9mm carbine keyholing.

My 995 is close to a tack driver @ 25yds with 124gr JHP's.

Slug the bore and see what the actual diameter is. I've seen 9x19 barrels slug all the way up to .358".

Hope this helps.

Fred

Might try coating some of them and try that....

You may have to double tumble coat that bullet to make it big enough to shoot well. Your standard 9MM FMJ is .355. The smallest 9MM lead bullet I would try is .358. If you tumble lube your bullets twice they might shoot better. I do not have one of those carbines and it is good advise to slug the bore with one of your bullets that you have flattened the top down with a hammer to increase the diameter more than what it comes out of the mold. For that matter the alloy you use might be dropping bullets smaller than advertised for the mold. Have you checked them before loading and then checked a finished round. A taper crimp on a lead bullet should be .002-.003 larger than on a jacketed bullet. If you did not adjust your taper crimp you might be squeezing the bullets down. Small bullets do not always automatically mean they will lead.

Back when I had my 995 I had the same problem with the same slug. Get Berry's 125 cone and the problem should go away. I also had good luck with their plated 115s and 124s as well. Both solid and HP functioned and shot well in mine.

Bullet diameter to small?

Barrel rate of twist different then pistol?

Bullets stripping the rifling from higher velocity then pistol? Alloy to soft, with a fast twist barrel. High pressure with maximum loadings.

Muzzle crown not correct?

I gave up on the lee 124's and use the lee 125 bullets for 38spl sized down to .358 (they drop about .360. I use them unsized for my 357's). Then I added a 38 s&w expander to my powder through die instead of the 9mm one to keep the case from swaging my ovesized bullet down. And I sold the factory crimp die. Those 3 things pretty much solved my accuracy issues with 9mm and lead.

I use that same bullet in the same rifle and have never had a problem. I do powder coat my bullets and size them to.358.

I have no experience with those TL bullets. Wonder if the longer barrel might be a problem. Strange there is no leading with that much on target keyholing though. You should find a way to shoot lead in that thing but it may take some doing. I have a couple C9's and they shoot anything my other 9MM's shoot well. Go figure that the carbine would be a problem.

Keyholing is caused by shooting a bullet too heavy for the rifling twist of your gun. In otherwords the twist is too slow to stabilize the bullet.. Also too light of loads with heavy bullets, ie not enough spin. Try a lighter bullets and it should go away.

Twist Rate?

What is your 'as cast' bullet size?

The reason I ask is because my wife shoots a Sig that drove me crazy with keyholing with my 9mm bullets sized to .356. Everything else I shot them through was fine. My 'as cast' is .357, so I tried a few without sizing them and the problem disappeared.

Not to do any HiPoint bashing (truly) but I had a C9 HP 9mm that wouldn't even shoot Berrys. All it took to solve my issue (which was key holing) was to use real jacketed projectiles. Lead or plated just would not hold up under rifling stress and would tumble at any velocity.
I attribute this to a slightly looser tolerance in the bore, though I have not mic'd it.

Mold to water is not the same as this.
Lyman - Heat Treatment of Cast Bullets to Harden Them

Q: Is there anything I can do to make the bullets harder?
A: Cast bullets can be heat treated to increase their hardness providing your alloy has some antimony present. To heat treat your bullets: Cast your bullets in the normal manner, saving several scrap bullets. Size your bullets but do not lubricate them. Place several scrap bullets on a pan in your oven at 450 degrees and increase the temperature until the bullets start to melt or slump. Be sure to use an accurate oven thermometer and a pan that will not be used again for food. Once the bullets start to melt or slump, back off the temperature about 5 to 10 degrees and slide in your first batch of good bullets. Leave these in the oven for a half hour. Remove the bullets from the oven and plunge them into cool water. Allow them to cool thoroughly. When you are ready to lubricate, install a sizing die .001" larger than the one used to initially size them. This will prevent the sides of the bullets from work-softening from contact with the sizing die. Next apply gas checks if required and lubricate. These are now ready for loading.