The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Guns, Politics, Gunsmithing & Reloading Gunsmithing 270 on a small ring mauser?Go | New | Find | Notify | Tools | Reply | |
| 270 on a small ring mauser? | Login/Join |
| One of Us |
I just purchased a modified mauser. It is a K98AZ, a small ring mauser, apparently of late WW1 vintage. It has a redfield full bridge scope mount on the receiver with a screw head that is striped, so I can't identify the year marking which someone said should be there. It has a heavy 270 barrel - straight taper to .68 dia, so its relatively heavy. As far as I can tell, it is close to having max headspace - using the not so good method of using a new case with shim material. It doesn't have the original bolt. The name on the barrel is Floyd E McCune. Anyone heard of him? Is the 270 too high of a pressure round for an action like this? The action appears to be in good condition. I shot some reduced loads in it yesterday. Phil Wiebe | ||
|
Moderator |
small ring 98? shouldn't be an issue 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 |
Hi Phil: Didn't know there was another Wiebe here on AR. I suppose if a large thread, small ring action were to come in for a 270 Win barrel, I probably try and talk the customer into something like a 6.5x55, 7x57 etc. Having said that, I've seen a number of such conversions without problems. | |||
|
one of us |
Small ring, large thread. I'd stick to something that operates a less pressure.  Aut vincere aut mori | |||
|
| One of Us |
Duane - My thought when I first saw an article on your work in a magazine a few years ago, was, I'd like to have a rifle built by someone with a similar name, not to mention I liked what I saw, an opinion that remains from the material on this site. I need advise - what is the best method to remove the stripped screw holding the scope mount? It's one on the front ring. I have a screw driver bit that's the right size, but the screw material is soft and giving way. This is my first attempt to post a picture, trust that it'll work OK. Is this a walnut stock, or birch or something else? I think that the rifle is worth the $229 that I paid for it. The rifling is good with no pitting - that is if it turns out to be accurate. Thanks all for your comment. Phil W Mauser 98 Kaz 270 bbl | |||
|
| one of us |
PRW If I wanted to shoot the rifle as is, I would just load the 270 to the same pressure level as the 7x57 and 8x57. The animals will never know the difference. DOUBLE RIFLE SHOOTERS SOCIETY | |||
|
one of us |
Have you tried using a center-punch to drive it counter-clockwise? Jason "You're not hard-core, unless you live hard-core." _______________________ Hunting in Africa is an adventure. The number of variables involved preclude the possibility of a perfect hunt. Some problems will arise. How you decide to handle them will determine how much you enjoy your hunt. Just tell yourself, "it's all part of the adventure." Remember, if Robert Ruark had gotten upset every time problems with Harry Selby's flat bed truck delayed the safari, Horn of the Hunter would have read like an indictment of Selby. But Ruark rolled with the punches, poured some gin, and enjoyed the adventure. -Jason Brown | |||
|
Moderator |
Phil, When you say the screw is stripped, do you mean the slot of the screw is chewed up and it is hard for the screwdriver to get a good purchase? If that is the case, it is possible the screw was installed with locktite and you can try heating the screw before you have another go with the screwdriver. You can use a soldering iron, or heat an old screwdriver, but I like to find a nail that has the head the same diameter as the screw, hold it with some vise grips and heat the head red with a torch and hold that to the stuck screw, then use your screwdriver. It doesn't have to be a nail, can be a piece of metal or an old bolt the same diameter, etc. for every hour in front of the computer you should have 3 hours outside | |||
|
| Moderator |
hodgedon/imr lists 270 win at 51,000K cup 8x57 at 49,500 cup with the same casehead - which means nearly identical bolt thrust i don't recal, but my memory may be fading, horror stories of these blowing up as 8x57 ... 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 |
A Forester Jig will keep the drill under control....that's how I get them out. Sometimes, an ez out will do, sometimes, I just run a tap in...follows the old thread every time | |||
|
| One of Us |
| |||
|
| Moderator |
Duane, Fair enough. 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 |
Tom and I discussed at length the pressure spikes found in Modern loadings. They were one of the primary reasons he advocated re-carburising Mauser actions. That said, the WWI era small ring 98's had design deficiancies. And yes, there were many in the original 8x57 that became takedown rifles. Aut vincere aut mori | |||
|
| One of Us |
Most interesting..were these failures documented? (You learn something new every day!) | |||
|
| One of Us |
Kar 98a small ring large thread actions are marginal. I have built many guns on them in 257 Roberts and Ack, 8mm, and 30-06. I do like and use them but know their shortcomings. They are not time bombs. The main culprit is some are soft and none of them have a lot of meat in thr front receiver. Many stretch a bit loosening the barrel. The soft ones have lug setback issues and also tend to not retain scope bases. They are a weak action but give plenty of warning when to stop shooting them. PA Bear Hunter, NRA Benefactor | |||
|
| one of us |
Yes, in fact, Tom himself posted about the issues these receivers have. Receiver ring stretch was a real problem with these rifles during WWI. Throughout the years improvements were made but in the end it far easier to use the small ring small thread design. Aut vincere aut mori | |||
|
| One of Us |
zir: Thank you..it's probably in the archives somewhere...but...did Tom ever discuss the old practice of grinding off the sides of the ring to make it sorta look like a small ring from the top? I remember doing a couple myself! I "figgered" that the original metal on top would re-inforce the locking recess, but in later years, when you fill a case full of bull's eye, the 98's fail horizontally at the (extractor slot) | |||
|
| one of us |
Duane, Yes, we did have discussions about "ovalising" receiver rings as Tom called it. Some receivers are suited to this treatment, others aren't. Most notably, the Peruvian 1909 being his preferred receiver to "ovalise". Of course, these actions had small ring threads and did not share the same "concern". Aut vincere aut mori | |||
|
| One of Us |
OK, since my K98a is a WWI, small ring, large thread action, with a 270 - what is the practical application as far as how it should be used? Shoot reduced 270 loads only? Above it was mentioned that there were in service problems during the war when used with the 8x57 cartridge. Should I continue to use this rifle and watch for problems, or bring it back to the store (there is a 30 day return on it)? The front ring is very thin at the top of the extractor cut. You will see from the picture I posted above that the barrel is very stiff, and does not taper until quite a ways out. Does this help with reducing the stress on the action? Thanks for your comments and the information. Phil W | |||
|
| one of us |
Recently there was an 09 Arg for sale here on AR that had been "ovalized". Seems like a bad idea on a large ring 98.... Jason "You're not hard-core, unless you live hard-core." _______________________ Hunting in Africa is an adventure. The number of variables involved preclude the possibility of a perfect hunt. Some problems will arise. How you decide to handle them will determine how much you enjoy your hunt. Just tell yourself, "it's all part of the adventure." Remember, if Robert Ruark had gotten upset every time problems with Harry Selby's flat bed truck delayed the safari, Horn of the Hunter would have read like an indictment of Selby. But Ruark rolled with the punches, poured some gin, and enjoyed the adventure. -Jason Brown | |||
|
| one of us |
Hard to say without inspecting it. On the whole I'd tend to agree but if the receiver had the right construction it may have lent itself to such conversion. Certainly the best receivers to use for this would be large ring small thread types. But that does not mean others cannot safely be used. It really depends on the individual receiver and of course the degree to which the receiver is altered. Aut vincere aut mori | |||
|
| one of us |
Aut vincere aut mori | |||
|
| One of Us |
As far as a hunting rifle that shoots 20 rounds a year it may last a lifetime. It is not a good choice for a high volume gun. Buy a set of headspace gauges from Brownell's or Midway and check it every so often. The gun may or may not pass a NoGo right now due to mismatched parts; don't rule it out for that reason. If it doesn't pass a Field gauge you have to make a decision as to try a new bolt or just give up on it. Use the headspace gauges properly. As a minimum take the striker assembly out of the bolt. You should use a stripped bolt but I leave the extractor on and insure the gauge is on the bolt face under the extractor hook. Gently close the bolt using fingertip pressure. Stop when you feel resistance. You can force the bolt closed on an otherwise serviceable chamber, DON'T Do That! If it passes a NoGo or Field, use it, and as stated earlier check it occassionally. If it starts to "grow" headspace, take it apart, save the barrel and bolt and discard the receiver. I have only had one 30-06 on a 1916 Kar 98A go unserviceable on me or friends. The 1917, 1918, and 1918/1920 double dated ones are generally considered "harder", so lug set back will not be as likely as the 1916 and earlier, but the weak receiver ring issue will still be there (inherant design flaw). Again these are not a ticking time bomb like a bad low number 03, but are a weak design that gives warning that it is wearing out. PA Bear Hunter, NRA Benefactor | |||
|
One of Us |
What about the Polish Radoms made in the 1930's, do they also suffer from the receiver stretching? | |||
|
| Moderator |
No .. the rounds are trying to blow OUT in all directions, equally. that's how the receivers stretch. Pushing "down range" in a mono-directional force, and a mistatement. broomstick'ed barrels, from obstructions, show this CLEARLY ... that most receivers part in a vertical strip is do to the path of least resistence of the matel .. but in no way does the bottom of the receiver take less stress than the top 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 |
Yes Jeff, the pressure pushes in all directions, I never said it was mono directional. But, the chamber wall is more than 1/4" thick and can easily contain the pressure upon firing. Unless the case head lets go, the barrel (and cartridge case) contains the pressure not the receiver ring. However, that same pressure IS acting acting against the barrel and boltface. The same pressure that is pushing the bullet down the bore is also pushing back on the bolt. It acts against the bolt face and the barrel thus stretching the receiver ring. Remember, the ring on these is as thin as 3/32". The failures in these actions resulted in the receiver ring seperating from the rest of the receiver just ahead of the "C" ring. The receiver was not blown out and would not be unless perhaps a case head let go and then the receiver itself was required to try and contain 50,000+ psi. Aut vincere aut mori | |||
|
one of us |
Mike check your Pms.  Doug Humbarger NRA Life member Tonkin Gulf Yacht Club 72'73. Yankee Station Try to look unimportant. Your enemy might be low on ammo. | |||
|
| Powered by Social Strata |
 | Please Wait. Your request is being processed... |
|
Visit our on-line store for AR Memorabilia