Bullet tumbling upon exit of barrel

[Balzer94]

We recently started casting our own bullets. We are using 125 gr round nose bullets sized to .356 inches and being shot out of an STI Spartan V 9mm and a beretta 92fs 9mm. I can't seem to find the twist rate in either barrel. According to the Hodgdon load data, they are flying just above 1000fps. When shooting 115gr plated bullets I get nice clean holes. But for whatever reason these making nice sideways bullet holes in the target at 10yds.

The same ammo worked just fine in our glock 17, and 19 both with lone wolf barrels. The twist in those seems a lot slower than in my beretta and STI.

Anyone have any suggestions?

 

[lx1x]

drop the powder charge.. and recheck. either you are crimping it too much also.

 

[Balzer94]

Okay thanks. I will definitely give that a try. I'm guessing to heavy of a bullet is spinning to fast, and going to fast, becomes unstable and that's why it's tumbling?

 

[lx1x]

Okay thanks. I will definitely give that a try. I'm guessing to heavy of a bullet is spinning to fast, and going to fast, becomes unstable and that's why it's tumbling?

yep. google bullet keyholing.

i reload 124gr.. it works fine on my sig and xdm.. but keyholing on my glock.. i dropped the charge and it working fine.

 

[Balzer94]

Okay thanks

 

[Pinecone]

What powder?

We found that shooting cast bullets in a Sig 229, with WW231 they would sometimes keyhole, but switching to HS-6, loaded to the same velocity worked fine.

If the initial pressure is too high, the bullet strips in the rifling and does not get spun up.

 

[Balzer94]

3.7 gr of tite group is what we were using

 

[Biggfoot44]

* In General * , that's not a fast load . The bullet is not properly spinning upon exiting the bbl. Potential issues are incorrect bullet to bbl sizing , incorrect alloy , or one or more of above excabriated by powder burning rate.

1st step , slug bbls.

 

[coopermania]

* In General * , that's not a fast load . The bullet is not properly spinning upon exiting the bbl. Potential issues are incorrect bullet to bbl sizing , incorrect alloy , or one or more of above excabriated by powder burning rate.

1st step , slug bbls.

slug the barrels and I think you will find you need a harder alloy and mabe need to size .357

 

[John from MD]

The bullet is too small a diameter. ideally, your cast bullets should be .002 over the bore size of the barrel. Additionally, unless you quench harden your bullets, you should stay around 850 FPS.

Since you were shooting these at 1000FPS and they were key holing, I would also check to see if you leaded up the barrel. If so, you need to scrub it out before testing again.

John

 

[Pinecone]

What alloy are you casting?

Could be too soft. And after the first few rounds, the rifling may have been leaded full.

 

[Balzer94]

Just slugged the barrels. About to run out but before sizing, the bullets had a decent amount of lead taken off in the 92fs and STI barrel and not so much in the glocks. Will measure though when I get a chance. We are using 2-6-92 lead with Brinell hardness of 17 from midatlantic bullets

 

[303_enfield]

To fast (sometimes) for a non gas checked boolit and you'll do better shooting as cast.

My 2¢

 

[Balzer94]

The measurements came out as expected from my results. The glocks came out at .353, and the 1911 and 92 came out at .355. The resized bullets were .356. I'll see if I can't find a .357 resizer

 

[Nanook]

The standard barrel on a M9/92FS causes standard ball ammo to go 'trans-sonic' about 40 yards out. In short, this means the shock wave catches up to the bullet as it slows down, potentially causing it to do 'weird things' as the force is redirected. You can fix this by loading sub-sonic or swapping barrels. Below is the stock 92FS with a 1/16 twist and a KKM match barrel with 1/32 twist...which keeps ball ammo super-sonic the whole way. Why your stuff is key holing at 10 yards is weird but good luck with the casting.

 

[John from MD]

The most important thing when shooting cast bullets is the fit in the bore. As a rule, .002 over bore diameter is the standard to shoot for. When the bullet fits correctly, it gives you more latitude on 1) lead alloy makeup and 2) speed at which it is shot. In most cases, undersized bullets will cause leading and give poor accuracy even if the alloy is hard. The reason for this is the gas cutting around the sides of the bullet.

For 9mm and 40 cal, I like to use a slower powder like HS 6 and keep the speed between 850 and 900 FPS. This works all of my actions with no problem and is very accurate.

John

 

[Balzer94]

Just left the range. I loaded up some rounds with a lighter powder charge, 3.45 grains of titegroup. Tried both sized at .356 and at .358 diameters. No crimp. The 1911 worked well with the sized .356 bullets and the lighter powder. The beretta not so much. The beretta consistently key holed. I'm going to try a little less powder next trip and if that doesn't work I will consider looking at a barrel with a slower twist rate

 

[101combatvet]

I shoot RN, .358, 125 grain out of my 92SF (out of box) and I've never had this problem. I use W231... can't recall the exact number of grains but they were at the low end of the chart.

 

[Nanook]

Just left the range. I loaded up some rounds with a lighter powder charge, 3.45 grains of titegroup. Tried both sized at .356 and at .358 diameters. No crimp. The 1911 worked well with the sized .356 bullets and the lighter powder. The beretta not so much. The beretta consistently key holed. I'm going to try a little less powder next trip and if that doesn't work I will consider looking at a barrel with a slower twist rate

Depending on where you are, I can let you borrow the barrel out of my match gun before you blow a couple hundred bucks.

Caveat: you break it, you buy me a new one. PM me if you're interested.

 

[Balzer94]

Depending on where you are, I can let you borrow the barrel out of my match gun before you blow a couple hundred bucks.

Caveat: you break it, you buy me a new one. PM me if you're interested.

Pm sent