PDA

View Full Version : Unusual barrel markings - Whats going on??



dareposte
02-21-2010, 08:53 PM
Hello everybody. My first post here, hopefully I can tap into the wealth of shooting knowledge here.

I have a Remington 700 that has never really shot all that well, maybe 1.5 MOA on a good day, 2.0 on a bad day. It had the factory Remington "varmint" weight barrel on it. I tried a few basic things in attempts to improve the accuracy, but nothing really worked.

So I figured I'd try shortening the barrel to see what that did, as a last resort before I eventually rebarrel it. I sawed it off to 20" in a band saw and recrowned it, but it didn't really change the accuracy much.

The interesting part is that it had quite a bit of copper fouling in it when I sawed it and re-crowned it. I removed the copper fouling after it was all done, and underneath it all I found a bunch of marks inside the barrel.

I was under the impression that Remington barrels were hammer forged, so I'm not sure what might have caused these marks. I'm fairly confident that the marks came this way from the factory, as I haven't done much to the barrel besides shoot it, clean it using standard patch/jag methods, and just recently saw it off and crown. The marks almost look like a deep hole drill mark, except the marks are both on the lands and the grooves which doesn't really make sense.

Anybody have some ideas?

http://derekyates.net/barrelmarks.JPG

The marks are all around the barrel, and I don't think I could have caused them recrowning or doing anything to the barrel. I spent a few hours tonight with rubbing compound on a tight patch "polishing" the bore, for lack of any other ideas. At the end of the polishing session the bore felt smoother but the marks are still clearly visible. The rifle has had a rough bore its entire life, showing pressure signs earlier than my other 700's and also having slower velocities for a given load.

Jan
02-21-2010, 09:17 PM
..present all the way down the bore? Is this section on the barrel or the cut off drop? Looks like someone spun a SS wire bristle brush around the bore,weird that the marks are in the grooves and on the lands too. Looks as though you cut it pretty straight for using as Hack Saw! It'stime to buy a new barrel. Good luck. I am sure some others will give you their 2 cents worth of free opinions also!

dareposte
02-21-2010, 09:24 PM
I'm not sure how far down in the bore it goes, I don't have a bore scope to look much further and the flashlight angle to see in gets pretty cramped past about 3/4".

I'm stumped! I bought the rifle new and have definitely not had anything in the bore besides a bronze brush and patches.

The marks are present in the cut-off sections as well as the end of the barrel. The picture shows the end of the barrel as it is currently on the gun at 20" long.

I cut down the factory barrel (26") in two sections, one test cut at 23" and the final cut at 20". The cut was definitely not straight, I had to file the end flat before cutting the crown.

I cut the crown using one of those piloted 11 degree crown cutting reamers. At first I thought that it may have caused the marks, but I don't think this is true as the marks were not apparent until after I cleaned all the copper fouling out of the bore. I didn't clean it until after it was cut and crowned, and the copper marks. Also the marks are present in the chopped off sections (after cleaning the copper out) which weren't crowned and extend over a total length of about 6".

Bob Kingsbury
02-21-2010, 09:27 PM
Did you buy this new.? It appears that some of the marks are
also on the copper

dareposte
02-21-2010, 09:34 PM
I did buy it new from the local dealer. I wouldn't say its the most reputable dealer in the world, but I wouldn't think they could pass off a used gun as new.

There is no copper left in the bore at this point, its been cleaned with RemClean, rubbing compound, and copper solvent to the point that patches come out clean and are not even a hint of blue. In the picture there is still some discoloration which also stumps me.

The gun was seriously copper fouled when I cut it down, it picks up copper fouling quick and the bore starts to look copper plated after about 20 rounds. I never really paid much attention before and just let it build up for a while between cleanings. Now that I have looked at the inside of the bore its no wonder it loads up so quickly.

dareposte
02-21-2010, 09:38 PM
Here's a picture of the other side.


http://derekyates.net/IMG_0924.JPG

dareposte
02-21-2010, 09:41 PM
And another picture, this one clearly showing the marks over the grooves and the lands both.

http://derekyates.net/IMG_0920.JPG

goodgrouper
02-21-2010, 09:58 PM
Tooling marks. See it frequently with factory guns. I have the great pleasure of working with barrels like this all too often. I shoot Tubb's Final Finish kits down them and it smooths them out quite a bit. But it's still a gamble on whether it will be accurate or not.

dareposte
02-21-2010, 10:11 PM
Ahhh... so it looks like my piloted crown cutter had a burr on it which made the mystery marks. I re-examined the rest of the cut-off parts and they only had the marks where I had practiced crowning them, and with some searching I did find a burr on the cap screw of the reamer.

The burr must have cut right through the copper and left a mark on the steel, so when the copper was brushed out it just looked like it was underneath.

d'oh! At least it was just a factory barrel!

Thanks to those who posted, it was helpful to get some ideas

Borg
02-22-2010, 01:10 AM
Your pilot wouldn't have marks on both the lands AND the grooves.
I've had a lot of problems with Rem in the late 90's, Three rifles in a row.
The first one was a Varmit SS spc, that, no matter what I did to it, it wouldn't shoot, pillar bedded and floated wouldn't do any better than 3" with hand loads.
Got to looking at the crown and noticed that I only had 3 lands, 4th was flat, then about 3/4" down, I noticed that there was a deep groove all the way across and past the depth of the grooves. Pilot guide ate it.
Contacted Rem and sent back, they sent me a new rifle,, exact same thing.
Called Rem again and really bittched attum, talked the CEO, and he had me send it att to him.
At this time, I went to a local shop and had a chance to look over all their rifles, out of 26, 17 had the same problem as mine.
Third new rifle, opened the box, looked at the crown,, same thing, said fugit and took it over a friends and we cut 1-1/2 " off it.
It still didn't shoot all that great, (1") because the bore was so rough that the first round coppered it up so bad.
About a year later, I ordered one of those 700 308 cal with the laminated stock, when I picked it up, I looked at the crown,, guess what. I cut 1" off that one also to get it to shoot, but at least the barrel wasn't as rough
Always check the crown and deeper with a cotton Q-tip, light and 10X loupe if you buy a Rem. I've been very disapointed in Rems for the last 12 years,, Hammer forged? mustave been using a 6oz ballpeen with a rough mandrill.
It looks like they just don't hammer forge enough to get out the DH drill rings.

f d shuster
02-22-2010, 03:33 AM
For a real eye opening education about factory barrels ( the subject barrel is a new, unfired Remington 7mm Magnum), checkout Dan Lilja's borescope video on the 6mmBR website. Expecting any real accuracy from the typical factory barrel, any brand, is a crap shoot, at best. If this were mine, the barrel would be removed, as quickly as possible, thrown in the garbage can and replaced with a Bartlein, Krieger, or any other known quality barrel. Trying to get something like this to shoot is a waste of time and money. If interested in the video: Go to the homepage, scroll down to and click-on "barrels", then "factory vs custom borescope video". It will make you sick, when you see what your money buys you today.

nhkuehl
02-22-2010, 11:01 AM
Using a bore scope in a very eye-opening journey! I've seen similar marks in both button rifled and hammer forged barrels and I'm guessing it's from a lack of lubrication that creates chatter during rifling. Commercial barrels are drilled, but not necessarily reamed or lapped before rifling, so you aren't starting with a smooth surface (free of tool marks) either.

I recently bought a new discount package Remington 700 .308 Win as an 'organ donor' and thought I'd run the bore scope through just for the heck of it and it was probably the best factory throat (symmetrical), rifling and crown I've seen, so I decided to shoot it. The only draw back was a very long throat, but it shoots under .5 MOA so it got a reprieve. nhk

Gary Morgan
02-22-2010, 01:33 PM
I have a Hawkeye bore scope, and I've looked at only about twenty or so factory barrels, mostly Remingtons and a few Savages, a Browning and a couple of Steyers. So far I haven't seen but a couple that didn't have a bunch of boring or machining marks in the barrel. One of the good looking ones was a Browning and a Remington Custom shop AWR 300 RSAUM.

Custom shop, though, doesn't guarantee you a good barrel. I have a .220 Swift 40X barrel that looks as bad as the worst factory 700 barrels I've seen. You shoot that 220 Swift about 40 times, and it gets so coppered up that the bore gets too small and starts with a heavy bolt lift, and if you don't stop then, it starts popping primers.

Roger T
02-23-2010, 08:07 AM
Did a STAINLESS bore brush get used/turned in this barrel ? I have seen this style of marks on rifles where the owner past/present twisted a stainless bore brush in the barrel trying to get some stubourn copper out.

brian roberts
02-23-2010, 02:17 PM
the marks of the drilling, or perhaps afterward, the reaming of the steel blank that's going into the rotoforge(hammer forming) machine. The blank is drilled, then (probably) NOT reamed by Remington, then thrown in the rotoforge, and hammered out. Some conscientious manufacturers would drill it, then ream it, then LAP it, THEN rotoforge it into a quality blank for fitting to their rifle. But, "Joe Sixpac" jus' wans a gunn thet he maht lose fore jacklitin' dem derr :eek:, so we gots to make it cheep, so hell byit, eh?? ;) That is most likely what you are seeing here, and it would explain why you see these marks through both the lands and grooves, simply because there was no effort to smooth up the initial operation before rifling. HTH :)

bisley
02-23-2010, 04:18 PM
Just looks like girlfriends remington .308 barrel.
I thought the the barrel was no good,but she managed to shoot a 5 1/2 inch group at a 1000 yards.
She also came 3rd in the 2009 united kingdom bench rest association,1000 yard factory sporter class.Beaten on by two savage 6.5 x 284 NORMA f class rifles.

The only problem is that it's real pain to clean,this barrels a copper magnet.
I have gone more KG 12 tring to get the copper out,that the down side.
My plan is to run MOLY in this barrel,and hopefully that will kill the copper fouling.

Hey don't right the rifle off,it may be a shooter.