9 mm keyholing at 26 yds.

shot my new sig mk-25 ( P-226 ) today with what I thought would be some good loads. Using Lyman 356402 tire wts. PB with magma lube and sized .356. Weighed 122-123 grs. Loaded with cci-500, and 3.9 grs, 4.0 grs and 4.1 grs of bullseye powder. 20 rds each with each powder wt. 10 of each were taper crimped with Lee factory crimp die and 10 of each were not crimped. Used virgin starline cases for all. Several of these loads keyholed in target.
I've previously shot same bullet with 3.8 and 3.5 grs of bullseye with perfectly round holes in tgt. at same distance. Have also use Acc #5, 231,and mostly power pistol powder. The bullets on the last listed powders was linotype and weighed 111-113 grs. and all holes in targets were perfectly round. I've cleaned bbl after each shooting session so no copper or lead in bbl when I shot today.
Any ideas on why I experienced keyholing today would be appreciated. Thanks.

Undersized boolits. Slug the bore of your barrel. Go .002" over slugged bore size if you can chamber them, if not try thinner brass - Remington is pretty thin. Try one of the "Cowboy" expanders (midsouth shooters used to sell them seperately) if your boolits are being swaged down when they are loaded into the brass. To find out, you'll have to pull a slug from a reloaded round. I had to go to a harder than wheelweight alloy. Throw some linotype or even foundry type in the mix. You may have to quit using the Lee factory crimp die. You just need enough crimp to close down any expanded swell at the mouth.

I think your lead is too soft forthe twist rate of the barrel and the amount of powder you are using.

I would reduce the velocity. I have a Sig P226 and have worked with the same issue. Problem went away at lower velocities. I believe the twist rate is 1 in ten on your gun. Try keeping the speed around 950. Use a heavier bullet for more knock down power if desired. I run a 135 grain bullet in my Sig.

Your load would work fine in a 1 in 16 barrel twist. I have a 1911 with a one in 16 twist and it shoots lead bullets better than the Sig.

Try a simple and easy solution first.....just size your boolits to .358".

I bought a used SIG SAUER P226 TACOPS 9MM E26R-9 in like new condition for a very reasonable price. I found out why when I started load development. I couldn't get anything J-words/boolits, different alloys, different sizes different powders and charges. I took it to a gunsmith and he told me the barrel was bad from the factory (that explains the reasonable price) I call SIG and the rep told me they only warrant their guns to the ORIGINAL PURCHASER --- I WILL NEVER BUY A USED SIG AGAIN.

that being said, I bought a barrel and I was able to get 5 shots - 1 hole groups at 35 feet.

lee 356-125 2R COWW, PC'd sized .358 over HP-38 3.9 grains. it also shot well sized .3565 and .3575

You could also try dropping them in water out of the mold, Quenching, then just tumble lube them without sizing if they'll chamber.

Check your target frame/paper. If the paper is not flat against the cardboard or wood, then the tearing effect as the bullet passes through may give what is appears to be an oblong hole. The target paper itself should be supported, in other words, by the backing. Rod BTW: wheel weight alloy 356402 home cast bullets, lubed with 50-50, and sized .356" over 3.5 - 4.0 gr. of Bullseye shoot well in my P226 Mk25...~2.5-3" gps at 25 yds from a rest. Rod

Your alloy is fine, but slug your bore. Had the same issue with a CZ 85, bore slugged at .357. Sizing .358 solved the problem.

What I was gonna say was already said..... .358 size and shoot 'em up. I had the same problem with a Glock 19 sizing at .356. They were hitting sideways and bouncing off the wood backstop. Sized to .358 and they shot like a target gun.

"10 of each were taper crimped with Lee factory crimp die and 10 of each were not crimped. Used virgin starline cases for all. Several of these loads keyholed in target."

Since you tried both with and without the use of the Lee FCD I supsect perhaps the "virgin Starline cases" maybe sizing the bullets further when seating them? Might pull (Kinetic puller) some of the bullets and see if they still mic .356.

Quote:

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Originally Posted by 1006

I think your lead is too soft for the twist rate of the barrel and the amount of powder you are using.

I would reduce the velocity. I have a Sig P226 and have worked with the same issue. Problem went away at lower velocities. I believe the twist rate is 1 in ten on your gun. Try keeping the speed around 950. Use a heavier bullet for more knock down power if desired. I run a 135 grain bullet in my Sig.

Your load would work fine in a 1 in 16 barrel twist. I have a 1911 with a one in 16 twist and it shoots lead bullets better than the Sig.

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yup either use the lower powder charge or water drop those bullets. Alot of handguns have very shallow rifling and it takes a hard bullet to not strip through it. id also try 357 and see if it runs good. Bigger is allways better. But to tumble at 25 yards takes a real problem and if anything using ww more velocity (pressure) is going to (i hate this term with a passion) bump up the bullet to fit the barrel. Now if you were just getting poor accuracy and no tumbling id say size was the problem because when bullets BUMP UP they are basically turning a bullet you spent time being anal with trying to make it perfect and turning into a lump of lead that isnt the same every time you shoot. Its why 9 times out of 10 a harder bullet will shoot better at any velocity. It maintains its shape and engages the rifling. its why as casters were always chasing jacketed level accuracy.

Pull the bullet of one of your loaded rounds, and measure the diameter of the bullet. Your crimping could be swaging the bullet down.

When you are loading the ammo you could try removing the barrel from the pistol and crimping little by little until the rounds just chamber. But slugging the barrel is the first order of business at this point.

First off, thanks for all the replies. I have read through all several times and have changed my loading procedures as follows.
I slugged the bore and it mikes out at .356". Therefore I am now sizing at .358" and the two loads I have ready to test at the range both fit in the Lyman 9mm ctg. gauge. Load one is 3.5 grs. BE with 356402 and # 2 is 3.5 BE with Lee 356-125-2R and both bullets are linotype lead.
I have H2O dropped Lyman # 2 and shot linotype bullets with the same loads that previously keyholed but sized at .358" so made two changes that didn't show keyholing. I have to yet try sizing the softer lead at .358" which is next on the to do list to verify the .358" is the way to go ( which I think it is ).
I have pulled dummy rounds sized at .358" in starline, FC and WW cases and all miked at .358" after pulling. Bullets not sizing down when seated.
I am no longer crimping. Have checked last round in mag. at range and not jumping COL so will continue with no crimp.
I will change the backing on my target but there is no mistaking a 356402 going sideways through the target.
I realize the Sig Sauer P-226 9 mm isn't a target pistol but what degree of accuracy should I expect at 26 yds. with cast bullets ? Thanks again for your replies of help.

When you get it all to come together your hand loads should equal or exceed 9mm ball ammo. And you may not need to size to .358. Try some at .357 and crimp only enough so they chamber.

Why go sooooooooo hard for 9MM. I have great results with COWW + a little time, PC'd and sized for my guns.
my Ruger likes .3565 my sig isn't ar picky, my Tauris needs .358

The 2 biggest problems loading 9MM
The 2 biggest problems/causes of failure with loading cast in 9MM are OVER-CRIMPING & downsizing the boolit when seating.
The 9MM has a tapered case.

Crimping, I use the Lee FCD and only crimp to where the boolit won't move when the cartridge is pushed against a hard object.

For seating I like the NOE neck sizing dies so much I talked with a member ob CB who made a Lee powder through die with the NOE profile of several different diameters. I've had good luck expanding the brass using the same diameter expanding plug as the boolit diameter (brass springs back .001 after expanding and that.
.001 does the job holding the boolit in place!

A 38spcl/357mag expander plug should work also

I used to expand the neck with the NOE neck sizing die the use the Lee powder through setup to charge the case.

Use a kinetic boolit puller and make sure you're not downsizing the boolit in either of these operations.

this will go a long way toward tightening up your groups and preventing leading/tumbling

The crimp doesn't prevent bullet setback. It's neck tension that does that.

Instead of saying crimp when it comes to cartridges that headspace on the case mouth we should say flare/bell removal.

As a side note my 9MM bullets were cast out of clip on WW metal and air cooled. Loaded on RCBS carbide dies too. Seat and crimp in 2 steps and only crimp to remove flare of case mouth. I still shoot the Lee 120 TC sized at .358 out of my Belg./Port. BHP MK3.