Hot-Rodding 7.65 Para

[Sieger]

Originally Posted by nukem556

they'd be just fine....a bullet will shoot precisely, up to the point the rpm exceeds the strength of the bullet jacket and it flies apart in a gray puff 100ft down range....I've seen it happen many times with hotrod 6.5/.284 shooters that push their loads to the ragged edge...the rounds that stay together are in the 10 ring at 1000yds.

Respectfully, you can have your own opinion, but 30 plus years of handloading for high-powered rifles tells me differently.

While developing a load, starting low and working up, you eventually reach a spot at which your load is most accurate. Adding more powder, after this point, makes your groups spread out rapidly to the point that you are not even on the paper.

There is a formula for determing proper twist, the Greenhill Formula. Velocity is a major factor in this formula.

Sieger

[nukem556]

Sieg...I've reading your posts since I joined this great site a little while back, and I've found them cogent and informative. I too, have been loading and shooting lo these 3 decades or so. You are correct, there will usually be a sweet spot for bullet weight/velocity/ sectional density when loading for extreme accuracy in rifles. I've just begun my tinkering with .30 Luger (last project was .25-20 Win out of a Contender, to show you how weird I am!). However, the extremes of ballistic performance from a rifle don't neccesarliy correlate to pistol catridge performance. I've just finishing refurbishing my 1900 Parabellum and have fired some Win and Fiocchi ammo that's chronoing about 1180 fps....its grouping superbly. I'm given to understand DWM specs were around 1250 from the 4 3/4 bbl. I'm going to put together a 6in .30 on another Luger and I'm gonna strive for around 1400-1450 with it...I'll let ya know if it stays on paper

[G.T.]

OK guys.. I really find this thread interesting... But both of you are waaaayyyy beyound me.. I'm still trying to figure out how African swallows got coconuts from Africa to Britain... ... so for the both of you, If you were going to build the ultimate .30 / 7.65 Luger shooter... what twist and bore dia.... .308 or .311 ??? and what barrel length??...... best to all, til...lat'r...GT

[Sieger]

Originally Posted by nukem556

I've just finishing refurbishing my 1900 Parabellum and have fired some Win and Fiocchi ammo that's chronoing about 1180 fps....its grouping superbly. I'm given to understand DWM specs were around 1250 from the 4 3/4 bbl. I'm going to put together a 6in .30 on another Luger and I'm gonna strive for around 1400-1450 with it...I'll let ya know if it stays on paper

Hi:

I learned a long time ago not to argue with success, so feel free to try your hotter loads and see if you can get both accurate groups and good function from your pistol.

If it were me, I'd stick with medium slow powders like Power Pistol, HS-6, AA#5 and SR 4756. You may want to try the slower powders like AA#7 and Blue Dot as well, as there should be enough room in the case for these too.

The original DWM specs. for the 7.65 Parabellum were as follows:

Bullet: 92.6 grs. at a measured (by me) .307 diameter

Cartridge O.A.L. 1.173 inches (round nose bullet)

Powder Charge: Unknown DWM Powder at 5.4 grs.

Velocity from a 4.73 Inch Barrel: 1,150 fps. (350 meters per second)

With a Luger, the impluse created by the cartridge is more critical than, lets say, in a Browning design pistol, to make the pistol function properly. Too light of a load, no function. Too hot of a load, no function. Truly, the cartridge's performance is an integral and critical part of the proper function of this pistol design.

Sieger

[Sieger]

Originally Posted by Rick W.

Thanks Sieger;

Always wondered why my 30 caliber bullets from my cheapo home brew barrels hit the paper........occasionally...... :-)

Kinda makes sense, the 10 twist really.

Rick


With super twisty barrels, one might consider a more heavily constructed bullet for some things.

Hi:

Or a longer bullet.

Sieger