Home Forums Hunting & Shooting Gunsmithing Hot bluing affecting accuracy?

Good day, I have read on one of the benchrest forums that guys have experienced a decrease in accuracy when the inside of their barrels were blued.

Have any of you guys experienced this? Most guys I have seen around here do not plug barrels when they hot blue rifles and I found it interesting when I read about the accuracy problems guys have experienced.

Pieter

Even in the benchrest circles, very, very few shooters go to the time and expense of conducting scientifically meaningful studies to determine of their pet theories prove out or not.

Unless someone has had at least 10 blued barrels and 10 unblued barrels from the same maker all chambered with the same reamer shot from the same return to battery action in an underground tunnel with the same ammo at least 10 10 shot groups from each barrel with the group sizes compared for mean, median, and mode then I'll take such comments as a nice theory albeit unproven. Even then, it could just show that one type of barrel prefers one type of ammunition over another.

All that aside, I thought most br shooter use stainless barrels?

The oxide film that hot blue makes is so thin that it is difficult to measure even in a top notch metrology lab. I have never heard of it affecting accuracy in 50 yrs in the gunsmithing hobby.

Benchrest shooters are no different than many other segments of the shooting hobby in that they are ready to believe almost anything suggested by so-called experts even if it might violate physical laws. They are especially susceptible to anything that might excuse worse than average groups. In other words, forgetaboutit.

RAN

This shouldn't happen unless the bluing salt is causing rust and pitting inside the barrel .

I have been a BR shooter since 1985. We use 99.9% SS barrels. I have used a few CM barrels that barrel makers furnished me to test. Bluing hurts nothing. BR shooters will look for any excuse for a bad shooting day.

Benchrest shooter don't believe much of anything until they see it proven to them. With that said they will go to the ends of the earth trying every damned idea or thing that comes along in an effort to gain an advantage.

BR shooters will believe anything they are told if it comes from a source they want to believe.
I have seen no evidence to indicate that bluing has any adverse effect. I have shot quite few CM match barrels which were blued and they were among my most accurate rifles. Having said this, if I test a CM barrel, in the white, and it shoots exceptionally well, I am too much a coward to blue it!
As Butch pointed out, it is rare to see any serious BR shooter using a CM barrel. Barrelmakers make their select match barrels with SS because they can more easilt produce a very good barrel.
I used one CM barrel which was competitive but that was over thirty-five years ago and competitive then and now are different animals. Aggregates in the mid-2's were just fine in the mid-to-late seventies. Today, the same agg won't make ya puke but it probably won't win you much either. GD

Ask Frank Green of Bartlein Barrels. He uses more CM than SS on his match barrels.

Many years ago when I worked in the Browning Arms Co. gunsmithing shop we experimented with blued vs. unblued rifle bores and found no difference in accuracy.

I had a rifle blued and when it came back I couldn't quit getting the rust out of the bore.
Never did really understand what happened...

The bluing (rust) process actually helps eliminate micro sized imperfections. It's used by many to refine or smooth out bullet molds. Smoother surface on the slugs and they drop from the mold more easily than from untreated surfaces.

Thanks for the replies guys. I just found it interesting that when I read about this as have never seen guys around here plugging bores.

Thanks

Pieter

I would think the polishing process would be the culprit. It's real easy to ding up the crown if one is not paying attention to what he is doing.

Pieter,
Why would they need to do that?

Butch, in the same discussion that mentioned the accuracy problems, the guys mentioned plugging bores to avoid bluing the inside of the barrel. But I guess it is pretty clear that there is no need for that.

Pieter

you should never plug the bore on a gun that is going to be blued (with the hot salts method).
The solution is near 300 degrees and the plugged barrels will build up pressure and spew the caustic and very hot chemicals everywhere

Well, for those of us that are required (by any number of circumstances) to forego bluing the actual working surfaces of high $$$ Chro-mo barrels, I'd have to inquire as to:

A.) Why we've all been so successful at "plugging" these barrels before they ride in the salts ?

B.) Whether or not you have any CLUE as to how we do this PROPERLY,e.g. the nuts and bolts of the operation ?

GTC

I got a Douglas factory long chambered 260 barrel that was factory blued. They blued the bore too.

That rifle fouled fast. To break it in, I have to wear the bluing out of the bore. I can't wear it off when it is covered with Copper.

Properly plugging a barrel, prior to hot bluing takes a little care, and attention.

It's not all that complicated, and requires simple commonly available, off the shelf materials.

The gear used is not the sort that flies to the edge of the known universe, or brain surgery.

GTC

Typical thread, ain't nobody changed their mind.

Worth playing catch up here.

Right, wrong, mediocre, foolish or brilliant,....SOME folks don't want the working surfaces of their Carbon steel barrels screwed up with porous iron oxides. Thus, one honors their opinions, doesn't argue, and makes it so.

Had to dig this gear out this AM , and seal up a 45 caliber barrel that's getting browned. I've been sealing barrels with this gear and throwing it in everything but molten nuclear waste, without one hiccup or burp, or fart, for a long time. As I noted when this thread was at the top, we're not talking rocket ship parts.

Some All thread is fitted with a Chamber plug. The Auto AC O-rings are some sorta' silicone that holds up just a BIT better than common Buna N,...I use both



Here's an assortment of muzzle plugs in the larger BP calibers, .45, 40, 375. One can note that while they've had the unmerciful piss blued outta' them, the interior faces are still as machined,...bright metal ( well almost, some of the stuff's been sitting in a drawer for years.) dab of common silicone seals the face of the Nyloc against a common ROOFING WASHER, or something out of the toilet repair parts bin,.... to seal the crown.



Here's a shot of the crown, sealed. Typically the rifle will have been shot, "In the White". The meticulously cleaned bore is filled with the patron's Bullet lube of choice,.....poured in molten around the all thread. The all thread has Heat shrink spaced all along it's length, ....to keep the threads from hitting the lands. If I have no spec. for bullet lube, I just use TC 1000. If you're a lead bullet shooter,.... think about this for just a second or two, you'll deduce that you are "pre-treating" the bore. That's an item that they've been discussing forever, isn't it ?




Particularly in the case of cast bullet guns, I'd say that the concensus is that they clean easier, and foul less.

I have another drawer with .30 and 22 caliber setups, and have used them on all of my own builds, in those calibers.

There it is,....my U.S. $0.02.

GTC

GTC, thanks for the info and pictures.

Pieter

For whatever quirk of geographic choice, most all of the outfits whose Hot Salts operations I pester, horse trade, finagle, and cajole into accessing are WELL above 4,000 FASL.



Low altitude temps there, and enviable.

The last outfit I used is just below 5,000

Up there we run over 400 * F.,....going through propane like there's no tomorrow, on a four tank setup.

The barrel sealing setup pictured / described above saw ZERO problems, through at least 6 bluing runs.

GTC

You have my apologies.....you do know what you are doing.....

My caution was for the typical hobbyist who may not understand what they are getting into....


and yes my altitude here is just under 500ft, I usually blue around 275-290 degrees.

No offense taken, to any and all,...this is one of the FINEST pastimes going, the building / rebuilding of accurate rifles. It's in this realm of dialogue that REAL advances can be disseminated and good "dope" distributed. Humbly going on record to state that I've learned a whole lot here on this forum, and tend to read more than I post these days.

Funny vignette regarding the "two tone" effect that plugging the muzzle with a very concentric seal,...that being the finished product LOOKING as though it has been relined. I had two characters heatedly arguing about one of my rifles parked in a rack at a range, some years back,....one swearing up and down it was a re-line, the other yelling back that I'd just told him the week before that I only did .22 liners ( and at the time that was all I DID do).
That all-thread an O-ring set up is used here for rust bluing, as well.
Man, you do NOT want to get THAT crap into your barrel !

GTC

Good info on the bore plugs. Thanx for the pix. I never worried about it in bluing, but I want to start parkerizing and this looks like the way to keep it out of the bores.

I made a sets of bore plugs for when I blue, parkerize and plate. Mine releases pressure in the bore when putting it in hot solution, only down fall that I found is if you don't remove when the barrel is still hot there hard to remove, a vacuum holds them fast. I sold alot of these plugs on ebay.

Bluing at 400F Cause your at 4000'....Strange the Colorado School of trades blues at 270F and they are over 5000'.

400 would ruin any receiver or barrel by quickly turning it red.

You must be mistaken. Bore plugs are dangerous and a waste of time. Bluing does not effect accuracy. Been there done that.

Lefty C

I agree that it doesn't effect accuracy but I plug anyways. My bore plugs can't blow out

probably am, re: temps......perhaps it was 300°,...know it was a round #

You are mistaken about bore plugs being "dangerous".

GTC

I have a factory long chambered 260 Rem 10"twist #3 taper from Douglas. It is factory blued inside and out.

That is the fasted Copper fouling barrel I own.