Widen Receiver forks?

Quentin · 05-11-2007, 09:22 PM

Of three receivers I have one fits much tighter on the frame than the others. I'd like to bend it very slightly, probably less than 1/16th" to reduce friction.

Has anyone done something like this? I was thinking of using a wooden wedge and tapping it between the forks. Maybe someone has a better idea? Of course my worry is getting heavy handed and breaking the receiver.

Thanks for any suggestions!

Bob

policeluger · 05-11-2007, 11:09 PM

Never try and bend forks, get use to tight fit and if it is so tight as to not function, work the toggle over with light grinding compound, but this is a last resort.....please do not bend anything Luger.....

zinfull · 05-12-2007, 01:57 AM

Now I find out. I have one that is tight and used threaded rods to seperate the forks. I moved them about 1/2" but it did not work so I quit before I did any harm.

Jerry

Brownie · 05-12-2007, 08:25 AM

Quote:

Originally posted by Quentin
I was thinking of using a wooden wedge and tapping it between the forks.

...the horror.......the horror. :icon501:

Lugerdoc · 05-12-2007, 09:16 AM

If a receiver is tight in your PO8 frame, opening up the "forks" would probably just make it worse. First check for dings or twist that could be cause this. Once these are cleared up, the recommended procedure would be "lapping" it in with a lapping (valve grinding) compound. TH

DaveinTN · 05-12-2007, 11:21 AM

Tac(aghast)foley is absolutely correct!

I work with a group of engineers who consider themselves "universal experts" on just about everything. I'm not an engineer, but I have a sign in my office which they truly despise.

The sign reads, " Measure with a micrometer, mark with a chalk, and cut with an ax."

My shooter has a tight fit too, but it functions just fine. I actually don't mind it because its part of that gun's "personality."

Wouldn't it be boring if all Lugers had parts that were as interchangeable as Glocks?

I would also suggest you read this thread in "New Collector's Forum:"

http://forum.lugerforum.com/showthre...074#post125074

Dave in TN

Quentin · 05-12-2007, 01:28 PM

I certainly agree you don't want to be heavy handed on a precision part but the tines of the receiver definitely are too tight by about 1/32" at the end. There's way too much friction with the breechblock compared to my other receivers. I have to slightly spread the prongs outward each time I install the toggle/breechblock after cleaning.

I know this is highly tempered steel but couldn't very gentle work with a wedge expand the gap at very end of the prongs by 1/32"? I know you can't spread them too wide or they'd just then make contact with the inside of the frame, so it would have to be a very fine adjustment.

There are no dings or twisting, it appears somehow over the years the tines got bent inward.

The pistol functions reliably and is a great shooter.

DaveinTN · 05-12-2007, 01:54 PM

Quentin,

I also have to spread the "forks" slightly to re-assemble my shooter, but maybe by less than you have to.

I've thought about spreading the forks just a little more than I usually do so that they would return to a slightly wider opening than they were in the "before" position. If I were to open the spread to a wider position, I wonder if that would disturb the alignment/operation of other components? I don't know...

For my pistol, this is not that big a deal. However I would hate for you to accidentally mess up your pistol.

I would suggest you contact either Policeluger or Lugerdoc for an idea of what they would charge to adjust your pistol.

Good luck!

Dave in TN.

G.T. · 05-12-2007, 02:04 PM

The first step.... BEFORE you bend / straighten anything!! Is to purchase, and learn how to use, a digital caliper.... you then measure across the receiver at the bottom front, and then measure across the rails at the bottom rear, and also all along the way, (toggle in or out, still have to arrive at straight sometime!) ... whatever the front is, that's what the back is supposed to be... it was machined straight in the beginning, and should be that now... Then measure the receiving slots in the frame..same thing, should be straight, front, back, middle..... you'll be surprised what it'll do for your Luger knowledge base.... Can't manage, or repair what you can't measure! best to all, til....lat'r......GT

Ron Wood · 05-12-2007, 02:21 PM

Quote:

I have to slightly spread the prongs outward each time I install the toggle/breechblock after cleaning

On a couple of my Lugers so do I. I agree with Dave, it is no big deal. Unless it causes the gun to malfunction when firing it isn't a problem. A 1/32" deflection is insignificant.

lugerholsterrepair · 05-12-2007, 02:45 PM

I very much agree with GT..Measurements are key to many things. A good dial caliper is worth the 15 bucks.

Like Ron, I have to spread the tail end a little on many of my Lugers. If your Luger functions well I would lube it good, I use Lithium white grease, and not spread the forks.

You must realize..to permanently spread the forks 1/32nd of an inch it might be necessary to widen them a good half to three quarters for the bend to permanently fix in the metal. Then you will just be guestamating with no real hope for any true accurate measurement fix.

Too..The metal parts have been hardned, heat treated. Forcing them apart could crack the thing up where it junctions with the chamber and is less flexable.

Better to leave sleeping dogs lie in my opinion.

DaveinTN · 05-12-2007, 09:59 PM

Although I cleaned and oiled my two Lugers earlier this week, this topic provided me with a good reason to take them out again. Using a 6" dial caliper accurate to 0.01" I measured the gap between the forks at the breech and at the extreme end on both pistols.

Having recently purchased the Plans CD from John Sabato, I checked on Page 3 and found the specification for the gap width to be 13 mm (which is 0.511".)

On my "tight" commercial shooter, the forks are 0.01" narrower at the far end. To spread the forks 1/32" would be just over 0.031" or 0.02" too much!

On my 1917 Erfurt, both measurements are 0.52" and the toggle assembly slides in effortlessly.

Here's a diagram of my results.... (isn't it a sad statement that on a Saturday night I have nothing better to do than measure pistols and play with Photoshop ...)

Dave in TN

G.T. · 05-12-2007, 10:12 PM

Hi DavidTN! You're definitely on the right track! BUT!!! You have to find a caliper that is capable of .0000" (the last place can measure in .0005" and be close enough) to get an accurate grip on the issue... Also, as you have noticed, your breechblock is kinda of a "go" "no go" type of gauge all by itself.... Lay a straight edge along BOTH sides of the receiver, hold it up to the light, and find out which of the forks is the offending member... (They're certainly not bent equally!) Then shim and clamp the receiver in a smooth jaw vice and give the bent fork a bit of a flex... you'll have to exceed straight to get it to stay... for lack of a better term, sneak up on it!! Take your time, little bit, little bit!!! ...and if it all goes to hell in a handbasket, you never heard from me!!!

Best of luck to you, til...lat'r....GT

DaveinTN · 05-12-2007, 10:38 PM

G.T.

A caliper accurate to four decimal places is a little bit of overkill for me, although I wouldn't mind having one so I could add it to my collection of tools that I never use (such as my non-electronic compensating polar planimeter...)

As I stated earlier in my response to Quentin, my shooter has a tight fit too, but it functions just fine. I actually don't mind it because its part of that gun's "personality."

After tinkering around and messing up more stuff than I would be comfortable to admit, I've learned that if it ain't broke too much, don't fix it....

However, thanks for the good advice!

Dave in TN.

Ron Wood · 05-12-2007, 11:58 PM

Y'all hear that?...if it ain't broke, don't fix it. By the way Dave, I don't think it is a sad statement at all. A heck of a lot more healthy and productive than a whole bunch of other activities. Thanks for taking the time to do it.

Dwight Gruber · 05-13-2007, 06:15 AM

Two things occur to me.

In addition to the breechblock fitting in the receiver rails, the receiver must also fit in the frame. If the receiver extension is spread too far, it may bind on the frame.

In operation, the breechblock does not go clear to the end of the receiver extension--its tavel ends about 3/4 inch before. The bitter ends of the rails may be close enough so that the breechblock is tight to reassemble, but in its operational travel it may be just fine.

--Dwight

Lugerdoc · 05-13-2007, 09:01 AM

Q, You would have to open up the rear of your receiver to over an inch gap before you would have any lasting widening when relaxed, so I don't advise it. If your luger is a mismatched shooter, I would advise trying a narrower breech block, as these will vary somewhat in dimentions. Like GT and an old German boss of mine told me as a junior IE at Anheuser-Busch "What you can't measure, you can't control". TH

Ron Wood · 05-13-2007, 09:53 AM

I could be wrong but this may be much ado about nothing. Even though the receiver forks might have to be sprung slightly to insert the breech block, once the toggle train is in place the rear toggle link maintains the proper spacing at the rear of the receiver.

Quentin · 05-13-2007, 12:42 PM

Thanks to everyone for your sound comments (especially Dave - sorry I didn't mean for you to start measuring your receivers and toiling away in Photoshop Saturday night)! Very helpful information from all and I sure appreciate the advice.

I should add more information concerning this "problem". I've owned the Luger in question over 30 years putting thousands of rounds through it. With good ammo it's been extremely reliable.

This is a mixed parts shooter, DWM frame & toggle assembly but a 1938 Mauser barrel/receiver. Recently I got a 1913 DWM barrel/receiver and that's when I noticed how much smoother and easier the toggle moved in it than in the Mauser receiver. On the firing range both receivers work fine so as has been pointed out this really isn't a problem, other than the extra friction and wear and tear.

Anyway, I plan to get an S/42 toggle assembly and will see how its breechblock works in the 1938 receiver. (Probably no change of course.) Since it's hard for most people to tell the frame is WWI vintage, I hope to end up with a shooter that can become WWI or WWII with a swap of the upper section. In effect a poor man's way to have two shooters.

This may seem stupid, why not just sell the mixed parts pistol and buy two shooters, but I've owned this Frankenstein so long I'd like to hang on to the parts now. At the time I was a dumb kid looking at Lugers and stumbled across this one in a pawn shop. As I compared what was for sale in town I kept coming back to look at this one. It was the cheapest and ugliest but looking at the parts it was obvious there was little wear from shooting, just careless handling over the years.

I must have been one of the few people interested in it because the guy dropped the price to $100 and I couldn't walk away. I couldn't believe it when I took it out in the desert and it gobbled up 50 rounds with no jams! So there is sentimental attachment and I want to hang on to the gun. Twenty years later I did get a second Luger, an excellent all matching 41 byf that's too nice to shoot so of course the ugly one is much more fun! Took it out yesterday with my son in law and had a great time. (No he wasn't the target.

)

DaveinTN · 05-13-2007, 01:02 PM

Brother Quentin,

When you have a chance, you really ought to post a few photos of your "problem child" Luger for us to see.

No need to apologize... I've actually learned quite a bit both from participating in this topic and by comparing the measurements of my two Lugers to each other and to the plans I bought from John S.

And thanks to GT, I'll probably spend some time tomorrow looking for a caliper accurate to four decimal places (No one can say I'm not obsessive-compulsive..)

Have a great week!

Dave in TN.

DAMN! I just realized this is my 101st post!!! Drinks on me for everyone!

05-11-2007, 09:22 PM	#1
Quentin User Join Date: Apr 2007 Location: NorthWest USA Posts: 124 Thanks: 59 Thanked 11 Times in 4 Posts	Widen Receiver forks? Of three receivers I have one fits much tighter on the frame than the others. I'd like to bend it very slightly, probably less than 1/16th" to reduce friction. Has anyone done something like this? I was thinking of using a wooden wedge and tapping it between the forks. Maybe someone has a better idea? Of course my worry is getting heavy handed and breaking the receiver. Thanks for any suggestions! Bob

05-12-2007, 09:16 AM	#5
Lugerdoc Patron LugerForum Patron Join Date: Jun 2002 Location: POB 398 St.Charles,MO. 63302 Posts: 5,089 Thanks: 6 Thanked 737 Times in 484 Posts	If a receiver is tight in your PO8 frame, opening up the "forks" would probably just make it worse. First check for dings or twist that could be cause this. Once these are cleared up, the recommended procedure would be "lapping" it in with a lapping (valve grinding) compound. TH __________________ Tom Heller POB 398 ST.Charles, MO. 63302 Tel 636-447-3006 lugerdoc@charter.net

05-12-2007, 02:04 PM	#9
G.T. Lifer Lifetime Forum Patron Join Date: Jun 2002 Location: Chandler Arizona Posts: 3,525 Thanks: 1,321 Thanked 3,709 Times in 1,013 Posts	First step! The first step.... BEFORE you bend / straighten anything!! Is to purchase, and learn how to use, a digital caliper.... you then measure across the receiver at the bottom front, and then measure across the rails at the bottom rear, and also all along the way, (toggle in or out, still have to arrive at straight sometime!) ... whatever the front is, that's what the back is supposed to be... it was machined straight in the beginning, and should be that now... Then measure the receiving slots in the frame..same thing, should be straight, front, back, middle..... you'll be surprised what it'll do for your Luger knowledge base.... Can't manage, or repair what you can't measure! best to all, til....lat'r......GT

05-12-2007, 02:45 PM	#11
lugerholsterrepair Moderator Lifetime Forum Patron Join Date: Jun 2002 Location: Arizona/Colorado Posts: 7,775 Thanks: 4,995 Thanked 3,133 Times in 1,439 Posts	I very much agree with GT..Measurements are key to many things. A good dial caliper is worth the 15 bucks. Like Ron, I have to spread the tail end a little on many of my Lugers. If your Luger functions well I would lube it good, I use Lithium white grease, and not spread the forks. You must realize..to permanently spread the forks 1/32nd of an inch it might be necessary to widen them a good half to three quarters for the bend to permanently fix in the metal. Then you will just be guestamating with no real hope for any true accurate measurement fix. Too..The metal parts have been hardned, heat treated. Forcing them apart could crack the thing up where it junctions with the chamber and is less flexable. Better to leave sleeping dogs lie in my opinion. __________________ Jerry Burney 11491 S. Guadalupe Drive Yuma AZ 85367-6182 lugerholsterrepair@earthlink.net 928 342-7583 (CO & AZ) Year Round 719 207-3331 (cell) "For those who Fight For It, Life has a flavor the protected will never know."

05-12-2007, 09:59 PM	#12
DaveinTN User Join Date: Nov 2006 Location: Tennessee Posts: 186 Thanks: 3 Thanked 15 Times in 11 Posts	Although I cleaned and oiled my two Lugers earlier this week, this topic provided me with a good reason to take them out again. Using a 6" dial caliper accurate to 0.01" I measured the gap between the forks at the breech and at the extreme end on both pistols. Having recently purchased the Plans CD from John Sabato, I checked on Page 3 and found the specification for the gap width to be 13 mm (which is 0.511".) On my "tight" commercial shooter, the forks are 0.01" narrower at the far end. To spread the forks 1/32" would be just over 0.031" or 0.02" too much! On my 1917 Erfurt, both measurements are 0.52" and the toggle assembly slides in effortlessly. Here's a diagram of my results.... (isn't it a sad statement that on a Saturday night I have nothing better to do than measure pistols and play with Photoshop ...) Dave in TN Attached Images

05-11-2007, 11:09 PM	#2
policeluger RIP Join Date: Jun 2002 Location: Ca. Posts: 2,141 Thanks: 8 Thanked 89 Times in 54 Posts	Never try and bend forks, get use to tight fit and if it is so tight as to not function, work the toggle over with light grinding compound, but this is a last resort.....please do not bend anything Luger.....

05-12-2007, 01:57 AM	#3
zinfull Lifer Lifetime Forum Patron Join Date: Dec 2004 Location: Sonoma County CA Posts: 244 Thanks: 5 Thanked 34 Times in 17 Posts	Now I find out. I have one that is tight and used threaded rods to seperate the forks. I moved them about 1/2" but it did not work so I quit before I did any harm. Jerry

05-12-2007, 11:21 AM	#6
DaveinTN User Join Date: Nov 2006 Location: Tennessee Posts: 186 Thanks: 3 Thanked 15 Times in 11 Posts	Tac(aghast)foley is absolutely correct! I work with a group of engineers who consider themselves "universal experts" on just about everything. I'm not an engineer, but I have a sign in my office which they truly despise. The sign reads, " Measure with a micrometer, mark with a chalk, and cut with an ax." My shooter has a tight fit too, but it functions just fine. I actually don't mind it because its part of that gun's "personality." Wouldn't it be boring if all Lugers had parts that were as interchangeable as Glocks? I would also suggest you read this thread in "New Collector's Forum:" http://forum.lugerforum.com/showthre...074#post125074 Dave in TN

05-12-2007, 01:28 PM	#7
Quentin User Join Date: Apr 2007 Location: NorthWest USA Posts: 124 Thanks: 59 Thanked 11 Times in 4 Posts	I certainly agree you don't want to be heavy handed on a precision part but the tines of the receiver definitely are too tight by about 1/32" at the end. There's way too much friction with the breechblock compared to my other receivers. I have to slightly spread the prongs outward each time I install the toggle/breechblock after cleaning. I know this is highly tempered steel but couldn't very gentle work with a wedge expand the gap at very end of the prongs by 1/32"? I know you can't spread them too wide or they'd just then make contact with the inside of the frame, so it would have to be a very fine adjustment. There are no dings or twisting, it appears somehow over the years the tines got bent inward. The pistol functions reliably and is a great shooter.

05-12-2007, 01:54 PM	#8
DaveinTN User Join Date: Nov 2006 Location: Tennessee Posts: 186 Thanks: 3 Thanked 15 Times in 11 Posts	Quentin, I also have to spread the "forks" slightly to re-assemble my shooter, but maybe by less than you have to. I've thought about spreading the forks just a little more than I usually do so that they would return to a slightly wider opening than they were in the "before" position. If I were to open the spread to a wider position, I wonder if that would disturb the alignment/operation of other components? I don't know... For my pistol, this is not that big a deal. However I would hate for you to accidentally mess up your pistol. I would suggest you contact either Policeluger or Lugerdoc for an idea of what they would charge to adjust your pistol. Good luck! Dave in TN.

05-12-2007, 10:12 PM	#13
G.T. Lifer Lifetime Forum Patron Join Date: Jun 2002 Location: Chandler Arizona Posts: 3,525 Thanks: 1,321 Thanked 3,709 Times in 1,013 Posts	Right track! Hi DavidTN! You're definitely on the right track! BUT!!! You have to find a caliper that is capable of .0000" (the last place can measure in .0005" and be close enough) to get an accurate grip on the issue... Also, as you have noticed, your breechblock is kinda of a "go" "no go" type of gauge all by itself.... Lay a straight edge along BOTH sides of the receiver, hold it up to the light, and find out which of the forks is the offending member... (They're certainly not bent equally!) Then shim and clamp the receiver in a smooth jaw vice and give the bent fork a bit of a flex... you'll have to exceed straight to get it to stay... for lack of a better term, sneak up on it!! Take your time, little bit, little bit!!! ...and if it all goes to hell in a handbasket, you never heard from me!!! Best of luck to you, til...lat'r....GT

05-12-2007, 10:38 PM	#14
DaveinTN User Join Date: Nov 2006 Location: Tennessee Posts: 186 Thanks: 3 Thanked 15 Times in 11 Posts	G.T. A caliper accurate to four decimal places is a little bit of overkill for me, although I wouldn't mind having one so I could add it to my collection of tools that I never use (such as my non-electronic compensating polar planimeter...) As I stated earlier in my response to Quentin, my shooter has a tight fit too, but it functions just fine. I actually don't mind it because its part of that gun's "personality." After tinkering around and messing up more stuff than I would be comfortable to admit, I've learned that if it ain't broke too much, don't fix it.... However, thanks for the good advice! Dave in TN.

05-12-2007, 11:58 PM	#15
Ron Wood Moderator 2010 LugerForum Patron Join Date: Jun 2002 Location: Santa Teresa New Mexico just outside of the West Texas town of El Paso Posts: 7,035 Thanks: 1,106 Thanked 5,242 Times in 1,719 Posts	Y'all hear that?...if it ain't broke, don't fix it. By the way Dave, I don't think it is a sad statement at all. A heck of a lot more healthy and productive than a whole bunch of other activities. Thanks for taking the time to do it. __________________ If it's made after 1918...it's a reproduction

05-13-2007, 06:15 AM	#16
Dwight Gruber User Join Date: Jun 2002 Location: Portland, Oregon Posts: 3,908 Thanks: 0 Thanked 1,330 Times in 435 Posts	Two things occur to me. In addition to the breechblock fitting in the receiver rails, the receiver must also fit in the frame. If the receiver extension is spread too far, it may bind on the frame. In operation, the breechblock does not go clear to the end of the receiver extension--its tavel ends about 3/4 inch before. The bitter ends of the rails may be close enough so that the breechblock is tight to reassemble, but in its operational travel it may be just fine. --Dwight

05-13-2007, 09:01 AM	#17
Lugerdoc Patron LugerForum Patron Join Date: Jun 2002 Location: POB 398 St.Charles,MO. 63302 Posts: 5,089 Thanks: 6 Thanked 737 Times in 484 Posts	Q, You would have to open up the rear of your receiver to over an inch gap before you would have any lasting widening when relaxed, so I don't advise it. If your luger is a mismatched shooter, I would advise trying a narrower breech block, as these will vary somewhat in dimentions. Like GT and an old German boss of mine told me as a junior IE at Anheuser-Busch "What you can't measure, you can't control". TH __________________ Tom Heller POB 398 ST.Charles, MO. 63302 Tel 636-447-3006 lugerdoc@charter.net

05-13-2007, 09:53 AM	#18
Ron Wood Moderator 2010 LugerForum Patron Join Date: Jun 2002 Location: Santa Teresa New Mexico just outside of the West Texas town of El Paso Posts: 7,035 Thanks: 1,106 Thanked 5,242 Times in 1,719 Posts	I could be wrong but this may be much ado about nothing. Even though the receiver forks might have to be sprung slightly to insert the breech block, once the toggle train is in place the rear toggle link maintains the proper spacing at the rear of the receiver. __________________ If it's made after 1918...it's a reproduction

05-13-2007, 12:42 PM	#19
Quentin User Join Date: Apr 2007 Location: NorthWest USA Posts: 124 Thanks: 59 Thanked 11 Times in 4 Posts	Thanks to everyone for your sound comments (especially Dave - sorry I didn't mean for you to start measuring your receivers and toiling away in Photoshop Saturday night)! Very helpful information from all and I sure appreciate the advice. I should add more information concerning this "problem". I've owned the Luger in question over 30 years putting thousands of rounds through it. With good ammo it's been extremely reliable. This is a mixed parts shooter, DWM frame & toggle assembly but a 1938 Mauser barrel/receiver. Recently I got a 1913 DWM barrel/receiver and that's when I noticed how much smoother and easier the toggle moved in it than in the Mauser receiver. On the firing range both receivers work fine so as has been pointed out this really isn't a problem, other than the extra friction and wear and tear. Anyway, I plan to get an S/42 toggle assembly and will see how its breechblock works in the 1938 receiver. (Probably no change of course.) Since it's hard for most people to tell the frame is WWI vintage, I hope to end up with a shooter that can become WWI or WWII with a swap of the upper section. In effect a poor man's way to have two shooters. This may seem stupid, why not just sell the mixed parts pistol and buy two shooters, but I've owned this Frankenstein so long I'd like to hang on to the parts now. At the time I was a dumb kid looking at Lugers and stumbled across this one in a pawn shop. As I compared what was for sale in town I kept coming back to look at this one. It was the cheapest and ugliest but looking at the parts it was obvious there was little wear from shooting, just careless handling over the years. I must have been one of the few people interested in it because the guy dropped the price to $100 and I couldn't walk away. I couldn't believe it when I took it out in the desert and it gobbled up 50 rounds with no jams! So there is sentimental attachment and I want to hang on to the gun. Twenty years later I did get a second Luger, an excellent all matching 41 byf that's too nice to shoot so of course the ugly one is much more fun! Took it out yesterday with my son in law and had a great time. (No he wasn't the target. )

05-13-2007, 01:02 PM	#20
DaveinTN User Join Date: Nov 2006 Location: Tennessee Posts: 186 Thanks: 3 Thanked 15 Times in 11 Posts	Brother Quentin, When you have a chance, you really ought to post a few photos of your "problem child" Luger for us to see. No need to apologize... I've actually learned quite a bit both from participating in this topic and by comparing the measurements of my two Lugers to each other and to the plans I bought from John S. And thanks to GT, I'll probably spend some time tomorrow looking for a caliper accurate to four decimal places (No one can say I'm not obsessive-compulsive..) Have a great week! Dave in TN. DAMN! I just realized this is my 101st post!!! Drinks on me for everyone!