The Rohrbaugh Forum

Rohrbaugh Products and Accessories => Cleaning and Maintenance of the R-9 => Topic started by: flintsghost on May 03, 2011, 03:15:10 PM

Title: Lapping the bore
Post by: flintsghost on May 03, 2011, 03:15:10 PM
I had read with some interest that some members who had fired and cleaned their pistols had noticed darkening around the edges of the lands and grooves of their bores that did not seem to want to come out with normal cleaning.

One thing that I had done in the past was to use a product called "JB Bore Cleaner" to restore older rifle barrels that looked like they had seen better years.  I had found in the past that this paste bore cleaner, which is intended to removed built up jacket fouling in a bore, has restored accuracy and seem to polish older rifle bores.  It is not intended to nor will it remove pits.   However it is an extremely fine abrasive paste compound and does obviously lap barrels when used.    

Lapping a bore is the final stage used by barrel makers who use the hook cutter method, i.e. Obermeyer, Chanlyn, Koozer and others, to give a final polish to the bore to remove any roughness or tool marks prior to sending a blank out.   In the case of both my own and my son's R9S's I did lap the bore with JB bore cleaner for about 10 minutes each prior to initial firing and did the same again after first range use.   Based on the accuracy of these two I would say it worked.

To lap a barrel it is suggested that one uses a vise with leather padding around the barrel.  I apply a liberal amount of paste to a Q tip and spread it inside the bore.  I also apply paste to a large patch and using a rod with a jag tip, push the patch into the barrel.  I put my finger over the muzzle end and that allows me to stop the patch before it exits the bore.   I work it back and forth for about 5 minutes and then remove it, respread any paste that has accumulated at the edges and add a bit of oil to the patch.  Then reinsert and polish briskly for another 5 minutes.   Then done and clean all residue off and keep patching it till a patch comes out perfectly clean.

An alternative and more correct manner would be to insert an old rod with a jag from the chamber end and hold the barrel vertically in a vice.  Using a patch around the rear of the jag to prevent anything from going by pour a small amount of molten lead into the barrel and allow it to cool forming a perfect lap on the end of the rod.   When it has cooled hard, pull it out and coat it with the bore cleaner and lap as before.  It will be a perfectly form lap to the lands and grooves and thus would be more efficient than a patch made lap.   The heated lead won't hurt the barrel at all as a bullet fired would develop higher temperatures, but it will form perfectly to the lands and grooves.

It works and for anyone who has had accuracy problems or believes that the barrel is a bit rough, this method with remove the roughness, eliminate the dark edges of the lands and groove and will also enhance accuracy.   The lead is soft and will not wear the barrel.  It will only help the lapping compound get where it needs to be to enhance the lands and grooves.
Title: Re: Lapping the bore
Post by: MRC on May 03, 2011, 05:13:55 PM
I am one of several members who have R9's with tool chatter marks the whole length of the bore.  Both of the R9's I have owned have had this.  I sent pictures  to Rohrbaugh of the first one and was told by Eric through Maria that this is normal for their "Old World Broached Rifling Method" and if the pistol functioned why would I care.  That pistol did not function and after I got mad they bought it back.

The second R9 is rough, but not nearly as bad.  I asked Eric about lapping the barrel and he said by the time the barrel was smoothed up, it would be out of spec and worthless.

flintsghost - If you would PM me your e-mail address, I would like to send you the pictures of the bore for your comments.  I would like to see if you think it is acceptable.
Title: Re: Lapping the bore
Post by: flintsghost on May 03, 2011, 09:17:11 PM
Got the pictures and for the record, I don't think that it would be acceptable to me.   Good luck
Title: Re: Lapping the bore
Post by: MRC on May 03, 2011, 09:22:44 PM
Thanks
Title: Re: Lapping the bore
Post by: sslater on June 09, 2011, 12:05:47 AM
The barrel on my very early R9 looks like the descriptions in this thread, and it bothered me, too.
Then I came across an article in an old issue of one of the popular gun magazines. (I'd write the name and date if I could find the darned thing again - way, way too many gun magazines in this house!)  The author is an old-timer tech editor who had just bought a Hawkeye Bore Scope and used it to compare rifling in a bunch of rifles he had on hand.  He looked at button rifling, single point hook (cut) rifling, etc.

I remember thinking my Rohrbaugh barrel looked just like the cut rifling photos in the article.  So the marks are not chatter, but witness marks from a single point cutting tool.  The Rohrbaugh comment about old-world broached rifling is a bit confusing.  I'd expect broach marks to be lengthwise....

As I recall (and I sure wish I could find that magazine again!), the author commented that his field experience indicated all types of rifling could yield good field accuracy, but cut rifling seemed to have a slight edge.

flintsghost's JB Borepaste lapping method sounds like the way to go if I ever get tired of compulsively scrubbing the bore of my R9 after every range session of 13 to 20 rounds.   ;D
Title: Re: Lapping the bore
Post by: MRC on June 09, 2011, 09:25:07 AM
JB's is a great product and I use it in cleaning nearly all my guns.  It is a very mild and "non-embedding" abrasive.  I spent a lot of years in the benchrest and long range precision rifle game and that is where I got to using it.  I have lapped rifle barrels and the lapping compound you use is a lot more abrasive than JB's.  JB's is closer to toothpaste than the lapping compounds I have used.

I sent pictures of my barrel to flintsghost and he agreed that there is not enough JB's in the world to smooth up that barrel.  His opinion was the rifling was broached with a very dull tool or there was something wrong with the machinery.  Why Eric Rohrbaugh would deem this barrel "good enough" is beyond me.

I like the R9 alot, but two things bother me;

   -Their use of barrels anyone else would reject
   -The undersized grip screws which require factory returns to fix.

Title: Re: Lapping the bore
Post by: tracker on June 09, 2011, 12:52:43 PM

Change out the factory screws with John's excellent screws and your outlook will become more positive. The barrel thing must have come about in recent years because I don't notice it on a 2004 model. I use JB also.
Title: Re: Lapping the bore
Post by: MRC on June 09, 2011, 01:39:13 PM
I switched to John's screws when I put the VZ grips on.  I hope that solved that problem.

I have  or had 2 R9's with serial #4XXX range and both have barrels that Kel tec would junk.

Spending a lot of time with benchrest rifles I learned that most things on a gun can be fixed.  Be it trigger, stock, scope, or bedding, they all can be repaired.  If the barrel is bad, throw it away as there is no fixing it.  A gun is only as good as it's barrel.
Title: Re: Lapping the bore
Post by: Joe_from_NY on June 09, 2011, 06:01:04 PM
Quote
Got the pictures and for the record, I don't think that it would be acceptable to me.   Good luck

How about posting a sample of the photos for the rest of us to compare ours to?
Title: Re: Lapping the bore
Post by: Reinz on June 09, 2011, 06:03:23 PM
I bet the Brothers will just love that.  :'(
Title: Re: Lapping the bore
Post by: Joe_from_NY on June 09, 2011, 06:10:35 PM
Quote
I bet the Brothers will just love that.  :'(

On the Seecamp forum, we routinely post photos of any mechanical anomalies encountered with our guns, and the owner of the company seems to appreciate it, as he comes on and addresses it and we all can give our experiences and opinions. Most of the time it is minor and inconsequential, and it is good that the gun owner's concern was put to rest.
Title: Re: Lapping the bore
Post by: Joe_from_NY on June 09, 2011, 06:17:08 PM
does anyone know the user names that the brothers use on this forum?
Title: Re: Lapping the bore
Post by: Reinz on June 09, 2011, 06:29:38 PM
Quote

On the Seecamp forum, we routinely post photos of any mechanical anomalies encountered with our guns, and the owner of the company seems to appreciate it, as he comes on and addresses it and we all can give our experiences and opinions. Most of the time it is minor and inconsequential, and it is good that an owner's concern was put to rest.


Yeah, but they have already dismissed the barrel issue.
Title: Re: Lapping the bore
Post by: Reinz on June 09, 2011, 06:30:41 PM
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does anyone know the user names that the brothers use on this forum?


I could be mistaken, but I believe that they are just lurkers.
Title: Re: Lapping the bore
Post by: Joe_from_NY on June 09, 2011, 06:32:03 PM
Quote


Yeah, but they have already dismissed the barrel issue.


Even so, there are alot of knowledgeable guys on this board who have many years of experience who might be able to give their opinion on the issue.
Title: Re: Lapping the bore
Post by: Joe_from_NY on June 09, 2011, 06:34:43 PM
Quote


I could be mistaken, but I believe that they are just lurkers.

thats funny, since Brother Eric is extremely active as ECR  on
http://www.longislandfirearms.com/forum/v-memberpanel/a-view/u-54/

with over 3700 posts.  He makes good interesting posts there.
Title: Re: Lapping the bore
Post by: Reinz on June 09, 2011, 06:36:27 PM
Oh, no, I would love to see the pics!

I was just saying earlier, that the Brothers would consider it a headache, that is if people started calling in thinking they all had barrel issues all of a sudden.
Title: Re: Lapping the bore
Post by: Reinz on June 09, 2011, 06:39:45 PM
Quote

thats funny, since Brother Eric is extremely active as ECR  on
http://www.longislandfirearms.com/forum/v-memberpanel/a-view/u-54/

with over 3700 posts.  He makes good interesting posts there.


Now that is interesting.
Title: Re: Lapping the bore
Post by: kjtrains on June 09, 2011, 10:49:08 PM
Quote
does anyone know the user names that the brothers use on this forum?

I don't think they have user names on the Forum.
Title: Re: Lapping the bore
Post by: backupr9 on July 02, 2011, 06:29:12 PM
POST THE DANG PICTURES.  IF THE BROTHERS DON'T LIKE IT, THEY CAN QUIT SELLING THE PISTOLS.  I DON'T KNOW OF ANY OTHER FORUM THAT WORRIES ABOUT THE MANUFACTURERS FEELINGS IF THERE ARE ISSUES WITH THE PRODUCT.  

My pup is in the 3200 range.  Barrel looks OK without bore scope.  At 7 to 10 yards it holds 3-4" on bullseye freehand one or two hand presentation, so I have no gripes at this time.  John
Title: Re: Lapping the bore
Post by: kjtrains on July 02, 2011, 07:36:58 PM
Quote
POST THE DANG PICTURES.  IF THE BROTHERS DON'T LIKE IT, THEY CAN QUIT SELLING THE PISTOLS.  I DON'T KNOW OF ANY OTHER FORUM THAT WORRIES ABOUT THE MANUFACTURERS FEELINGS IF THERE ARE ISSUES WITH THE PRODUCT.  

My pup is in the 3200 range.  Barrel looks OK without bore scope.  At 7 to 10 yards it holds 3-4" on bullseye freehand one or two hand presentation, so I have no gripes at this time.  John

Don't concern yourself with the brothers.  They want to know of any issues that are out there.    :)
Title: Re: Lapping the bore
Post by: tracker on July 02, 2011, 08:23:56 PM

They already know about this one but it is a concern to multiple forum members.
Title: Re: Lapping the bore
Post by: Relic on July 07, 2011, 12:33:02 AM
I'd like to see some bore pictures.  My bore isn't polished to perfection, it does look a little rough, but my R9 can shoot 2" 5 shot groups at 15 meters, if I do my part, of course.  I've posted a 1.75", 15 meter 5 round group picture here on the forum (my best to date with the R9).

Obviously these are slow fire groups, but my R9 seems to be a tack driver.  I'm stunned with the accuracy potential of this pistol.  Maybe I got the gem?

Is there an accuracy concern with the rough bore, or is this just a cosmetic issue?
Title: Re: Lapping the bore
Post by: Relic on July 07, 2011, 12:14:05 PM
OK, I have to agree, that is a butt-ugly bore.  Thanks for the pix.  Mine is similar but not quite so rough.

The rough bore doesn't seem to affect the accuracy.  So, at least for my R9, it's just a cosmetic issue.  But it sure is some ugly machining on an otherwise gorgeous pistol.
Title: Re: Lapping the bore
Post by: sslater on July 07, 2011, 01:16:23 PM
I suppose there would be the occasional bad guy who objects to being center-punched with a grungy-looking bore.  :o

Seriously, the rough finish of the lands does make cleaning a pain but the R9 shoots pretty darn good for such a little squirmy gun.
Midway gets to sell me lots of patches and bronze brushes.

Incidentally, I found that my particular gun with my particular style of hold requires a six o'clock hold.  I'd been holding center of mass and was pretty inconsistent from session to session.  Now I'm getting good, tight little groups at 7 and 10 yards.  (Sometimes....)


S.
Title: Re: Lapping the bore
Post by: Relic on July 07, 2011, 05:10:40 PM
For paper punching I find a 6 o'clock hold works most consistently for me, also.  It's simpler to align the same way for each shot.

As far as cleaning, a couple of minutes of solvent and a couple of run throughs with a bore snake are plenty clean enough to hold 2" slowfire groups at 15 meters.  I clean after every shooting session, however.

I see little, if any, copper buildup at these velocities and the low round counts these pistols see.  But if you like scrubbing, by all means, enjoy.  :)
Title: Re: Lapping the bore
Post by: JohnBT on August 30, 2011, 06:32:47 PM
"Lapping a bore is the final stage used by barrel makers who use the hook cutter method, i.e. Obermeyer, Chanlyn, Koozer and others, to give a final polish to the bore to remove any roughness or tool marks prior to sending a blank out. "

BUT, however, wait a minute, that's not the whole story.

That blank you're talking about gets the ends trimmed when it's chambered and crowned. If you go lapping a finished barrel you could ruin it.

Read the Lilja FAQ called "Why is there a saw cut near the muzzle end of your rifle barrels?"

www.riflebarrels.com/faq_lilja_rifle_barrels.htm#hand

Because lapping wears the ends of the barrel more than the center section.