"Preferred Barrel Blanks" Vendor -- Opinions

[L.Sherm]

No, but the lap does. Can you tell me what makes the tool marks? The reamer in the bore after drilling or the button?

Exactly thats why if you dont pre lap a button barrel before the button is pulled
there will be tooling marks.

 

[L.Sherm]

If done correctly the bore reamer should take out the drill marks and about 30 pre laps take out any bore reamer marks

 

[butchlambert]

Drill or bore reamer.

Bore reamer or drill?

 

[KMart]

I see that they have an additional charge to lap the barrel. Am I wrong in thinking that is standard procedure for most barrel manufacturers?

Stan said Douglas doesn't. Someone made the comment that Douglas barrels were lapped.

From another thread.

Stan Taylor said:
You are totally wrong Douglas barrels are not lapped.

 

[butchlambert]

So this is only on button rifling? What is different in the drilled and reamed bore of a cut rifled barrel? No, Douglas didn't lap their barrels.

 

[redrockranger]

If done correctly the bore reamer should take out the drill marks and about 30 pre laps take out any bore reamer marks

Would you explain the Sunnen honing process and what it accomplishes . Thanks.

 

[L.Sherm]

Would you explain the Sunnen honing process and what it accomplishes . Thanks.

From my understanding it hones with a machine instead of hand lapping which I believe pac nor did or still does.

 

[L.Sherm]

So this is only on button rifling? What is different in the drilled and reamed bore of a cut rifled barrel? No, Douglas didn't lap their barrels.

What are you after Butch?

 

[butchlambert]

Would you explain the Sunnen honing process and what it accomplishes . Thanks.

It precisely sizes the bore and hopefully any tool marks. Is it worth the expense? I'm not sure.

 

[butchlambert]

What are you after Butch?

Sir, you have talked button barrels and I wonder why you haven't mentioned cut barrels. Do they not have tooling marks as they are drilled and reamed the same way?

 

[butchlambert]

From my understanding it hones with a machine instead of hand lapping which I believe pac nor did or still does.

Don't know about Pac Nor, but Bartlein tried it and may still be doing it as well Shilen tried it. I do not know if either are still doing it.

 

[butchlambert]

I'm off the net. Time to eat and do other things.

 

[L.Sherm]

Sir, you have talked button barrels and I wonder why you haven't mentioned cut barrels. Do they not have tooling marks as they are drilled and reamed the same way?

I have no experience with cut barrels.
Its not what I was referring to either was it.

 

[Machinist John]

I lap all new barrels in my shop. Just because.

Back to back ball bearings in the handle piece.

Rod guide screws onto barrel. Left hand piece is a adjustable stop so the lap will not exit the muzzle.

Breech end

Lap

Ready to lap. Note the grease fitting on the handle piece, to lubricate the bearings.

I have several lapping rods, they are interchangeable. Diameters to fit the bore size.

 

[JasonT]

What’s that lap made of? Looks like leather or something?

 

[6MMsteve]

I lap all new barrels in my shop. Just because.

Back to back ball bearings in the handle piece.

Rod guide screws onto barrel. Left hand piece is a adjustable stop so the lap will not exit the muzzle.

Breech end

Lap

Ready to lap. Note the grease fitting on the handle piece, to lubricate the bearings.

I have several lapping rods, they are interchangeable. Diameters to fit the bore size.

Give us a little class on lapping, I have no clue about it just like to kinda know the hows and why, if you don't it's fine if the wolves will stay sittin down and keep the paws off the keys

 

[Dave M.]

I came across their site yesterday while researching prefits for my shot out RPR. I wonder who’s blank they’re using?

I put a proof research stainless steel barrel on my RPR and had it chambered by Pierce Engineering in Lansing, MI. Shoots lights out.

 

[Mark W]

I put a proof research stainless steel barrel on my RPR and had it chambered by Pierce Engineering in Lansing, MI. Shoots lights out.

Thanks! I’ll check them out.

 

[Ray123]

Never used Prefered Barrel blanks, they seem middle of the road, not lapping unless requested is "interesting"...but I did look at their site, lots of twist rates non standard for button rifling. Might try an experimental barrel. I use Blanks from cut rifled barrels mostly, and Bartlein and Proof Research S.S., and a few button rifled from Shilen.
You can make your own polishing lap if ya have a lathe, and fit a 4" long piece of aluminum with a slip fit to your Dewey cleaning rod over the AR barrel extension or over the chamber end of the barrel...The long alum parallel section keeps the cleaning rod stiff and straight, a tight patch with Iosso paste and Kroil ...bump it in the bore with the heal of your hand and polish away and repeat. Clean with Kroil ... a few wraps of electrical tape on your cleaning rod will be your stop...you can feel the bore...in an AR polish burrs off the gas port, and you'll feel the gas port hole as you go by.
Do not polish in the muzzle area, but very lightly, and why you have the tape stop...imagine a .0001 bore taper slightly larger at the chamber and smaller at the muzzle...I do this instead of barrel break in, even on the Bartlein & Proof barrel as they can have a fairly coarse lap on some of their barrels. Check with a borescope...nice barrel finish. This May not be your cup of tea don't do it ... or ruin your break in proceedure, don't do it. Do what you're comfortable with, as barrels are expensive, and it's yours, and your dime.

 

[Ray123]

Boring, drilling, reaming, honing, lapping, grinding, sawing, turning, milling, forging, casting, printing, etc.. a few terms used to form metal into useful objects for use..and each term is a description of a different process used or required. Lapping and honing are different. Honing has a long thin stone attached to a quick change aluminum backing plate, with oil pumped in (cutting fluid). Lapping is a close fitting mendrel to the prepped hole with metal cutting compound applied to the lap and oil applied to abrasive cutting compound. Nice finishes more precise and slower process .. 8 RMS is possible with CNC milling machines. But we are talking holes, ...drills are for roughing in a hole, reamers are gettig correct diameter of the drilled hole, but leave perpendicular lines to the bore and fair finishes. The perpendicular lines going round in circles are reamer lines...more pronounced because of slight runout, the more runout the more lines and an inaccurate hole. A rifling button can smooth some of these out, but some will remain, the more reamer runout the more lines left, depending on the hole size and rifling button size difference. To get the lines out of reamed holes lapping before rifling will really help getting lines going in the direction of the bullet...both cut and button rifled barrels will have slight perpendicular reamer lines, (more serious lines ...the barrels should be discarded or re drilled/reamed to larger caliber) , before lapping. Sunen makes honing and lapping machines, I've ran their old honing machines, and gun drills...A hone is not what you'd use on a gun barrel it has rotational lines, even long cross hatched are rotational. A lap runs lenght wise just like a bullet, keeping copper foulingto a minimum... Todays barrels are probably machine lapped before rifling and maybe hand lapped after rifling. But this new computer controlled machinery may eliminate that...I think I prefer hand lapped for a finish but I'm retired from the industry. My last Bartlein barrel had a more cosrse lapped finish then I'm accustomed to...the last 2 Proof Research were better finished, lapped wise...