Poor grouping with my Lee 124 gn lrn cast boolits

[ichthyo]

I'm trying to tighten up my groups in my 995TS 9mm carbine.

I powder coat and then resize to .356, but the groups are not very tight. I'm using 4.0gns of Bullseye. Any suggestions on how to tackle the issue?

[Grmps]

the 9mm is a tapered case and very easy to over crimp. a lot of 9mm problems are people are crimping down the diameter of the boolit.
have you slugged your gun to see if .356 is big enough?

[knifemaker]

You need to slug your barrel to determine the groove dia. My Springfield armory EMP pistol in 9mm did not have good accuracy using .355 or .356 dia. boolits. slug the barrel and the groove dia. was .356. I went to using 125 gr. boolits made for the 38 special-357 mag. at a dia. of .357 and accuracy improved greatly.

[MUSTANG]

+1 on the 9mm being sized to .357. For my Beretta 92F, 1918 Luger and 1941 Luger pistols; they shoot wide groups at .356; and tighten up to be very accurate at .357 using the exact same Lee Mold.

[Ed_Shot]

I have a 995TS 9MM carbine. I reload for several different 9MM's of various makes in my family. I size all my 9MM boolits to .358 and I have not personally seen a 9MM that didn't like a .358 dia. boolit . My Lee 9MM molds will luckily size to .358 or they'd be long gone. Having said that, let me say that my 995TS while 100% reliable with all my ammo is obviously picky about what boolit and load it likes for best accuracy. I tried Lyman 358242 (120 gr) and 356402, the Lee 356-120-TC and 356-125-2R with various powders and loads. The Lee 356-120-TC over Promo 3.8 gr. is the clear winner at 50 yds while other combinations had various degrees of success/disappointment. I must say that the Lee 356-120-TC is definitely not my first choice for pistol accuracy. You are going to have to figure out what your weapon likes best.....that's the fun of it.

[ichthyo]

Thanks everyone. My mold drops them right at .356 and they slide through the sizer with little effort. I may powder coat some and not size them to get a better fit. I have slugged all my other guns, so I guess I need to do that too.

[asmith80]

.358 seems to be the size that works the best for my 9mm loadings. I don't really bother slugging the bore on any new 9mm I get anymore, I just check to make sure my OAL is good for reliable feeding and keep using the .358 boolits

[Shingle]

That bullet has always been good to me even in my 995,ar 9's,and every Glock Iv ever had as long as it is sized rite. Try .357 and dont over crimp.

[GhostHawk]

I had 2 that keyholed and had big sloppy groups. One was a stub job rifle barrel in a handi rifle.

The other was a pawn shop Hipoint C9 pistol.

.358 125 6 cavity mold cast at .359 with roughly 50% COWW and 50% range scrap with 1% tin or pewter added.

As cast they came out at .359 to .3595 and once loaded keyholing was gone and groups were tight.

I would start at .358 but go as big as you have to go.

I would be tempted to try not sizing after powder coat. See what will chamber and what it does.

[winelover]

What kind of expander are you using? I would recommend at least a Lyman "M" die/expander. Most 9mm expanders are made for jacketed bullets and do not expand the case enough for cast. You could be sizing down your bullets, during the loading/seating process. The correctly sized expander will also help seating your bullets more concentrically. When I seat any bullet, I will seat the bullet half way, then turn the case a quarter turn before fully seating...........another concentricity aid. I have also given up with seating and crimping in the same step. I always crimp separately............with a taper crimp die for 9 mm.

I have been working with a CZ Scorpion carbine. Velocities measured by a Lab Radar unit are significantly higher than the same load out of a pistol length barrel. Two to four hundred feet per second higher, depending on load. Thus, I have gone to gas checks for all my 9mm carbine loadings..........I do not powder coat.

Winelover

[TCLouis]

Shooting one load with one powder is not the way to develop/prove precision with a load other than maybe to show what does not work.
Vary load from bottom to top of the suggested range for that powder.
DO NOT loaded shorter than AOL, but try slightly longer (what will the magazine feed does that get into the rifling.
Sometimes we stumble over a precise load, sometimes it takes some effort to develop one and some guns just aren't that good, no matter what we feed them.

[smokeater]

Shooting the same bullet in a Glock 17 and Glock 19, sized.356 BHN of 11 - 12. No leading (extremely well broken in barrels) and shoot like lasers. Only shot out to 25 yds though.

[trapper9260]

Some of my will take .356 and then I have others that take .358 like my 357mag take.I use the dies for the 38spl/357 to do the .358to do the 9mm that take that size boolit.

[rintinglen]

Order a 38 S&W expander die from Lee (not 38 Special) and size to .358. I'm disposed to think that your 9mm troubles will be greatly diminished.
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