D&t'd A Barrel For A Scout Scope Mount

[Sailormilan2]

I guy I know wanted me to install a forward scope on the barrel of his Turk Mauser. The barrel was cut down to 21", and devoid of all sights and the sight base. I finally got my Forster Universal sight tool last week, and then had to order the barrel clamps and hardened D&T guides so it would work. This would be my first time using the Forster sight tool. Nothing like On the Job Training. I was nervous. Paranoid that I would drill into the bore and ruin the barrel.

What he wanted me to install was a scope mount from a Thompsen Contender. It is a perfect fit in the gap in the upper handguard that surrounds the Mauser sight. However, the holes have non standard spacing, which won't align with the holes in the jig.

This meant I had to drill and tap one hole. Then mount the sight. Then slide the jig guide into position, run the tap through the guide into the next screw hole in the base to make sure it was aligned. Lock the jig guide stop in position, drop the barreled action out of position to unscrew and remove the base. Then lift the barreled action back up so the hardened guides would touch the barrel.

Plus, determine the diameter of the barrel(.785"), subtract the bore diameter(.323"), and divide that result by 2 to get the amount of metal I had to work with. Approx. .230". I made a collar to go around the drill so I could regulate the depth. To lock the collar in place, I D&T'd two holes and used surplus 6x48 screws to lock the collar in place on the drill bit.

Being very paranoid(VERY PARANOID) about drilling into the bore, I drilled the first hole too shallow, so that the screw wouldn't tighten down the base. I started out at a depth .135". I ended up going to a depth of .2" to get it to work without shortening the screws. I wanted as much screw contact as I could get.

So, after redrilling, that is deepening the first hole 4 times, I pretty much got things down. Second hole was a bit easier. Third hole went well.....................................until I went to mount the base to position for the last hole. Then I found I was off on the third hole by 1/2 a screw diameter. I have no idea how that happened. I went ahead and did the 4th hole. Then I went back and repaired my error.

I found a spare mounting screw, and thoroughly cleaned it and the hole with acetone. I put on some Lock Tite. Screwed the screw in tight,then cut it off, and ground it down close to flush. I then took a hammer and peened it flush.

Remounted the base, got my spacing, and redrilled and tapped the hole. Everything went well.

I cleaned all the cutting oil off, then reinstalled the base, loctiting the screws down. Everything went together as it should. Sight fit perfectly in the hole in the handguard.

Gentleman showed up this afternoon to get his gun. He loved the installation. We put on his rings, and found he was missing one ring screw. I tried to use a spare, but couldn't. Leupold apparently changed the screw size from 6x48s, to 8x32s. All I had was one 6x48. Then I noticed that the rear bell of the scope was resting on the front receiver ring. He needs higher rings. What he had was medium rings, and all I had were two sets of lows.

Oh well, Gunshow will be here this weekend, so he can find some there.

I found a Mauser stock/handguard band that would fit. He had a plastic tie holding the handguard to the stock. So I drilled two holes through the band, and ran two small wood screws into the stock to hold it on. Now his rifle will stay together and he has a front sling swivel.

All in all, it took me about 2 1/2 hours to do everything. What with double checking depths, and placements. I really didn't want to screw up someone else's rifle.

Now I can install some sights on the barrels of a couple of my rifles.

We decided the check the headspace, since he had never fired it. Using the Forster guages I got from Mike, I couldn't get the bolt to close on a Go Gauge. However, it would close on a factory round. I know the chamber specs for the 8mm Mauser has changed over the years. My understanding from a 20* 48" shoulder to a 19* shoulder. But these guages were marked 20* 48". So, I don't know what the problem is. At least the headspace isn't too long.