I bought a marlin 1894 in 44 mag (pre safety, made in 1981). Shoots great, is really fun, and I love it.
I never really liked the open rear sight on the barrel and wanted a receiver mounted rear peep sight. I bought one from ranger point precision and really like it. It looks great and was exactly what I was looking for.

So I go to sight it in and I had to crank the rear aperture all the way to the left until it touched the sight protector ear, and I am still about 1/2 to 1 inch off center at 50 yards. WTF? I had zero windage issues with the factory barrel mounted rear sight. My groups were noticeably tighter with the new rear sight, just not hitting center.

Well long story short, using small bubble levels, I found out that the front sight is canted, by quite a large amount. In fact, it is not just the front sight, but the notch for the rear sight as well. So the factory barrel mounted sights line up perfectly with each other, hence the reason I had no issue with windage before the swap to receiver mounted rear sight, they just do not line up with the flat top of the receiver.
Not to spend too much time speculating, but either both the sights were drilled/machined canted, or the barrel was not properly/completely indexed. The extractor groove lines up fine and it seems to have no headspace issues.  
I have no idea if the barrel was drilled for the sights before or after it was installed in the receiver. Anyways, at this point it does not really matter.

The best way to fix it would be to have the front sight re mounted. There is enough room on the barrel to move it forward 1/4 inch or so and drill a new set of holes. The sight would also cover the original holes so you would not see the old ones. If I ever wanted to change back to the original rear sight, I could move it back to the original holes. Pretty simple, however there are no gunsmiths in my area I really trust enough to do this.  

So I got thinking. There are a lot of high quality 2 part epoxy out there. I was wondering if you degreased the barrel and the sight real good, if the epoxy would bond well enough to hold the front sight in place? With a little heat, I'm sure there would be no issue removing it if ever needed. I just am not sure if it would hold up to the recoil of a 44 mag?

Has anyone ever done anything like this? Am I stupid for even thinking about it? I have read in the past where there have been people using epoxy to hold a scope mount onto a undrilled 22lr rifle receiver. But that is 22lr, and not 44 mag.

Probably wouldn't hold up to the heat and vibration...

It might work, but you'll never know when it will fail and likely it will at the worst time.

Epoxies just won't do it, and neither will JB Weld, which is just epoxy with powdered metal added in.
The shock and vibration is just too much.

The only "glue" that might last is Loctite Black Max.  This is a superglue mixed with a rubbery binder and is used in the car industry.
Brownell's say it's usable to bond shotgun sights........

https://www.brownells.com/gunsmith-tools-supplies/general-gunsmith-tools/thread-locking-liquids/black-max-adhesive-prod6139.aspx

Never seen or heard of that stuff before.
Reading the reviews on there and other sites, it seems like if anything will work, that stuff has the best chance. I think I will pick up some and give it a try. Thanks for the link.

I am not really worried about losing it if it falls off. It is a range toy, and I have my own personal shooting range next to my house, so if it does fall off, it can only go so far.

If using a glue bonder, make sure to REALLY clean the metal of the barrel and sight, and rough up the bonding surfaces on both parts with sand cloth to give the bonder a "tooth" to bond to.

I start out with a strong liquid cleaner like Simply Green or Greased Lightning, rise, then use Acetone, then finish with a liberal flush with 91% or denatured alcohol, ending with WARMING the metal with a hair dryer to evaporate the alcohol and bring out and dry any moisture.
NOTE: Hair dryer and WARM, NOT a torch or heat gun and HOT.
Over heating will prevent a bonder from working properly.

I just ordered some of the locktite black max linked above. I'll give that a try first.
I think I will take a little modeling clay and fill in the original screw holes so there is less of a chance of getting that stuff in the holes.
I have carb cleaner and acetone to clean the parts with. If that stuff will not strip off the oil, nothing will.

I will update when it get's here and I get it installed.

Auto Ordnance used to use it on their M1 Tommy gun until Kahr Arms started pinning them in place. I had a front sight fly off mine and sent it back, they pinned it in place.

Sure why not if that's the only way.

It isn't a rifle but I epoxied (JB Welded) an XS Big Dot sight on my mossberg shockwave. It's still holding up very well. What helps is that it was installed over a bead sight which is threaded into the barrel. I also roughed up the surface of the brass bead a bit before installing the XS Sight.

Im not sure how a sight epoxied to the barrel only would hold up.

I did this per XS Sights directions.

Well I figure it is at least worth a try. Worst that can happen is it does not work. Then I will try and find a skilled gunsmith to drill/tap (harder to find than you might think)

Got the loctite 380 in. I removed the front sight and could not find my clay anywhere. I might have accidently threw it away. I look around for something else to use and remembered a pack of crayons in the cabinet.
I use some carb cleaner and degrease the sight and barrel, as well as the sight holes. I then fill the holes with the crayon and press it firmly in the holes with a flat blade screwdriver and use a razor to trim it smooth.
I clean the surfaces again with acetone and a clean rag. I level the gun off the top of the receiver, apply some of the glue to the sight, carefully set the level on the sight and carefully set it on the barrel. I firmly hold it in place with my fingers for around 30-60 seconds. I then do not touch it for about 12 hours.
I pull, tug, and twist the sight and it does not move, it feels very sturdy. I tap it a few times with the handle of a screwdriver and it stayed put. The true test however, will be when I actually fire it, and fire enough rounds to warm up the barrel. However that might be a while as the weather does not look to be worth a crap for a while.
I will update with the good or bad when I get a chance to shoot it.

If the glue does not hold here's another idea...

Can you loosen the screws holding the front sight and wiggle the sight side to side a bit, enough to get it to line up closer to center? If so, slide a shim* under one side of the sight (to cock the sight to one side) then tighten the screws.

* sliver of pop can, piece of cardboard, etc to get the thickness needed

How about silver soldering it on if the glue fails?

Finally got time and a break in the weather to shoot it.
It held up fine for 3 shots, then on the 4th it came off. So no go on the loctite.
It looked like the loctite itself failed, as there was still some on both the sight and the barrel.

I used a heat gun to soften and removed the loctite, cleaned everything again and this time I tried some of the two part epoxy I had.
I will update when I get another chance to shoot it. It is currently curing.

If it fails, then I will start the hunt for a gunsmith to redrill the barrel.

Epoxy should hold as long as it's been properly degreased. I've kinda banged my shockwave around, put hundreds of rounds through it, and accidently smacked the sight against my safe a few times when taking it out. It's still solid.

Brazing/Having a Gunsmith install is is the best way to go as far as durability though.

If I recall I used the high heat clay epoxy

If the sights on the barrel are canted have a gunsmith re time the barrel? Any good lever gun smith would make quick work of it. Or you could cut a dovetail into the barrel for the front sight and use a marbles sight.

Well to update, I fired 30 rounds yesterday out of it and the front sight is still in place. Did not have to touch the windage or elevation, it was spot on at 50 yards.
So far the epoxy seems to be holding. The most I fired back to back was 10 rounds and the barrel was warm to the touch but not hot. I generally do not shoot my guns till the barrel gets too hot to touch.
I will update if it ever comes off.

The silver-soldered front sight came off my Winchester 1894.  I used JB Weld to reattach it and have had zero issues.

Show me a picture of the barrel. You can get one of these and clamp it to the barrel and re thread it yourself:


https://www.amazon.com/Big-Gator-Tools-MDG1000NP-V-Drill/dp/B00CYNOFM0/ref=asc_df_B00CYNOFM0/?tag=hyprod-20&linkCode=df0&hvadid=312003160272&hvpos=&hvnetw=g&hvrand=17329258561338187411&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9014962&hvtargid=pla-490923365668&psc=1

It has a V guide on it for a round barrel. Clamp it to the barrel before you thread it. This solution while more costly is fixing it right instead of using epoxy. Which will probably skate by for working.

Is the barrel over-timed (or under-timed), or are the sight mounts/dovetails canted?  It sounds to me like the barrel is improperly timed.  Hard to say without having it in-hand.