Got my Teslong today.  Didn't take long to discover why I've been so frustrated with my Rainier Match .308 the past few months.  They make a barrel that's unbelievably accurate, for a short window of life.  Less than 2k rounds on this tube.


Borescope2 by Professor Horseyhead, on Flickr


Borescope1 by Professor Horseyhead, on Flickr

Wow. Neato...also, sucks.

Surely there are better barrels out there. 2k rounds seems really low.

It looks to me like you are only seeing the throat and leade.  Those bore scopes have freaked more people out than they’ve helped.  Personally, I’d keep looking for your problem because I see nothing that gives me concern.

What did the group size fall off to?

Seems common knowledge is around a 4-5k accurate service life for a 308 barrel.

What defines "Unbelievably accurate" and does 2k rounds seem reasonable?

If it were a bolt gun having the barrel set back wouldnt be too big a deal.   A semiauto a bit bigger problem.   But are we talking still sub MOA a majority of the time?

So all that sharp rifling and then one area where it's all worn away and looks like someone sanded the fuck out of just a tiny part of the barrel, that's normal and totally acceptable?

.5-.75" at 100, 1-1.25" at 200 with FGMM 175 and 168 last summer, and now 2.5-3" at 100 for same.




Apparently not all of them.



See above, for a gas gun with me as the shooter, I was wildly happy with what it did originally.



Of course it doesn't.



Yes I'm aware of all that.  I wasn't asking for assistance. I've been around a long time this is just a new account.



No. 2.5-3MOA with factory match ammo and multiple shooters churning out sub-MOA with gas guns and sub-half with bolt guns in the same range session.

I’m as far away from an expert as one can get and I thought we were looking at the throat/leade as well.

Look at the video.  There's a clear demarcation on the rifling (chamber is to the "right" in the video/photos) for most of the circumference except the photos which look like someone put something in there and ground the rifling away.

Those are machining marks. I’d wager the reamer wasn’t centered/concentric. Did you scope the barrel new?

Borescopes are wonderful tools for the majority of people to find features of a barrel that they are unqualified to identify.

And great for spreading panic.

The reamer has the throat cut into it where there is no rifling left and the area where the bullet rests in front of the case mouth.  This area can vary in length from almost nothing to quite long.  This is also called the freebore.  Then it tapers from no rifling to full rifling.  This area is called the leade. The reamer cuts the taper from the throat to the rifled bore so you gradually see the rifling vanishing in the leade section.  That’s what I think you are seeing.  My opinion is worth what you are paying for it but I’d wager if you check other barrels with that bore scope you’ll be thinking all your barrels are shot out.  My advice, return it and get your money back.  Unless you are very familiar with what you are looking at they cause more trouble than they’re worth and spread panic faster than CV-19.

Took the mirrored portion off so you can see how uneven the rifling is past the freebore.


no mirror by Professor Horseyhead, on Flickr

edited
2k seems low for a 308, but I don’t think it’s shot out.

@SuperJLarge this isn't a buy/sell forum.  ~d16man

I never offered to buy anything, but was willing to try and help troubleshoot.

It's already earmarked.

 
So the leade is cut with rifling in one side of it but not the other side? That seems like an impressive task since everything is spinning when being cut.  How do they keep rifling on one half but not the other?

Because that's what we're looking at if you look at the video and/or the most recent photo i just posted.

For comparison I just went thru my 22" Criterion Creedmoor barrel and all the rifling starts in the same location around the circumference, as opposed to the barrel in question which has some very strong rifling and some not even in existence.

Shitty reaming. If that was straight, it'd probably be fine.

That is the kind of information I was looking for.

Yeah that is a hell of a change.   If you are losing throat like that in a bolt gun just seat out further and see if y9u restore accuracy.   But with a semiauto the magazine length makes that a pain.

I have a 300WinMag PSS that is accurate as hell with handloads but that is because I seat almost .250 further out than what you would see with Federal Gold Medal 190grn.   But I dont see the groups with FGM due to the jump.



My JP Enterprises 25in bull in 223 shot accurate as hell with tons of loads for better part of 2500 rounds.   Now I am starting to have to handload to get subMOA groups.   But for a semiauto I am still pretty pleased.

Going to 3moa would suck.

If the rifling is as suspected then it seems it was reamed with an undersized pilot and allowed to drift and not indexed, zeroed, properly before reaming.  If that's the case, I am amazed that it ever shot well at all.  If it shot so well to begin with, 2K rounds are not enough IMO to wear the throat and leade so much as to cause a problem, unless you were doing mag dumps and burning the throat up, but it doesn't look like it has been mistreated.  And the situation would have deteriorated gradually, not gone to hell all at once.  Before doing anything I'd be checking the barrel nut to make sure it has not cracked and loosened, make sure the scope mounts have not gotten loose or the scope given up the ghost.  The only time I have ever had a rifle go to crap all at one was when one of those cheap assed PA QD mounts on a red dot broke on my .475 TREMOR.  It went from a good shooter to a shotgun.  The other time is when my Leupold VXIII LR 8.5-25, which had been on my .50 BMG for years but I have been using it over the last 5 years as a test scope for load development, when it seemed I could not shoot consistently good groups anymore.  I thought it was me at first because I am older than dirt, but then when it started going out of focus, I sent it back to Leupold for a once over.  It had broken and once back, I found I was not too old to be shooting after all.

This. Barrels wear there first. But, that barrel looks to have plenty of life left.

Did you look at it/take pictures of that area when it was new?

I ask because I bought one of those bore scopes the other day and I've been looking at three new pistol barrels.  Storm Lake, EFK Firedragon and Apex barrels I've bought for some pistols.  That circular pattern across the lands/grooves is in one of those new barrels.  One of them has stains/dark spots, scratches, patches of what looks like either pits or humps, or both in the chamber and spots in the barrel.  One of them is just a little rough looking here and there.

That bore scope may just scare the hell out of you.  Check out a few barrels and compare the images of ones that shoot good (to suit you) vs. the ones that don't and you may find ugly barrels that still shoot good.  That may indicated a loss of accuracy is due to something else, not barrel wear.

The best shooting (well, second best shooting) center fire semi-auto pistol I've ever shot is my old P07 Duty.  With the naked eye it has always looks like a polished gray mirror.  With the bore scope it was just floored by the appearance of gouges, scratches, dark spots/patches, etc.  The ugly appearance affects the accuracy (in that barrel) not at all.  I clean that pistol every time I shoot it.  I've shot it for 8 or 9 years and it's my EDC concealed pistol.  I cleaned the barrel on it and the three new barrels above with Bore Tech Eliminator to remove copper residue and carbon fouling and it was cleaner than any of the new barrels.  Less evidence of copper fouling and carbon build up based on the color of the patches.  And with the bore scope it's kind of scary looking.  But it sure does impress me with the small groups it shoots.

I haven't been impressed by the two Rainier Match barrels I've had at all.

The first was a 308 with their match chamber that I cant get to feed anything more than 2 rounds at a time. The second is a 18" 223 Wylde SPR barrel I got 2 weeks ago. Inspecting the bore I noticed a large burr or something about halfway down the barrel and I cant clean it out with a brush, patches or boresnake leading me to believe it's a manufacturing defect. I'm still waiting on a scope for this build so I have shot it yet. Should have went with the Douglas from CLE like I had originally planned

It is chambered with a solid pilot reamer. That is why it is off to one side. That is why you have a floating pilot to center the reamer. It is a cheap production barrel. You think that is bad you should see RRA barrels. Straight from the inventory shelf they are worse.

Clean it thoroughly. It looks like a lot of built up copper in the chamber neck area. I use a copper removing solvent and follow the instructions. Sweet's is my go to, but others work fine.

If you still don't get satisfaction I would try David Tubb's Final Finish bullets after a thorough cleaning. You have nothing to lose if the barrel is "shot out". I've had many worn out match barrels and even a Mini-14 start shooting better after using his product. I would never recommend this for a new barrel, buy it can bring an old one back to life.

I have used Rainier's Select Match barrels and have been happy with them. Have you engaged in magazine dumps and hip shooting? Most barrels are ruined by high heat. .308 gets hot a lot faster than .223.

I think the new wave of affordable bore scopes is going to cause more concern for consumers and questions for vendors than are likely warranted.

I had a factory 700 that had noticeable scratches in the lands/groves. No bore scope needed, it looked rough. The rifle still shot close to half moa. Low std. dev. numbers and numerous sub 4” groups at 600yds.

Believe the bullet and the results, especially on a new barrel. If a barrel starts to go south, then check it out to see if there are noticeable concerns. But, you have to know what you’re looking at, and what impact it can have.

I’ve had friends whose gas gun barrels were shot out, only to have a loose gas block or scope and viola, the barrel started shooting again.

99% don't know what they are looking at. Just because it looks bad does not mean it will not shoot well. The throat and crown are the main things to worry about. That throat does not look too bad. Find someone to re crown the barrel and go from there. Or look up the poormans crown tool. I have done this and it has worked very well.

Everything on the rifle was appropriately tight.  Optic was replaced with the one that was on top of my varmint rig (white oak barrel, 1/2MOA 5-shot gun, 10 round groups hover around 3/4) and known to be fine, same result, ruling out the scope/mount.  Barrel nut is the MATEN specific nut (not the megalithic, the MKM version with the extended upper face and handguard that attaches directly to the upper) and it's fine, undamaged, and was properly torqued IAW Mega's written instructions.

It is what it is, just waiting on BHW/CRA to get to my order.  Got it apart and the barrel is headed to a friend who teaches an armorer's course to use as a teaching aid.  I have plenty of rifles to shoot in the meantime until the new barrel arrives.  

As mentioned above everything was checked after the first bad outing.  Barrel nut was removed/inspected, and everything put back together with an armorer friend next to me just to ensure i wasn't completely boning something basic (i only mention because i've definitely done that before ) and he was over at my place anyway machining some 80s.  

Everything was cleaned thoroughly, important bits relubed, and back to the range with the known good hunting and BTHP handloads as well as some FGMM in hand.  Still couldn't get a decent group out of it.  Even swapped the muzzle device over to a crush washer *JUST* in case, but that didn't do anything different either.

Ah well.  C'est la vie.  I've had other non-related issues with this specific MATEN on numerous other occasions so it's kind of expected at this point

not sure when the BHW barrel will arrive (could be next week, could be next month, they're CRAZY backed up due to that smokin sale they've had running) but i'm not in any huge rush to get it.  When it comes, i'll report back with an update.  Appreciate you and everyone else taking the time to sound off with suggestions.

I will say this was plagued with feed issues early on, and i discovered I *NEEDED* to be running a small-base die and FL sizing every time as the chamber is/was quite tight.  My 700 that was rebarreled by CCA and an astonishingly good shooter I could easily get away with 2-3 jaunts of neck only before i needed to FL size again.

Hopefully the BHW tube remedies it.