stchasking

I pulled the second valve slide and the main tuning slide and mic'd the inside diameter as 0.457-0.460. Do you all agree that the nominal for Bach L is 0.460?

That doesn't seem all that large. Schilke shows 0.460 as ML
and M as .450.

I just found this: Bore sizes

camelbrass

I always though a large bore Bach was .462


Regards,



Trevor

IAmBrassman

Bore sizes are relative, vary manufacturer to manufacturer, and even vary over time. I'm not very familiar with Schilke, but that designation and size does not surprise me. A few other thoughts / comparisons for your reading pleasure:

Bach original bores were 0.448", 0.453" and 0.462" and were called small, medium and large bore repsectively. After the 0.468" bore was introduced, it was originally called extra large, but later these four sizes were adjusted and designations changed. [This section of original post removed -- more accurate information below].

Getzen refered to their 0.460" horn as medium-large, and the 0.464" as large, back in the 1970's. They also offered a 0.458" option that was the 'symphonic' medium-large.

Callet's horns are all typically larger bore than most commercial horns (exclude other large bore specialists like Flip Oakes and others). He designates the 0.460" as medium-large and the 0.464" as large in the Superchops/Stratosphere series, but also offers a horn with progressive taper, the Symphonique/Jazz series, that is 0.470".

All that being said, to answer your original question: See ZeuSter's post below.

ZeuSter

A large bore Bach is a .462.
What you have is a Bach ML .459.
A Bach XL is .468
A Bach Medium bore is .453
Other manufacturers' bore sizes vary as the earlier post indicated.

Scooter01

My old Strad Model 25 was .462"

IAmBrassman

Zeuster very likely has more current info than I do -- go with his designations on the Bach stuff.

Schwab

Zeuster is right, but it isn't recent info, those have always been Bach specs.

Bach trumpets built in the 1930's often have the bell stamps of 10-53 or 7-59, or 7-10-62 (25-62).

The bell flare is first, the second number is the bore size, M, ML, L.

stchasking

I checked them again and it could be .462. It sure isn't much different than a ML.
The valve cluster has the L stamped on it. I think a ball gage is the correct tool to measure the inside of pipe. I am using an inside spanner type micrometer which is not the right tool for the job.

No matter what it is if I look at a Schilke at ITG the only significant smaller bore would be a B7. I liked the B7 last time. Nice blow with the #1 taper.

We know that bore size isn't supposed to matter so I am going to try some more Bach's and Schilke's and try to come up with a conclusion.

Ed Kennedy

Sometimes the 2nd slide will get flared inward just a bit from being repeatedly removed and reinserted. That could easily account for an undersized reading of the inside calipers.

IAmBrassman

According to the Bach site, the ML was not originally the 0.459" it is today, but that is going back into the very early serial numbers. A brief snip from bachbrass dotcom, bachology article 6:

"Bach originally intended to offer three bore sizes: 0.448, 0.453 and 0.462 inches. He started out calling these bore sizes small, medium and large, respectively. It appears that very early in production, Bach decided to introduce an even larger bore size--0.468 inches. At this point, he had to decide what to call it. The authors think that Bach decided to call it large, but that meant he had to rename the 0.462-inch bore size. He renamed that one medium-large, and he continued with that convention for a couple of years or so. He stamped the second valve casings on the instruments made during this period accordingly. Trumpet #69 is one of these, a large bore trumpet stamped ML on the second valve casing. Some time later, Bach reverted to his original scheme and again began calling his 0.462-inch bore size large."

I apologize if my earlier post caused any confusion -- I have removed the erroneous information.