The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Guns, Politics, Gunsmithing & Reloading Gunsmithing Lug Set Back on 1898 Mauser ActionsGo | New | Find | Notify | Tools | Reply | |
| Lug Set Back on 1898 Mauser Actions | Login/Join |
| One of Us |
Ladies and Gentlemen: I am curious, how many of you have a military and/or original commercial 1898 Mauser action based rifle either showing bolt lug setback or no bolt lug setback? I am only interested in 1898 Mauser actions made before 1946. Please specify the manufacturing plant, approximate date of manufacture, which part's serial numbers matched and any modifications done to the action, for example lengthening it to accept 375 H&H length cartridges or machining it to handle the various magnum size cartridges, and were the bolt lugs lapped in. Also, describe the cartridge used, number of rounds fired in that rifle and any overloading of that cartridge as evidenced by leaking and/or blown primers, seized bolts and/or any other indications of excessive pressure. Lastly, describe what if any re-heat treatment or re-case hardening that you have done, the applied case depth and later use after having this procedure done. I'll begin. Presently, I have two barreled 1898 Mauser's. One is an earlier BRNO, not VZ-24, manufactured in the Czech Republic, date unknown, has matching serial numbers, which is barreled with a Douglas Air Gauged 24", #2 contour, 1x9 twist, stainless steel in 7x57 AI. I lapped the lugs in for almost full engagement. I have approximately 400 rounds through this rifle, ranging from case forming through one over loaded cartridge that seized the bolt and blew the primer. This rifle has no apparent bolt lug set back. It was not re-heat treated. The other rifle is a 1908 Brazilian Mauser manufactured at DWM in Berlin, date unknown, with matching serial numbers. This, too was lapped in for almost full bolt lug engagement, and was barreled with a 24", #2 Pac-Nor, 1x9 twist, chrome moly barrel in 6.5-06. This had approximately 300 rounds through it. I pulled the barrel, and am in the process of using this action for something else. It shows no evidence of bolt lug set back and has seen no over loaded cartridges. It was not re-heat treated. Sincerely, Chris Bemis | ||
|
one of us |
Chris, I have encountered lug set back in a variety of Mauser 98's. None are immune to it.  Aut vincere aut mori | |||
|
One of Us |
 Set back????------ At least 2 maybe 3. No heat treat!! 2 ea were wildcats built on the .404 case. rogerOld age is a high price to pay for maturity!!! Some never pay and some pay and never reap the reward. Wisdom comes with age! Sometimes age comes alone.. | |||
|
| one of us |
2ea 30-06 & 1ea 300WM & 1ea 376 steyr & 1ea 458WM on VZ-24 1937&38 lite lapping(before assy) no matching bolts, Lots of rounds each W/no setback  1ea 30-06 DWM 1909 Arg. mismatched, bolt lite lapping, 600 rds. no setback 2ea orig all matching DWM 1909 arg 7.65X53 1500 rds I have fired in each W/ no setback I have never stuck a bolt. I allways stop at any pressure signs & back off. I have never had anything RE HEAT-TREATED & have not YET seen any reason to!! I also would not use an action that has any Measurable lug setback Oh yea, a 1896 sweede(husk) mfg 1908 with 760 rds I have put down range. all matching W/no setback 1ea VZ-24 1938 non matching bolt, waiting for a 375 Ruger reamer   | |||
|
| one of us |
I've seen setback on more than one of each of those actions listed. Some where damn near new. Of those that I've had heat treated, none have exhibited any setback. Hmm, bad luck maybe? Naw, just know how to measure. Aut vincere aut mori | |||
|
| one of us |
Must be it!  | |||
|
| one of us |
I have only seen this when folks used "hi intensity" magnums like the Weatherbys etc, never with calibers like the 270, 06, etc. Same with the FNs. Maybe I'm lucky? Ray Atkinson Atkinson Hunting Adventures 10 Ward Lane, Filer, Idaho, 83328 208-731-4120 rayatkinsonhunting@gmail.com | |||
|
One of Us |
A very large number of Mausers have been converted to sporters by professionals and by back yard "blacksmiths" and without even the thought of heat treating the receivers. It is possible that all of them have some setback but has not yet been identified and/or measured. Of the ones I have owned none of them have presented a functional problem and the chamberings have been for the 220 Swift, .25-06, 6 mm Rem, 7 X 57, 280 Rem, 270 Win 300 Win Mag. This does not mean they didn't have setback.....one must be careful about what he knows and what is thought. My past experience does not qualify as proof of anything......except that I've not encountered problems due to not heat treating actions such as 1908 Brazilllians and 1909 Argies.....but when I build one today I have them heat treated as a precaution. So many folks here have posted this recommendation that it has to be observed. /////////////////////////////////////////////////////////////////////////// "Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery." Winston Churchill | |||
|
| one of us |
I have seen it several times-once on a rifle that cost north of $20k. Set back in under 10 shells of factory ammo. I know you like to quote the Walsh book, but what respected gunamkers do you see hold it in high esteem? I am not really sure how to write this where it is taken correctly on the internet because tone is almost impossible to judge when reading words on a screen. So please understand that I am not being argumentative or trying to "talk down" to anyone here. I am just stating a fact that no gunmakers that I know consider the Walsh book to be more than a shade tree, back yard mechanic type book. Flaco's review of it for you was spot-on, even if the delivery was not as gentle as it could have been. If you quoted more authoritative and respectied sources it would give your argument more creedence. I know you always say he is an angnieer, but I am an engieer and have managed them in a lot of countries. I would not let the overwhelming majority of them anywhere near a gunshop. It is true that there are a lot of Mausers out there with good service and no post-factory heat treatments. There are also a lot that have set back. If you are doing something on the cheap and have a definition of "custom rifle" for anything that is not as it left the factory, then you don't have much to lose if it has problems anyway. If you are building nice rifles then $100 for the assurance that things are right is of no consequence. It is far cheaper than the repair to the rifle, and more importantly incredibly cheaper than what will be needed to repair the reputation of the gunmaker. Personally, I don't care what you do to your actions. Luckily we are still in a free country and can choose to reheat treat or leave as-is | |||
|
| One of Us |
I have a custom .280 Newton (.30 Newton case necked to 7mm)...overbore cartridge. loads of pressure...I fire max. hot loads all the time to get near 7mmSTW top velocities... The receiver is a 1909 Argentine action...NOT heat treated, all original...and have had no lug set back or any other problems with it. That's my experience. I've also had other surplus Mauser actions...one an old Yugo military action...pre WW2 I believe, built into a hot, high pressure .22 Newton (P.O. Ackley barrel)...no problems with that original old Mauser action either. Over the years, I've never had any lug set back with any of my old Mausers. If someone says he has had lug set back, I have to believe him...but in my experience I have not had ANY. Which leads to why? Why some get lug set back & others not? I would assume the manufacturing process would be standardized...so there should be either all lug set backs or no lug set backs. Why therefor, some are & some not? Perhaps a manufacturing change in some years...dunno, leave it for the savants to figure it. My experience: never a lug set back in perhaps 50 years of playing with Mausers. That's all I know, my experience. Best Regards, Tom | |||
|
| one of us |
[QUOTE]Originally posted by Marc_Stokeld: I have seen it several times-once on a rifle that cost north of $20k. Set back in under 10 shells of factory ammo. I am not really sure how to write this where it is taken correctly on the internet because tone is almost impossible to judge when reading words on a screen. So please understand that I am not being argumentative or trying to "talk down" to anyone here. Verry well said!!  | |||
|
| One of Us |
I would venture an opinion that lug set back ... in Most instances would be some type of abuse... such as overloads, excessive pressures...I don't see why normal useage should cause this? Best Regards, Tom | |||
|
| one of us |
You must define normal first. What are "normal" loads? For what it's worth, the majority of the cases I've seen were in original condition rifles. Many f which were in damn near new condition. Of course many more were well used. Aut vincere aut mori | |||
|
| one of us |
My own 1943 Oberndorf M98 had spotty case hardening so it was redone. My point is that why go through the process and cost of making up a custom gun and risk having to do it all over .War time guns are especially likely to be poorly heat treated .From my background as a metallurgist I'll always reharden the action, it's well worth it. | |||
|
one of us |
I did a fair amount of research on the design and construction of M98 based hunting rifles several years ago and after all my research and many talks with gunsmiths kind enough to give me a few minutes of their time, this is my contribution to this thread: The question in my mind as I read this thread is how exactly is everyone measuring set back? Does everyone set up a dial indicator to read a stripped bolt as it cams through its lockup? Are we examining the lug recesses for dips and shiny spots before we install the barrel? Or, are we using the feel of the bolt to gauge whether or the lugs are setting back? Most gunsmithing is measured by thousandths of an inch and the hardened surface of a properly carburzied Mausers is only a few thousandths deep. Further, it only takes .003"-.004" of a inch for a chamber to fall out of spec. My question is then if bolt set back on that perfectly chambered, unissued Mauser, how could you tell if it bad set back or not without some precision measuring equipment? I submit that you cannot. All my research has convinced me that it is highly possible for a Mauser to experience lug set back. And just as Mike drilled into my head five years ago when he was mentoring me through the beginning stages of my first Mauser project, $100 is cheap to send a box of receivers off to a metallurgy house for recarburization. Further most of us are going to spend between $400-$1000+ to build the Mauser we want, why not spend a couple of bucks more and do it up right the first time? That is my opinion. Take it for whatever its worth. Jason "Chance favors the prepared mind." | |||
|
| one of us |
There is an old thread on this subject. I believe Darcy Echols had basically the same advice as Marc and Tex. Through the years I have barreled a lot of 98 Mausers of various models with out reheat treatment and luckily I am not aware of any suffering from lug set back. However I have observed lug set back in several 98 Mausers that other people have rebarreled. One was a high grade custom built by a well respected gunsmith in caliber .284 Winchester. Now that I am older and try to avoid any risks I consider recarburizing cheap insurance when building a rifle of any value. Craftsman | |||
|
| One of Us |
Near as I can tell, "normal/average" pressures for the 4 most common (6.5x55, 7x57, 7.65x53, 8x57)Mauser chamberings run between 41 and 47,000 psi. Rebarrel your Mauser to an '06, 270, 308 and (lots of other rounds) and you can get to 50,000 psi easily. "Hot loads" will go even higher. But naw, nobody ever uses hot loads.  | |||
|
one of us |
I've seen it bad,bad,bad once with a Santa Barbara commercial mauser. Bolt had a thump and then open feel to it. No way I would ever stick a live round in it. I personally try to never go over 55000 PSI with any of mine. A little anemic for some, but I've never had any trouble killing animals and there is usually a very accurate load hiding around that number.  Terry -------------------------------------------- Well, other than that Mrs. Lincoln, how was the play? | |||
|
| One of Us |
I set the lugs back on a 6.5 Jap by loading it with 38.0 grains of Bullseye. | |||
|
| One of Us |
  What were you trying to do? Prove P.O. Ackley wrong? Thaine "Begging hands and bleeding hearts will always cry out for more..." Ayn Rand "Life may not be the party we hoped for, but while we are here, we might as well dance" Jeanne C. Stein | |||
|
| One of Us |
Ladies and Gentlemen: Thank you for all of your input on this issue. I will post exact measurements on lug set back or lack thereof on another 1898 military Mauser actioned rifle that I am putting together. First, I'll start with the depth from the receiver face to the bolt face before and after light engagement lug lapping, and then I'll measure it again at 500 round increments after pulling the barrel each time. This rifle will be a 7x57 Ackley Improved. Also, I'm going to buy a rough 1898 Mauser, and will section the receiver and bolt through the lugs and lug recesses. I'll have the steel core assayed and have the hardened bolt lug and lug recesses depth measured to see how deeply the lug area was hardened by the factory. Lastly, if possible, I'll have the actual lug surfaces Rockwell tested to know how hard the actual bolt lug and lug recess surfaces are. This final Rockwell test will probably require another action, and may require a creative anvil. This will take a while, and my free time is about to end, so it won't be up next week. Sincerely, Chris Bemis | |||
|
| One of Us |
Well, it sounds like a fun project. Also, time consuming and expensive. And your sampling still won't be significant. Why not just go back and read what Tom Burgess so generously posted? Few, if any will ever match his knowledge of Mausers. He's devoted his life to this. flaco N.B. Don't mean to be too rude, as I'm certain we've all admired your good manners here. But there is so much to learn, if only folks would take the time to go through the AR archives. But you still have to know which posts have credibility, and if you've never heard of D'Arcy Echols, or Tom Burgess, you might not appreciate the depth of their knowledge. | |||
|
| one of us |
No one seems to doubt that it is a good idea to check headspace on a surplus Mauser. It would also be agreed that it would be good practice to check headspace on a custom Mauser if one were buying it as a used gun. Tell me, then, where the excess headspace comes from when a rifle that presumably left the arsenal or gunsmith shop with proper headspace does develop a problem. I would submit that it just about always comes from lug setback. The barrel and chamber don't stretch, and I have never seen a barrel unscrew itself (although I concede that some sloppy custom jobs might!). Clemson  NRA Endowment Member US Army Veteran CWP Holder Gunsmith | |||
|
One of Us |
1 ea., DWM 1909 Arg. 7.65X53mm used with heavy load of IMR 4350 and 200-grain bullets, no change in headspace. 1 ea., orig FN-made M1924 Venezuelan 7X57mm, matching bolt, used with modern full-charge loads, (140 grain bullet @ 2950 FPS), no setback. "Bitte, trinks du nicht das Wasser. Dahin haben die Kuhen gesheissen." | |||
|
| One of Us |
I have pulled the barrels on 50 ~100 Mausers. I have a couple with lug set back. I overload Mausers until the brass squeezes like putty, and I can't get the lugs to set back. I don't know how they did it. | |||
|
| One of Us |
rogerOld age is a high price to pay for maturity!!! Some never pay and some pay and never reap the reward. Wisdom comes with age! Sometimes age comes alone.. | |||
|
| One of Us |
I don't disagree with this but then I cannot explain that of the guns I have personally owned that had (or developed) excess headspace was the following: Remington 760 Winchester M-70 Pre 64 (1957) Savage M-99 but then I don't check my Mausers after several hundred rounds either. /////////////////////////////////////////////////////////////////////////// "Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery." Winston Churchill | |||
|
| One of Us |
In a properly set up tightly headspaced mauser 98, if it develops excessive headspace, you will probably experience some misfires due to light/shallow firing pin blows....... "Bitte, trinks du nicht das Wasser. Dahin haben die Kuhen gesheissen." | |||
|
| One of Us |
All of my Mausers are tightly headspaced from touching on the go gauge to a slight crush on the go gage. I've never in my life (yet) had a misfire with a '98 Mauser.....let me find some wood to knock on!!!!! /////////////////////////////////////////////////////////////////////////// "Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery." Winston Churchill | |||
|
Moderator |
Is this the load techinique required to exceeds 2300FPS in a 458 lott? jeffe opinions vary band of bubbas and STC hunting Club Information on Ammoguide about the416AR, 458AR, 470AR, 500AR What is an AR round? Case Drawings 416-458-470AR and 500AR. 476AR, http://www.weaponsmith.com | |||
|
| one of us |
Not likely. The firing pin tolerances are +/- .005", excess headspace is well within that range. That is not to say that you won't experience light pins strikes but don't count on it and don't wait for it as an indicator. Aut vincere aut mori | |||
|
One of Us |
One thing I'd like to talk about is over-doing the lapping of the lugs. They are only set hardened, and if lapping through the hard surface, set back is to be expected. The more lapping, the thinner the surface, the lesser preassure it takes to set back. If a M98 requires a lot of lapping, I tell the customer to get a new action. Bent Fossdal Reiso 5685 Uggdal Norway | |||
|
| One of Us |
I've had about the same experience with them. Excess breech pressure can set back about any lug. I think it comes as much from too much lube on the cases & chambers, as the actual load (chamber) pressure. With a dry chamber & round, breech pressure is fairly non-existant Still it's (lug setback) pretty rare in my experience. I usually just set the barrel back & rec-chambered or re-barreled. I'd be interested to see some research data on testing of military 98's to see what actual heat treating variations there are. "You can lead a horticulture, ... but you can't make 'er think" Florida Gardener | |||
|
one of us |
As a C&R collector, I have headspace gauges on hand to check each and every rifle I purchase before I do anything at all with it. Every rifle I own headspaces perfectly. I have an all-matching A prefix Argentine, a Brazilian all-matching action, Peruvian-all matching action and a few Argentine actions. I have seen evidence of bolt set back in one Argentine. No others. I have several Brno m98/22's: A, B, and C prefixes all-matching no set-back. I also have a few all-matching German pre-War Guild rifles and K98's. No set-back. Great spirits have always found violent opposition from mediocre minds. The latter cannot understand it when a man does not thoughtlessly submit to hereditary prejudices but honestly and courageously uses his intelligence. Albert Einstein Better living through chemistry (I'm a chemist) You can piddle with the puppies, or run with the wolves... | |||
|
| one of us |
>>>As a C&R collector, I have headspace gauges on hand to check each and every rifle I purchase before I do anything at all with it.<<<< Where did you get the 7.65 head space guages? | |||
|
| one of us |
Headspace guages alone will not reveal lug set back. When lugs have set back and you insert a HS guage the locking lug must first climb up over the portion that was not affected, at that position you will get a normal reading, then the lugs will fall down into their new seat that was created when they set back. The only positive way to check with out disassembling the gun is with a dial indicator set up to read the bolt body position while you are rotating it into locked position. You zero the guage at the beginning of lock up and if set back exists the dial indicator will show the bolt moving to the rear as it drops down into the "recess" created by the set back. I have seen readings as big as .008. Simply setting the barrel back or rebarreling will not cure lug set back. The lug recess must be leveled by machining or lapping. Then the case hardening is too thin or totally gone and the action must be reheat treated to restore the case hardened skin. Craftsman | |||
|
| one of us |
Better make a slight correction here. When lug set back exists and the lugs have to "climb" over, it is not a high area at the front of the lug seat. My first post probably left that impression. In a Mauser the left lug is split for the ejector. When the lugs are driven into the seats, the split lug leaves a reverse imprint of the split creating a "lump". This is what the lugs climb over giving you a false headspace indication. It is also what causes hard extraction when the locking lugs have been set back. Craftsman | |||
|
| One of Us |
 Thank you ! That makes perfect sense to me. rogerOld age is a high price to pay for maturity!!! Some never pay and some pay and never reap the reward. Wisdom comes with age! Sometimes age comes alone.. | |||
|
| One of Us |
Dear Craftsman: Poignant and accurate observation concerning the hump in the top receiver lug between the split left hand bolt lug. I have some unused 1908 Brazilians covered in original grease that upon disassembly showed a shiney mark between the split bolt lug engagement in the top lug recess. I assume this was caused during proof loads, that "seated" the bolt. Therefore the ride over caused the shiney area when cycling the bolt. I found that slight lapping removes that problem. Interestingly, I have not had the hump return after both bolt lugs were fully engaged on the two receivers that I barreled up, even with a severe overload that expanded the case head in the BRNO. On the other hand, I recently purchased a 98k 1940 Berlin production where the lower lug seems to be the only engaged lug. This gun definately saw use, probably for the German Army and afterwards as a converted sporter. All of the above actions have matching serial number receivers and bolts. Thanks again for your observation and knowledge. Sincerely, Chris Bemis | |||
|
One of Us |
are there any books or other places that I can learn all the ins-&-outs of hardening the action, what actions need such treatment, what benefits it provides, where and how much$. White Bison, I would love to see some pictures of that 280 Newton | |||
|
| Powered by Social Strata | Page 1 2 |
 | Please Wait. Your request is being processed... |
|
The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Guns, Politics, Gunsmithing & Reloading Gunsmithing Lug Set Back on 1898 Mauser Actions
Visit our on-line store for AR Memorabilia