Luger Heavy Barrel Not Cycling

[John Sabato]

Thanks for including your blueprint... such details will assist others with similar aspirations of rebarreling their shooters...

[rhuff]

I know of no other ammo available in the USA in 30 Luger but the Winchester and Fiocchi. Their power factors/velocities are well within range of error for either brand.

I feel that the modern 30 Luger ammo is down loaded somewhat to be sure not to explode any of the antique handguns using it.....like they do for 45 Long Colt ammo here in the USA. I have no way of knowing what the original muzzle velocities and power factors actually were out of a 4 in bbl, and the chamber pressures that they produced.

[Blastattack]

Originally Posted by John Sabato

Thanks for including your blueprint... such details will assist others with similar aspirations of rebarreling their shooters...

My pleasure! You blueprint CD, which I bought from you way back in October of 2010, was of immense help to my efforts. All the information for the threading and breech work was taken from your prints.

I do have more blueprints for the receiver support block and the action wrench if anyone is interested, plus a number of other prints relating to other parts and modifications. I have designed, though not yet machined and proven, a sight base to allow the installation of either a Micro sight or Bowen Classic Arms Ruger Flat-top rear sight for the toggle. If anyone is interested in any of this stuff I can either share it via PM or make a thread dedicated to the information.

[unspellable]

First, be sure you're not limp wristing.

Winchester 30 Luger is under loaded and will not make the advertized velocity.

The Wolfe springs I've seen don't look anything like a Luger spring.

The 7.65 spring is different than the 9 mm spring. But cutting a 9 mm spring is NOT the way to go.

The action is operated by recoil which is determined by the load impulse. Pressure is not even considered in the calculation and has no bearing. The pressure should drop to zero before the action begins to unlock and has nothing to do with extraction.

The recoil spring MUST reliably close the action. The disconnector will allow the Luger to FIRE with the action not fully locked. That can get ugly. The recoil spring must be strong enough for reliable closing with the over weight barrel.

All this may lead to a hand load that is hotter than current factory offerings to get adequate slide velocity.

The action will take higher pressure than a SAAMI spec load with out turning a hair. The real danger in too hot a load is too much impulse leading to too high a slide velocity and cracking the toggle or abusing the linkage.

[Blastattack]

Interesting. So the opening of the toggle and ejection is solely determined by the rearward velocity of the breechblock? Cool.

So if the action is 100% recoil operated, and to my understanding it is on the short recoil principle, introducing a heavier bullet at at equal or higher velocity would improve cycling performance? Would subbing in a 110gr. .30 carbine bullet work? And if so, what would a suitable starting load be? I have ordered and received my set of Wolff springs, though have not had the opportunity to visit my pistol and install them.

[RAY1946]

If you go with a 110 gr. bullet, be sure you also use a slow powder. I am thinking Accurate #7. I think with this combination the pressure would be pretty much even all the way to the muzzle, thus insuring enough rearward inertia from the recoiling members to create a full cycle of the toggle and reciever.

Along with the above, you might want to get the LOWER power Wolff spring. I think its rated at 36lb.........................

Good Luck...........

[lfid]

Re :

I do have more blueprints for the receiver support block and the action wrench if anyone is interested, plus a number of other prints relating to other parts and modifications. I have designed, though not yet machined and proven, a sight base to allow the installation of either a Micro sight or Bowen Classic Arms Ruger Flat-top rear sight for the toggle. If anyone is interested in any of this stuff I can either share it via PM or make a thread dedicated to the information.

These addl blueprints would be very interesting and appreciated !!!
The bowen sight seems like better choice - but locked down and windage only probably best

thanks
Bill

[unspellable]

DWM claimed the original 7.65 pistol load ran a 93 grain bullet out of a 4.5 inch pistol (not test barrel) at 1220 fps. I have reason to believe this claim is quite true.

Winchester claims 93 grains at 1220 fps from a 4.5 inch barrel. I have a LOT of reason to believe this is NOT true. I'e never got close to 1220 from any of several pistols with 4, 4.5, 5, or 6 inch basrrels.

The original carbine load ran around 40,000 cup and I believe the working carbine load also served as the proof load for the pistol.

SAAMi spec is 28,000 cup for the 7.65 vs 32,000 cup for ythe 9 mm. Hey guys! It's the same pistol in either caliber! Why down grade the 7.65?

Timing: The Luger unlocks fairly late compared to say, a 1911. The pressure will drop to zero before unlocking begins.

At a given velocity, a heavier bullet will provide more impulse. Keeping in mind there is a pressure limit.

[lfid]

for possible reference here is an original dewey custom luger base with the original micro sight replaced with a bowen sight

the original micro sight had a damaged front section from usage as elevation - was bent at the point of the elevation adj screw

thanks
Bill

[Blastattack]

Quite a deal of activity here in this last week. I have been out of the country for the past week, but have been watching the thread progress via my email notifications on my phone. I'm definitely going to try loading up some 110 gr. loads, just to see if I can get the thing to work. I have received my Wolff springs and will install it when I get a chance. The laws in Canada are... awkward for this, and I cannot posses my Luger until is gets reclassified from Prohibited to Restricted, which is apparently rather easy to do, so fingers crossed.

Bill/lfid:

Thank you for more pictures of the rear sight base. I plan on doing something nearly identical to that. How is it attached to the pistol? I see a roll pin there, but I cannot fathom what purpose it serves.
I'll shoot you a PM back soon. However, tonight is late and I'm weary from travel. Having said that, I am very interested.

Cheers all, and thank you for your continued interest in this project!

[rhuff]

I, for one, am interested in how your development comes along with loading the 110gr jacketed bullet into the 30 Lugar brass. Please keep us informed.

[lfid]

Re :

Thank you for more pictures of the rear sight base. I plan on doing something nearly identical to that. How is it attached to the pistol? I see a roll pin there, but I cannot fathom what purpose it serves.
I'll shoot you a PM back soon. However, tonight is late and I'm weary from travel. Having said that, I am very interested.

the Dewey rear sight base appears to be well soldered to a machined flat that removed the rear toggle original axle bump and sight. the front pin is the pivot point for the elevation on the micro sight/bowen eqivalent. the rear side "pin" near the soldered base line is actually a very small allen head screw that engages the elevation screw threads to prevent it loosening up from the toggle sight dynamics. problem in using elevation screw is that it likely fails - I suspect due to the bounce effect when the sight elevation springs get hammered by the toggle slap against the luger rear frame stop.
the Werle web sight has a reference that future target lugers would have elevation locked down and so elevation would be in the front sight. the pinned blade in your blueprint should allow variable height blades as needed - but the prewar colt woodsman 22 front sight method might be a better as allows adjustments.
VERY interesting project !!!
thanks
Bill

[lfid]

some more detail re the side lock pin and base design

[alanint]

A very nicely done rear sight.

Any further news on cycling and reliability for your pistol?

[Blastattack]

Originally Posted by alanint

A very nicely done rear sight.

Any further news on cycling and reliability for your pistol?

Nothing yet. I haven't had the chance to visit my pistol in nearly two months. Between Saturday overtime shifts and sickness, I haven't been able to muster the energy to make the trip out to my friends' place. I did, however, get my hands on one hundred each of 100gr. and 110gr. bullets, Hornady "half-jacket" and Sierra RNSP, respectively, and have 500 Starline Cases on order.

Interesting how the base is attached. I didn't expect it to be soldered on. Figures though, and could potentially be better than a dovetail, or other friction based attachment. I'll post my other blueprints later. busy busy.

[Michael Zeleny]

My most reliable Luger is a 7.65 Para W+F P06/29 National Match with a 200mm pencil barrel. Just sayin'.

[lfid]

Re the function of the Dewey example I pictured earlier, I have not tested it yet - but plan to do so with the winchester white box 9mm in a few weeks - after go/no go check and another check for any visible cracks anywhere

the former owner provided a partial box of corbon type 9mm which he stated a gun shop had recommeded since Lugers need heavy loads etc. - apparently the corbon functioned ok for his test of at least 8 rounds - but the original micro steel sight had a bent body and the front pin came out in three pieces and the elevation screw was also loose - the original base seems ok

anyone have any Dewey luger test results ?
thanks
Bill

[Blastattack]

Here are my wrench plans:

The wrench head is made from 4140 Cold Rolled rectangular bar, 1" x 4". The handle is made of 4140 Heat Treated & Stress Relieved (HTSR, also Quenched and Tempered), received in Turned, Ground and Polished condition, and is 13" x 1.000" diameter. The handle has a 1" long by .751" diameter section on one end and is pressed into the body of the wrench. I also drilled and tapped a 1/4-20 hold and further secured the handle with a bolt.

[sheepherder]

What CAD program are you using???

[sheepherder]

Originally Posted by Blastattack

I do have more blueprints for the receiver support block and the action wrench if anyone is interested, plus a number of other prints relating to other parts and modifications...

I'd be interested...I like to wallpaper the walls of my shop with prints...

Originally Posted by Rick W.

As much as I admire John's offering of prints of the Luger breeching system, the real numbers for your pistol is in front of you after you remove the barrel.

Instruments(depth mic and outside mic) are your best friends, they will tell you the measurements directly without interpretations.

+ 1

It bears repeating that the German/Metric system does not readily translate to 'Yankee'/inch conventions...Example - 75% thread depth; round/flat thread peaks/valleys; thread angle; Metric/Yankee allowances/tolerances; etc...

The best blueprint is the part itself...