View Full Version : 300Win Mag/98 mauser

January 30, 2012, 07:09 PM
Was given a 300 Win Mag on A 98 Mauser action.I have shot a couple hundred rounds through it.Have taken deer bear and a moose with it.It locked up the other day with factory ammo.My gunsmith said to use it as a tomato stake.He told me the gun should have never been made with the 300 and that I was lucky it lasted as long as it did.I thought the action could take it.Anyone out there with Mauser know how with an option on this.

Harry Bonar
January 30, 2012, 09:00 PM
The 98 Mauser is the finest action on the planet. Those made after WWI; between WWI and WWII were the finest made. I especially like the VZ24 action!
ALL HIGH INTENSITY CARTRIDGES WORK AT ROUGHLY THE SAME PRESSURE! The Germand load ammo for the 98 at almost 50,000 C.U.P.!
I have built 9.3X62s, 9.3sX64 and 416 Taylors and have absolutely no problems. However, yjere is more to rebarreling a 98 than just screwing a barrel in it!
Harry B.

James K
January 30, 2012, 10:58 PM
As I posted on another site in response to that same question, I think there is something else involved, but .300 Win Mag can go up to 64k psi in factory loading (SAAMI max), well above the 50k or so of the German 7.9 or the American .30-'06. Still, as I said before, a good Model 98 should handle the .300 WM fine, so I suspect something else is involved.


January 30, 2012, 11:50 PM
The '98 Mauser is plenty strong enough to hold the pressures of the 300 WM.

If something "locked up" it wasn't because of a weak action, something else is the culpert, hard to say what, dirty chamber, faulty loads, or what ever...........I can't see it from here but it's not because the action is too week.

As a side note, find another gunsmith.

January 31, 2012, 12:36 PM
What he said.

January 31, 2012, 06:43 PM
Not having seen the rifle in question, it is hard to say whether the work was done correctly. That aside, a Mauser 98 is a fantastic action, and considering it unworthy of being chambered for any cartridge is foolish. And someone telling a customer that their gun is worthless is very un-businesslike, enough so that I would agree that you need a different gunsmith.

roberto mervicini
January 31, 2012, 08:15 PM
I have a .300 win mag. build on a 98 mauser action since over 30 yrs, it is my favorite hunting rifle, fired over towsend rounds and never experience a problem, lately using a 98 Brno action, 1934 contract for Brazil I made a .338 win mag here also didn't experience any problem.

January 31, 2012, 08:19 PM
I had many hours of shooting the gun at the range.Never any signs of any thing wrong.Then that first round out of the new box of factory rounds.Smoke come back around the bolt.Had to take a rubber hammer to open it up.Primer gone.Parts of the bolt face gone.Had the chamber cast.Chamber was out of round.Sent the rest of the box back to the factory.Have not heard anything yet.

February 1, 2012, 08:25 AM
A number of things are possible.
It is not a sure thing that you got some bad ammo,but it is a possibility.

I suggest you contact the ammo mfg ,have a stock # and lot #.Ask them if they know of any trouble with that lot of ammo.I do not suggest accusing them of anything.
In fact,other possibilities exist.It may be they will ask you to send them the ammo so they can check to see if there is a problem.

If I may ask,do you make it a practice to run a clean,dry patch through the barrel before you go to the range?

Oil/grease in the bore can be a problem.

Some mud dauber wasp or other bug in the bore,or something equally ridiculous.

Bummer about your rifle,it sounds hurt bad,but given what you describe,regardless of what is to blame,be very grateful you are not seriously injured or dead.You have good reason to be happy.

Long ago,I had a 1967 Chevelle SS396.My driver's license developed a problem,so my girlfriend became driver.he showed up,shook,with an accident report to my workplace.I just asked,"Did anybody get hurt?"She said"No"
I said"Then it was the best wreck you could have had" and I just let the car go.

February 2, 2012, 06:50 PM
I sent the rest of the box back to the factory.I always check the barrel before I put the first round in.Was it that round or was that the last one it could handle.I probably will never know.I know that that action should be able to take the 300 and over the last few days have been told by many the samething.I keep a book on all my guns. On loads, how they shot that day,any problems closing or opening the bolt .When sizing the brass I always use a full length die .Trim them as soon as they need it.Never went near a max load with that gun.I followed the same routine I have been doing for 48 years of shooting.All I know is I lost a very good gun and do not know why

February 3, 2012, 10:17 AM
I found the guy who built the gun.He wants to see it as soon as I can get it to him.He is agreeing with the post on here that the action should take a300.I'll post the results when he gets back to me

Clifford L. Hughes
February 3, 2012, 02:52 PM

I have a small ring Mexican Mauser rebarreled to 243. When I was young and dumb I thought that I was smarter than the publishers of reloading manuals. I pulled some bullets from goverment issue 308 Match ammo. I resized the cases to 243 without reaming the necks. Next, I interpolated the salvaged powder charge and I seated 100 grain Sierra in the cases. I was shooting under 110 degree desert sun from the hood of my car. The first two rounds went off fine; however the third blew the stock off of the rifle and froze the action. The late P.O. Ackley replaced the bolt and I'm still shooting the rifle to this day. I know that I was foolish but my experience shines light on how strong a 98 Mauser is.

Semper Fi.

Gunnery sergeant
Clifford L. Hughes USMC Retired

February 3, 2012, 03:04 PM
I had many hours of shooting the gun at the range.Never any signs of any thing wrong.Then that first round out of the new box of factory rounds.Smoke come back around the bolt.Had to take a rubber hammer to open it up.Primer gone.Parts of the bolt face gone.Had the chamber cast.Chamber was out of round.Sent the rest of the box back to the factory.Have not heard anything yet.

If you are having lug set back in the receiver, due to soft receiver surfaces, then the action is only useful as a tomato stake.

The 98 Mauser goes all the way back to 1898. Metallurgy was awfully primitive and inconsistent back then.

So while the 98 is an outstanding design, you could have one of the M1909 Argentine, or Brazilian actions that look great but are made of plain carbon steels that were never high quality to begin with.

By the time you get to the 50's, metals processes are vastly better. Modern alloy steels are even better, much higher yeild strengths.

You never said just what vintage your Mauser. Interarm Mark X mauser actions were chambered in 300 Win Mag and if your Mauser is one of those, it should hold.

But a chamber out of round? If pressures were so high as to deform the chamber, and you are not hurt, then I think your Mauser did pretty good in protecting you.

February 5, 2012, 01:11 PM
I was wondering about the quality of the tempering, and whether it's an "absolute given" that there could be no issue with any 98 mauser action in that regard.

I know I'd be leery about chambering an action that old in .300 WM.

I know you could check an action for cracks/defects, but is there a non-destructive way to check temper?

February 5, 2012, 08:31 PM
My understanding:The typical mauser was not hardened on all surfaces.The rails,and most of the receiver body are soft.They will stretch,bend,etc,but they won't fracture.

Only the critical areas such as the locking lug recesses ,extractor cam surface,etc were locally hardened.

I cannot say there is no such thing as a mauser that is soft in the wrong places,but it is wrong to reject a Mauser receiver if the body of the receiver seems soft.

February 6, 2012, 06:16 PM
From what I see, the 7.92 x 57- that it was designed for- has a maximum chamber pressure of 57,000 PSI.

The .300 WM has a maximum pressure of 64,000 PSI.

February 7, 2012, 12:31 AM
As a milsurp mauser is sometimes made up of mismatched parts,I have run across a situation where the safety locking lug of the bolt was bearing,and the two main locking lugs were not.One of many possibilities.

The part about the bbl apparently stretching,as "The Chamber was out of round" and "Small pieces of bolt missing"

Unless I mis-interpet that,it indicates higher than normal pressure,even for a 300 win mag,or any cartridge.As the OP still has his eyes,fingers,and apparently does not have a bolt protruding from his head,the action strength is not a problem.

So,how many ways do we get an overpressure event?

Our OP says factory load.If true,it is either a serious ammo recall,or the ammo was a normal,safe factory round and there is another problem.

The ammo mfgr has the ammo.We should get feedback,simple yes/no.

If the ammo is not,as told,factory ammo,even if it was sold as factory ammo,then there is a whole series of questions.

For good,factory ammo to result in gun damage,something had to run the pressure up.Generally,it would be some bore obstruction category.

I see bad factory ammo,bad handload,or,whether rust,mud,patchgrease,whatever,something obstructed the bullet.

Or,maybe,our maligned original gunsmith appraised a level of workmanship he found substandard,and maybe "go use it for a tomato stake" was that colorful,succinct gunsmith way of speaking.Too many unknowns!

February 9, 2012, 11:35 AM
I converted at VZ24 actions to 300 Win Mag and 7mmRemMag with the same 300 H&H case head. Those cartridges may be registered at 64kpsi, 61kpsi, and 54 kcup respectively, but they are all good for 72kpsi and long brass life.

I fired what Quickload thinks is a 108 kpsi load in my 7mmRM VZ24 and it jammed the rifle.

I got the bolt out. I don't remember if I pounded the bolt handle with a hammer of pulled the barrel off. I have done both so many times that I lose track.

The bolt had swollen in outside diameter right behind the lugs. The receiver had constricted in inside diameter at the lug abutments.

I put some valve grinding compound on the bolt and lapped out the tight spot.
Then in 2011 I took the rifle hunting, and shot a mule deer and an antelope.

I have hundreds of rifles, and could have just thrown that rifle away, but I did not give up on it.