Dovetail cut in BB barrel? - Aperture Sights for BI 7-2, Engineering Grade Epoxy

[NOOk22]

Hello,

I really love my BB to death, but also really love aperture sights.
Have any of you had a dovetail cut into your barrel to install one?
I now have two rifles with no front aperture sights,
and it's either cut a dovetail or use one of these types of adapters.

If I could find a clamp on dovetail that would work better,
but all the ones I have seen are huge blocks.
I bought this adapter for my 10/22, and it looks OK, but Im still not too sure if I like it.
I can get another one that slips over the BB Barrel,
but you still have to loc-tite it on there, and that seems chintzy to me.

What would you recommend for using a front Lyman globe sight on a BB?

[AzizaVFR]

You do not have to get a dovetail cut into the barrel.

Under that weaver rails are the three mounting holes
the factory dovetail uses to mount the 11mm sight rail for the aperture sights.

It is the same spacing used with the 7-3/4, since it is the same receiver.
I have been trying now for months to get RAAC to sell me the one rail they have in stock, by mistake.
I am truly fed up with then not wanting to take my money.
I will make my own.
The receiver is 1.166" in diameter.
Brownells sells a Dovetail scope base you can use to make a base.
They sell the base in 12" lengths.

[aom22]

Originally Posted by NOOk22

I really love my BB to death, but also really love aperture sights....

This thread may have some interesting information.

BB and Aperture sights ...
Clamp-on Barrel Band with Base & Rear Sight Base Adapter

[aom22]

Originally Posted by NOOk22

If I could find a clamp on dovetail that would work better ...
I can get another one that slips over the BB Barrel,
but you still have to loc-tite it on there, and that seems chintzy to me.

A permanent solution would be to silver solder the dovetail block in-place.

Brazing / Silver Soldering

Silver solder requires temperatures of 600 o C up to 800 o C,
or in some cases, even higher.

The two usual heat sources are propane and oxy-acetalene ....

Caution: The heat of the brazing/soldering process
will harm the finish of the rifle barrel.

And, it is reversible.

[doubs43]

AOM, a Pistolsmith I once knew used Accraglass to permanently mount sight bases and sights.
It grips like death but can be broken loose with roughly 300 degrees of heat.
He never had a sight put on with Accraglass fail.

[aom22]

Originally Posted by NOOk22

If I could find a clamp on dovetail that would work better,
but all the ones I have seen are huge blocks
... I can get another one that slips over the BB

Originally Posted by doubs43

... I once knew used Accraglass to permanently mount sight bases and sights.
It grips like death but can be broken loose with roughly 300 degrees of heat.
He never had a sight put on with Accraglass fail.

The BI 7-2,3,4 series use an engineering grade epoxy to secure the barrel to the receiver.
I do not know the source of the adhesive used by Izhmash.

When I first learned of this, I wasn't very confident in the technique.
Apparently, Izhmash has had good expericance with this process.

Perhaps the lack of recoil of a rimfire is the explaination.

NOOk22 for your application: Choose A Glue: Metal-to-Metal

I think Loctite 271 would work well.

OEM specified as 271

High temperature, high strength for heavy duty applications

Designed for larger fasteners 3/8" to 1" (9.5mm to 25mm)

Locks studs, bushings and large fasteners against vibration loosening

Strengthens slip and light press fits

Removable with heat and hand tools

[AzizaVFR]

Now that I have had some time last night to get this made, I feel better.
I used the rail from Brownells I posted above.
For anyone else wanted to make their own, I have made this template.
The foot long piece from Brownells will make two rails.

Drawing diagram:


Dovetail and factory Weaver rail


Dovetail rail mounted


It took about an hour with all the measuring and drilling to get this completed.
Now I have to figure out the right front and rear sight.
For the front I have chosen the Lipski barrel band in 0.750" diameter from Brownells.
Once I select the sights, I can figure out which front base to get in order to get them lined up with the bore.

[davemustaine]

Nice work. Now, go ahead and make a second rail for the rear and sell it to me.
I have been thinking about converting my BB over to peeps as well.
What sights are you going to use for the rear?
I was going to go the same route for the front.

[AzizaVFR]

I just ordered the rest of the parts for the sight system.
The most cost effective rear sight is the Daisy Avanti sight sold by Pyramyd Air.
I have the same rear sight on my Daisy Powerline 953 and it works quite well on it.
Any sight with the name Anshutz on the side costs almost as much as the rifle.

Clyde from RAAC does not have any complete rear sights for the Biathlon when I spoke to him earlier today.
From talking to him, it sounds like he is getting the runaround from his import contacts.

For the front sight, I was able to mock up the sight arrangement.
One of the scope mounts on my Winchester 52 is a perfect fit for the Lipski barrel mount.
I transferred it over to mount the front Avanti sight for the proof of concept.
Everything looked good mounted.

Back over to Brownells' for the Lipski 0.225" sight base,
and a Lyman 93 Target front sight.

[AzizaVFR]

Here is what all the parts I have listed looks like assembled.

Complete shot:


Front sight: Lipski barrel band, 0.225" dovetail, and Lyman 93 Match sight:


Rear sight: Daisy Avanti rear aperture, Brownells dovetail base:


If it were not an evening concall, I would have gone and testing this arrangment.

[midwest swiss]

Looks great ...just like it came that way.
Nice job AzzizaVFR.
I have been toying with the idea installing iron sights
on my BB also.

Swiss

[aom22]

AzizaVFR ... Excellent Project Results

In my case, I'm trying to avoid target sights.
Rather, a plinking or hunting style aperture is what I like.
Either way, your dovetail rail is the key to making this possible.

Contact Williams Gun Sight, Inc.

Williams FP-AG Receiver Peep Sight

For air guns and .22 rifles with dovetail grooved receivers and high line of sights.
(No drilling and tapping required.)

Williams WGRS-54 Guide Receiver Peep

This is a very versatile sight in that it can be fitted on most of the dovetails on the receivers of .22 rifles.

[AzizaVFR]

Those are good alternatives.
If you choose either one of those rear sights, I would change over the front base
from the 0.225" for the 0.175" one to help keep the sight line as low as possible.
The advantage to using the target sight is you can get it closer to your eye than the receiver mounted ones.
I have almost the same shoulder mounting between my pellet rifle and the Biathlon, making one off-hand hold work for both rifles.
Now I just need to get to cutting the new stock.

[AzizaVFR]

I was able to take the Biathlon out for a test firing last night. With the sight arrangement as stated above, it aims quite nicely. It will shoot perfect dead center 1/4" groups off-hand at 12m with the rear sight at its lowest setting. At 25yards, it is about an inch high. I ran out of downward adjustment in the rear sight. I have found some different sized front bases on Champions Choice ranging from 0.175"- 0.795". From my calculations, my front base is 0.152" too short. I guess the ideal choice would be the E sized, 0.375" base, found here.

[aom22]

Originally Posted by AzizaVFR

I was able to take the Biathlon out for a test firing last night.

AzizaVFR,
I for one really appreciate the effort you are puting into this project.
Especially, the follow-up findings and source links.

This thread is destined to become the reference for mounting iron sights on Biathlon Basics.

aom22