This has been bothering me for sometime so thought I would ask.

I have seen the thumb-cut feature on many original .416 Rigby rifles. Unless the standard length military action has been lengthened to accept the larger cartridge,what is the thumb-cut feature doing on a magnum sized sporting calibre action? Do educate me, please. Thank you for your replies.

Best-
Locksley,R

Robin. I think it was included on the magnum length action to facilitate loading.

I think it was Finn Aagaard that wrote that he found the thumb cutout useful in reloading. I can see how.

Particularly as so many early magnum actioned rifles were not scoped.

I will have to try it with mine to see if it is quicker/easier to reload the magazine.

Cheers, Chris

Go out in cold weather with very heavy gloves and try to load a non-cut FN Mauser (not scoped). Then try to load a thumb cut 98 (not scoped). You will see there is a world of difference if you are cold and stiff.

It seems the ATFE , in the Peoples Republic of The United States, has deemed that thumb cut makes a sporting rifle a potential terrorist
assault weapon. All Kayda has been deltt another serious blow by the gubberment again, whew!!, I can sleep better now.

I have seen some original .416 Rigbys that were made from Militaryactions extensively opened up. Some developed headspace problems as a result of using these actions. They were really nice handling rifles though. The thumb cut is a big advantage in loading with gloved hands.- Rob

Bell Mentioned the handiness of the cut , or rather lamented its absence on "newer rifle actions" in on of his last writings, I believe it was the piece published in the American Rifleman shortly after his death.

I find it really handy , and catch myself looking down to load when using a newer style Mauser action ,such as the late FN.

Thank you for your replies!

Speaking of which:

http://www.champlinarms.com/De...StyleID=2&GunID=2584

A detail from the Champlin link, Rigby's use of Brevex with thumb cut from 1959 for about $20K asking now ($19,800):






At DSC they had 3 new versions of the .416 Rigby.
The budget-priced one goes for about $12K (7500 British pounds Sterling) and used the first of only two Mauser-made M98 Magnum actions,
I was told, that they have built with so far.
The other rifle using this action was present too, a .375 H&H IIRC.

The higher-priced .416 Rigby's used the Prechtel M98 Magnum action without the mauser billboard on the left side of the action.
IIRC they were going for 22,000 pounds and 30,000 pounds or about $36K and $49K.

The basic model with Mauser-made action has the standard Mauser "flag" safety.
I like to call it a Mauser "flag" as opposed to Winchester "wing" (unlike Champlin in the link) because a flag stands up, while a wing flaps on the side.

DSC pics from iPhone at Rigby booth:

Middle and high end rifles, L to R:



Middle, high, and low-end rifles, 25", 23", and 22" barrel lengths respectively, L to R:



Low-end front receiver ring:



Mid-range cost front receiver ring:



High-end front receiver ring:



The Mauser billboard on the low-end rifle, no markings at this location on the higher-cost, Prechtl-actioned versions:







Mid-range left action side:



High-end left action side, so dazzling the focus failed:




Middle and high-end front sights and sling attachment details:





Low-end front sight and sling attachment details, sight hood removed for demo, or do they charge extra for the hood?:



Another version of the "stepped barrel" contour by Rigby:



I don't think this will put a genuine London Rigby .416 Rigby in every home, but they are working on it.
There is at least one in existence for about $12K (or whatever 7500 British Pounds Sterling is).
They are taking orders.
I'll bet they would do a thumb cut and whatever safety you want, maybe some scope mounting provisions, for some extra cash ...

I handled the low-end rifle, and it did not seem overly heavy. Surely with it's 22" heavy barrel it will be accurate enough to scope.
Q: How to scope the budget Rigby?
A: There goes the budget!

The so called 'Thumb Cut" found on 98 Mausers both military and commercial made by Mauser have nothing to to do with loading or the military.

The cut is the Mauser patented gas escape hole.

The Bolt Action, Vol. I, pg. 8, by Stuart Otteson:

"The M98 receiver is a carbon-steel forging. Commonly referred to as a siderail type, it has a flat bottom, integral recoil lug, two relatively flat siderails for a midsection, and a closed bridge. The left siderail is cut out to form a deep thumb clearance just forward of the bridge. The primary function of this notch is to aid clip charging of the magazine, but it also creates a gas-release point for the left raceway (D.R.G.M. 56,068 issued Aug. 9, 1895). When clip charging is not a factor, the desirability of this notch becomes suspect, since it does seriously weaken the receiver midsection. Thus it has not been carried over in present-day commercial Mausers."

The gas-release function seems to be an afterthought, add-on idea to the patent application for the prolific Mr. Paul Mauser.
Gas has many other exits, fore, aft, above and below, before it gets to the thumb cut out of port side of midship,
which by the way empties in the general direction of the right-handed shooter's left ear.
Surely it was primarily meant as an aid for stripper clip loading.
I do not see it as any aid at all unless stripper clips are being used.
I would like to see the quote of Saint Finn where he said it was helpful without a stripper clip.
It only makes the action weaker, less rigid, in midsection.
I doubt the current Rigby's of London would consider defacing the Mauser billboard on the left side of the M98 Magnum action for a thumb cut out.

Michael's premise has some veracity due to what he has read, and if all users were right handed -- but the military has to deal with a fair number of left handed soldiers as well.
I too am of the opinion that the thumb cut on the M-98 was primarily to facilitate loading with stripper clips. As has already been pointed out,it helps in the cold as well, which is why I cut one in my MK X .458. And am glad I did as it helps when speed is an issue, even without stripper clips.

My book of Mauser Rifles shows and mentions a half cut appearing on some of the later Model 95 Mausers, whose use was to aid stripper clip loading.

A diagrammed sequence in the same book showing how to load from stripper clips shows that if done correctly, pushing the cartridges down into the magazine with the thumb, the half or full notch is not necessary for a right-handed shooter. Personally I think the notch is for left handed shooters.

As to weakening the action, this is not correct as the forward locking bolt locks it's lugs into recesses in the receiver ring and anything behind that is is only to contain the magazine guide the bolt and mount a scope on.

A rear locking action is where rigidity counts to prevent action stretch.

quote:

Originally posted by ALF:


Nope I don't think so, conjecture
Michael is absolutely correct and it was not some trumped up afterthought to attach the gas escape aspect to it.

The patent Number is DRGM 56086 of 9 August 1895 and it precedes the M98 by 3 years.
The patent was also applied for in Austria, Switzerland, Belgium, England and Hungary.
The patent description can be found in Korn's Mauser Gewehre und patente page 279

Exactly right, Michael and Alf.

This much have I learned and confirmed.

Mauser have always and rightly recommended the right thumb for loading rounds into the magazine.

Apart from southpaws, of course.

For whom the general run of advice has always been: Learn to live right handed!

I'd love to see stripper clips in 416 Rigby
Better yet belt feed!

Unfortunately anything written about the 'purpose' of the many features of the M98 Mauser action is conjuncture on the part of the writer EXCEPT when written by Paul Mauser or when quoting Paul Mauser.

As noted by Alf and Michael the thumb cut was one of the many features added to the M98 to direct, or redirect, chamber pressures during an ammunition mishap to prevent it blowing back directly into the shooters aiming' eye.

It is only happenstance that the thumb cut was found desirable by some to 'assist in feeding' ammunition into the magazine. It is not required feature to empty a stripper clip of ammo into the magazine.

It is unfortunate that these persistent writings that the M98 Mauser thumb cut was a 'military feature' to assist in ammunition feeding is the basis of the BATF's current importation ban on rifles/actions with this feature. If the idiots would have properly referred to Mauser's patents regarding this feature we wouldn't be in this current situation...

Also, left handlers during that timeframe would most likely have been taught by the military to shoot from the right shoulder just as most geezers of today were taught to write right handed in school. Uniformity ruled the day!

Also, I've not heard any left handlers whining that the '03 Springfield didn't have a thumb cut to assist them in charging the magazine with stripper clips.

Herr Mauser lost an eye to gas release .. not an after thought

It has been accepted for the last 70 years as far as I can tell that the thumb cut is strictly for stripper clip feeding, any German Officer knows that and taught that in training..How in the world would it have any effect at all on pressure, it has no means of gas escape there. The gas escape is directed away from the eye by the bolt housing sheild itself!

The only gas escape is a hole in the left side of the front ring of the receiver on some Mauser and the sheield of the bolt housing.

I have seen several std. 98 Mausers in 416 Rigy .. In fact Paul Zorn a well known PH in Africa has been shooting a Wesely Richards for many years now and its a lovely rifle..

I believe, but wouldn't swear to it that most of the big name English makers, at one time or another, used std. surplus 98s to build a few .416 Rigbys.

If openned as much as possible in the rear and as little as possible in the front it should work just fine..I don't doubt that some developed headspace, but I also suspect that it was the softness of the individual action and a lack of proper heat treatment that was the culprit as opposed to the conversion..

Lots of soft Mausers out there, and its pretty much ignored as far as the more accepted Mauser actions like the 1909 or whatever go. However it is argueable that all Mausers should be tested for hardness prior to conversions and its not a bad idea to bring themm down to soft then back up to specs since it only costs about $50. to $75.

DArcy Echols believes all Mausers, including the 1909 Argentine for instance, should be treated, Jack Belk, on the other hand, says
that's like painting a new tin barn..So there ya go, two of the best metal smiths in the world with opposing ideas on the subject. That said I don't think the English treated those Mausers.

RIP,

Thank you for the photos of the Rigby rifles.

Harry Selby's 416 Rigby was built on a standard milsurp mauser, iirc.

Rich

Stripper clips, no stripper clips, gases, no gases, strength, weakened, all I know is that having the thumb cut makes loading a rifle much damn easier to me. If I had a choice between two Oberndorf actions, one with a thumb cut and one without, I would take the one with the thumb cut every time.

quote:

Originally posted by Idaho Sharpshooter:
Harry Selby's 416 Rigby was built on a standard milsurp mauser, iirc.

Rich

nope.. spec commercial standard length action .. NOT SURPLUS ..

quote:

Originally posted by RobinOLocksley:
RIP,

Thank you for the photos of the Rigby rifles.

Welcome, ROL, my pleasure.

So much for Stuart Otteson's interpretation then.
Thanks to Alf for the patent illustration that Mr. Otteson was referring to in my quote of him above:
"... The primary function of this notch is to aid clip charging of the magazine,but it also creates a gas-release point for the left raceway (D.R.G.M. 56,068 issued Aug. 9, 1895). When clip charging is not a factor, the desirability of this notch becomes suspect, since it does seriously weaken the receiver midsection. Thus it has not been carried over in present-day commercial Mausers."

OK,I see that the gas escape holes in the bolt body point to the left side of the action when the bolt is closed, lugs locked.
Thus some utility in venting the left siderail with that big cut.
That concept is illustrated in Ludwig Olson's MAUSER BOLT RIFLES Third Edition Updated 7th Printing, pg. 96:

"Two 5 x 10 mm. gas escape ports in side of bolt align with left locking lug guideway of receiver when action is locked. Gas can thus escape easily through thumb cut in left wall of receiver."

So the thumb cut is a bigger ventilation, but before gas gets to that thumb cut it is vented above and below the bolt, well ahead of the thumb cut, into the sky above and into the magazine below.
The sloppy, battle-functional fit of the Mauser bolt in the action guideways is famous afterall.

Thanks for clearing up my misconception that the thumb cut was for ease of loading.

The same illustrations ALF has shown of the stripper clip ("Mauser cartridge clip") loading are on page 100 of Olson.
Funny how it does not seem to indicate any real utility for the thumb cut in loading the rifle by a right-handed shooter.
Yes, maybe more helpful for a lefty shooting a right-handed Mauser.

My conclusion, from summary of what is presented here, is that the thumb cut is ineffective at doing anything for an action other than weakening it.

The modern Mauser action builders have done well to do away with it.

While it is obvious that the patent states the reason for the "thumb cut" is for gas escape, it is not out of the realm of possibility that, due to the military aspirations of Germany, it could have been applied for that way simply to remain unnoticed, as the M-98 already was one of the best at handling ruptured cases.

The reason I even bring this up anymore is I see custom rifles with the stock covering most of the thumb-cut or the thumb cut welded up. I don't see as many these days but they still show up from time to time.

If you will look at a 98-Mauser bolt on the left side you will see two oblong holes, one in front of the extractor collar and one behind, this moves any escaping gas from inside the bolt to the left rail.

quote:

While it is obvious that the patent states the reason for the "thumb cut" is for gas escape, it is not out of the realm of possibility that, due to the military aspirations of Germany, it could have been applied for that way simply to remain unnoticed, as the M-98 already was one of the best at handling ruptured cases.

Mauser' rifle's were sold to many countries besides Germany, plus Paul lost an eye to vented gases from a ruptured case.

The ruptured case gas handling was greatly improved for the M98 Mauser including the enhanced gas shield on the bolt sleeve - all to prevent these gases being vented directly into the shooter's eye.

If this 'reloading thumb slot' was so important to stripper clip reloading why didn't the US adopt it for the '03 Springfield and later P14/M17 actions? The Mauser rifle action patents may have inhibited its use on the '03 - although the US Gov't was forced to pay royalties to Mauser for many of Mauser's patented features used on the '03 Springfield - they certainly didn't inhibit their use in the P14/M17 as the patents expired when Germany lost WWI.

Guess that's a long answer to say not likely; take the patent language for what it states, not what it does not state.

quote:

Originally posted by Michael Petrov:
The reason I even bring this up anymore is I see custom rifles with the stock covering most of the thumb-cut or the thumb cut welded up. I don't see as many these days but they still show up from time to time.

If you will look at a 98-Mauser bolt on the left side you will see two oblong holes, one in front of the extractor collar and one behind, this moves any escaping gas from inside the bolt to the left rail.

Yep, and add in the enhanced gas seal on the bolt sleeve:

and the gas will be blocked to escape out the slot.

Gentlemen, thank you for all the information. I have really learned something from this thread.

Cheers, Chris

I am very pleased that I asked the question. There is so much I learned from this thread.The sheer depth of the knowledge of you gents is amazing.

Thank you everyone.

Best-
Locksley,R

quote:

Originally posted by capoward:

quote:

While it is obvious that the patent states the reason for the "thumb cut" is for gas escape, it is not out of the realm of possibility that, due to the military aspirations of Germany, it could have been applied for that way simply to remain unnoticed, as the M-98 already was one of the best at handling ruptured cases.

Mauser' rifle's were sold to many countries besides Germany, plus Paul lost an eye to vented gases from a ruptured case.

The ruptured case gas handling was greatly improved for the M98 Mauser including the enhanced gas shield on the bolt sleeve - all to prevent these gases being vented directly into the shooter's eye.

If this 'reloading thumb slot' was so important to stripper clip reloading why didn't the US adopt it for the '03 Springfield and later P14/M17 actions? The Mauser rifle action patents may have inhibited its use on the '03 - although the US Gov't was forced to pay royalties to Mauser for many of Mauser's patented features used on the '03 Springfield - they certainly didn't inhibit their use in the P14/M17 as the patents expired when Germany lost WWI.

Guess that's a long answer to say not likely; take the patent language for what it states, not what it does not state.

Most likely you are correct but, if the thumb cut was so important as a gas relief then why was it not copied ?
Paul Mauser was no fool

There are thumb cuts and vestiges of the thumb cut in many rifles.

The M96 Swedish Mauser has the thumb cut but it does not have the large gas vent slots in the bottom of the bolt.

It was applied to Gew 88s when they were modified in 1905. Patent or no patent.


SMLEs have a dip in the left receiver wall and there is no lug race way to vent gas out of.

The MAS 36 Has the thumb cut - again there is no lug race way to vent gas out of.

The M 91 Mauser has no notch and it is a pain in the ass to load.

The top inside edge of many actions is rebated in that same area to ease loading.
Including the Type 38 Arisaka, Ruger M77 and others that do not even use stripper clips.

quote:

Originally posted by ALF:
Because Mauser held the patent!

It was copied and this resulted in discusssions law suits over patent rights.

I can assure you the Brits and French never gave Mauser a nickle.

quote:

Originally posted by ALF:
Yes and Mauser were paid handsomely for the use of their patents as were many others at the time.

Von Männlicher at one time had 109 patents in operation !

Alf and Michael have adequately pointed out that the original Mauser patent specifies that the thumb cut was for gas relief, but the fact is that, even today, an overwhelming number of serious users still find it a help during rapid reloading. I seriously doubt that additional benefit escaped the fertile mind of Paul Mauser.

quote:

Originally posted by RIP:
A detail from the Champlin link, Rigby's use of Brevex with thumb cut from 1959 for about $20K asking now ($19,800):

Don't intend to offend all the "experts" here but has anyone ever seen a Brevex with a thumb slot? Or with such a bloody big hole drilled through the left-hand side of the receiver? In Kentucky, perhaps, but not in the real world...

Observation's a wonderful thing...

Here is what no one bothers to point out about that notch's gas venting capability.

If you are a right handed shooter shoulder the rifle and look at the notch with your LEFT eye.
So now which eye do you want gases dumped into because that notch is set up to blast your left eye?

quote:

Originally posted by 458Win:
Alf and Michael have adequately pointed out that the original Mauser patent specifies that the thumb cut was for gas relief, but the fact is that, even today, an overwhelming number of serious users still find it a help during rapid reloading. I seriously doubt that additional benefit escaped the fertile mind of Paul Mauser.

quote:

Originally posted by jvw375:

quote:

Originally posted by RIP:
A detail from the Champlin link, Rigby's use of Brevex with thumb cut from 1959 for about $20K asking now ($19,800):

Don't intend to offend all the "experts" here but has anyone ever seen a Brevex with a thumb slot? Or with such a bloody big hole drilled through the left-hand side of the receiver? In Kentucky, perhaps, but not in the real world...

Observation's a wonderful thing...

I am no expert for sure, so you do not offend me.
Is that a badly modified Brevex?
Certainly not to this Kentuckian's taste.

Champlin's ID on the action, not mine:

quote:

Originally posted by SR4759:
Here is what no one bothers to point out about that notch's gas venting capability.

If you are a right handed shooter shoulder the rifle and look at the notch with your LEFT eye.
So now which eye do you want gases dumped into because that notch is set up to blast your left eye?

Aye.

Frank de Haas BOLT ACTION RIFLES points out that the Brevex Magnum Mauser
" ... does however have a gas vent hole in the left side of the receiver, which regular Mausers do not."
A picture in de Haas's book shows the underside of the Brevex magnum bolt has two circular gas vent holes that are not as generous as the "rectangular" larger holes on the standard M98.
The "thumbcut" of the left siderail does seem to be custom work, if that is a Brevex pictured in the Champlin's ad.
We don't see too many Brevex actions here in Kentucky, and I never paid much attention to them before.

quote:

Originally posted by ALF:
The thumbcut in the shown rifle is custom..

Must have been put there as additional gas relief