To Kyrie, preasure data.

[HÃ?Â¥kan Spuhr]

Hi Kyrie, you asked earlyer of preasure data.

I havent found it on police service ammo yet but i have it for the military round.


105 gr bullet.

1440 fps out of a 10" subgun barrel.

250 MPA preassure.

Steel jacketed bullet


Regards HÃ?Â¥kan





http://www.vapensmedjan.com

HI guys! I know that this discussion about chamber pressure originated with a question I had about hold open, so I'd to interject that issue again. Last night I removed the cannons from the 2 guns in question and inserted various different magazines. I was amazed by the variation in how high the hold open would rise with the different mags. In one gun, an FXO mag pushed the h.o up almost a half an inch, but a seemingly identical Schmeisser mag would only raise it by 1/16th or 1/32". (Sorry for the English measurments, Hakan). The spring strength seemed the same in both mags. The mag that worked best was a Mec Gar that I had worked on and added a stronger spring from Wolff's. I also switched out the h.o. devices between the two guns, and found the 1915 seems to work better than the 1916. Found what might be a minute burr on the surface of the 1916 frame -- the cavity in which the h.o. rests. (The notch of both breehblocks seems adequate, as do the magazine cathes.)


In other words, I still find an overwhelming number of variables to cope with. What do you guys think? Thanks.

[Frank]

First, you are correct in the variations in pistol and magazine dimensions. The magazine follower button diameter, the button slot length in relation to the magazine catch notch, spring force are among the potential problem areas.


Then there are differences in various ammunition.


I would select the magazine that seems to work the best, manually. Then, I can't remember who mentioned this, but I agree with it. Place one round in the magazine and fire it. If the magazine will hold open manually and the round fails to hold open, then the problem is probably the ammunition. Hope this helps.

Thanks Frank. ALL of the mags work manually. When I put an empty mag in and pull the toggle back, it always holds open. Some ammo works well with a certain combination of gun and mag, but not with another combination.


(For my test last night, I was trying to obeserve what it looked like inside the gun when I was shooting. I loaded a snap cap in the mags, inserted the mags in the guns, with the cannons removed, and then briskly stripped the snap cap off the mag with my thumb. There was a tremendous variation between different combinations of mags, guns, and switching h.o. mechanisms between guns.)


Regarding ammo, I generally shoot Winchester white box 115 gr FMJ. I did find that 147 grain Winchester FMJ, which is hard for me to find, works flawlessly in terms of h.o. in both guns. I guess because the heavier slug must cause more chamber pressure. But I also hear you guys say to shoot the lightest bullet possible to be kind to your gun.


Sorry to be so long-winded about this, but any comments would be appreciated. Thanks.

Don, your comment about shooting the "lightest" load possible may have been misinterpurted. I think what they mean is "lightest" in pressure not necessarly bullet weight. Some 115 gr ammo can have significant pressure. It's a reloading thing!!

Thanks, Bob,


Clearly chamber pressure, bullet weight, reloading, etc. are unexplored territory to me. First, assuming case, primer, poweder, etc. were all identical, and only bullet weight varied, would a 147 grain slug create more chamber pressure and be harder on a gun than 115? I don't have any specs on the Winchester ammo, so I'm not sure if the powder load is the same and only the weight of the slug is different, or whatever. Thanks.

[Frank]

Have these pistols been "worked-on"? If the 147 grain bullets always work and the lighter bullets work sometimes, the difficulty could be in the main spring or sliding fit (lube). If you are convinced the pistol has adequate lubricant (and that means not too much, as well as too little) and if someone has "messed" with the pistol, then you might consider a main spring change to a lighter one. This is not an easy task if you have never done it, so make sure it's something you really want to do. Wolff Springs makes a set of these springs. Other forum members have much more experience with this operation than I do, so hopefully they will step up.

[Thor]

i caint! Youuns have banned me from posting, my nose hurts, thanks hu!

[Frank]

[Patrick]

Georg Luger could change the main spring - in the dark with one hand behind his back. He performed this feat in front of the U.S. Acceptance Board (it�´s said he used his teeth). Patrick

[Thor]

WOW, not I really feel bad, with my handicap of light and two hands, shoot, I really got to get better at this! Thor

[HÃ?Â¥kan Spuhr]

THe heavyer the bullet is the better will the gun work.

Simply because the recoil impulse is heavyer with a heavy bullet.

I don't belive the heavy bullet stresses the gun more than a ligth bullet.


But Don this aboslutetly proves that you must test a ligher recoilspring.


REgards HÃ?Â¥kan



http://www.vapensmedjan.com

[Thor]

A std spring and std load of 124 gr bullet at 1150 should function your gun! I test lots of these and if it doesnt something is amiss. This is with a brand new Wolff std factory replacement spring! 147gr bullet will produce a little more recoil but it not necessay, the gun was DESIGNED for the 124 gr weight! I dont know what the gram equivalent is, but I have read and heard from many sources that it was designed for the 124 gr bullet. Heck you can get the 30 Luger to funcition with a 93 gr bullet but not as well! Thor

[HÃ?Â¥kan Spuhr]

I agree, the gun is made to work with 124 gr bullets, but with heavyer loaded than much ammo today.

White and Munhall published many years ago some original loading data for service amoo that was 1280 fps.

That is a bit different from ammo today.

regards HÃ?Â¥kan



http://www.vapensmedjan.com

[Frank]

[Kyrie]

Hi HÃ?Â¥kan,


Thank you kindly, sir!


Is that a crusher methodology pressure or a transducer methodology pressure? It's hard to do a comparison without knowing which metodology produced the measurement.


Best regards,


Kyrie

The contract ammunition was 1400 feet per second on 115 grain bullet. Military surplus will give you this performance but not commercial. The gun was proofed tested at 15 tons per square inch. We "older" guys have and know of many people who bought cheap machine gun ammo (2000 fps) or 20 tons per square inch and used with no problems (4 inch barrel).


M. Reese II (Luger Tips) suggests if you want to shoot todays commercial ammo then cut off two coils from the main spring. If you do cut the spring don't go back to the as designed ammo.


Reloaders need to modify the propellant manufactures "recommended" loads to get back to original design performance as the manufactures quote loads safe enough for the Saturday night specials, these light loads are also used for commercial ammo.


Hope this helps.

[Thor]

If you cut two coils off, I do think that std ammo will hammer most guns a little hard, std ammo and the springs in the guns, even a stiff Wolff spring that is has quite a bit more tension than most older springs (agreed they have some mileage on them) work fine in all the guns I have looked out that were sound mechanically. Why batter an 80 yr gun? But these guys are the experts and I am just speaking from experience! I will shoot the std ammo and be happy my guns (and the reworks I do) rest a little easier and last a little longer! If the round has enough power to lock the toggle back EVERY TIME, there really is no reason to lessen the spring tension is there? Thor

[Thor]

BTW, I have broke two ejectors shooting hotter reloads, primarily a 100 gr bullet at around 1300 fps, why hammer the gun more? To each his own, but I prefer just enough, to too much! Thor

[HÃ?Â¥kan Spuhr]

Thor a differnce why the guns works very well for you but maybe not for others might be that you actually holds the gun harder than mostly others.

It's this way possible that your gun in your hand will be as battered as a gun with a lighter spring in more loose hands will be.

I have as well experinced problems with modern ammo in some pistols and i belive that cut a few coils of might be the solution.


Regards HÃ?Â¥kan



http://www.vapensmedjan.com