Third Party Press

K98k with SEM Saddle mount ("objective mount")

Absolut

Senior Member
First of all, the correct designation for what is often referred as "objective mount" is in fact a Suhler Claw Mount which originally is called "Suhler Einhak-Montage" in German, abbreviated as "SEM". There are various types of Claw Mounts, but the Suhler Einhak-Montage can be identified by the fact that the catch/release is a sliding part in the rear base. Secondly, the term "objective mount" is misleading in that this mount can also be attached to other parts than the objective. The position of the soldered on scope rings is most often determined by where the bases on the rifle can be placed, and the eye distance the scope requires.

But to finally get to the topic: recently scrolling through local (meaning my country, but it isn't so large so for US dimensions it can be called local) ads for selling weapons I came across a listing for a Mauser 98 hunting rifle. The sportered rifle caught my attention for featuring SEM bases of a saddle type (which therefore do not weaken the receiver ring, since the dovetailed part sits on top of it). This also requires a higher rear scope base and a higher rear scope ring and usually results in the scope being a bit higher above the barrel line than being dovetailed directly into the receiver.

After a quick inspection of the rather very poor pictures I quickly noticed the saddle bases are very identical to the ones of Dave Roberts rifle. The bolt also appeared to be of the military pattern and the barrel still had the military steps and full length, while the open sights were sportered. The price was low (basically covering the parts costs), so I shot the seller a message. He then sold the rifle to me and I finally received it yesterday, not knowing precisely what I had bought.

Having it in hands, I did have some surprises. The bads were that none of the parts seemed to be matching numbers, the model designation on the receiver wall were scrubbed as the serial number on the receiver. The good thing however was that at least the mismatching bolt happened to be a good surprise in that it was a G.33/40 bolt of which I anyway had been in need for a rifle which recently was discovered on an attic, lacking its bolt (and funnily both are even in the same letter block). The second surprise was that a very closeby inspection unveiled that the scope bases both on bottom and front have a serial number on them - and this serial number matches the serial number inside the barrel channel of the heavily sportered stock (even the buttplate it sportered - but seemed to originate from the same military rifle since it still features the same WaA as on the receiver ring).

The absence of the serial number and the fact that many parts are mismatching (plus of course the scope bases covering the receiver ring) make it very hard to tell who originally made this rifle. Based on the WaA26 I believe I can make out on the right side of the receiver ring I am inclined to believe this rifle was originally made by BLM. Possibly someone more experienced with those can even give approx. year for it.
 

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Since I anyway can only post 10 pictures per reply I thought I would split some text between the messages too ... so there we continue:

The scope bases are highly interesting in that the rear scope base has a serial number on right side bottom of the catch/release slider. Exactly this same serial number can also be found on bottom of the dovetailed front scope base, but additionally featuring the letters "AR" as prefix.

Once having had in hands a military Dialytan scope for those sniper rifles which still had the front scope base coming with it I do remember that this base was different in lettering since it had no prefixes. And I think it also was of different dimensions (higher but shorter). And I also know another member here has one of those sniper rifles, but his rifle has the rifle serial marked on front of the rear scope base instead of on bottom as on mine.

Given the different numbering and the slightly different design, I had thought that the rifle I had purchased might be the Army variant of the Suhler Einhakmontage we recently had been discussing. Any thoughts regarding that would be highly appreciated - also I would ask anyone who owns such a rifle to check the bottom sides of his bases to maybe be able to see if the numbers are in identical or different bases!
 

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It’s a 1941 Borsigwalde which probably explains the prefix of “AR” in the serial. Having serialized bases doesn’t necessarily point to anything military about it, likely just used for the tracking of handfit parts of which there are many in an SEM. The claws alone have 24 hand fit surfaces in an SEM. There were many such sporters built out of ex military and often out of rejected military parts, the lack of any commercial proofs could mean it was some kind of total basement job, not really sure there. Is it simply the sighting groove down the saddle giving the impression of military? Otherwise there are lots of other saddle mounted SEM’s out there on commercial hunting rifles.
 
K98 Semi Saddle

I have a similar K98. I checked for serial numbers on the rear mount and see none. The front mount seems unmovable, so I could not check. The rifle is a bolt MM and came with capture papers. With it came Russian TOZ 35 22 cal. rifle on the same papers. I would be nice to have Dave Roberts check it as he is a local NH person. Regards Banjomike
 
It’s a 1941 Borsigwalde which probably explains the prefix of “AR” in the serial.
So you mean they re-used the receiver code as prefix?

Having serialized bases doesn’t necessarily point to anything military about it, likely just used for the tracking of handfit parts of which there are many in an SEM. The claws alone have 24 hand fit surfaces in an SEM. There were many such sporters built out of ex military and often out of rejected military parts, the lack of any commercial proofs could mean it was some kind of total basement job, not really sure there. Is it simply the sighting groove down the saddle giving the impression of military? Otherwise there are lots of other saddle mounted SEM’s out there on commercial hunting rifles.
I agree that this is no proof. But the military SEM are distinctively different from commercial ones, especially in the outer shape. The rifle here is no basement job. Note the screw slots perfectly aligning in the rear scope base - exactly identical as on Dave Roberts rifle. In my opinion this was a military rifle which just had any swastikas and serial numbers being scrubbed.
 
Cool find! I will be keeping track of this thread since I have quite an interest in this particular variant of K-98k sniper. Thank you for sharing!
 
The AR prefix in the serial number is just a guess, just would seem an odd coincidence given that this is more than likely an AR 41, it could very well be a 243 coded receiver though as well and that would totally kill that theory.

Here’s what I’m looking at on the receiver, with any kind of base mounting of this type, saddle, SC, Turret etc we usually see prior receiver prep work, hand filling showing from under the base edges, that is all rather minor prep work to correct any machining inconsistencies for the base to receiver fitment which of course has to be very tight to form a strong solder joint. This of course would not take off the serial and proofing. Looking at your receiver the contours appear very perfectly round especially at the base edges. Presume there was an existing serial and proof mark here, how could that depth of material removal be accomplished without a severely noticeable low spot in the receiver contour? Notice the depth and irregular contour of the mod 98 removal as well as its poor execution, how could (presumably) the same guy have done such precise job to remove punched numbers and proofs within such close proximity to the base edges. Say your punched/roll marked number depth was somewhere around .015 deep, the blend ratio required to remove that much material would leave a noticeable low spot in the contour, based on that alone I believe the receiver was severely recontoured to the point of serial removal prior to the base install, just my opinion based on what I’m seeing in the pictures.
 
That is of course assuming a military application of these mounts would not have been acceptable to completely remove/obscure the receiver serial and proofing, to that question I will have to defer to the collective knowledge of observed examples of these. This was of course acceptable later on in the case of the SC bases, however so was the omission of receiver serials in this time frame as well.


***this forward receiver section would be very helpful to see from the front to determine if the contour is true or not, hard to tell from the pictures, if this is indeed a low spot then I would agree with proof removal.
 

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The more I look at that forward section the more I think it might have had a proof ground, only looking from the back end of the receiver ring makes it hard to tell. Would certainly be awesome if it is deemed authentic! The other thing it has going for it is the milling at the charging bridge, it’s milled forward instead of removing more material from the rear base like most commercial SEM mounts, possibly a military feature??
 
Serial and proof on left receiver have been removed pretty crude too. You still can make out the top line of the proof (wings top). See yourself..

Edit: milling forward of rear scope base is typical for military SEM mounts. See Dave Roberts rifle on the website of Matt here: https://www.wwiigermansniper.com/objective-mount-double-claw
 

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That’s a better picture thanks for the detail, I’m not seeing the proof remnants but such things can be hard to photograph for sure, the presence of a proof is beside my point however. Perhaps I didn’t explain my reasoinging well, but after seeing more detail with this picture I have to return to my prior statement, I believe the receiver was ground before the mount went on, that was the whole basis for my point. Seeing as this is a Borsigwalde you can compare exact proof and serial locations and the numbering would have fallen nearly level with the edge of the saddle that would make for a very obvious serial removal if done AFTER the saddle was mounted. That is my whole point on the subject.

Notice the same kind of numbering/ proof location on Dave’s, imagine trying to grind/file those away while in direct contact with the attached saddle, it wouldn’t be pretty.
 
I have a similar K98. I checked for serial numbers on the rear mount and see none. The front mount seems unmovable, so I could not check. The rifle is a bolt MM and came with capture papers. With it came Russian TOZ 35 22 cal. rifle on the same papers. I would be nice to have Dave Roberts check it as he is a local NH person. Regards Banjomike

Hi Mike
If You want to set a time for me to come up and have a look I would be happy to do so . Best Regards .
 
It’s a 1941 Borsigwalde which probably explains the prefix of “AR” in the serial. Having serialized bases doesn’t necessarily point to anything military about it, likely just used for the tracking of handfit parts of which there are many in an SEM. The claws alone have 24 hand fit surfaces in an SEM. There were many such sporters built out of ex military and often out of rejected military parts, the lack of any commercial proofs could mean it was some kind of total basement job, not really sure there. Is it simply the sighting groove down the saddle giving the impression of military? Otherwise there are lots of other saddle mounted SEM’s out there on commercial hunting rifles.

IMHO , this Barreled Action and Bases are Military put together as apposed to a Basement Job . The best evidence for this is the direction on the screw slots on rear base which are inline with Barrel and the screws slots not being all buggered up help prove this fact Every one of these Rifles I know of that are original have this distinct screw installation method screw slots are always inline with barrel . Up to this point there are 3 known Rifle Manufacturers which were used for these Rifles Sauer , BLM and BSW , there could be others types but I am not aware of any .

I will point out one thing that no one else seemed to have picked up on , the Rear Base on Georg`s Barreled Action is different in one respect from my 2 Rifles . Look at Middle Grove Machined my Rear Bases . Georg`s has No Groove .
 

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Thanks for weighing in on it Dave. Do you think contour prepping of the receiver to the point of serial removal before base installation might have been a possibility in military trim? This is my sole point of reasoning/point of contention with the rifle. The vise marks on the receiver are also a point of concern, sure they might be from the secondary sporterizing/ removal of the model designation but who knows.

Prior military acceptance while a good sign for the validation of the rifle also doesn’t prove it either, many makers in Thuringia built sporters out of previously accepted military actions/barreled actions, even during the war. I might have one myself although I can’t prove it because there are no visible military proofs, it is built on an Astrawerke receiver though, and built in the fall of 1943. I have seen others though where no effort was made to remove the military proofing but of course have additional commercial proofing. Seeing rifles like that utilizing current military arms components make it hard to make calls on rifles like this (to me) because who is to say that even the bases weren’t a rejected item and up for grabs to the many small makers in the area. As to the screw alignment, that seems to be fairly standard practice on SEM mounts from what I’ve seen on the commercial side, here’s a picture of one of mine for instance. As far as details
on military SEM’s I can’t comment on specifics as I believe every one I have seen was yours! :thumbsup:
 

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There are three proofs on the side of the receiver. Looks like maybe 26?
I have even mentioned that in my starting posts that it has 26 proofs on the receiver. Didn't you read it? Anyway, does this distinctively mean it is an AR41 rifle?

Flynaked, noone would scrub the receiver markings that ugly and then fully professionally add perfectly seated and screw slot aligned bases. This makes no sense. The bases were installed prior to the receiver being scrubbed.

Dave, thanks for pointing out the sighting line on your bases. The other SEM mounted K98k rifles you are aware of, do they have this slot too? And additionally, your rear scope base is serialized facing towards the front. Does this mean it does NOT have the serial number on bottom of the catch/release as on mine? That would then be another difference. Have you ever removed the dovetailed part of the front scope and compared the serial number there? And would you be able to measure the front dovetailed part in height, width and length (on bottom) so I can compare it with mine? Your rifle is a 1938 rifle, right? Maybe we now really have found the two variants (Army and SS).
 
Took out the DSLR and did higher quality pics after having quickly brushed off some of the dirt .. Due to the amount of pics I'll have to split it into seperate posts since I can only post 10 pictures per post.
 

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Maybe the biggest surprise was after detailed checking the receiver with the front claw base removed that the receiver nevertheless has been milled flat on top too. This will also be the reason why the base is not only soldered, but also screwed two times. I'm 100% sure they first properly prepared the receiver (you still can see the file markings), soldered and screwed the saddle in place and then in ONE SINGLE STEP milled the dovetail for the front claw base.
 

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Finally the last picture. All dimensions shown are in metric system. The paper background has 5mm squares, what therefore means the dovetailed part is exactly 20 mm long and around 27 mm broad with a height of 5.3 mm. Dave, it would be highly appreciated if you could take off dimensions from your front claw base of your rifle.
 

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