303 bullets in 7.62x39?

black_hog_down · January 10, 2018, 10:17 PM

This is for a Ruger M77.
There are lots of competing theories on the exact caliber of this model of Ruger but most seem to agree that it is 310.
Is it safe to run 303 caliber (.312) bullets in a 310 barrel? What if it is closer to 308?

FrankenMauser · January 10, 2018, 10:24 PM

If neck diameter and throat geometry allow the cartridge to chamber with a .311/.312/.313 bullet seated, and you start low and work up as appropriate, it should be fine.

None of us can give you a guarantee that it's safe, as it's your responsibility to determine the safety of your own loads (and firearms).

But I will tell you that I used to regularly shoot .312" and .313" jacketed bullets, and .314" and .315" cast bullets (all of the previous intended for 7.62x54R or .32 handgun cartridges) ... in a .30-30 that slugged at .304"x.308".

Road_Clam · January 11, 2018, 06:50 AM

Heck I even tested 160 gr Sierra .308 spitzers in my Yugo AK47 with Benchmark powder and they shot great out to 200 meters. Good stability, I was surprised.

black_hog_down · January 11, 2018, 09:55 AM

Sweet. That's what I figured. I'll start low and work up.
Anybody know where I can find RN SP like these? I see hard cast and I see the 180+ grain 303 bullets but nothing in the 123 grain range. These are PRVI and I think they are discontinued.

mikld · January 11, 2018, 11:38 AM

Why don't you slug the barrel and make sure of the dimensions? I would want to know for sure and, in my opinion, refrain from .312" jacketed bullets in a .308" barrel (but that's just .002" extra of engagement, prolly no problems)...

T. O'Heir · January 11, 2018, 01:38 PM

Like mikld says, slug the barrel. Ruger made Mini-30's with .308" barrels, long ago. Then switched to .311" the way Comrade Kalashnikov intended. The 7.62 x 39 M77 dates from long after the switch.
"....324"..." That'd be a .314".
"...303 caliber (.312) bullets..." .303 Brit uses a .311" bullet. Not a .312. Issue is the barrel diameters on Lee-Enfields. They can vary from .311" to .315" and be considered ok. Commercial bullets and ammo comes in .311" or .312" with up to .314" cast bullet available.
"...nothing in the 123 grain range..." Lots of 'em. Hornady makes a .310", a .3105". Their .312" are for .303 Brit and 7.62 x 54R, et al. Sierra makes a 125(close enough) at .311". No$ler does a .310" they think is for the 7.62 x 39. Close enough too. Federal loads ammo, but doesn't sell bullets. Berry makes a .311" plated 123. Barnes does a 123 grain .310" TSX. They do a .310" 108 grain Frangible too.
Whole thing is about what's available locally and how much you want to spend.

black_hog_down · January 12, 2018, 06:15 AM

Thanks. I can find 123 grain bullets. I'm looking for 123 grain round nose soft point. Like these...

res45 · January 12, 2018, 09:20 AM

PPU discontinued using and selling that bullet as a reloading component in the 7.62 x 39 ammo a few years ago an switched over to 123 gr. PSP.

There is lots of speculation as to what the actual groove dia. of the rifles bore is some say is .308 others have slugged the bore and came up with .309 and still other have written Rugers Engineering Dept. and have been told it .310 to .3115 to accommodate bullets from .308 to .313. So your best bet is to slug the bore and go from there, I always slug the bore on all my rifle to begin with and go from there as cast lead is all I ever really shot in them these day.

Basically if your rifle shoots the .310" dia. jacketed bullets best the ballistic tips or soft points are going to be your only choice.

T. O'Heir · January 12, 2018, 01:39 PM

123 grain round nose soft point are few and far between. No semi-auto uses 'em.
There are some .32 calibre RN pistol bullets, but those are light weight and too short.

oldscot3 · January 13, 2018, 09:20 AM

Also the 7.65 Argentine is "303" as well as 7.7 Jap. Most of the brands of bullets I have purchased are right at .3115".

seanc · January 17, 2018, 01:37 AM

The PPU round nose rounds are available at the following:

https://www.sportsmansguide.com/prod...unds?a=1584498

http://www.sgammo.com/product/prvi-p...mmo-prvi-parti

January 10, 2018, 10:17 PM	#1
black_hog_down Senior Member Join Date: May 13, 2016 Posts: 111	303 bullets in 7.62x39? This is for a Ruger M77. There are lots of competing theories on the exact caliber of this model of Ruger but most seem to agree that it is 310. Is it safe to run 303 caliber (.312) bullets in a 310 barrel? What if it is closer to 308?

January 10, 2018, 10:24 PM	#2
FrankenMauser Senior Member Join Date: August 25, 2008 Location: In the valley above the plain Posts: 13,424	If neck diameter and throat geometry allow the cartridge to chamber with a .311/.312/.313 bullet seated, and you start low and work up as appropriate, it should be fine. None of us can give you a guarantee that it's safe, as it's your responsibility to determine the safety of your own loads (and firearms). But I will tell you that I used to regularly shoot .312" and .313" jacketed bullets, and .314" and .315" cast bullets (all of the previous intended for 7.62x54R or .32 handgun cartridges) ... in a .30-30 that slugged at .304"x.308". __________________ Don't even try it. It's even worse than the internet would lead you to believe. Last edited by FrankenMauser; January 11, 2018 at 03:28 PM. Reason: BAD typo! Fixed it.

January 11, 2018, 06:50 AM	#3
Road_Clam Senior Member Join Date: November 21, 2013 Location: New Hampshire Posts: 1,695	Heck I even tested 160 gr Sierra .308 spitzers in my Yugo AK47 with Benchmark powder and they shot great out to 200 meters. Good stability, I was surprised. __________________ "To be old an wise you must have been young and stupid"

January 11, 2018, 11:38 AM	#5
mikld Senior Member Join Date: February 7, 2009 Location: Southern Oregon! Posts: 2,891	Why don't you slug the barrel and make sure of the dimensions? I would want to know for sure and, in my opinion, refrain from .312" jacketed bullets in a .308" barrel (but that's just .002" extra of engagement, prolly no problems)... __________________ My Anchor is holding fast! I've learned how to stand on my own two knees...

January 11, 2018, 01:38 PM	#6
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	Like mikld says, slug the barrel. Ruger made Mini-30's with .308" barrels, long ago. Then switched to .311" the way Comrade Kalashnikov intended. The 7.62 x 39 M77 dates from long after the switch. "....324"..." That'd be a .314". "...303 caliber (.312) bullets..." .303 Brit uses a .311" bullet. Not a .312. Issue is the barrel diameters on Lee-Enfields. They can vary from .311" to .315" and be considered ok. Commercial bullets and ammo comes in .311" or .312" with up to .314" cast bullet available. "...nothing in the 123 grain range..." Lots of 'em. Hornady makes a .310", a .3105". Their .312" are for .303 Brit and 7.62 x 54R, et al. Sierra makes a 125(close enough) at .311". No$ler does a .310" they think is for the 7.62 x 39. Close enough too. Federal loads ammo, but doesn't sell bullets. Berry makes a .311" plated 123. Barnes does a 123 grain .310" TSX. They do a .310" 108 grain Frangible too. Whole thing is about what's available locally and how much you want to spend. __________________ Spelling and grammar count!

January 11, 2018, 09:55 AM	#4
black_hog_down Senior Member Join Date: May 13, 2016 Posts: 111	Sweet. That's what I figured. I'll start low and work up. Anybody know where I can find RN SP like these? I see hard cast and I see the 180+ grain 303 bullets but nothing in the 123 grain range. These are PRVI and I think they are discontinued.

January 12, 2018, 06:15 AM	#7
black_hog_down Senior Member Join Date: May 13, 2016 Posts: 111	Thanks. I can find 123 grain bullets. I'm looking for 123 grain round nose soft point. Like these...

January 12, 2018, 09:20 AM	#8
res45 Senior Member Join Date: September 15, 2007 Location: NC Posts: 753	PPU discontinued using and selling that bullet as a reloading component in the 7.62 x 39 ammo a few years ago an switched over to 123 gr. PSP. There is lots of speculation as to what the actual groove dia. of the rifles bore is some say is .308 others have slugged the bore and came up with .309 and still other have written Rugers Engineering Dept. and have been told it .310 to .3115 to accommodate bullets from .308 to .313. So your best bet is to slug the bore and go from there, I always slug the bore on all my rifle to begin with and go from there as cast lead is all I ever really shot in them these day. Basically if your rifle shoots the .310" dia. jacketed bullets best the ballistic tips or soft points are going to be your only choice.

January 12, 2018, 01:39 PM	#9
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	123 grain round nose soft point are few and far between. No semi-auto uses 'em. There are some .32 calibre RN pistol bullets, but those are light weight and too short. __________________ Spelling and grammar count!

January 13, 2018, 09:20 AM	#10
oldscot3 Senior Member Join Date: July 1, 2007 Location: texas Posts: 997	Also the 7.65 Argentine is "303" as well as 7.7 Jap. Most of the brands of bullets I have purchased are right at .3115".

January 17, 2018, 01:37 AM	#11
seanc Senior Member Join Date: December 28, 1998 Posts: 590	The PPU round nose rounds are available at the following: https://www.sportsmansguide.com/prod...unds?a=1584498 http://www.sgammo.com/product/prvi-p...mmo-prvi-parti