F
Frank Green
Guest
Donovan, Not an easy question to answer and no short answer! It's one of those things that it is more by feel at times than anything else. There are basic guide lines to follow but you are always changing things here and there.
To start with on finish lapping (we prelap our barrels before rifling also) after the barrel is rifle and cleaned out you cast a finish lap in it.
After it cools you apply some lapping compound to the lead lap. We mix/make the lapping compound ourselves. Same formula we use here that Tracy came up with when we we're at Krieger.
The lapping compound is usually either a 180 or a 240 grit is how it starts out. As you use it, it will break down to around 1000-1500 grit.
Now for all the variables. We mix our own lead also. If the lead is to hard or to soft the compound won't do it's job properly.
As far as the number of strokes? Again this varies. Why? The nicer the finish when the barrel gets out of the rifler from the tooling, the quality of the barrel steel etc...the less lapping that is needed. Remember the lapping process is being used to just give a final polish to the barrel. Also the nicer the finish the bore reamer left and the prelapping process (Prelapping is after the barrel is reamed and before it gets rifled) the easier the finish lapping process.
Check out Warner Tools website at www.warner-tool.com and click on custom rifles on the top of his page and scroll down to the middle of the page and look at the finish on the breech end of the barrel they get from machining alone. Getting a finish like that just doing threading is something you learn over time. Finding what insert works the best, with what type of material and the coolant being used etc....What I'm getting at here also is the prep time and the things you do leading up to the finish product.
It's like a guy who works in a body shop and paints cars. The more prep time and the tools and products you use and paying attention to detail thru out the process the nicer the finish product.
You shouldn't be using the lapping process to remove real heavy tooling marks from the reamer and rifling etc...you can go over lap a barrel also and change the sizes internally of the bore.
Number of strokes? As an average number say the 40-80 strokes. I can't give an exact number because of the variables involved. If the lap starts out working/cutting right away and the nicer the finish in the barrel before you started lapping the less strokes you will have to do with it.
After you pull the lap say 15-20 strokes you index it to another groove and you do another 15-20 strokes etc...Also on the last 15-20 strokes that we do we just add oil. No additional compound.
To me it's one of those things that some one should teach you the in and out of and you have to do it for a while. You won't pick it up doing one barrel here and there. Even a guy who has done it over and over again a lot of people cannot get the hang of it. It's one of those things that is done by feel and you cannot teach feel. Either you have it or you don't. It's not one of those things where you look at a step by step instruction booklet and it comes out the way the instruction book shows.
As far as making a video? Neat idea but a lot of other barrel makers would like to see that one. What we do here we pretty much keep to ourselves. So I don't think a video is any where in the future plans even though it would probably sell like hot cakes.
I would offer this to you. If you are ever in the area and want to stop in we would be happy to show you around and a thing or two
.
Give me a call. I can usually answer your questions faster and in more detail on the phone.
Later, Frank
Bartlein
262-649-1574
To start with on finish lapping (we prelap our barrels before rifling also) after the barrel is rifle and cleaned out you cast a finish lap in it.
After it cools you apply some lapping compound to the lead lap. We mix/make the lapping compound ourselves. Same formula we use here that Tracy came up with when we we're at Krieger.
The lapping compound is usually either a 180 or a 240 grit is how it starts out. As you use it, it will break down to around 1000-1500 grit.
Now for all the variables. We mix our own lead also. If the lead is to hard or to soft the compound won't do it's job properly.
As far as the number of strokes? Again this varies. Why? The nicer the finish when the barrel gets out of the rifler from the tooling, the quality of the barrel steel etc...the less lapping that is needed. Remember the lapping process is being used to just give a final polish to the barrel. Also the nicer the finish the bore reamer left and the prelapping process (Prelapping is after the barrel is reamed and before it gets rifled) the easier the finish lapping process.
Check out Warner Tools website at www.warner-tool.com and click on custom rifles on the top of his page and scroll down to the middle of the page and look at the finish on the breech end of the barrel they get from machining alone. Getting a finish like that just doing threading is something you learn over time. Finding what insert works the best, with what type of material and the coolant being used etc....What I'm getting at here also is the prep time and the things you do leading up to the finish product.
It's like a guy who works in a body shop and paints cars. The more prep time and the tools and products you use and paying attention to detail thru out the process the nicer the finish product.
You shouldn't be using the lapping process to remove real heavy tooling marks from the reamer and rifling etc...you can go over lap a barrel also and change the sizes internally of the bore.
Number of strokes? As an average number say the 40-80 strokes. I can't give an exact number because of the variables involved. If the lap starts out working/cutting right away and the nicer the finish in the barrel before you started lapping the less strokes you will have to do with it.
After you pull the lap say 15-20 strokes you index it to another groove and you do another 15-20 strokes etc...Also on the last 15-20 strokes that we do we just add oil. No additional compound.
To me it's one of those things that some one should teach you the in and out of and you have to do it for a while. You won't pick it up doing one barrel here and there. Even a guy who has done it over and over again a lot of people cannot get the hang of it. It's one of those things that is done by feel and you cannot teach feel. Either you have it or you don't. It's not one of those things where you look at a step by step instruction booklet and it comes out the way the instruction book shows.
As far as making a video? Neat idea but a lot of other barrel makers would like to see that one. What we do here we pretty much keep to ourselves. So I don't think a video is any where in the future plans even though it would probably sell like hot cakes.
I would offer this to you. If you are ever in the area and want to stop in we would be happy to show you around and a thing or two
.Give me a call. I can usually answer your questions faster and in more detail on the phone.
Later, Frank
Bartlein
262-649-1574