Herters J9 Scope bases

JJessup

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Hi everyone. I think this is really the first time I've posted a question on this forum before but I'm hoping someone(s) can be of help.

I recently purchased a Herters/Interarms model J9 and I've got an issue with scope mounting.

It came with bases/scope already installed but could tell there was something wrong. I pulled it all apart and found the heights on the bases front to rear are way out. I've tried every combo of large ring Mauser bases 20a/55 (listed for Mark X) and 46/45(listed for other commercial 98 actions).

I understand that I could technically shim these but they are out A LOT and to be honest I don't want to shim them.

My question for everyone is if anyone has been through this and found a good solution or combination that works. I have seen the EGW listing for the one piece base. But I'm concerned it won't work. I also have to load this rifle from the top, something to keep in mind for one piece bases.
 

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It appears to be the same as a commercial large ring FN... but you say you have tried 46/45. Its a puzzle then... I think 55 has the same hole spacing as 45 but a different height.
 
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From Weaver's website.

Heters J9.jpg

It would appear a standard 45/46 should work. Maybe you have a BSA action, then 28/28. Or you have the round receiver then, 36/35.
 

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Jessup:

What are the numbers showing on your mounted bases?

They look to me to be Tasco bases [the rounded-recesses].

I've just looked at a few of my Weaver #45 & #46/402 bases.

If you measure across the base from the very top across [you can ignore the concave bottom of the base for this purpose as they are both the same and you will not be able to measure the saddle recess on your bases because they have rounded bottoms instead of the newer flat-bottom style], you should get 0.467" for the #45 & 0.276" for the #46 or 402. For the steel S45 & S46, I got 0.465" & 0.274" respectively. Notice the 0.191" difference in both cases, despite the steel base numbers being a wee bit different.

As Dennis suggested, you might try a #55 rear base and also ensure that you have a #46 front base.

If, however, something is really off here are the numbers you want to look for:

Weaver # Base Length Hole Spacing Diameter Thickness
Rear
18 0.812 0.504 1.05 0.182
55 0.812 0.504 1.05 0.310
45 0.812 0.504 1.05 0.396
Front
35 1.168 0.86 1.29 0.147
40A 1.84 0.86 1.29 0.147
46 1.168 0.86 1.29 0.222
 
I have not tried to mount a scope onto a Herter's action, but I do not believe Herter's ever made anything - I think they bought and re-branded and re-sold stuff - looking at your rifle stamping on the side wall - not seeing the Herter's name there at all - but I can not read the very first word before "Interarms".

Is common that a Weaver #46 front and a Weaver #55 work on a Small ring Mauser - or is close. Weaver #46 front and Weaver #45 rear was very common for an FN style Large ring Mauser (in your picture), or a Mauser 98 action that has had the charger ridge ground off - depends on the grinding job on the receiver, I suppose - whether one or other base needed shim.

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Can see in picture above - on right is Weaver #46 with square groove; then a Weaver #45, then a Weaver #55 on right. Note the difference in height between the middle and right side one - one of those go on rear of most Mausers. I had a Swede Mauser where #55 was too short and #45 was too tall - but hole space was correct and was all that I had on hand - ended up to hand file a shim that made the difference - I used the short one with a shim to get even and square top to the front one. Either front or rear can be reversed to get slot in slightly different position. Old school Weaver scope rings had rounded cross bar and big knob - hence old school Weaver bases had half round cross grooves. More modern Weaver scope rings have much smaller knob and cross bar that falls out of the ring when not tightened - a much "squarer" profile - hence most more modern Weaver bases have rectangular (flat bottomed) cross slots. I think the round bar rings work in the flat bottom slot bases - not sure if the rectangular bar rings actually fit properly into half round slot bases. Both flat bottom slots and half round slots came in same size numbers from Weaver - #45, #46, #55, etc.
 

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Hey everyone thanks for all the comments and suggestions and information.

Just to clarify on the rifle it's self Incase it matters.

It's a commercial 98 action- I call it a Herters as the top of the reciever is stamped with that Name, and the barrel is stamped with "Model J9". It also has Mark X on the side of the reciever.

The reciever markings on the side are Interarms with Im assuming the actual manufacturer being Zastava Yugoslavia.

The 20a/55 base combo is what is in the photo.

The 46/45 combo produces the same result only higher overall

I tried the 46 front/55 rear and it is the opposite result. Quite a large gab on the back side instead of the front.

I also tried a 40a front base also. It produces basically the same result.

The 20a /55 base set im using came on the rifle, as someone pointed out they might not be Weaver ? Perhaps one of them is not correct. I don't think so personally but I have not tried a modern 20a/55 base.
 
Use the 46/45 bases and mount a scope and see how that actually works... the rear is supposed to be higher so the scope tilts down into the trajectory of the bullet.
 
Use the 46/45 bases and mount a scope and see how that actually works... the rear is supposed to be higher so the scope tilts down into the trajectory of the bullet.

Really? Wouldn't this put a tremendous amount of stress on the scope tube unless something like the Burris rings with the floating inserts was used?
 
Really? Wouldn't this put a tremendous amount of stress on the scope tube unless something like the Burris rings with the floating inserts was used?

It would not be the first time a scope had a bit of stress... The bases may be correct... I would prefer a ring that has a bottom half mounted on the base... then a scope can be laid in the bottom halves and a bore sighter used to see if it is going to work.

Possiblly just take it to a gunsmith for mounting and see what he has to say...
 
Thanks for all the suggestions. I'm going to go the Burris rout and call it a day. Took the rifle to Epps and with the selection of mounts and rings thats the best solution aside from machine work.
 
If the scope bases are not level [I use a steel straight edge laid on both bases], unless they are both canted so that they are on the same plane [like a 20 or 30 moa 1 piece base is], you WILL bend the scope tube when you tighten the rings.

Once the scope bases are level to each other, the scope's internal adjustments are what are used to bring the POA to the intended POI. If your scope does not have enough adjustment, either your scope base holes are out of whack, or the barrels' bore is not correctly aligned to the receiver's centre-line, presuming again that your scope base holes are drilled to the receiver's centre-line.
 
The amount that the bases are out will absolutely destroy a scope tube, my only option is the Burris style rings with the inserts or custom machining of base or shimming. Since I do not want to shim them (it's A LOT) I have found a combo that is the closest and will proceed with the Burris rings.

I tried a one piece base and although the hole spacing is correct for individual bases the spacing between bridges is wrong. Close but wrong.

I have more Mausers than I can count and I've never seen one this far out. Let alone a commercial one at that. It's also the first and only Mark X I'll own because of this.



Thanks again for all the input!
 
An option to the Burris rings is bedding the bases to the action with them being held in the mounted rings ... a little tricky to do it but I did several that way over the years...

Release agent on the action and in the screw holes... release agent on the sides and tops of the bases and the screws, bedding compound between the bases and the action and the screws loose (just used to locate the bases) ... with the scope mounted in the rings, attach the rings to the bases... now the bases are held at the correct angle by the mounted scope... and the whole mess is sitting on the action... let it cure... then remove the rings and remove excess bedding compound. Assemble with blue Loctite on snug screws.
 
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Yugo machining, not know for quality, avoid their ss guns. One cracked receiver gun on the EE for parts and people still sell em and think they’re special. Not sure why people even buy em when Higgins and other off brand FN built guns are just as cheap or cheaper.
 
An option to the Burris rings is bedding the bases to the action with them being held in the mounted rings ... a little tricky to do it but I did several that way over the years...

Release agent on the action and in the screw holes... release agent on the sides and tops of the bases and the screws, bedding compound between the bases and the action and the screws loose (just used to locate the bases) ... with the scope mounted in the rings, attach the rings to the bases... now the bases are held at the correct angle by the mounted scope... and the whole mess is sitting on the action... let it cure... then remove the rings and remove excess bedding compound. Assemble with blue Loctite on snug screws.

Did similar on one wonky receiver I had. Can also be used to just make sure you have a 100% tight fit on receivers that are less misshapen.- dan
 
An option to the Burris rings is bedding the bases to the action with them being held in the mounted rings ... a little tricky to do it but I did several that way over the years...

Release agent on the action and in the screw holes... release agent on the sides and tops of the bases and the screws, bedding compound between the bases and the action and the screws loose (just used to locate the bases) ... with the scope mounted in the rings, attach the rings to the bases... now the bases are held at the correct angle by the mounted scope... and the whole mess is sitting on the action... let it cure... then remove the rings and remove excess bedding compound. Assemble with blue Loctite on snug screws.

Yes. Have done this a couple times as well to get a perfect stress free mounting. Works well and really not that hard to do.
 
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