Gunsmithing bore darkening?

[Sirshredalot]

Ive got a 280ai barrel with about 600-625 rounds through it at this point....accuracy had faded and was sending flyers off target, erratic pressure signs...time to clean right?

So...i bought a teslong borescope, a 16oz bottle of boretech eliminator, new bronze brushes...etc. scrubbed the copper out(cr10)...scrubbed the carbon, and 25-30 patches later and a scrubbing with jb bore brite on a patch around a brush, the first half of the bore is still very dark...like carbon staining?

The last half of the bore is bright and shiny.

Throat erosion is minimal with fire cracking only in the first 1/16" or less. Ive not shot it since cleaning, but my questions are...

Should the entire bore be shiny?

What causes this darkness?

Is it detrimental?

I never let the bore get too hot, but i shoot in 90degree heat in direct sunlight...the tube heats up quickly and stays warm to the touch....5 shot strings, then 10min cool.

Did i ruin my barrel by only having ever cleaned with hoppes during break in?

Carbon causing pressure signs?

Loads after fireforming have been relativley warm?...59gr h4831sc(or 58gr rl23)/168gr @ 2850-2900fps...26" barrel.

I will try and upload pictures tomorrow...i am technologically challenged.

Please and thank you
Shred

 

[Sirshredalot]

start of throat.

Crown, before brake

middle of bore

 

[Ledzep]

Should the entire bore be shiny?

As you put rounds on it the first 6-10" will get black no matter what. You can clean with abrasives to get it shiny again but it's not worth the effort. Does nothing other than look different (and potentially abrade away too much bore).

What causes this darkness?

Carbon fouling

Is it detrimental?

If you let it build up, yes. It will cause accuracy and pressure problems.

Did i ruin my barrel by only having ever cleaned with hoppes during break in?

Most likely not, but the more you let build up, the harder it is to clean out. I suggest cleaning every 100-200 rounds (depends on caliber, some overbore and/or magnum chamberings could handle every 50).

Carbon causing pressure signs?

Yes.

 

[1moaoff]

Shoot the rifle, sell the bore scope, clean effectively with out going overboard, trust your barrel and results down range!!!!

Oh, take notes on your rifle!

 

[Steel head]

Barrel looks nice!
Clean it and shoot it.
You should see the bore on my 1500+ 7 saum!

Its scary looking but still hammering!

 

[Sirshredalot]

This puts my mind to rest...and my wallet...i had bartlein on standby.

One more question.

Wth is this?

This is before cleaning and it is not a shadow...last 2" of the barrel.

Please and thank you
Shred

 

[1moaoff]

Sell borescope

 

[Sirshredalot]

Ive heard that before, thank you...really.

I have real problems with this rifle though...it still isnt consistent with velocity or flyers.

Shot today after a deep cleaning.
3x 3 shot strings with 10 min cool downs(lighter barrel.. .685 muzzle od).

Error, 2963, 2957...10ish min....
3010, 3016, 3025...showing pressure.
Drop a grain of powder
2931, 2963, 2970

Hornady new 280rem brass, fireformed 2x, federal gold medal match magnum primer, rl23, nosler custom comp [email protected]"
Lee collet neck die, trimmed 2.215, vld chamfer, outside neck chamfered. No anneal yet...i have a home made annealer....annealeze clone(sorry annealeze...diapers and daycare come first)

Each short string is close velocity wise, but huge spreads in velocity over time., tried winchester lrp, cci lrp, federal standard primer, Winchester brass, lapua bullets, speers bullets, nosler bullets,, hornady bullets, hodgdon, alliant, etc.....same results...inconsistent velocity(sometimes huge spreads..150fps), inconsistent poi.

Im trying my best as a shooter, ive shot the best group of my life with this gun/barrel(1/3 moa@300)...but it wont do it twice in a row.

Bedding is good, scope is good, rings and mount are good,McMillan stock....it puts 3-4 consecutive shots into the same hole at 300yds then throws the next one or two 2" high and/or right.

Ive tried different dies(rcbs, hornady, lee..redding on the way), chronographs, powders, bullets, brakes, full length size, neck size, etc....even replaced my press....still getting shit compared to what the interweb says i should get...and frustration at the range.

Wasted a lot of time and money trying to get this gun consistent.

Im ready to rebarrel or re-learn reloading...or give up.

Shred

 

[1moaoff]

Have you considered asking some one to shoot the rifle? Not sure what your experience is.

Also some rifles shoot better dirty.

 

[Steel head]

Ive heard that before, thank you...really.

I have real problems with this rifle though...it still isnt consistent with velocity or flyers.

Shot today after a deep cleaning.
3x 3 shot strings with 10 min cool downs(lighter barrel.. .685 muzzle od).

Error, 2963, 2957...10ish min....
3010, 3016, 3025...showing pressure.
Drop a grain of powder
2931, 2963, 2970

Hornady new 280rem brass, fireformed 2x, federal gold medal match magnum primer, rl23, nosler custom comp [email protected]"
Lee collet neck die, trimmed 2.215, vld chamfer, outside neck chamfered. No anneal yet...i have a home made annealer....annealeze clone(sorry annealeze...diapers and daycare come first)

Each short string is close velocity wise, but huge spreads in velocity over time., tried winchester lrp, cci lrp, federal standard primer, Winchester brass, lapua bullets, speers bullets, nosler bullets,, hornady bullets, hodgdon, alliant, etc.....same results...inconsistent velocity(sometimes huge spreads..150fps), inconsistent poi.

Im trying my best as a shooter, ive shot the best group of my life with this gun/barrel(1/3 moa@300)...but it wont do it twice in a row.

Bedding is good, scope is good, rings and mount are good,McMillan stock....it puts 3-4 consecutive shots into the same hole at 300yds then throws the next one or two 2" high and/or right.

Ive tried different dies(rcbs, hornady, lee..redding on the way), chronographs, powders, bullets, brakes, full length size, neck size, etc....even replaced my press....still getting shit compared to what the interweb says i should get...and frustration at the range.

Wasted a lot of time and money trying to get this gun consistent.

Im ready to rebarrel or re-learn reloading...or give up.

Shred

Dump those magnum primers.
They are probably hurting more than helping

what crony?

 

[Sirshredalot]

Have you considered asking some one to shoot the rifle? Not sure what your experience is.

Also some rifles shoot better dirty.

I have considered that, but dont really know any other shooters...i know blasters and plinkers. I asked for help on a local forum, but plans fell through.

Dump those magnum primers.
They are probably hurting more than helping

what crony?

I have other primers to use...my second best results where with winchesters.

The chrony is a caldwell...its been replaced under warranty, same results. I shoot indoors with no other lighting to interfere within view of the chrono. Skyscreens and leds in use. I dont know anyone else with a chrony.

I know its cheap, but all this has to be done on a budget...my brother and i are saving to split a labradar.

 

[Ledzep]

I would try to get out to 600-800yd to verify if velocity spreads are happening. 150fps should show up in your elevation turret.

Fouling build up does slowly increase pressure and velocity over time. I've chronographed some 50-shot strings before (5x 10 shots) and you see a steady increase in MV but IIRC the worst ones I saw were maybe 30fps on the average. 150fps I've seen before, but it was a Savage 6.5PRC and it took 150ish rounds with no cleaning.

 

[1moaoff]

What part of the country are you in?

 

[Sirshredalot]

Central indiana.

Shred

 

[1moaoff]

Theres some guys over that way. I'm in southern oh