Thread choke is killing me

Brad

Benevolent Overlord and site owner
Staff member
I could use my Surface but the iPad is so much more convenient. It goes everywhere I go In the house. Great for YouTube videos too, things like reassembly of a 1911.
 

Brad

Benevolent Overlord and site owner
Staff member
I would guess that the compound would lap the brass as we as the barrel.
Not really. I don’t resize my brass for lapping. No need for it. Maybe a tiny bit to just keep bullet from telescoping.
 

Ian

Notorious member
Grit embeds in the brass too. I don't risk it getting in my loading dies. Load once with laps and toss is my recommendation.
 

358156 hp

At large, whereabouts unknown.
I use the Wheeler Bore lapping kit. Mine is ancient, but I'm still using the original compounds. I have thinned them down a couple of times over the years though. I'll be going to the machine shop tomorrow, and will be taking empty containers to "borrow" some fresh lapping compounds. They have about six different grits of Clover compounds and I think it's probably time for some fresh stuff.
https://www.wheelertools.com/gunsmithing-tools/bore-lapping/bore-lapping-kit/299849.html

It's a decent kit, but the lapping plates are miserably small.
 

Tomme boy

Well-Known Member
I have shot lapping bullets in a couple of 9mm as they have not throat. I use the lee 120tc bullets that were gifted to me already impregnated and 0.7gr of bullseye. Then just shoot them into a bucket of brass in the basement. Lower than 0.7gr and it might not make it out the barrel. I am out of them now and need to do my AR9. I don't like to load them as short as they are to get them to not stick in the throat.
 

Hawk

North Central Texas
I got my lapping compound from Veral Smith. I got his kit and use his instructions.
Roll between pieces of glass and press down hard. Be careful not to break the glass.
Use old brass and throw awayit after one loading.
Usually doesn't take many rounds, but stainless steel may take more.
Shoot 8 or 10 rounds, clean thoroughly, check your progress. Repeat as required.
A very worthwhile endeavor. Can make a real shooter out of an awe s@*t gun.
 

358156 hp

At large, whereabouts unknown.
I always run lapping bullets in lots of six or five in revolvers to keep in line with the cylinder count. The cylinder throats "lap" too, just at a reduced rate compared to the barrel- 1 to 6, or 1 to 5, in most cases. Semi-autos & rifles are a different game entirely of course.
 

JWFilips

Well-Known Member
I ditch all brass used for firelapping. It's a good use for very tired brass.
Yes that Is a good Idea! That brass should not be used again for normal shooting.

I have only fire lapped mil surps , never a S&W revolver....I think I would be scared!

I inherited a number of tins of old Clover compounds from My wife's Dad! Some were never opened!
He was a firm believer in lapping Auto Vales himself in the 1960's.

Also Back about 10 years a go I did a photoshoot for Saint Gobain. They make industrial diamond powders. They gave me about 4 oz samples of all their grits.
I only had to do micrographs through a microscope so I only needed a pinch of each! They told me just to trash the bottles because they could not restocked because the seals were broken!
Well they were trashed....... right to my workshop! ;) !

Once you get to their 1000 grit series they are dangerous to your lungs and eyes so I needed to wear protection handling them.
(Their "ultra fine" series: I was told, can be put into solution and will not completely precipitate for 2 years)
I have used some of these grits to make lapping bullets for my 98 Saurer und Sohn Mauser
 

RedHawk357Mag

New Member
What bullet style is commonly used in typical revolvers? I got most typical styles SWC,WC, RN, RNFPs. I understand that bore riders are to be avoided as per Bear Tooth instructions. While looking on Accurate mold site I read a warning on a mold over there, I think it was a 36 180E, that it had a bore riding size which made me think maybe I don't quite grasp the concept of a bore riding bullet quite as well as I thought. Thanks.
 

Brad

Benevolent Overlord and site owner
Staff member
Revolvers will shoot about any bullet style.
What you need to watch for is having a band or portion of the nose that enters the cylinder throats that is too large to easily enter. Loaded rounds will become difficult to chamber. Size to the right size, a snug slip fit in the throats, and that is no longer an issue.
 

Brad

Benevolent Overlord and site owner
Staff member
Got it solved.
Thread choke wasn’t the issue, a rough forcing cone was. I had lapped the cone some but had a steep angle that didn’t allow me to get far enough into the bore to smooth it all out. I used a shallower angle lap and cut a little deeper. This cleaned the bottom of the grooves far better.

Fired 100 rounds today with PC and had zero leading.

I will be paying far more attention thorough forcing cones going forward.
 

Ian

Notorious member
S&W and Ruger have used the same chowdered-up step drill to form forcing cones at various poonts through the years. I really wanted a Taylor forcing cone reamer kit but the expense and lack of availability drove me to make and use laps.
 

Tomme boy

Well-Known Member
My Ruger looked like it was done with a chain sprocket it had so many grooves in it. I told them this and they sent me a Match Champion for the troubles of sending it back to them. It was still rough but nowhere near as bad as the GP100 I first bought.