odies dad Posted February 21, 2007 Report Share Posted February 21, 2007 There has been a quite a bit of discussion about the safety of some of the small ring Mausers when converted to higher pressure cartridges. I have a 1916 Spanish Mauser that was converted to 308CETME. This cartridge, while being the same physical size as a 308 NATO or 308 Winchester, was loaded to much lower levels. The Mauser design is strong and can handle a quite a bit, but, the pre 98 actions were not designed to vent escaping gasses very well in the event of a primer rupture. This issue was addressed on the 98 models by introducing larger gas escape vents in the bolt and the addition of a flange on the bolt shroud to deflect the gasses away from the shooter’s face. I read that Sarco commissioned White labs to pressure test the 1916 Spanish Mauser for safety with 308 Win ammo and found the receiver to be plenty strong. This still does not address the gas handling issues. I recently read a post from a gentleman who welded a flange onto a pre98 shroud to do just this. I decided to replicate this and show pictures as to how it is done. The cost was minimal. Materials included a washer, a pre 98 shroud, a drill press (because I don’t have a mill yet) with a ¼” mill bit, a round file, a tig welder, a dremmel with a small grinding stone, a hacksaw and a buffer. I started with a washer approximately 1 ¼” or so in diameter and drilled the center to ¾”. I then scribed a line around the outside of the bolt shroud with the washer in position. Next I milled out the rough shape of the hole needed and finished it with a file. This is the result. This is how it fits on the shroud. The washer is back about 1/16” from the front of the shroud due to a notch in the bolt handle. Do lots of test fitting before you weld. Don’t worry about small gaps as the welding will fill these in. Tig weld around the top part of the shroud. The bottom will be cut off. After grinding down the weld and cutting off the bottom of the washer. After polishing and buffing. Installed on the bolt. Installed on the rifle. I may file some off the outside to reduce the diameter a bit, but it doesn’t look too bad as is. The bolt cycles fine. Link to comment Share on other sites More sharing options...
ken98k Posted February 21, 2007 Report Share Posted February 21, 2007 Pretty cool. I'm guessing that you must also have had to open up the groove at the root of the bolt handle also? Kenny Link to comment Share on other sites More sharing options...
odies dad Posted February 21, 2007 Author Report Share Posted February 21, 2007 No, I just set the washer back a tad to clear. Link to comment Share on other sites More sharing options...
ken98k Posted February 21, 2007 Report Share Posted February 21, 2007 No, I just set the washer back a tad to clear. I guess I need to start reading these post before asking stupid questions. Kenny Link to comment Share on other sites More sharing options...
bubbamauser Posted February 23, 2007 Report Share Posted February 23, 2007 This is a cool post. If I drilled a hole in the side of the action and 2 in the bolt so they face down when closed, add the sheild would it approximate the gas handling of a 98? I realize all opinions are worth what I've paid for them, so let me know what you think Thanks, Roy Link to comment Share on other sites More sharing options...
724wd Posted February 23, 2007 Report Share Posted February 23, 2007 there is still a difference in the shrouds. 98's have a step in front of the safety ring that adds yet another obstical for hot gases... but i do like the idea. Link to comment Share on other sites More sharing options...
BobVZ Posted February 23, 2007 Report Share Posted February 23, 2007 I like the idea too. Since '93's don't have the enlarged cocking cam area at the rear of the bolt to divert gas, this adds a layer of protection. One gas path that is often over-looked in '93's is the bottom of the bolt raceway. The M93 employs a square bottomed boltface that slides in a corresponding channel. When the bolt is locked, the square part of the bolt rotates to the left lug raceway, opening the square corners of this channel all the way back to the shooters face. If some small triangular nibs could be left on the bottom of the gas ring it would help block this path as well. These nibs, however, might interfere with proper function when closing the bolt if not lined-up properly. Link to comment Share on other sites More sharing options...
oldfart Posted February 25, 2007 Report Share Posted February 25, 2007 There are probably a number of things you could do to redirect escaping gas from a split case, but the simplest thing is to use ammo that is of relatively recent manufacture. Shooting 90 year old Turkish 8mm is inviting catastrophe. The Romanian and Yugoslavian stuff is much better but neither are as good as hand-loaded. Excessive headspace could lead to a separated head but would probably show up first as stretched cases. What is much more likely is a small amount of blow-back from a punctured primer. I had that happen to me, resulting in a small cut on my forehead from a piece of the metal primer. That incident led me to installing a similar flange on my bolt and - of course- I've never had a punctured primer since. Link to comment Share on other sites More sharing options...
cold shot Posted February 25, 2007 Report Share Posted February 25, 2007 very nice is all i can say. keep up the good work . dave Link to comment Share on other sites More sharing options...
CTI Posted February 25, 2007 Report Share Posted February 25, 2007 Truly an excellent idea worth looking into .. great job with the pics.. Link to comment Share on other sites More sharing options...
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