Skip to comments.Fire Honing (bore polishing)
Posted on 08/18/2012 4:15:22 PM PDT by nomad
I`ve heard it refered to as "fire honing" or the process of polishing out minor bore imperfections thru the use of a fine grit dusted, low powered projectile, discharged thru the firearm. Does anyone have more info on this process and where one could find supplies?
Generally referred to as “Fire lapping” check out these people for a commercial setup:
I used their 22 cal kit for a pretty rough S&W Model 22A barrel that substantially improved accuracy.
Midway USA has bullets in various calibers that can be handloaded to polish the bore of a rifle or handgun barrel.
I would not worry about any minor imperfections unless the gun is shooting poorly.
With these older mil surps it’s usually a better bet to rework the muzzle crown because the crown is usually worn out or damaged from improper or excessive wear caused by the cleaning rod during cleaning
David Tubb sells bore lapping kits. www.davidtubb.com
Midway USA sells the pre-loaded ammunition in several calibers. The .223 just happens to be backordered.
Yup! Buy the cheap carb cleaner at WalMart works great.
Tubb final finish
you don’t need ammo to lap a bore, you can do it by hand.
I am completely of a divided opinion as for the need for this (see rdcbn’s post). I ‘think’ I improved a Savage 110’s accuracy doing this, but I’m not certain. If I did, the difference was small and could be attributable to operator error/deviation.
Then, last September, at 168 yards (why the odd distance...max range on that particular lane), with a Model 70 in 30-06, I shot a 7/8” 3-shot group. That rifle has the most unholy looking bore I’ve ever scoped and I’ve owned it from new in ‘94.
When I was building my last Savage 10, I followed the 50 round procedure Savage recommends for their barrels. I was more than happy with the outcome. It was kinda drawn out and took a while and several six packs and bore brushes to accomplish.
By the end of the break in, the barrel remains relatively clean and is very accurate for a suppressed 24”.
Not sure is this is what you are looking for, but the procedure is listed on the Savage website.
How do you hand lap?
ping for further ruminations...
The older gunsmithing books will have a description of this. Basically, you need to either cast a lap in your bore over a pilot that screws into a cleaning rod, or you upset a piece of lead wire until you have to wedge it into the bore. Coat with a very fine lapping compound and start pulling it through the bore.
You need to pay special attention to getting the slug to exit the barrel cleanly at either end - and this is where the fire-lapping is better than hand-lapping on a barrel that’s already cut to size and chambered.
Most custom barrels that are hand-lapped are hand-lapped prior to being chambered and crowned. I lop off 1 to 1.5” of the barrel blank at the muzzle end to eliminate any “belling” from the lapping. The chamber reaming eliminates the other end’s belling, so that’s not cut back as far.
Minor bore imperfections in a Moisin Nagant don’t matter, unless you have one of the sniper models.
How much is a new barrel or are they even sold?
Maybe a good cleaning would do the trick?
At any rate, you would want to make sure that any excess carbon or copper fouling is removed before fire lapping.
Found this interesting article about making your own electronic bore cleaner.