I finally understand the importance of correct sizing

I picked up a new to me Beretta M9 today. First thing I did was take it home to clean it, then I headed to the range with some Xtreme 124 gn plated and some of my own cast 130RN sized to 357. The first 70 rounds were the plated and my groups were all over the place for me. I then switched to my own cast rounds and low and behold my groups tightened exponentially!

I went home and slugged the barrel and found it to be .3568. My cast mic’d at .3566 and the plated mic’d at .3550. I could stand to try a sizing die at .358 perhaps?

The top group is a sample of my cast group, and the bottom two show the variation I got with the plated rounds.

All shots off hand 7 yards. Each group is one mag.

https://uploads.tapatalk-cdn.com/201...4c7450dcd5.jpg

If the barrel has a throat big enough to accept a .358" that would likely work quite well. See if you can get a pic of the throat and post it..

You would have to beagle your mold to get it to drop larger so you can size to .358" or use another mold. The plated ones well, they are what they are and that's about it unless you want to put each one on the flat part of a vise and smack it with a hammer to expand it then try sizing it to .358" :bigsmyl2:

Beretta M9 and 92fs barrels typically slug at around .357. The chambers are generous enough to chamber a .358-.360 slug with no problems and throating isn't usually an issue with them.
They also usually shoot cast quite well. That is why I use Beretta barrels in my Taurus PT92 pistols.
I would at least try some boolits sized to .358 to see if there is an improvement in accuracy. Going any larger than .358 probably won't improve anything.
The ones I tried which were in the .359-.360 area were because I was too lazy to run them through my sizer. They fed and fired fine. Accuracy was good too, but not better than .358. It just isn't necessary to size that large. After I acquired a couple of other pistols in 9mm, I had to size everything to .358 at the largest because of chamber variations. Some just won't accept larger sizes.

My concern would be the brass swaging the boolit down below the as-sized diameter.

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Originally Posted by DougGuy

If the barrel has a throat big enough to accept a .358" that would likely work quite well. See if you can get a pic of the throat and post it..

You would have to beagle your mold to get it to drop larger so you can size to .358" or use another mold. The plated ones well, they are what they are and that's about it unless you want to put each one on the flat part of a vise and smack it with a hammer to expand it then try sizing it to .358" :bigsmyl2:

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I suppose I should have mentioned that I PC. After PC and before sizing they run about .359 and some change. So I should be able to size to .358 without beagling, ya?

My berretta 9s was a poor performer with .356 dia bullets cast, plated or jacketed. going up to .358-.359 really tightened groups up for me. This not only gave a better fit of the bullet in the bore but also a better fit of the loaded round in the chamber. You will want a bigger expander for these bullets when loading them.
Yes you should be able to size your PCd bullets from .359 to .358 with no problems or issues. You might consider trying them unsized even at the .359 and change. Load a couple dummies and do a plunk test if they chamber, Load a few as is and give them a try, it may not need sizing.

try the 358.
your groups might not get any better but they might stay more consistent with fewer flyers over time.

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Originally Posted by tazman

Beretta M9 and 92fs barrels typically slug at around .357. The chambers are generous enough to chamber a .358-.360 slug with no problems and throating isn't usually an issue with them.
They also usually shoot cast quite well. That is why I use Beretta barrels in my Taurus PT92 pistols.
I would at least try some boolits sized to .358 to see if there is an improvement in accuracy. Going any larger than .358 probably won't improve anything.
The ones I tried which were in the .359-.360 area were because I was too lazy to run them through my sizer. They fed and fired fine. Accuracy was good too, but not better than .358. It just isn't necessary to size that large. After I acquired a couple of other pistols in 9mm, I had to size everything to .358 at the largest because of chamber variations. Some just won't accept larger sizes.

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Originally Posted by nicholst55

My concern would be the brass swaging the boolit down below the as-sized diameter.

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I’ll likely try out the .358 sizer, though as nicholst55 mentioned, I wonder if my cases will start swaging the boolits. Pulling my boolits as-is, reveals little to no swaging.

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Originally Posted by country gent

My berretta 9s was a poor performer with .356 dia bullets cast, plated or jacketed. going up to .358-.359 really tightened groups up for me. This not only gave a better fit of the bullet in the bore but also a better fit of the loaded round in the chamber. You will want a bigger expander for these bullets when loading them.
Yes you should be able to size your PCd bullets from .359 to .358 with no problems or issues. You might consider trying them unsized even at the .359 and change. Load a couple dummies and do a plunk test if they chamber, Load a few as is and give them a try, it may not need sizing.

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That’s a good point about the expander. Ive seen lots of threads that address the Lee expander, but I haven’t seen any good threads about powder through setups that will fit my Dillon 650. I’ll have to research a bit.

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Originally Posted by runfiverun

try the 358.
your groups might not get any better but they might stay more consistent with fewer flyers over time.

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I attribute 100% of those fliers to user error!

my groups with a pistol are all flyers.
I shoot 1" groups no problem, they just happen to be 3"s apart.

I have 3 9MM's. The EAA Witness Match Elite groups jwords very well. It also loves my cast .358 HP via my Mihec mold. This is the one with the smooth sides and no lube grooves at all. I PC those and they group better in the Witness than the factory jwords.

I also have a SCCY compact in 9MM that I bought for my wife but she has difficulty in working the slide so now she carries a Charter Arms Patriot 2.5" Revolver in 327 Magnum. This has 6 chambers and she shoots this one very well and she packs it in a Simply Rugged holster on a stiff belt by Beltman. The SCCY is a small auto which I bought for her a few years ago when I thought she might like a .380 ACP.

She looked and handled a bunch of them and then my gunny showed her the SCCY and it fit her hand perfectly. I thought it was a 380 ACP and I was surprised to learn it was a 9MM. This is my car gun and resides on a powerful magnet on the underside of my dashboard near the steering column.

The last 9mm I have is a Browning Hi Power circa '82. I bought it used and upon examination I believe that it was fired for less then 50 rds as there was not any evidence of firing on the bolt face at all and it was perfect in every way. Not a scratch or ding anywhere and perfectly clean. This one however demands a boolit to be sized to at least .358 in order to work properly.

I had made some rounds utilizing some boolits with diameters of .3565 to .357 and it gave less than stellar performance. Accuracy was terrible and the empty fired cases were heavily sooted on the sides.

When fed .358 to .3585 boolits it thrives and delivers good accuracy and excellent reliability. It is one of my favorite carry guns as I did equip it with a clip it metal device which allows carry inside the belt without a holster. It is a comfortable gun to carry with the clip it device and after a time you get used to it and forget that you are carrying a lethal weapon with 16 rounds at your disposal.

On other days I may carry a .44 Special by Charter Arms (Bulldog Pug 2.5"), 41 Magnum Model 57 Smith or my Taurus 1911 in .45 ACP. The .44 can be carried in my right cargo pocket or in a OWB Simply Rugged holster, the Smith and the Taurus live in a shoulder holster by Andrews leather in Florida.

The pair of shoulder rigs by Andrews also pack my Ka-Bar mini and cost pretty much more than the Smith and Taurus combined. You get what you pay for, at least in quality holsters.