lowmileage
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I have a 25-06 on a M98 Mauser action that will swallow a no-go AND a field gauge. Is it OK to ask for gunsmith recommendations that maybe could take a look and fix this?
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Can a rifle barrel "walk" open to create an excess headspace problem?
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lowmileage
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M98 action from 1938. If what you said happened, can the barrel be salvaged? Cut a thread/rechambered or something?
earplug
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If the action is not damaged the barrel can be salvaged.
BTW, there is no economical way to restore it if the receiver lug recesses have deformed. Do you recently buy the rifle or have you been having issues with it?
If it is yours, .25-06 pressure levels are above the 7x57 or 8x57 military chamberings that these were designed for. WWI era receivers are relatively soft metal and can deform under high pressure loads.
If it is new to you, it is possible that someone botched chambering it either by the mfg or whoever installed it, another issue is that when rebarrelling a m98 action (aside from some later commercial m98 variants) you cannot go off of front of the receiver ring but have to have the barrel shank contact the locking ring inside the receiver. Otherwise you get long headspacing because the shoulder of the barrel prevents the barrel from engaging the locking surface. It might also be that the cartridge chamber of the barrel does not match whatever is stamped on it.
If it is yours, .25-06 pressure levels are above the 7x57 or 8x57 military chamberings that these were designed for. WWI era receivers are relatively soft metal and can deform under high pressure loads.
If it is new to you, it is possible that someone botched chambering it either by the mfg or whoever installed it, another issue is that when rebarrelling a m98 action (aside from some later commercial m98 variants) you cannot go off of front of the receiver ring but have to have the barrel shank contact the locking ring inside the receiver. Otherwise you get long headspacing because the shoulder of the barrel prevents the barrel from engaging the locking surface. It might also be that the cartridge chamber of the barrel does not match whatever is stamped on it.
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lowmileage
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Correct.
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lowmileage
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I posted on this 2 years ago and don't want to open up a can of worms again and waste anyone's time. I am now researching what gunsmith to send the gun to. I built this in 1968. It has a "Flaigs" barrel that were touted to be made by Douglas. Flaigs was a company in Pennsylvania that is now out of business. Flaigs did the barreling to the action. A letter to the NRA back in 1968 said my action was one of the best M98 actions and that it was made in 1938.
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lowmileage
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Yeah, I guess that could be a possibility but I have fired less than 500 rounds thru it and the loads shouldn't have been at maximum. I have only fired handloads thru it.
milboltnut
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have the barrel set back
243winxb
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Google -
So, your chamber may not be standard SAAMI ??
This
63,000 PSI for the 25-06
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243winxb
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Some old actions didnt have a forward stop. With no cartridge in the chamber, the bold would go forward more then normal. Rattle??
When loading a round, it was possible to "size" the round if slamming the bolt closed.
Not sure where i remember this info from? Hatcher's Notebook?? Could be wrong.
Since you have had it since 1968, and apparently do not see the barrel literally unscrewing itself from the receiver which I assume was your original post title from two years ago, then 1) the receiver was soft--Mausers were case hardened carbon steel and the softer core can deform under high pressure loads--even a Czech or German Mauser made prewar WWII. However, there should be warning signs, bulged cartridges, primer issues, progressively harder bolt lift and extraction, if you were firing it grossly out of headspace for long unless you only use new brass and discard it. You haven't reported that, normally 500 rounds would not do it unless you load the max and do not use a chronograph to check load velocities. Chamber pressures can vary a bit compared with what is printed in the manuals and a sign of a hot load in your rifle is chronograph speeds that exceed what the manual says. If you are firing handloads made with powder from the 1960's, that could do it too as the burn rate can change with old powder.
Or, 2) You might be using your headspace gauges wrong--you can crush fit a headspace gage into a chamber and crush the gage by closing the bolt. There is enough leverage to do that in a lot of bolt actions. The proper way to check the headspace is thorough cleaning of the chamber, lug recesses, bolt face, and chamber face. Remove the firing pin assembly and extractor from the bolt. Then using finger pressure only, gently try to close the bolt. BTW, if you did force the bolt handle closed, you have probably ruined the gage.
Or, 3) SAAMI did not approve the .25-06 until 1969 as an official cartridge. As a wildcat, reamers and chambers could and did vary a bit. It is possible that you had a long chamber reamed versus the SAAMI std. which a chamber cast would tell you. If the rifle otherwise is accurate, then you could fireform brass only for that rifle and only neck size brass. 243winxb covered this one.
If you do have lug recess setback, setting the barrel back will not work in the long run as the lug recesses will continue to deform under use.
Or, 2) You might be using your headspace gauges wrong--you can crush fit a headspace gage into a chamber and crush the gage by closing the bolt. There is enough leverage to do that in a lot of bolt actions. The proper way to check the headspace is thorough cleaning of the chamber, lug recesses, bolt face, and chamber face. Remove the firing pin assembly and extractor from the bolt. Then using finger pressure only, gently try to close the bolt. BTW, if you did force the bolt handle closed, you have probably ruined the gage.
Or, 3) SAAMI did not approve the .25-06 until 1969 as an official cartridge. As a wildcat, reamers and chambers could and did vary a bit. It is possible that you had a long chamber reamed versus the SAAMI std. which a chamber cast would tell you. If the rifle otherwise is accurate, then you could fireform brass only for that rifle and only neck size brass. 243winxb covered this one.
If you do have lug recess setback, setting the barrel back will not work in the long run as the lug recesses will continue to deform under use.
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lowmileage
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Thanks 243. I carefully worked up loads and never tried to reach a maximum point. All extractions were easy. Your point on the non-standard chamber? I would think the SAAMI chamber would be the same as the chambers of rifles made when the cartridge was a Wildcat. That then is not necessarily the case?
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lowmileage
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Thanks, I did it the right way.
BBBBill
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No it is not the case.
As boom boom noted - "As a wildcat, reamers and chambers could and did vary a bit. It is possible that you had a long chamber reamed versus the SAAMI std."
Wildcats often appear in several variations based on who was involved with it from beginning to end of development. Several different folks may play with a design and each come up with their own variations while still identifying the wildcat the same as the originator. Then the factories that standardize the round may make further modifications to suit their manufacturing requirements or to address any concerns that their own ballisticians may have.
I've dealt with that very issue with a .30 Herrett Contender.
243winxb
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I am not a gunsmith, just my opinion. You should seek out a local professional.
More on the subject.. https://www.thehighroad.org/index.php?threads/m98-mauser-receivers.828104/
More on the subject.. https://www.thehighroad.org/index.php?threads/m98-mauser-receivers.828104/
Reamers to cut chambers may be different when there is no standard in place. The SAAMI standard has tolerances in the specifications. About .010" for the chamber. A very small amount. The 25-06, 270 win, 30-06 all have the same head to datum measurement.
This is not good if shooting factory ammo. A reloader can make adjustments when sizing to compensate for the large chamber.
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lowmileage
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View attachment 833478
Ok, if I assume I have a long chamber. I was thinking of doing this but not until I get word that it's OK. I took a 30/06 case and started running it thru a 25/06 sizing die. I kept going until the bolt was ALMOST closed and need just a touch of effort to close completely. I would think now that the case rim is supported by the bolt face. Does this now have to be fire formed to form the shoulder or is that step unnecessary? Or am I completely off base with this idea? Thanks as always for any help.
Thanks.
Ok, if I assume I have a long chamber. I was thinking of doing this but not until I get word that it's OK. I took a 30/06 case and started running it thru a 25/06 sizing die. I kept going until the bolt was ALMOST closed and need just a touch of effort to close completely. I would think now that the case rim is supported by the bolt face. Does this now have to be fire formed to form the shoulder or is that step unnecessary? Or am I completely off base with this idea? Thanks as always for any help.
Thanks.
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243winxb
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Your photo shows a false shoulder. A good method to fire form wildcat cartridge brass, Check trim length. Load and fire. Measure Head to datum.
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lowmileage
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Sorry for the ignorance, do I have to fire form or can I just "load up" test loads and am good to go? Here's the results I was getting before problems started. NOTE: THESE LOADS MAY NOT BE SAFE IN YOUR RIFLE, USE CAUTION. Use reputable loading data from established sources when working up loads.
243winxb
Member
No, not good to go. Imo. The rifle has excessive headspace. Fire forming with the false shoulder, keeps the case head against the bolt face. Less chance of a case separation on firing.
The problem being excess headspace? When barrel was installed in 1968, did you personaally check the headspace with gauges?
If you know for a fact that the headspace has changed from 1968 to now, i would retire the rifle.
I am not a gunsmith, just my opinion. You should seek out a local professional.
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lowmileage
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Ok, thanks. No, never checked the headspace personally after the barrel was put on the action. They MAY have sent me a fired case which I recall vaguely but I don't recall it now -it was a long time ago. Thanks for the advice.
243winxb
Member
https://www.thehighroad.org/index.php?threads/25-06-blowing-primers.821501/
After reading the old post.......
Have a gunsmith set the barrel back and cut a new chamber. But only if the gunsmith knows its safe to do so.
After reading the old post.......
Have a gunsmith set the barrel back and cut a new chamber. But only if the gunsmith knows its safe to do so.
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lowmileage
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Will do, better be safe than sorry. Thanks 243
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