Dimension Question

[hogpatrol]

The actual base to .237 ogive measurement is perfect for a 52 FB, which is what I wanted.

Very confusing. I just want a dimension on a reamer print that says: "this is base to ogive dimension at .xxxx (hopefully bore) diameter." I'm not trying to make this more complicated, actually trying for easy............

Still learning, after all these years...........

You will not find that number on any reamer print and even if you did, it would only be good for one bullet. There are too many variables in bullet design (tangent, ogive and hybrid), ogive radii and length. For example, in 6mm with hundreds of different bullets being manufactured by OEMs and customs, you could have a hundred different base to ogive measurements. Take three or four bullets and measure the base to ogive. Hopefully that light will shine.

 

[Richard Jones]

You will not find that number on any reamer print and even if you did, it would only be good for one bullet. There are too many variables in bullet design (tangent, ogive and hybrid), ogive radii and length. For example, in 6mm with hundreds of different bullets being manufactured by OEMs and customs, you could have a hundred different base to ogive measurements. Take three or four bullets and measure the base to ogive. Hopefully that light will shine.

Understand that. What I mean is: A dimension from base to .237, which is bore diameter. That would give you a realistic dimension from which to see if your particular bullet would fit with proper freebore.

 

[JRS]

Load em up and shoot, Rich. Thats the best way to find out If you are looking for absolute zero tolerance on a reamer to match a bullet exactly, you are looking at major bucks.

 

[Ggmac]

Load em up and shoot, Rich. Thats the best way to find out If you are looking for absolute zero tolerance on a reamer to match a bullet exactly, you are looking at major bucks.

And I'd like to add it would only work if the tool manufacturer ( reamer ) make the barrel and bullets .

 

[geo.ulrich]

Understand that. What I mean is: A dimension from base to .237, which is bore diameter. That would give you a realistic dimension from which to see if your particular bullet would fit with proper freebore.

no not really different ogives hit on different parts of leade ie. 9 ogive is about centered in a 1.5 * leade ,or what I do is take a barrel stub and run reamer in till freebore cuts and 45* at end of neck just kisses barrel stub then you can drop whatever bullet you want in and see what you would have in neck.

 

[Richard Jones]

no not really different ogives hit on different parts of leade ie. 9 ogive is about centered in a 1.5 * leade ,or what I do is take a barrel stub and run reamer in till freebore cuts and 45* at end of neck just kisses barrel stub then you can drop whatever bullet you want in and see what you would have in neck.

So there's really no way to determine base to bore size, in this case, .237, from a reamer print? Thanks, George.

 

[JRS]

Rich,

Remember, the reamer is manufactured to a +/- tolerance. The reamer probably will not exactly match the dimensions on the print. Don't beat your head against a wall. You'll end up with CTE

 

[geo.ulrich]

So there's really no way to determine base to bore size, in this case, .237, from a reamer print? Thanks, George.

Pretty much without a print of bullet no....

 

[Richard Jones]

I realize there will be some discrepancy between print and actual, no problem with that. Just wish there was a better dimensioning 'system', without this guesswork. That's all we need, one more dimension on a reamer print...... so I guess no one is interested in my spreadsheet?

 

[Ggmac]

It's not just the reamer print , it's a combination of bore and bullet also , each are made to +\- . A diff of .0002 in bore is going to change your ogive contact . Everything is a compromise . The reamer is a tool , it will actually cut dif sizes in dif materials . Not by much , probably so small the usual tools couldn't measure , but also cut dif sizes at dif temp .
I think the largest variable will be the bore size and rifling depth / height .
Just my $.02

 

[Richard Jones]

It's not just the reamer print , it's a combination of bore and bullet also , each are made to +\- . A diff of .0002 in bore is going to change your ogive contact . Everything is a compromise . The reamer is a tool , it will actually cut dif sizes in dif materials . Not by much , probably so small the usual tools couldn't measure , but also cut dif sizes at dif temp .
I think the largest variable will be the bore size and rifling depth / height .
Just my $.02

Yep, for sure. And I think my little spreadsheet will get me close enough to choose the appropriate reamer.
I really appreciate the input from everyone. Have learned a lot, and that's always good. Don't want to reinvent the wheel, just maybe make it a bit rounder......I guess that's why we're all here.......