.355 Or .356

[tpe187]

Hi,

I have been reloading for my .38 super for several years now, using a .356 bullet made specifically for 38 super.

My question is that I just realized the Schueman Ultimatch barrel says .355 on it. Do you think I would get better results with 9mm bullets? Just curious. I'm getting good accuracy now with what I have. Thanks for your thoughts.

Tom

[Jake Di Vita]

Never go to a smaller diameter bullet if you've fired bigger diameter through the same barrel.

[George]

I will go with Jakes caution and agree with it if you have been shooting the larger bullet for quite some time. It won't hurt to test a few batches of .356 and .355 to see which a bbl likes when it new, but generally it is a better process to actually slug the bbl with a soft lead plug and see what the groove diameter is then apply the following rule:

In theory, jacketed should be the same diameter as the grooves in the bbl (max dimension) and lead should be .001 over that. In practice, .001 over bbl groove diameter in jacketed seems to work for some folks and not for others while equal, or even .001" under groove diameter in jacketed works for some and not others. That's why reloading is so much fun ;-)

I will also state that if the larger bullet was a lead one, then his warning does not apply as lead should always be .001 larger than a jacketed bullet in the same bbl.

I run .355" 9mm JHP 124's in 9x19, 9x21 (major) and .38 stupor in honor of the KISS philosophy. I used to run 147 hard cast lead in the .38 souper sized to .357" and it loved them, but I ran lead sized to .356 in the same 9x21 bbl that is running .355" JHP's now because it didn't like the .357 lead bullets.

I had an earlier .38 stupor bbl that I ran Nosler 147 FMJ's at .357" diameter through and it loved them better than the .356 CP RN 135's I had been running (I got a few thousandof the .357 Nosler'soff a prize table and stuck with them until the bbl wore out). My second stupor bbl was set for .355"'s from the start so I can buy one bullet in bulk for all my 9x and .38 guns (Remington Golden Saber 124 JHP).

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Regards,

[TMC]

Will Schueman says he shoots Remington .357's in his guns. Gas cutting caused by the bullet not sealing the barrel is worse than forcing a slightly oversized bullet down the bore.

[tpe187]

Thanks for the replies. George, your really helping me out a lot lately.

I probably should have said I have reloaded for it for several years, but only in small batches. Due to some time in the sand box, I couldn't shoot, so in reality, it really has only had about 500rds put through it, and those were 130gr plated Rainiers I thought that might make a difference. I'm going to be moving to a new bullet and working up a new load, so I figured I would try a few different ones and see what she likes. I'm using Supercomp brass, Winchester small rifle primers and Viht 3N38. My gun is an SVI 5.5" barrel, 8 port comp gun. I'm either going to go to a Montana Gold bullet, or a Zero bullet. Going to a 9mm bullet would help with logistics. Got any good starting recipe's? Thanks again.

Tom

[George]

The general idea is that the bullet should fill the bore, but not really be oversized (except in the case of lead ones). The gas front kicks the bullet in the butt hard enough to cause it to obdurate (or upset) a little and squeeze to plug the bore at the base as it starts to move. This is supposed to seal immediately and yet prevent excess friction increasing pressure beyond safe bounds before the desired velocity is achieved.

In practice bbls are called out in their land (not groove) dimensions for caliber. .223 for example has a .224 groove diameter so .223 bullets are .224 in diameter. This is why most recovered jacketed bullets look pristine everywhere but where the rifling gripped them.

Wil is correct in that the damage can be real if the bullet never obdurates enough to seal, but you need to know how those bbl's slug out to see what's really going on. If the bbl he is shooting .357's in (BTW, .357 is correct for a true .38 caliber pistola) has a .356 land diameter, then using .357 jacketed is probably correct for that gun. The land diameter may be what the bbl is stamped for anyway. Slug the bbl and choose a jacketed bullet that is .001 over land diameter, or exactly groove diameter and you will (almost) always be fine.

Using jacketed that are .001 over groove diameter won't always be a problem either, but it can raise pressures fast and may push you over other folks load values for the same charge. So remember folks, always ask what diameter bbl and bullet combo someone else is using before just duplicating their recipe (make sure they understand what the difference between groove and land diameter are and what theirs is). Powder charge and OAL do not tell the whole story. The smoothness of a bbl can affect all of this greatly too.

I just love reloading :-)

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Regards,