Whats My Borescope Telling Me

[HunterMann]

Thanks all. Rifle was cleaned to bare metal prior to shooting. He uses 150 gr core lokts. 90% of his shots are likely inside 75 yds. He's going to Saskatchewan in November. No shots over 200, most inside 100. I think a little more fouling will help. He only shoots a few rounds a year. Offered one of my rifles, but he wants to use his.

And I agree with all who have experience with this rifle. The trigger feels like gravel in a pair of slip joint pliers; gravel, not sand lol. None of it is conducive to accuracy. Was just wondering if what I see in the barrel is consistent with what I see on paper. Regardless, sounds like it's not out of the ordinary. Had a slide action when I was a kid. Shot 1.5- 2 MOA with most ammo.

For some reason beyond my skill set, a lot of the Remington slide actions seem to be slightly more accurate than the semi auto models. Maybe it's the chamber or the gentler loading of cartridge or some other factor I don't know. However, a buddy of mine has a Browning BAR that shoots under 1MOA with factory ammo.

 

[pavementends]

Sold a ton of 742's in the 70's. Most wound up with a wide view Redfield 3x9 in see through mounts. As bad as the were there were a bunch of deer killed with them. I set a mentor of mine, excellent shotgunner but not much rifle experience, with a 742 in 30/06 with a Leupold 2.5 scope low mounts and several boxes of Rem 150gr bronze points. I have lost count of how many deer he killed over the years. Hunting in the south in the 60's and 70's was much different than today. Deer herds were also smaller. A rifle that would consistently group 1.5 to 2" would put a lot of meat on the table.

 

[Brad Quarnberg]

As stated already: it looks like some fire cracking and a bunch of copper fouling. Clean it with copper cleaner and then check the bore before again before shooting it again. See what it does then.
Also, as many have stated, these rifles are not noted for being very accurate, but I've seen them be very effective in the hands of seasoned hunters used to jump shooting on deer drives where shots are 100yards or less.

 

[DDB TX]

For some reason beyond my skill set, a lot of the Remington slide actions seem to be slightly more accurate than the semi auto models. Maybe it's the chamber or the gentler loading of cartridge or some other factor I don't know. However, a buddy of mine has a Browning BAR that shoots under 1MOA with factory ammo.

The slide action 760 rifles' barrels are basically free floated after the receiver; the side bars and the grip itself do not contact the barrel (or at least SHOULD not contact the barrel! There may be enough slop to allow the bars or grip to touch the barrel though. The shooter should be aware of this and be sure he is not putting pressure on the grip side to side.)
Also, my understanding is that the early to mid 60s BDL (fancy) versions of the 760 also had a slight hump in the rear of the receiver, this added thickness and stiffness to the receiver itself, because of more metal. See first photo, the top is a regular ADL 760 in 30-06 and the bottom is that shortened .270, a BDL, with a small hump in the receiver by the rear scope mount. I checked when I had it disasembled and it really is thicker metal, not a different stamping.
Unfortunately the early 760s also had a ring around the barrel for the forward sling swivel to be mounted on. Horrible idea for accuracy. Later replaced by sling swivels that mounted onto the slide itself. (see second picture) And the barrels were I believe press-fitted into the receivers.

The 740s, being semis, did not have (potentially) free floating barrels. As with, say, a milspec M16A2, the barrel is attached to the handguard and other items, making it less accurate.

 

[hesse]

You could run the tubbs bullets to try to clean it up

 

[Frog4aday]

Hey @Tiny Tim
The barrel you've shown is rough but not horrible. It could shoot better after a good cleaning but not by much. The crown is most likely the biggest issue as pointed out by @milo-2 and @LRhunter514

<snipped stuff> I bet most of those rifles were cleaned from the muzzle and chances of crown damage increased. <snipped stuff>

I have a old 742 30/06 carbine that would not shoot well so I took it apart and cleaned the bbl. Just by chance I measured the id on the muzzle with some of my chamber reamer bushings and found the bbl was belled at the muzzle end. So I cut the bell out which was about .250" long and recrowned the bbl and threaded for a muzzle break. The rifle is not a bench rest gun but it shoots almost moa.

My buddy had same problem - a used Rem 742 in .30-06 Sprgfld he bought shot patterns, not groups. Turns out muzzle was belled (oblong) from poor cleaning rod use & gunsmith cut the barrel back & recrowned it getting it down to a 1.75 MOA level with ammo it liked.

For what your friend has planned, the current 3" groups @ 100yds will work, but if he wants the gun to shoot better a trip to the gunsmith to have the barrel crown recut would be a smart move. Then buy him a boresnake for a Christmas present so he does less harm to the gun in the future.

I also agree with the Tubbs Final Finish recommendations if he wants to smooth out the bore & reduce that copper fouling. Helps accuracy, too (but it can't fix a bad crown!)

 

[slikmrc]

Guy should at least be up for trying some other factory ammo. Don't know when he's heading to Sask, I'd make sure the action on the rifle is clean and not wet with lube. If this gun is the same as most Remington semi's, it aint going to like the cold if isn't run dry.

 

[OG10]

pitting, delaminating,copper build up.that is what I see.

 

[Tiny Tim]

HeyTiny Tim
The barrel you've shown is rough but not horrible. It could shoot better after a good cleaning but not by much. The crown is most likely the biggest issue as pointed out by @milo-2

I checked the crown before I shot the rifle. It has that 90s vintage recessed target type crown. It looked excellent as far as I could tell.

Rifle has likely less than 100 rounds through it. Ammo looks old and he still has several boxes. Not certain he's willing to invest in it as he only rifle hunts part of a week per year typically.

Great suggestions from all. Thanks.

 

[VinceMule]

The Teslong presents a Digital image, not a true optical image like the Hawkeye Bore scope offers at 10x the cost of the Teslong. Often the pitted appearance is carbon build-up.

I have seen some very good shooting 7400s and some that were horrible. Start at the start, clean bore.

My brother has a 7400 that shoots incredibly with 130g Winchester SP hand loads, and 90g Sierra Hp. With several 7400s in 30/06 shooting the Semi point style bullets are fantastic, family members.

The trigger group is like a rem 1100, and I usually re sprung the triggers, with no failures.

I had rather eat a rat than deal with a 7400, 742. I have owned some very good shooting BARs with BOSS on them, 270 Win, 30/06, and 7 Rem Mag.

 

[Tiny Tim]

The Teslong presents a Digital image, not a true optical image like the Hawkeye Bore scope offers at 10x the cost of the Teslong. Often the pitted appearance is carbon build-up.

I have seen some very good shooting 7400s and some that were horrible. Start at the start, clean bore.

Good to know. Thanks.

As far as the cleaning, it was clean. Pics are after I shot about 15 rounds.

 

[VinceMule]

I had barrels that shot incredibly for 9 rounds, then copper killed the accuracy, FAST.

 

[Tiny Tim]

I had barrels that shot incredibly for 9 rounds, then copper killed the accuracy, FAST.

Me too. Seen some really interesting phenomenon. This one seems to be shooting "better" as round count increases.

Got a friend with a Savage 99 that consistently starts 6-7" high and 3-4" left. Will walk down at a 45 degree angle til centered vertically then straight down to center. After that, the cold bore and following shots are about 1.5 MOA until it's cleaned again. Lol

 

[xsn10s]

Thanks all. Rifle was cleaned to bare metal prior to shooting. He uses 150 gr core lokts. 90% of his shots are likely inside 75 yds. He's going to Saskatchewan in November. No shots over 200, most inside 100. I think a little more fouling will help. He only shoots a few rounds a year. Offered one of my rifles, but he wants to use his.

And I agree with all who have experience with this rifle. The trigger feels like gravel in a pair of slip joint pliers; gravel, not sand lol. None of it is conducive to accuracy. Was just wondering if what I see in the barrel is consistent with what I see on paper. Regardless, sounds like it's not out of the ordinary. Had a slide action when I was a kid. Shot 1.5- 2 MOA with most ammo.

No shots over 200 yards, most inside 75 yards his current accuracy should be fine. I still say some handloads using a more premium bullet and some H4895 would help. But given how he hunts it should be fine. Cleaning and oiling the trigger could help. You could always have a smith do that.