98B/S&B PMII BoreSite Issue

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98B/S&B PMII BoreSite Issue

Postby Smokehouse on Sun 26 Jul, 2009 7:58 am

I have a 98B and a S&B PMII 5-25x56 and use Badger Ordnance rings. My problem is in trying to boresite this configuration. Does anyone know if there are Rings available like Barret's XRings in 34mm? I am using up way too much MOA trying to get on target, I am shooting way low.

I admit I am pretty ignorant on boresiting and if someone has any knowledge with this configuration I am all ears

Thanks for any help

Jeff
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Re: 98B/S&B PMII BoreSite Issue

Postby Shadow on Sun 26 Jul, 2009 9:05 pm

Smokehouse wrote:I have a 98B and a S&B PMII 5-25x56 and use Badger Ordnance rings. My problem is in trying to boresite this configuration. Does anyone know if there are Rings available like Barret's XRings in 34mm? I am using up way too much MOA trying to get on target, I am shooting way low.

I admit I am pretty ignorant on boresiting and if someone has any knowledge with this configuration I am all ears

Thanks for any help

Jeff

Well, you say: "I am using up way too much MOA trying to get on target, I am shooting way low."

How much of your elevation is used up to get on target? And what range is your target?

Anyway, I'd guess your scope has about 56MOA max elevation and a set of 34mm rings like Barrett's 30mm XRings don't exist (I'm pretty sure, anyway).

I'd say you'd like about 20-25 more MOA? So, I suggest calling Badger Ordnance and asking them if their AR Riser Rail will work and mount "rock solid" on the 98B rail. The AR Riser Rail (part #249-45), has 22MOA of forward cant built into it. So, it may be the simplest solution (provided it can mount solidly on the 98B rail). That way you get another 22MOA, from the start, to get to a "zero range" for your rifle.

Or you can see if Barrett can get a set of XRings made for your 34mm tube (unlikely).

Othwise, I don't have any other suggestions. Other than have the rail replaced on the 98B with another one that has the cant built in. Only Barrett can answer that question, I'd guess. :det:
Good luck.
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Re: 98B/S&B PMII BoreSite Issue

Postby paulyfly on Sun 26 Jul, 2009 9:20 pm

Hey Smokehouse, take a look at one of these...

http://stores.homestead.com/Laruetactic ... .bok?no=32

:cheer:

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Re: 98B/S&B PMII BoreSite Issue

Postby Shadow on Sun 26 Jul, 2009 9:27 pm

paulyfly wrote:Hey Smokehouse, take a look at one of these...

http://stores.homestead.com/Laruetactic ... .bok?no=32

:cheer:

paulyfly

+1 paulyfly - problem solved. I see he can get it in 34mm. Too bad it's almost $300. Ouch.... :mrgreen:
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Re: 98B/S&B PMII BoreSite Issue

Postby paulyfly on Sun 26 Jul, 2009 9:52 pm

You do tend to get what you pay for, in my experience! LaRue rocks!

:headbang:

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Re: 98B/S&B PMII BoreSite Issue

Postby Smokehouse on Mon 27 Jul, 2009 5:58 am

Thanks Shadow & Paulyfly Both options you have shown will solve my problem

You guys are great :bow:

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Re: 98B/S&B PMII BoreSite Issue

Postby JTinIN on Mon 27 Jul, 2009 6:43 pm

A quick check indicates you scope may have a total of 118 MOA vertical adjustment thus in theory the 30 MOA added offset will not be a major factor and since the 98B does not appear to have an offset rail, it would actually be a postive at extended range (~mile+)
http://www.sportoptics.com/schmidt-bender-pm-5-25x56-P3MOA.aspx

However, if you are shooting a lot low there is always a chance that something is not setup correctly (i.e. ring not fully in a slot, the ring hitting the slope by the zoom or turret, scope not fully seated in the scope, on some setups you can have issues if the front and rear rings are swapped etc.). Thus for this nice of setup, I would take a careful look, and then take everything appart and put it back together, while making sure that each ring is down in the slot, all tape & labels are off, the scope fits freely in the rings etc.

Would be interested in how you are bore sighting (feel free to e-mail and we can talk by phone). With some type of bore sighting systems there is a chance for alinment issues (i.e. optical device on the muzzle brake face that does not aline, laser not in line with the bore, checking too close etc.). For a control I would setup my scope with the controls set in the center (i.e. equal adjustment up and down per you count, but go carefully and make sure you don't have a zero stop set ;) and then look down the bore at a point 25 yards and if possible 100 yards away (corner of the barn roof, a light etc.). You can use an unprimed case in the bore if needed. Thus if your scope is looking at a point lower than than what you see though the bore, then you will be shooting high (and the inverse is true, in partical afte the first zero crossing at 25 to 65 yards).

Regards
John
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Re: 98B/S&B PMII BoreSite Issue

Postby Smokehouse on Mon 27 Jul, 2009 7:12 pm

John

Private message sent

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Re: 98B/S&B PMII BoreSite Issue

Postby Smokehouse on Mon 27 Jul, 2009 7:37 pm

Just for info for anyone contemplating a Schmidt & Bender PMII here is the following from the S&B manual....

In scopes for hunting the reticle is generally centered optically and mechanically
in order to receive the same amount of travel in all directions and to make the
mounting of the scope to the firearm easier (see picture 2).
In order to make the elevation adjustment range usable in its full extent it is
necessary to preset the reticle of the PMII scopes out of the center already at
the Schmidt & Bender factory (see picture 3). As a consequence the gunsmith
is obliged to consider the preset position of the reticle in the elevation range
when mounting the scope to the firearm (see picture 4). With this setup the full
elevation range is usable in one direction allowing to shoot at distances up to
2000m depending on the used calibre and scope type.
Determining the correct forward angle
The necessary forward angle is depending on the used type of elevation
adjustment. At the Schmidt & Bender factory the reticles of PMII scopes are
adjusted out of center by half the amount of the full elevation range. This value
must be compensated in the mount system.
Forward angled mounts or rails for every Schmidt & Bender PMII scope type
are available from all renowned mount manufacturers.
Example for determining the required forward angle:
A standard elevation turret (Single Turn) with an elevation range of 13mrad
(equals 130cm at 100m distance) requires a forward angle of 65cm at 100m
(equalling the half of the full elevation range). For a gunsmith compensating for
this value using the mounts the following rule of thumb applies: If the space
between the two mount rings is 100mm the front mount should be 0.65mm
lower than the rear mount.

I did not realize this prior to ordering the scope & rings (Badger Ordnance,,,will be for sale btw) The La Rue Tactical mount with 30 MOA forward cant may be the ticket until Barret has pity on us S&B owners and make the X-Rings in 34mm ;)
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Re: 98B/S&B PMII BoreSite Issue

Postby paulyfly on Mon 27 Jul, 2009 7:44 pm

Let us know how you make out, Smoke. And we like pics!

:rl: :rl: :rl:

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Re: 98B/S&B PMII BoreSite Issue

Postby Smokehouse on Mon 27 Jul, 2009 7:47 pm

paulyfly wrote:Let us know how you make out, Smoke. And we like pics!

:rl: :rl: :rl:

paulyfly




Paulyfly, A soon as I get the new mount I will post pics. Thanks again !!

Smoke'
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Re: 98B/S&B PMII BoreSite Issue

Postby Shadow on Mon 27 Jul, 2009 9:35 pm

Smokehouse wrote:Just for info for anyone contemplating a Schmidt & Bender PMII here is the following from the S&B manual....

I did not realize this prior to ordering the scope & rings (Badger Ordnance,,,will be for sale btw) The La Rue Tactical mount with 30 MOA forward cant may be the ticket until Barret has pity on us S&B owners and make the X-Rings in 34mm ;)


The necessary forward angle is depending on the used type of elevation adjustment. At the Schmidt & Bender factory the reticles of PMII scopes are
adjusted out of center by half the amount of the full elevation range. This value
must be compensated in the mount system. Forward angled mounts or rails for every Schmidt & Bender PMII scope type are available from all renowned mount manufacturers.


One last try. :poke: I'd guess it's now pretty clear, even since the first posts. :poke:

IMHO, before you go out and spend $$ on the LaRue mount, I'd suggest calling Badger Ordnance - explain your problem to them and simply ask them about the rail, I referenced. Would it be a "ROCK SOLID" mount? They'll know (being experts), if it'll meet the needs of the .338LM recoil, etc.

Personally, I'd rather have a Robust set of rings, rather than a "quick release" - "fixed horizontal spacing" setup, especially on a .338LM. But that's just me. :mrgreen:

Good luck.
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Re: 98B/S&B PMII BoreSite Issue

Postby Smokehouse on Tue 28 Jul, 2009 10:00 am

Shadow, I am in agreement with you regarding a solid mount, I plan to call all parties to find out exactly how much MOA offset I need for the S&B, which I feel is the #1 issue.

Thanks to you all I have several options to choose from.

Here is another solution (albiet expensive) that a forum member sent to me that is pretty interesting. It has adjustable MOA & Windage in the rings
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Re: 98B/S&B PMII BoreSite Issue

Postby Smokehouse on Wed 29 Jul, 2009 11:29 am

Thanks again to all. I have decided to go with the adjustable MOA rings by Ivey Shooting in the pic from my last post. They will ship around Aug 31st. They are capable of up to 150 MOA adjustment and allow for a 65 mm objective. The knob on the right is not for windage but for locking in your MOA adjustment.This will more than solve my issue.

Cheers

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