High performance 7.62x39

[Slamfire]

Increasing pressure signs as I worked up from starting. But not apparently excessive. Not to overdo it. Firearm abuse BAD. Should always be a safety margin to allow for temperature extremes, metal fouling,....tidal effects, etc.

**************


Settled on the Hornady 180gr RN at 2175 fps MV as the standard load. 1900 ft-lbs muzzle energy. Groups as shown.

***************


Lots of practice shooting off hand at 200 meters with my 7.62x39 Remington 799 (with Weaver 1-3x scope) using milsurp ammo. Pattern as shown. Not too bad considering this ammo groups around 3" to 4" at 100 meters off the benchrest. Off hand shooting practice to improve field marksmanship.

 

[MiG25]

Does Ruger mention whether the #1 has a 308 barrel or a a .310" barrel? A 308 would have a greater selection of bullets.

These are supposed to be left over 303 British barrels, SAAMI (of which Ruger is a member) calls for a 314" groove diameter.

 

[mbogo3]

Wonder why they didn't use .311 on the .303 British who makes .314 bullets these days?

 

[VanIsleCam]

Hats off for Slamfire! Nicely done mate!!

 

[Slamfire]

^^
Thanks!


SAAMI specifications for the 7.62x39 -

p.65: http://www.saami.org/specifications_and_information/publications/download/Z299-4_ANSI-SAAMI_CFR.pdf

bore diameter: 0.300"

groove diameter: 0.310"

 

[fiddler]

I've had some success loading for this caliber for my ex girlfriend's cz527 bolt gun. I don't consider it to be a long range bullet but by going up to 150 or 170gr gives a lot more energy for hunting loads in your given distance. I don't care much for shooting good brass in my sks because it just tears them up, if in fact I can find it once ejected.

I did some playing with the 125gr bullets that group well, but I discovered that the commercial prvi soft point loads that I bought for the brass shoots a half inch group at 100 yards right out of the box. I just didn't see the point of trying to improve on that, if I could. It was obviously a great round for that little cz bolt gun, and I had a a few dozen boxes of the stuff on the shelf.

X39 is a great little round to play with and has lots of possibilities. Its easy on the brass, easy on the gun, and easy on the shoulder.

 

[Slamfire]

7.62x39 loaded with 150gr bullets at standard speed work pretty good on Deer. Maybe a slight increase in range over standard speed 123gr.

Chasing ejected brass from an autoloader sure is a pain. This here brass catcher doesn't work too bad.

 

[tessy2ton]

Three pages of what a great rifle , and not a stick of real reloading data.

 

[Slamfire]

A lighter and crisper trigger would make it shoot more consistently. A single set trigger would be about perfect. Need to review what's available for the No.1 rifle.

 

[madtrapper143]

I know you have been asked once but I will ask again, what powder are you using to obtain these velocities? Don't worry about liability as I am not about to attempt what you are doing.

Darryl

 

[Slamfire]

 

[Ganderite]

Increasing pressure signs as I worked up from starting. But not apparently excessive. Not to overdo it. Firearm abuse BAD. Should always be a safety margin to allow for temperature extremes, metal fouling,....tidal effects, etc.

**************


Settled on the Hornady 180gr RN at 2175 fps MV as the standard load. 1900 ft-lbs muzzle energy. Groups as shown.

Lots of practice shooting off hand at 200 meters with my 7.62x39 Remington 799 (with Weaver 1-3x scope) using milsurp ammo. Pattern as shown. Not too bad considering this ammo groups around 3" to 4" at 100 meters off the benchrest. Off hand shooting practice to improve field

According to the Hornady box, those are 308 bullets. ??

 

[Slamfire]

And these don't shoot too bad. With less back pressure than 0.310" bullets.

 

[MiG25]

^^
Thanks!


SAAMI specifications for the 7.62x39 -

p.65: http://www.saami.org/specifications_and_information/publications/download/Z299-4_ANSI-SAAMI_CFR.pdf

bore diameter: 0.300"

groove diameter: 0.310"

Not to labour the point, but SAAMI spec for 303 British is 303/314, and we are told these are leftover barrels.

Have you slugged it? I should slug my #1 303.

 

[Slamfire]

May well be but accuracy would likely suffer, and surprisingly it would be a non-SAAMI spec rifle. Even less back pressure if so. On my to-do list.


p.121: http://www.saami.org/specifications_and_information/publications/download/Z299-4_ANSI-SAAMI_CFR.pdf

 

[madtrapper143]

I don't get it but I assume you are telling me to stop asking questions about your "experiment". Will do enjoy your thread.

Darryl

 

[jethunter]

And these don't shoot too bad. With less back pressure than 0.310" bullets.

...also probably less velocity and lowered accuracy as well but for plinking at paper it doesn't matter too much.

 

[Slamfire]

The 0.308" 125gr SST's, or maybe even the 0.308" 130gr SP's, with the same powder charge should provide higher muzzle speed than the 0.310" 123gr SST's. Less resistance. Next thing to try.

 

[Neilm]

but less pressure also which would lead to a lower velocity unless it is a 308 groove diameter which Ruger used previously.

 

[Slamfire]

Hornady .308" 130gr vs. PRVI .310" 123gr. Same powder charge. Results as shown. 130gr doesn't fit as tight so less friction through the .310" barrel. Weighs 6% more than the 123gr. So muzzle speed is a bit lower. Tighter group with the 123gr.