Keyholing

[DanTheFarmer]

Good Evening,

Yesterday was an interesting day at the range.

I had two 9mm Bersas with me. Both have been reasonably accurate in the past when shot from a rest. I was shooting mixed headstamp cases, WSP primers, 124 grain plated round nose flat based Berry's (not the thick plated) over 4.4 grains of Titegroup. I've chronographed this load before and expect the bullets to be travelling around 1075 fps.

Both pistols were keyholing quite badly. I shot at 7 yards and was accurate but keyholing and at 10 yards the accuracy was terrible. Soon after I started shooting I suspected something wasn't right. The holes looked a little too ragged and then another shooter gave me some targets on heavier stock, about like an index card. As some of the bullets went through these targets I got perfect little profiles, a flat base, some parallel sides, and a rounded top.

The pistols were clean before shooting and I found very little fouling of any kind when I cleaned them later that evening. I fired 50 rounds from each pistol.

What would cause the keyholing?
Too hot a load? The powder charge I used is listed as max for jacketed bullets but the velocity is well under where I would suspect problems.
Did I get a batch of undersized bullets?
Did they become undersized because it was quite cold?
I used the Lee Factory Crimp die when I loaded them. Can the FCD squish the bullets too much?

Any input is appreciated. Thanks.

Dan

 

[rcmodel]

Did they become undersized because it was quite cold?

No amount of cold can shrink a bullet undersize.
And even if it could, it would shrink the bore undersize too.

I used the Lee Factory Crimp die when I loaded them. Can the FCD squish the bullets too much?

Yes it can if adjusted to far.
Especially with lead or plated bullets which are bigger then jacketed bullets in the first place.

The FCD is designed for jacketed bullets, which are smaller to start with.
You squish the case?
What's inside it gets squished too!

rc

 

[Dr.Zubrato]

The load you're using is too hot. You should be loading plated bullets to lead specs, which I believe the max is 4.0 gr titegroup.
Next, you may be crimping the bullets too much, and cutting the plating on the rounds, exposing the lead core and putting your accuracy in the crapper.

The Lee FCD should not be squishing down your rounds, unless something is definitely wrong with them. I load lead 9mm to .357in, and plated rounds are .356in without squishing. This step is most likely where you are applying too much crimp on the case. If you can see the crimp, it's too much. You should be removing the belling you applied on the case mouth, and not more.

Try pulling some bullets youve seated and take some pictures.

 

[Walkalong]

I've chronographed this load before and expect the bullets to be travelling around 1075 fps.

Plated bullets can take this easily. The load is not too hot. 124/5 Gr plated bullets at 1050 to 1075ish in 9MM is a nice soft shooting load. That happens to be my favorite 9MM load actually. (Different powder & plated bullet.)

Tumbling happens when bullets are not stabilized. This can happen from to slow a twist, or a leaded barrel where they bullets are skidding which imparts very little spin, or a load where a bullet is driven so hard it cannot hold the rifling. None of these things are happening.

Skip the FCD and try it again. An undersized bullet which is not holding the rifling will tumble.

 

[Dr.Zubrato]

I know Walkalong and RC have more reloading and shooting knowledge in one fnger than I do my body, but I can't fully agree having loaded the same grain and manufacturer bullets myself with the same powder, titegroup.
I don't know what your COAL is, but the Berry's website states,
"When loading plated bullets we have found best results using low- to mid-range jacketed data in the load manual. You must use data for a bullet that has the same weight and profile as the one you are loading. Do not exceed mid-range loads. "
However, 4.4gr of titegroup is the MAX load for Jacketed 125gr (per Modern Reloading 2nd Ed), and Berry's states not to load higher than Mid range jacketed loads.
I don't have access to a chronograph, nor have I chronographed my loads. My apologies if the author has worked up these loads carefully, and checked for high pressure, fps, and accuracy. However, the original story didn't seem to indicate this.

I don't mean to say it's why the bullets are tumbling at 10 yards, but it's a possibility. It's more likely it's a combination of factors and possibly too hard of a crimp.

I only posted my opinion as a caution, because titegroup moreso than other powders has a reputation to create spikes in chamber pressures when compressed and possibly cause a kB in some scenarios where the case cannot properly headspace on the case mouth due to over taper crimping, or a double charge.

Hope you find out what's causing your troubles. Try what RCmodel and Walkalong have suggested, be safe and have fun.

 

[sexybeast]

4.4gr of titegroup is too hot. I shoot 122-126gr lead every week with Titegroup and have done quite a bit of testing. Right around 4gr the accuracy is starting to "open up" and at 4.4gr [which would be max for jacketed] they would be all over the place which is what you are describing.
The starting load for lead is 3.6gr with a max of 4.0. I use 3.5gr and they are very accurate. You can push plated a "little" harder than lead but not as hard as jacketed. Start out and work up. Velocity is not a concern for me, accuracy is.
Remove the factory crimp die as Walkalong suggested and adjust your taper crimp die to do the job. The factory crimp die "squeezes" the bullet in the case and it may become undersized and even less accurate and erratic.

 

[Walkalong]

I suppose Titegroup could be too fast to get 1075 FPS with that bullet under max pressure, but I still don't think that is the problem. I would load 10 rounds without the FCD and test them. If they do not tumble, you have found the problem. If they do tumble, back off the Titgroup, or get a more suitable powder, and test again. As stated, you are at or around max with Titegroup for jacketed, and between the burn rate and high Nitro levels of the powder, it may indeed be over pressure. Did you test lighter charges first?

 

[mtrmn]

Measure the dia of a new bullet, then pull one of your loaded rounds and measure that bullet.

 

[Taterhead]

Berry's can be made to run right if adhering to a few basic techniques. All of them are are done to avoid disturbing the thin copper.

Give a generous flare of the case mouth.

Seat longish as your gun will permit.

Seat and crimp in separate steps (you are doing this).

Modest charges and velocities. If you are at max, you're too hot -- especialy with a fast-burner like TG.

Crimp only enough to barely remove the flare. A lot of us are not a fan of the LFC die concept. I prefer a traditional taper crimp. But you should be able to setup your crimp die to just remove the flair. No post sizing or engraving the bullet in any way. If you were to crimp the bullet and then pull it, you shouldn't see a ring where the case mouth is biting th bullet. Just close up the flair. That, other than modest charge weights, is the most critical setting for plated bullets.

 

[sexybeast]

I just re-read your post and there are a few things you can do for you own knowledge and piece of mind. First: slug your barrel. Find out your barrels diameter. There are some good videos on utube.
Measure your bullets. Make sure they are at least .355 or larger. Pull a bullet after you load it and measure the base. It should be the same size as the unloaded ones. If they are not this IS a problem.
This is a process of elimination. The more information you have about your guns and bullets you are loading the more you can understand whats happening.
Load some rounds only with a taper crimp and shoot those along with the bullets you loaded with the factory crimp die. See what difference you are getting.
And last: Start some soft loads and start to work up and put them on paper on a seperate target while bench rested. For myself I like to start just a little below starting loads for two reasons: To see what kind of accuracy I get and to see the guns function. This will help you to understand whats happening as the loads get hotter. I wish I had taken some pictures of the targets as I was working up and experimenting with some loads. Its quite interesting to see the load working real well and then start to open up and then start to keyhole and become what you are describing as you load hotter and hotter.
As far as the amount of crimp? I like a good crimp that does leave a ring around the bullet. With a light crimp I have had some bullets setback while feeding and jamming up the gun. "I crimp so the bullet stays put"
Finally I see no reason to go for "max" velocity with any bullet for what you are doing. Shooting at paper and having it look like a shotgun pattern is not something to be proud of. Accuracy should be your first concern.
My long winded 2cents.

 

[splattergun]

Leading has only been mentioned once, so far in this thread. I would check the barrels of both guns for fouling, in addition to checking to be sure you're not scoring the plate with an over-tight crimp. Berry's plating can be stripped by an over-tight crimp. In that case you may be experiencing fouling, or perhaps bullet deformation, if the plating is being stripped off. Some have suggested trying without the FCD, I would agree to that, or at least reducing the amount of crimp you use. The neck tension is what holds your bullet in the 9mm case.

I think your velocity is fine for Berry's plated.
http://www.berrysmfg.com/faq-q10-c1-How_fast_can_I_shoot_these_bullets.aspx

 

[verb0s]

Dan,
Excessive use of the FCD will squish the bullet to a smaller diameter... but should not cause keyholing.
I've experienced keyholing due to too much or too little spin, but i doubt anything you can make with 9mm can do that...
I'm guessing the bore needs a good cleaning.
You can also try roll crimping instead of the FCD. I roll crimp my loads, I give them a light crimp. I haven't use the FCD for a long time.

As other people are brought up, perhaps you're loading too hot, although i don't see why that can cause keyholing.

 

[sexybeast]

The pistols were clean before shooting and I found very little fouling of any kind when I cleaned them later that evening. I fired 50 rounds from each pistol.

Probably why most of us did not mention leading.

Excessive use of the FCD will squish the bullet to a smaller diameter... but should not cause keyholing.

Yes it will. The bullet is smaller in diameter especially at the base after being sized down. As its starts down the barrel gasses go around the bullet keeping it from engaging the rifleing enough to stabalize. It comes out tumbling. Thats why I told him to shoot side by side rounds that have been loaded with a FCD and ones that have not.

 

[ngnrd]

Doesn't 9mm headspace on the mouth? In that case, would not a roll crimp be a bad idea?



Disclaimer: I don't load 9mm.

 

[sexybeast]

Roll crimp is for revolvers [and lever actions] Untill the Factory Crimp Die was introduced as the "new best thing" there was the taper die for autos. In almost every bullet set die the taper die is built in and was adjusted by simply turning the entire die.

Edit: There are taper dies also used on a seperate station.

 

[wlkjr]

Have you tried the loads through a non Bersa pistol just for reference?
I had some factory 147 gr. subsonic (950fps) reloads keyhole about 1 out of every 5 shots through two different Glocks. I got in touch with the manufacturer and was told by the head tech that they used Berry bullets and sometimes had that issue in Glocks because of the plating. They replaced my order with some 115 gr. that I had shot before and had no more keyholing. Unfortunately I have a box of 147 gr. Berrys that I plan to load with Titegroup and hope I don't have that problem.
As a new reloader, I'm very interested in what the answer is to your problem.

 

[sexybeast]

I have a box of 147 gr. Berrys that I plan to load with Titegroup and hope I don't have that problem.

It can be done but it is harder than some slightly slower powders. Expect to use only about 3.0-3.3gr of titegroup. Also you won't be getting much velocity.

 

[wlkjr]

The guy I bought the 147's from uses 3.2 gr TG or 4.6 gr HS-6 with oal 1.115