Ruger MKII 77 Davidson's 7.62x39 carbine Ideas for loads

[Coltrane]

I am the proud owner of one of these trim, compact rifles and have been experimenting with .308 diameter bullets to stay within the bore diameter.

So far I have tried 30M1 carbine 110gr FMJs and softpoints under 24.5grs
of AA1680, with halfway decent results at 65 yds (around 2.5 inches, 5 shots).

The other day, I picked up some Sierra 125gr flat nose hollowpoints for a 30/30. These are very promising, under a less than max charge of 1680.
At 75 yds, I achieved a 5 shot group at just under 2 inches.

I also loaded some 150gr Nosler Ballistic Tips. At 25 yds for the initial sight in, 5 shots under an inch. But at 75, I couldn't even hit the paper.

I have noted some potential problems.

1. I haven't used the .308 expander ball. I have used the .311 expander.
    When I seat the bullets, it has been by hand, not the die. I then
    crimped the bullet with a factory crimp die. Consistant bullet depth has
    probably not been achieved.

2. The 110gr bullets may not have enough bearing surface to hit the
    rifling. They are a rather stubby bullet and may just be too short for
    more promising accuracy.

3. The crimp die is not providing enough crimp to close the .311 diameter
    case around a .308 bullet. I may be losing some pwer due to gas
    leakage around the base of the bullet.

4. The Nosler is a boattail design and this may also create additional leak
    from the base. The length is, in my opinion, an aid to accuracy as
    there is increased bearing surface to engage the rifling and overcome
    the long throat.

Guys, am I missing something? Or am I wrong about my theories?  I am
limited to 1680 powder as I can't afford to branch out with a variety of powders to try.

Any advice would be appreciated.

Thanks to all who respond.

Coltrane

[De41mag]

Coltrane;

I have one of the Davidison's 7.62X39 Rugers but I haven't handloaded for it yet. Maybe you should use a Speer 125gr. bullet they make just for the Russian round,  it's a .311 dia. bullet. I've just shot the Wolf and Barnul stuff. Which I'm well pleased, and at $81.00 / 1000 of the JHP bullet delivered to the door, I can live with 2 to 2-1/2 inch groups at 100yds. Man that's almost 22LR prices. Keep me posted on your results, and what I've read your using the ideal powder.
Dennis.  :wink:

[Nobade]

You might check out Paco Kelly's article on loading for that rifle. I recall he was getting some eye opening performance out of it. Now that he's moved most of his stuff to Leverguns.com you might find it there but it was originally published on sixgunner.com. Gotta still be out there some where!

[Coltrane]

Nobade,

I actually emailed Paco Kelley about this rifle last April to get some reloading tips and he was very forthcoming. The carbine bullets were a brainstorm I came up with on my own.

My questions to him were concerning the use of .312 diameter bullets, like the 125gr Speer Hot Cor spitzer or the Winchester 123gr FMJ. I was concerned about pressures gettting too high with a .308 bore. Paco reassured me the Ruger is safe to shoot with these bullets as the caliber is not that high pressure to begin with and the gun is more than amply strong to withstand whatever I could stuff into the magazine.

He agreed with my decision to use Winchester and Lapua cases as they have the large rifle primer hole as opposed to the Remington with its small rifle primer. This will give a little more "oomph" towards achieving a cleaner burn of all powder.

I will continue to experiment and play around with my theories and update as I can. Wife and a baby drain a lot of my free time, preventing me from doing my all for science!

[K2]

Coltrane

You are missing a bunch to say the least.  To begin with use the right size expander for the bullets you are using.  The cartridge you are using has much in common with the PPC series and very fine accuracy can be obtained with it.  

You biggest accuracy gains will come from using the right size expander, until you do that there is no sense in discussing other ideas.  

No doubt you are fairly new to reloading and there is lots to learn!
Have fun ;~)

I am the proud owner of one of these trim, compact rifles and have been experimenting with .308 diameter bullets to stay within the bore diameter.

So far I have tried 30M1 carbine 110gr FMJs and softpoints under 24.5grs
of AA1680, with halfway decent results at 65 yds (around 2.5 inches, 5 shots).

The other day, I picked up some Sierra 125gr flat nose hollowpoints for a 30/30. These are very promising, under a less than max charge of 1680.
At 75 yds, I achieved a 5 shot group at just under 2 inches.

I also loaded some 150gr Nosler Ballistic Tips. At 25 yds for the initial sight in, 5 shots under an inch. But at 75, I couldn't even hit the paper.

I have noted some potential problems.

1. I haven't used the .308 expander ball. I have used the .311 expander.
    When I seat the bullets, it has been by hand, not the die. I then
    crimped the bullet with a factory crimp die. Consistant bullet depth has
    probably not been achieved.

2. The 110gr bullets may not have enough bearing surface to hit the
    rifling. They are a rather stubby bullet and may just be too short for
    more promising accuracy.

3. The crimp die is not providing enough crimp to close the .311 diameter
    case around a .308 bullet. I may be losing some pwer due to gas
    leakage around the base of the bullet.

4. The Nosler is a boattail design and this may also create additional leak
    from the base. The length is, in my opinion, an aid to accuracy as
    there is increased bearing surface to engage the rifling and overcome
    the long throat.

Guys, am I missing something? Or am I wrong about my theories?  I am
limited to 1680 powder as I can't afford to branch out with a variety of powders to try.

Any advice would be appreciated.

Thanks to all who respond.

Coltrane