feel.

 

[Walkalong]

I have shot a ton of those Ranier 115 Gr bullets at up to 1400 FPS (from a carbine). I do not use a Lee FCD die, but I do give them just a light taper crimp with a C&H crimp die in a fourth step. Never a tumbling problem.

 

[D. Manley]

I have shot a ton of those Ranier 115 Gr bullets at up to 1400 FPS (from a carbine). I do not use a Lee FCD die, but I do give them just a light taper crimp with a C&H crimp die in a fourth step. Never a tumbling problem.
__________________

Yep, me too. I've ran thousands through the Dillon SDB with never a problem. Matter of fact, with the right load they shoot pretty much as well as jacketed. Most of the problems I've seen noted with plated bullets tumbling involved the Berry's 147 grain and again, Clays powder. I've never thought Clays worked particularly well in 9MM and I know for certain it don't for me with 115's but still, I'll bet it's a squeezed bullet or crimp deal.

 

[unloaded]

I agree, pull a few and see how they look. Also are you belling the case enough? I've scraped the plating before not belling quite enough. I like to crimp, in a seperate step, just enough to remove the bell.

peace.
unloaded

 

[editingfx]

I've pulled at least 6 while setting crimp, and there's a fine line on the plating, but no where near enough to cut-through. It's just enough of a line to see & feel. Case mouth size at the crimp is .377.

I didn't get a chance to chrono today at the event, so I *still* don't know what PF this is doing. Any chance it's still too light of a load?

Oh yeah, didn't mention, OAL is usually 1.18 to 1.22. Seems to vary a bit. I went longer than lead data (1.10), as I wanted some safety margin due to higher load than lead.

 

[Steve C]

115gr Lead bullet load per Hodgdon's website is 3.0 to 3.4grs. 3.9grs is maximum for jacketed bullets. Try dropping your charge down to no more than 3.4grs and see if that doesn't stabilize the bullets. I think your just running them too hot.

 

[editingfx]

Nope - as per 1st post, loads < 3.6 won't cycle my M&P Pro reliably. Tested on many rounds 1st. Stovepipes. Listed load data in 1st post also.

I'm starting to think it's just a bad powder for this bullet/gun combo. I've yet to see better-than-factory ammo accuracy from it yet. But the powder was free with the press, so complaint is worth what I paid for it....

Still, managed to shoot halfway between Marksman & Sharpshooter with my handloads...

 

[D. Manley]

I've pulled at least 6 while setting crimp, and there's a fine line on the plating, but no where near enough to cut-through. It's just enough of a line to see & feel. Case mouth size at the crimp is .377.

I didn't get a chance to chrono today at the event, so I *still* don't know what PF this is doing. Any chance it's still too light of a load?

Oh yeah, didn't mention, OAL is usually 1.18 to 1.22. Seems to vary a bit. I went longer than lead data (1.10), as I wanted some safety margin due to higher load than lead.

Crimp sounds fine but I think you've identified the problem. Max SAAMI OAL for 9MM is 1.169 and you're loading a good bit longer. Load a few at 1.14 to 1.16 and shoot them again. I don't think the short 115 bullet is allowing enough pressure to build up with so little case tension holding it. Also, at 1.22, unless your gun is very deep throated you may even be touching the rifling.

 

[Walkalong]

I am loading them at 1.130 to 1.135 O.A.L. I shoot for 1.133ish and they all fall into that spread.

 

[ants]

A few notes from my humble experience

Sometimes we need to sit down and take a breath. Maybe a glass of iced tea. Take it slow and easy, one step at a time.

I'll bet 1.22 inches would barely fit his magazine, it won't fit mine. I'll bet he means 1.118 to 1.122 inches. Perhaps this tells me that he's excited and not getting all the facts down on paper accurately. Doesn't mean he's not keyholing, it just means that there are other things to consider. In fact, I might bet a dollar to a doughnut that he's not keyholing.

For instance, sometimes 9mm plated bullets strip off a bit of plating and spin it around like a mini weed whacker while it flight. Suprisingly the slug will still fly fairly straight, but it'll cut up the edges of the hole in the target. He and his buddies at the match may interpret this as keyholing. My Glock 19 does that with plated bullets, and occasionally my 92FS. My home-built Caspian with Colt barrel and my S&W 5906 will never do that. Seems to be peculiar to the gun and bullet.

Even with magnum primer, I would expect that 3.8 Clays at 1.120" will probably not keyhole. That's one of my old fallback favorite plinking rounds (with standard SP, not magnum), usually at 1.130 to 1.140 inches with a Berry's copper plated bullet. For now, I would only check the OAL and go easy on the FCD. You may be surprised that little or no FCD is needed for a 9mm round, if you bell the case just enough to take the bullet. Tension alone may hold that bullet for an M&P.

If you're using the Lee disk by following the chart, you're NOT getting 3.8 grains Clays. You're probably getting 85% of that, which is why the starting load didn't cycle (that's a good pistol, it will cycle a good load, including any load listed by Hodgdon). Get a scale and weigh your charges properly. I would not be surprised if you are only 110 or 115 power factor.

If it is keyholing, the 9mm pistols with which I have experience (in my humble experience) may keyhole if your loads are way too hot, or way too soft. Most any manufacturer's listed load will shoot right. Verify your powder charge, verify your OAL, go light on the bell, go light on the crimp, verify your velocity when you get a chance, and go shoot some more.

 

[Mal H]

Some thoughts on what might be happening -

Let's assume you are indeed getting keyholes with the 3 or 4 rounds. It's easy enough to visually see them, so I'm calling that a fact.

You are only getting roughly 4% tumbling/not-tumbling rounds. That's not a very high percentage. If something was drastically wrong, most if not all of the rounds would have keyholed the target. So that means either something was not quite right with those few rounds which is impossible to know at this point since the evidence has gone up in smoke down range - or - all of the rounds as loaded were on the hairy edge of keyholing and those rounds that did crossed that threshold.

If it's the former of the above, there's not much you can do at this point except double check your reloading processes for consistency. But, if it's the latter, then you can check to see even now after the fact. Make some more rounds with the exact same characteristics and chrono them. If at all possible, capture a fired bullet to check for widened grooves, detached plating, etc.

A theory which I don't think anyone has mentioned, or at least they've overlooked, is the involvement of magnum primers. A magnum primer in a small capacity case such as a 9mm may get the bullet moving much sooner (ballistically speaking) than it should for good combustion. IOW, the bullet is pushed almost out of the case by the pressure from the primer alone before the powder has been fully ignited (primers are that strong and that fast). That would give you a much larger case volume resulting in reduced peak pressure. Only a chronograph would be able to detect that. Well, you also might be seeing some unburned powder in the barrel at times. But if you shoot a "good" round as the last one, even that evidence would be gone.

 

[Walkalong]

An excellent thought.

 

[Larry Burchfield]

Keyholing

I may have missed it but did the gentleman say at what distance the targets where that he got the keyholing. If they were close targets the bullet may have not stabalized yet.
Larry Burchfield
SEABEES/RVN/67/68/69
DAV

 

[243winxb]

Bullet diameter undersize for what ever reason. Or the groove diameter is on the large size.

 

[editingfx]

First off, thanks for all the input & thought! I really enjoy a thread that goes beyond "what gun should I buy". What can be especially helpful to new handloaders like myself are comments like below:

A magnum primer in a small capacity case such as a 9mm may get the bullet moving much sooner (ballistically speaking) than it should for good combustion.

I never would have considered this aspect of the dynamics involved. I'd been thinking "how much more pressure are the mag primers adding", not the possibility that in fact there may be LOWER pressure due to increased case volume! Another shooter at the match commented how some rounds sounded a bit soft. Perhaps Mal has hit upon the crux issue? Now I'm REALLY bummed I missed the chance to chrono! And none of the local indoor ranges have them to rent.

But then again, Ants had a point to consider:

For instance, sometimes 9mm plated bullets strip off a bit of plating and spin it around like a mini weed whacker while it flight. Suprisingly the slug will still fly fairly straight, but it'll cut up the edges of the hole in the target. He and his buddies at the match may interpret this as keyholing.

Grin... maybe I'll settle on this possibility as the answer.... at least until the standard primers I've ordered finally come in... lol But, must say that it really did look like a keyhole, where one side of the hole was noticeably larger - clean, but larger.

As for distance, the stage where the keyholes were noticed was 10 yards. The 20 yard stage showed none, FWIW. (But there were 50% fewer rounds fired on the longer stage. Thank God. lol)

In reply to a comment about the OAL's, yeah, I got my #'s confused while typing - OAL is running 1.118 to 1.125.

Also, I always zero my Lee scale at the start of a loading session, throw a few, weigh, load a 100 or so, weigh again. When I was working up this load, I started with the auto disc's lighter throw (3.4) and trickled .1 grain sequentially up to 3.9. Found that 3.5 stovepiped, and 3.6+ didn't. Next auto disc throw up was 3.8, so there I was.

And off-topic, this was my 1st match with the M&P Pro, and oh man, do I love it!

PS - learning all these aspects of what happens after the trigger breaks is, for me, the most rewarding part of handloading!

 

[rbernie]

Try using zero crimp.

If the copper wash on the plated Raniers and Berrys is cracked during the crimp process, it will be shed immediately upon exiting the barrel and will destabilize the bullet PDQ. This can happen if you push plated bullets too fast (1200fps seems to be a upper limit) but it is more commonly experienced when overcrimping.

BTDT.