Barrel Feed Ramp Angle?
 

I'm rebarrel a 1917 DWM with barrel blank that I'm machining. Hoping someone can help me with the angle of the feed ramp please. Many Thanks

barrel angle
 

Hi Kiwi Mark! The feed ramp angle, for some reason, doesn't seem to be a finite measurement.. It just kind of appears if you follow the prints measurements on all other cuts? But, I can tell you this, as to what we have discovered at G.T. Specialties.. If you install in the barrel bore, back extending thru the chamber, a 8.8 MM drill blank / rod, or one that even more closely fits your bore, a new heavy duty Stanly Razor Knife blade will make an "EXACT" gauge for the angle present from the factory? We then measured the blade angle and it was exactly 50 degrees from the bore center line, to the ramp angle inclusive. I think most of the machinist guys here have found 46 degrees to be close to what the print says?... We cut all of ours 50 degrees and then by hand, polish to a quite full / throated finished shape. Very important you don't go to deep, as the case mouth will stop right at the ramps end in the chamber... Very tight vertical Jam will result! .....;)..... How's that? Will that help! Best to you, til...lat'r.....GT

Thank you GT, much appreciated. I have also read your New Project for Shooters, with the photo and comments gives me the info I need. I was going to have a 5 inch bull barrel, but I'll machine the barrel down to reduce the weight. Again, many thanks. Mark

Mark,
a 5" bull barrel of "GT" design works quite well and has a great balance; it is slightly reduced from the round profile by flats on the top and sides.

Here are a couple picture of mine; I also added an adjustable(windage) rear sight.:D

barrel ramps!
 

Hi to all! Both Olle & Don have been very instrumental in getting the GTST barrels of all lengths up and running! The barrels were designed to be a relatively inexpensive but desirable alternative to the factory designs.. The P.08 bull barrel profile is magic as soon as you shoot one!!!.. 4" feels best to me, 5" is preferred by a few, and might just be the best all around?.. 6" is popular, but it is right at the edge of design limits, and kind of defeats the ease of use philosophy, as main spring tuning and hand loading might be required to get 100% performance...
Dons rear sight is interesting and nicely done! I'm trying to go that route as well, but too many irons in the fire... ;)... Thanks to all for your support! til....lat'r....GT ......;)

I have pondered the feed ramp in a Luger barrel a little. Still not satisfied with my endeavors theoretically yet, things seem to work and seem safe, but still there are parameters to consider further if you will. Always something has to be learned and paid for.

I would suspect that the ramp would be done in a mill or in a milling adapter on a lathe.

So what are a few considerations?

angle off bore line......as discussed above perhaps. Lots of ways to find the angle reference to bore line I reckon; oem barrel indicated in a lathe.

Width and depth of cut............kinda influence one another with the cutter.

projection into the barrel bore proper. The cartridges for the Luger are fairly intense in the psi department. We all know that brass cases are thicker at the rear than in front for safety in retaining said pressures intact.

so if the cut is made too deep into the barrel bore, the case begins to possibly become unsupported. Thin brass walls and pressure can become testy.

In these few parameters of the many probably, the depth into the bore seems to have more weight sorta speak to me. Just my simple opinion. I think angle is just one of the considerations for a proper feed ramp; but know everyone is thinking about other parameters for basic safety of the finished product.

I like improved sights on the Luger nowadays, the old basic is too tough for me now. A nice sight picture ala a fine target gun is the thing that helps me out a lot. But even that goes. An optical sight, redot or scope really allows one to align to the target.............and sometimes even hit it. Optics are not for everyone, but as in the other disciplines, optics can be a bit of a boon in those environments.

Rick,
you are overthinking the ramp, IMO.

Just take an original barrel and duplicate the ramp; by eye is "close enough".
If you look at many luger pistols, you will see that the ramps vary a bit, maybe even a lot.

The original drawings are available and show the design specs. They were likely done on/ with a milling machine and fixture and special cutter.

I made a fixture for cutting the extractor groove, but "cut" the ramp by hand.
I use a grinding stone, then a sanding cylinder, and polish with an abrasive tip. This serves me quite well.

I like the bull barrel with flats and the front sight for windage. I'm going to mill the rear sight vee sight with 3mm TC end mill to square it off as I
can't see the vee. I'll make the front sight alot higher & file it down at the range until I get the desired results. Before you start to recommend different sights, in New Zealand, we can't import stuff. So I made it. I really appreciate the comments, many thanks.

Be sure to post pictures of the finished barrel and sights, please.:thumbup:

I have a friend in New Zealand that has told me some about how it is with importing etc, we all hope for better times to come.

OTS sights for the Luger here are pretty scarce here too. I reckon the Marbles #27 was about the last. I see that G.T. is going thru great lengths to help out in the front sight arena for us. Obiviously the old Mauser front is around yet some, but takes a little moding for elevation etc. If you can cut your own dovetailing or make such a ramp, that will open up some other options.

Improved rear sights on the toggle as you know take a beating. Adjustable sights here are mainly(for the very few that do them) modifications of existing sights available. FWIW, I have found over the years that if I got rid of the elevation characteristic of the rear adjustable sight, that durability went up. A lot of homebrew fixed sights attached in various ways, or specialized milling or made up sub-bases for something like the S&W rear or the old Bomar sights appear here from time to time.

Finding a scope mount for the Luger.......well, guess not too many around, I have never seen one that was not out of someone's shop as a one of, type of thing. I was really pleasantly surprised with the ability of the scope on the Luger, but I also realize tis not for everyone. Really shows the real capabilities of a slender tapered 14" barrel in 30 cal. I showed my rendition once here, but will never again.

The beauty of the Luger barrel is that it is not too complex to replicate, probably the most effort is in the integral front sight base if so desired. Slabbed barrels should be fairly easy on the lathe/mill, and keep the barrel in alignment some during recoil.

No hassle intended on my part, my best to you on your project.

Rick W.

barrel ramp.....
 

Hi guys, actually, I am in agreement with both of the notes by Don and Rick... I think that from a one time practical sense, just about any ramp will do, and it is amazing how close one can come by eye to the correct final angle?... But, I would not be telling the truth if I didn't say that it bothers me more than just a little to see the ramp extend deeper and deeper into the chamber proper as we break edges, throat chamber mouths, and so forth?... On the first range shot, I always inspect the brass for ANY signs of pressure or deformation as a result of possible incorrect chamber dimensions, or relief cuts?... So far so good!
But, I always look down from the top of the barrel to INSURE that the feed ramp does NOT exceed the depth of the extractor cut, actually, I like to see it some what shy of the extractor relief cut... although I also agree, the brass is pretty tolerant of this unsupported area in question?... Thanks to you both for your input, great stuff this Luger puzzle... Best to all, til...lat'r....GT...;)

Hi, Finally finished except for the front sight needs to be blued after some range shooting. Barrel ended up at 4 3/4 inches long, for no reason other than that's what happens. You can see that I spent a bit of work milling the front sight lug in the Dividing head, a new and higher front sight. Also a first for me, I made a recoil spring as I can't get one in NZ. I really appreciate another member showing the barrel removal tools and all the great feedback by everyone .

:confused: You can't order a spring from New Zealand? What is the restriction on ordering springs?

Hi, One has to apply for a Import Permit from the Police which can take 6 months to approve. Then you have to find a company in the US who has an Export Licence. Then the minimum postage is $60. Easier to make stuff. Google is good as it puts you through to a U Tube clip. Next trip to the US, I'll be doing the Gun shows. US has banned the export of barrel blanks. The barrel on the Luger shown, I made it with a button we imported years ago. You guys are so lucky, don't let anyone spoil that.

Just to buy a couple of springs? How would they know they were gun related? Do you have to declare what they will be used for?

Hi John,
Exporters have to fill out the Customs Delcaration and will not falsify information. Since 9/11 everything has changed. Being able to make stuff is a form of freedom. I'm inspired by people like youself who pass on their knowledge and skills. Many thanks. Mark