Why do we get fanatical over barrel alignment?

[tobnpr]

I'm sure some Smith's went to some Machinist School or were trained in a machine shop, But to say that self taught Gunsmiths are any less isn't fair at all, There are many top Smiths that taught themselves, And there are many shooters that do their own work and do very good work.

Eight years ago when I first set up my shop, I wasn't yet confident enough in some ops so I sought out a local smith that I had do some of my work. Nice guy, decades of experience, did subcontract work for a few well known manuf's, and local LE were frequent visitors. Two big CNC Bridgeports, and a Clausing lathe- crammed into his single car garage shop. Could barely get in the door.

Took a rifle that had come in for muzzle threading/brake and Cerakote to him to do the threading.
Picked it up and when I got back to the shop I test fit the brake and about hit the roof. I didn't know much at this point- but I certainly knew that the brake shouldn't be visibly crooked, which it was... Needless to say, it was at that point I realized that "experience" doesn't necessarily mean those that have it know what they're doing. He was one hell of a pistol smith, but I don't think rifles were his forte. In any case, threads concentric to the bore is pretty basic shit so that was the last job I gave him.

Buried myself in the Machinery's Handbook, some respected smithing books and bought a bunch of stock (first acetal, then steel) to finish learning myself. I well remember the unease at first- there's often no way to fix a "mistake" in this business, particularly working on a firearm that can't be replaced by simply ordering a new one online.

One thing I learned, is that most everything we do can be measured to determine whether it's "right".
Indicators don't lie, and the printing at the target isn't directly tied to how many years experience the person who did the machining has under their belt. Experience is much more relevant IMO when it comes to troubleshooting, and being familiar with the countless types of rifles from 150 years ago to present.
There's SOO much out there to know- which is why the old school "general gunsmiths" are all but disappearing. Many shops tend to specialize, just like medical practitioners- concentrate in a specific discipline. I don't do trigger jobs on Glocks and 1911's, and most pistol smiths don't build custom rifles.

 

[Sniperhandle]

One last thing and I'm done, John Moses Browning was self taught mostly, He learned a little bit from his Father, But no one will argue that he wasn't a very proficient machinist, But being a machinist is secondary in my opinion to a creative mind.

The Browning M2 is still in use and was created by a self taught GUNSMITH, A marvel of engineering by a man who had never been to any University or Trade School.

 

[gunsandgunsmithing]

One last thing and I'm done, John Moses Browning was self taught mostly, He learned a little bit from his Father, But no one will argue that he wasn't a very proficient machinist, But being a machinist is secondary in my opinion to a creative mind.

The Browning M2 is still in use and was created by a self taught GUNSMITH, A marvel of engineering by a man who had never been to any University or Trade School.

Sniper, I think you have taken my comments toward being self taught negatively, when that wasn't my intention. Again, there are many, many very good self taught gunsmiths out there, doing very good work. There are also things that can only be learned by training or study, like proper thread clearances and design. Threading to fit the part in hand works but it lacks standardization. Without that, you can't know that two parts will always fit on a non standard thread. That's all I was saying with that example used earlier.

 

[Sniperhandle]

I'm good, No offense taken. I doubt John Browning had thread wires.

 

[Sniperhandle]

Actually I've been to the museum twice, He used an 8" South Bend, Pretty primitive.

 

[Sniperhandle]

I


I never understood taper boring. Seems like extra work for the same outcome. I have a carbide reamer that prefers if I step bore the very start of the chamber, otherwise it squeals like worn brake pads.

I have never used a carbide chamber reamer, But my guess would be that you aren't turning it fast enough, Carbide wants to be turned fast, Where high speed steel not so much.

 

[LVLAaron]

I have never used a carbide chamber reamer, But my guess would be that you aren't turning it fast enough, Carbide wants to be turned fast, Where high speed steel not so much.

It liked 5-600 rpm - It DID NOT like the knife edge of the pre-bore on the shoulder portion of the reamer. So I bore a little ring on the breech end and soak it in rapid tap heavy for the first cut. Once it starts, it's very particular about feed pressure but manageable. The finish is unbelievable though...

 

[gunsandgunsmithing]

Actually I've been to the museum twice, He used an 8" South Bend, Pretty primitive.
View attachment 1370770
View attachment 1370771

Second drawer from the left. Lol!

 

[Sniperhandle]

Second drawer from the left. Lol!

I'm pretty sure you are right, That's where the thread mic is!

 

[WSnyder]

Most people claim the grooves matter most but I'm not sure how they quantify that statement.

Might it be that the land to groove ratio is highly biased to the groove? I know that’s what sways my bias towards the grooves as being more important to indicate to. As you said you must see what you have and decide what to do from there with whatever is out of whack.

Another thing is that I cringe a bit when people claim to bore to the same angle as the chamber, when chamber reamer makers only guarantee +/- 1/4 of a degree. Do the math on that.

Easy peasy and no math involved. Throw that reamer into the chuck pilot first then bring up that tail stock. Grab your indicator, put it on the compound and run it back and forth along a reamer flute adjusting the compound angle until your indicator doesn’t move anymore and lock it down. Now your compound is dead on to the angle ground into that reamer. Now I step bore chambers myself but if you want to angle bore it’s not hard to set it up perfectly to your reamer.

 

[gunsandgunsmithing]

Might it be that the land to groove ratio is highly biased to the groove? I know that’s what sways my bias towards the grooves as being more important to indicate to. As you said you must see what you have and decide what to do from there with whatever is out of whack.

Easy peasy and no math involved. Throw that reamer into the chuck pilot first then bring up that tail stock. Grab your indicator, put it on the compound and run it back and forth along a reamer flute adjusting the compound angle until your indicator doesn’t move anymore and lock it down. Now your compound is dead on to the angle ground into that reamer. Now I step bore chambers myself but if you want to angle bore it’s not hard to set it up perfectly to your reamer.

That's a good idea. Never tried it but I'm sure it works. Thanks!

 

[Sniperhandle]

Might it be that the land to groove ratio is highly biased to the groove? I know that’s what sways my bias towards the grooves as being more important to indicate to. As you said you must see what you have and decide what to do from there with whatever is out of whack.

Easy peasy and no math involved. Throw that reamer into the chuck pilot first then bring up that tail stock. Grab your indicator, put it on the compound and run it back and forth along a reamer flute adjusting the compound angle until your indicator doesn’t move anymore and lock it down. Now your compound is dead on to the angle ground into that reamer. Now I step bore chambers myself but if you want to angle bore it’s not hard to set it up perfectly to your reamer.

Now we are talking, This is the kind of info we needed here, That makes it simple!

And I would think since many bores are honed, The honed part would be the groove and so it should be the most accurate surface to indicate from? Or would it be the other way around?

 

[FireMedic]

Exactly right and exactly what most shooters SHOULD worry about. Anyone that doesn't understand that even a high end lathe has more runout from the FACTORY than what most internet posters EXPECT, should really focus on things that matter the most to their results. Let the smiths split those other hairs. I have trouble when smiths or anyone else starts splitting tenths, when they are self taught with a basement lathe. Sorry, but true.

I'm sure some Smith's went to some Machinist School or were trained in a machine shop, But to say that self taught Gunsmiths are any less isn't fair at all, There are many top Smiths that taught themselves, And there are many shooters that do their own work and do very good work.

I’d venture to say a lot of world records have been set with barrels that have came out of a self taught gunsmith’s basement.

 

[gunsandgunsmithing]

I’d venture to say a lot of world records have been set with barrels that have came out of a self taught gunsmith’s basement.

Yes, most of them, I'd say. Keep reading.

 

[Dusty Stevens]

Now we are talking, This is the kind of info we needed here, That makes it simple!

And I would think since many bores are honed, The honed part would be the groove and so it should be the most accurate surface to indicate from? Or would it be the other way around?

The honed part is the land. Cutting metal away makes the groove

 

[Sniperhandle]

The honed part is the land. Cutting metal away makes the groove

Yeah afterwards I thought about it and you are right, So the land on a cut rifled barrel should be good, But I will say my 2 most accurate rifles have button rifling. 1 is a Broughton and the other is a Hart.

 

[Dusty Stevens]

Yeah afterwards I thought about it and you are right, So the land on a cut rifled barrel should be good, But I will say my 2 most accurate rifles have button rifling. 1 is a Broughton and the other is a Hart.

On a button rifled barrel the honed surface is on both the lands and grooves

 

[jackieschmidt]

This is very true, imo. Also, machining isn't just putting a cutter to metal but about figuring out setups for doing it well. This is a lost skill set in an age of cnc programmers coming out of trade schools and where someone like Jackie truly excells in his trade. His pics show lots of impressive ingenuity.

I have taught quite a few young men though the decades, not only in general machine shop practice but also what we in shipyards called “outside machinist”, more commonly referred to as Millwrights.

the one thing I impress upon them from day one is while it is important to know HOW we do do things, it is just as important, perhaps even more so, to learn WHY we do things.

 

[gunsandgunsmithing]

I have taught quite a few young men though the decades, not only in general machine shop practice but also what we in shipyards called “outside machinist”, more commonly referred to as Millwrights.

the one thing I impress upon them from day one is while it is important to know HOW we do do things, it is just as important, perhaps even more so, to learn WHY we do things.

I agree sir! Kudos to you for trying to pass on your trade.

 

[Sniperhandle]

On a button rifled barrel the honed surface is on both the lands and grooves

Right, But dragging a button through it may change it, The cut rifled barrel shouldn't touch the land? I'm not arguing either method, I have both types and they all shoot good.