9mm conundrum

[bigted]

Have the Kimber custom II pistol in 9mm 1911 A1 in hand and just beginning my load development for it.

Problem is with the 120 grain Lee TC boolits that I PC'd with lite Ford blue powder from Eastwood. Loaded Lee 125 grain SWC coated the same with exactly the same results.

These went wildly awry. I have never had such terrible accuracy with anything in my life. They wound up flying some 4 FEET groups at 25 yds ... yep I said 4 FEET groups.

Load is 4 grains Bullseye with CCI small pistol prime in Rem cases. Ran boolits thru a .357 size die after PCing. Alloy is close to Lymans # 2 mix and water dropped after PCing.

The Lee 95 grain fp PC'd same shot into 2 inch at 10 yds and at 25 I could consistantly hit the clay pigeons ... so I know it isnt the barrel. The FMJ's in 115 grain from Rem factory loads did good as well.

As stated, I have never had loads go so wild from anything ever before.

Upon cleaning at home, I also discovered another first for me. Shoving a tight patch through from the breech, I found it hard to overcome the chamber end where the rifling began. This is a much larger STEP from chamber to bore then anything I have encountered before as well.

My first encounter loading and shooting 9mm so I am in yet another learning curve.

Any ideas here? Seems that the factory fmj's and my 95 grain PC'd boolits would go astray if it were the barrel or the .357 sized boolits. Just grasping at straws here ...

Hoping some body has an explanation for the wild 4 foot groups at such short range. Something happening here that this ol coon dog has not seen before.

Thanks in advance.

[Bigslug]

Pull a bullet from one of your loaded rounds and check the diameter at the base. I'd guess you have the common 9mm issue of the inside taper of the brass sizing your bullets down below optimal spec. The answers are harder bullets and a larger expander.

[DougGuy]

Sounds typical of modern mfgr's barrels, ZERO throat to speak of. Even SAAMI chamber specs call for freebore before the leade ins begin but since the only ammo that anyone shoots anymore is factory store bought stuff, they don't need any throat if it chambers wal mart ammo right?

If you have rifling running right down to the chamber mouth, with no or very little freebore, it will only ever shoot but so good without improvement.

This is what the throat should look like for proper function and accuracy with cast boolits:

[bigted]

Pull a bullet from one of your loaded rounds and check the diameter at the base. I'd guess you have the common 9mm issue of the inside taper of the brass sizing your bullets down below optimal spec. The answers are harder bullets and a larger expander.

Well did as you suggested and BINGO!!! Dang things sized em down to .349 inch. Amazing. Cant load em out further as the ogive hits the rifling. Very well may need to get a throating ream and give just a bit more forgivness room in there for my cast boolits. Gotta be able to shoot cast cause I am NOT gonna pay these exorbitant prices for loading my rounds.

[Kenstone]

Well did as you suggested and BINGO!!! Dang things sized em down to .349 inch. Amazing. Cant load em out further as the ogive hits the rifling. Very well may need to get a throating ream and give just a bit more forgivness room in there for my cast boolits. Gotta be able to shoot cast cause I am NOT gonna pay these exorbitant prices for loading my rounds.

A larger expander fixed this for me (and many others) so if you are using a Lee PTX die, this expander is a direct swap:
https://leeprecision.com/pm-expan-plg-38-s-w.html
worked for me,

Edit: if you are using mixed brass you will find some have a thicker wall thickness closer to the end, some even have steps
You will need to separate your brass and eliminate the thicker/stepped wall stuff.

[rancher1913]

I had to go with a fcd to overcome the same problem. 9mm are the biggest learning curve to load. you will need to watch case length very closely as they headspace on the brass

[bigted]

Thanks for the suggestion. Sounds right to me. So far all I am using is rem brass.

[Kenstone]

Thanks for the suggestion. Sounds right to me. So far all I am using is rem brass.

So far, I have found R-P brass to run the thinnest of all I've measured.

[gwpercle]

Well did as you suggested and BINGO!!! Dang things sized em down to .349 inch. Amazing. Cant load em out further as the ogive hits the rifling. Very well may need to get a throating ream and give just a bit more forgivness room in there for my cast boolits. Gotta be able to shoot cast cause I am NOT gonna pay these exorbitant prices for loading my rounds.

Something that helped me was Gas Checked Boolits. A 4 cavity NOE 358-124-TC - GC mould along with a NOE custom case expander plug made all the difference in the world . The gas check helped stop boolit size down and the correct sized expander plug made seating easy . I size them .357 and lube conventionally ( not powder).
I had never encountered so much trouble in loading cast boolits as when I took on the 9mm,
It's not easy , especially the "no Throat" situation....but all the details can be worked out without resorting to a throat job. Throating will make life a bit easier though and give you more leeway in seating depths .
Gary

[rintinglen]

A larger expander fixed this for me (and many others) so if you are using a Lee PTX die, this expander is a direct swap:
https://leeprecision.com/pm-expan-plg-38-s-w.html
worked for me,

Edit: if you are using mixed brass you will find some have a thicker wall thickness closer to the end, some even have steps
You will need to separate your brass and eliminate the thicker/stepped wall stuff.

Good Post
The 38 S&W expander made my 9's much more cast friendly.

[bigted]

Anybody be able to steer me to a throat ream that will carve the rifling to a more suitable lead in angle? Or should I take it to or send it to a smith?

How bout a recomendation for a fellow castboolits member to make it cast friendly.

[toallmy]

Dougguy can fix your throat .

[tazman]

Anybody be able to steer me to a throat ream that will carve the rifling to a more suitable lead in angle? Or should I take it to or send it to a smith?

How bout a recomendation for a fellow castboolits member to make it cast friendly.

Dougguy does this and his work is excellent. Many on this site have used his services. I have had him do a couple of barrels for me and it fixed all the chambering problems.

[oldhenry]

+1 on DougGuy

[doghawg]

bigted
After 40+ years of handloading I was beginning to think I had learned a few things but the 9mm with cast bullets has been a humbling experience. I recently bought a Springfield RO Elite 9mm and gave cast bullets another try. This 1911 shoots very well with jacketed.
The cast load is the 120 Lee TC coated with Harbor Freight red and sized .357" after coating. Powder is 5gr. Power Pistol with WSP primer in range pickup Blaser brass loaded to 1.075". Function has been perfect and it was shooting tight clusters on the 25 yard swinger so I tried it from a rest at 50 yards on a freshly painted swinger and it grouped 4". That's the limit of my ability with iron sights and the best performance I've had with cast bullets in a 9.
I happened on a bunch of CBC once fired brass and tried the above load. Lucky that I tried the plunk test before loading up 100 rounds...they wouldn't chamber. The loaded round diameter was .004" fatter than same bullet in R-P, Blaser or Fed brass! I sort 9mm brass by headstamp due to the variation from between brands.
It sounds like you've found the problem with your 9 but I thought I'd toss this in as a FWIW.

[asmith80]

I've had issues with CBC, Aguila, PPU and military brass. Every other headstamp I have has no issues plunking in every one of my 9mm barrels. Those three were giving me bulges and in general not chambering consistently. I now just toss them every time I see them and don't worry about it