9mm throat reaming?

[Ateam]

My problem child;
A browning hp that slugs at .357, and leads with everything that I have cast so far. I cant get anything larger than 356 to chamber unless stuffed dangerously far in the case. I am casting the lee 105 swc .358 with ww aloy, and think it could be the answer to my problems but the absence of a throat will not let it chamber. I am tempted to ream the throat to let a greater diameter/oal function.

Other things I think I might try before reaming,
Water dropping my ww boolits.
I could try seating my boolit deeper (flush with mouth) but my seating stem (rcbs carbide) is bottomed out at about 1.00 oal. Any one else have this problem?

The search function turns up a few posts on this, but not much current info. Has any one reamed a 9mm before? Does anyone have one they are willing to let me borrow?

[jcren]

Double post

[jcren]

Check with Douguy. He is the local chamber/throat/lead guru.

[Ateam]

i forgot to add I have tried sizing .356, .357, and .358 with a conventional lyman sizer, no powder coat.

[Outpost75]

Rechamber barrel to NATO chamber in accordance with STANAG 4090 and it will accept .358" cast bullets.

FNGPs and Berettas sold to the Euro market already have this chamber. The SAAMI-dimensioned chamber is too tight!

[Bzcraig]

Check with Douguy. He is the local chamber/throat/lead guru.

This.....

[DougGuy]

There is no practical workaround for not enough throat. From what you are describing, you can't load even to SAAMI specs/dimensions without having problems. Seating deeper is a poor workaround, and in some cases can be quite dangerous. On the other hand, if you are pushing the boolits into the barrel forcefully, and you happen to suffer a bit of setback, and you happen to be loading near max pressures when setback occurs, you could have a catastrophic over pressure event happen.

The barrel just needs throating so you can seat out ever how long you like, problem solved, gun runs like a singer sewing machine afterwards, send a PM for details.

This is a Glock throat but the same principle applies to all autoloaders, after throat reaming this barrel shoots cast with no issues and no leading:

[HangFireW8]

Not sure what generation your HP is, but an aftermarket barrel might be an affodable option.

-HF

[GhostHawk]

I think throating/reaming is probably a good idea, however.

Things to consider or try before that.

A What bullet are you using now? Nose shape can make a huge difference.
My problem child was a 7.62x25 and switching from a round nose to a TC made all the difference in the world.

Just something to consider.

If your chamber is tight you want a bullet that is not full sized until it meets the brass case. Or possibly just in front of the case.

Looking at that picture the step at the case mouth looks pretty abrupt, and seems like it sticks out into the center more than it should have to. Now I know it sets headspace on the brass case mouth. But I suspect that it is your problem.

What does it do with factory FMJ ammo?

Plunk test should tell you when you find the right answer.

Or as you said ream it and fix the problem.

Good luck.

[Ateam]

I have a conventional lyman mold that is a round nose, but it drops ww at .356. My barrel slugs at 357, so I thought a 358 might do the trick. Unfortunately there is no throat, it is 357 all the way to the case lip. If anyone knows of any .358 RN or TC in a weight suitable for a 9, I might go that route.

Jacketed shoots great in my HP, but the rifling marks while sharp have never been deep. I am currently casting the lee 105swc .358 for this project.

I took the seating post from my seat/ crimp die and turned two threads off on the lathe, a little work with a jewelers file and it went right back in the die body, but now I can seat a few thou deeper. I will make up a few rounds with the drive bad flush with the case mouth and see how they do.

Thanks for all the input.

[Alstep]

Save yourself a lot of trouble and aggravation and send it to DougGuy. He makes a lot of sense and does good work. You won't be disappointed.

[knifemaker]

Having Dougguy ream the throat is far cheaper then a aftermarket barrel that was suggested above. Being that it is a Browning High Power, the odds are very good that you have a good barrel except for the throat problem. Have that throating done and enjoy the pistol.

[Meatpuppet]

I have had to throat ream (not chamber ream) all of my CZ's in order to reliably chamber 147gr round nose with an OAL of 1.10.

I used an $80 hand reamer by manson reamers and it only took a half-hour working slowly. If it is just one gun I would recommend sending the barrel out for reaming.

[gwpercle]

I got my no throat 9's to chamber by seating the Lee 105 gr. SWC so that the top driving band was all the way in the case, maybe just a fingernail thickness protrudes...but no much. The 105 is a short boolit so the powder space isn't crowded . It would feed fire and function in three different 9 mm's, a WWII Walther P-38 , Baretta M9 and modern Springfield.
I had doubts about the short OAL and short truncated cone (SWC) feeding ...but all 3 fed them without a hitch . I sized .357 and .358 and it didn't make any difference in my guns that I could tell.
The P-38 loves this boolit , shoots tight groups and dead center with the hard to adjust iron sights.
Gary

[Ateam]

I got my no throat 9's to chamber by seating the Lee 105 gr. SWC so that the top driving band was all the way in the case, maybe just a fingernail thickness protrudes...but no much. The 105 is a short boolit so the powder space isn't crowded . It would feed fire and function in three different 9 mm's, a WWII Walther P-38 , Baretta M9 and modern Springfield.
I had doubts about the short OAL and short truncated cone (SWC) feeding ...but all 3 fed them without a hitch . I sized .357 and .358 and it didn't make any difference in my guns that I could tell.
The P-38 loves this boolit , shoots tight groups and dead center with the hard to adjust iron sights.
Gary

Did you have to adapt your die to seat it that far down?