.355 vs .356 in 9mm ?

[tercel89]

What is the difference ? From what I undertsand , .355 is for 9mm and .356 is for .38 super and ???? I read that some use .356 for 9mm cast bullets. Please fill me in in all this .

I am loading 9mm and used .355 on my first batch. Now that I am going to buy more I noticed the .355 and the .356.

 

[leroy]

Tercel.... The .356 bullets are usually cast bullets for 9mm... It's not unusual to have cast bullets a thousands or two oversize... Lots of 38 specials shoot .357 jacketed bullets and .358 cast... As to the .356 jacketed bullet thing; they are, indeed, for the 38 super....  I've shot a bunch of .357 in supers (...140 grain...) in the old days....

 

Hope this helps a bit....

leroy

[Garufa]

Cast bullets are usually .001" greater in diameter than jacketed.  Creates a better seal in the barrel and help reduce lead fouling.

[Jct1911]

Lots of casters I know of actually shoot .358 in 9mm. 9mm bores are all over the place, especially surplus and foreign guns. With jacketed, standard is .355 for the auto's and .357 for revolvers. 35cal rifles(358winchester, etc..) use .358 jacketed bullets.

[Jonnin]

I shoot the same projectile in all 9 and 38/357 ... a cheap lead 380 round that I bought like 5000 of.   Granted, the 357 load is extra weak.   I have heavier projectiles for the full loads. 

[Caster]

I size mine to .357 because that's the biggest I can horseshoe into a case and chamber reliably. If I could get bigger....I would.

For any PROPERLY cut chamber, you will never be able to chamber a CAST bullet that's too large to be safely fired. Same CANNOT be said for jacketed and know that!

I regularly size as much as .003 or .004 over for rifle. My .358 Winchester slugs .3575 but I can chambe .360 without sizing e bullet down during seating....so that's what I run.

[tercel89]

Great information everyone , I am really learning a lot. Why is that you use an oversize bullet when using lead ? Are you wanting the bullet to grab or sink into the rifing's lands and grooves more ?

[tercel89]

Cast bullets are usually .001" greater in diameter than jacketed.  Creates a better seal in the barrel and help reduce lead fouling.

Oops , i may have answered my own question in the last post after looking at your post. So is it that  the slightly bigger lead bullet will grab a hold of the barrels lands and grooves ?

[Caster]

The idea of oversizing is to make a seal. Without a near perfect seal, you get gas cutting. Gas cutting equals leading and pisspoor accuracy.
Oversizing also prevents skidding. Basically, think of stripped threads. This is the major function of a gas check by the way. To give the rifling something tougher to bite into that won't skip over the rifling at higher pressures.


Fit is king. Cast bullets will never work without proper fit.

[tercel89]

The idea of oversizing is to make a seal. Without a near perfect seal, you get gas cutting. Gas cutting equals leading and pisspoor accuracy.
Oversizing also prevents skidding. Basically, think of stripped threads. This is the major function of a gas check by the way. To give the rifling something tougher to bite into that won't skip over the rifling at higher pressures.


Fit is king. Cast bullets will never work without proper fit.

 

 That is an awesome and very understandable explanation , Thanks :up:

[Dolomite_supafly]

The size has more to do with leading than either the alloy or the lube used. I have shot plain, as in no lube, bullets and got no leading. I have also shot lubed, but undersized, bullets and it took forever to get the lead out.

I have shot .313" cast bullets in my 300 Blackout. That is 13 thousandths over the lands and 5 thousandths over the valleys. And I ran the same load I do for .310" bullets without any signs of pressure. So as long as it will chamber it will be ok with cast bullets. And those billets had LONG bearing surfaces and weighed 245+ grains.

For my 9mm I use .357" cast bullets and have zero issues.

[Caster]

Lube doesn't really lube much either.  Not in the traditional sense of lubrication.  It's function is much more of a sealer and lubrication is secondary.  Think about that wax ring under the toilet.  Any imperfections in the fit, the lube will try to take up the slack.  It'll only do so much mind you.  Any lubricant residue left in the barrel kinda slicks it up for the next shot.  Different hardnesses, tackiness, how it reacts under pressure, it's a deep subject on lube and one that gets pretty heated arguments.  

 

The old saying goes, Lube doesn't matter...until it does.  If what you're using is working, you probably shouldn't think about it anymore.  Just go with it.  

 

 

Blackpowder is a whole 'nuther mess a crap.  Lube is extremely important unless you enjoy scrubbing baked on powder fouling.  

[tercel89]

hey guys , instead of me starting a new thread , let me ask you about .45acp.  I just got some Dies for that caliber. I see .45acp bullets in .451 and some in .452.  Both are copper coated/jacketed round nose .

 Which should I use for target stuff ? .451 or .452 ?  My hornady book shows all copper/jacketed ones at .451 and the lead at .452 ?

  Again , any help is appreciated and not trying to bother you guys .

Edited March 29, 2015 by tercel89

[Ray Z]

The old 38 super used .356 diameter bullets. If I remember right, it was a 130gr bullet. Today's pistols us the same.355 bullets that 9mm luger cartridge uses. Those of us that shoot 38 super or 38 supercomp in an open gun [USPSA] can go up to .356 after their barrels start waring out. Say, 60-70 thousand rounds.

[Caster]

hey guys , instead of me starting a new thread , let me ask you about .45acp.  I just got some Dies for that caliber. I see .45acp bullets in .451 and some in .452.  Both are copper coated/jacketed round nose .
 Which should I use for target stuff ? .451 or .452 ?  My hornady book shows all copper/jacketed ones at .451 and the lead at .452 ?
  Again , any help is appreciated and not trying to bother you guys .

For a jacketed or plated bullet, they.452 will work great with most every 45 auto out there.

[tercel89]

Thanks Caster. I am looking at getting a box of X-Treme Bullets. That's all my local gun store had in 230grain FMJ . I went to their website and it showed .452 diameter.  Does that .001 difference really mean that much ? Kinda seems like it would be smaller than a hair .

[Caster]

For what you're working with and what you'll likely be doing with it?

No.


Larger bores are always more forgiving. Edited March 30, 2015 by Caster

[tercel89]

Ok Mr. Caster , one last question : These X-Treme brand bullets are copper plated. I beleive the plating is a lot thinner than Jacketed bullets. Will they work the same in my Lee die that SEATS and CRIMPS the bullet at the same time ?

[Caster]

Yes BUT you should not be seating and crimping in the same operation. YES, the die will do it but that doesn't make it a good idea.

With the .45 acp and NONcast loads, you'd be doing yourself a big favor to get a Lee factory crimp die. You run into problems potentially using a factory crimp die with cast but with plated or jacketed, it's the cats meow.

Even if you don't get a FCD, set the die to seat but not crimp, seat them all, then back off the seating stem to where it doesn't touch and crimp. You will find you get a much more uniform crimp and your overall length will be more consistent.

[Caster]

ALSO!
Be absolutely certain your die isn't making a roll crimp. Many 45 acp dies are made to also handle 45 auto rim for revolvers. They would use a roll crimp but an automatic would absolutely NOT use a roll crimp. The case head spaces off the mouth. Roll crimping throws your headspace out into wild blue yonder. A very bad thing.
Lee assumes most not only know this but also use their factory crimp die with automatics as MOST Lee die sets come with the factory crimp die. Edited March 30, 2015 by Caster

[tercel89]

ALSO!
Be absolutely certain your die isn't making a roll crimp. Many 45 acp dies are made to also handle 45 auto rim for revolvers. They would use a roll crimp but an automatic would absolutely NOT use a roll crimp. The case head spaces off the mouth. Roll crimping throws your headspace out into wild blue yonder. A very bad thing.
Lee assumes most not only know this but also use their factory crimp die with automatics as MOST Lee die sets come with the factory crimp die.

 

 Ok , so use my Lee three die set but on my seating and crimping die , only use the seating portion and then buy and use a Factory Crimp Die to crimp it or just to "take the bell" out of the case ? Is this correct ?

[Caster]

With a factory crimp die, unless you get all ham fisted and torque things really stupid tight, you not really gonna over crimp.  They come with VERY simple instructions.  

I would lay out exactly how I do it but I go by feel and double check dimensions with a micrometer where needed.  You load several and you'll understand.