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  #1  
Old 09-26-2008, 09:00 PM
Det. Charlie Det. Charlie is offline
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BoMar Cut?




Is this a BoMar cut?

Many Thanx.
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  #2  
Old 09-26-2008, 11:36 PM
lilricky2 lilricky2 is offline
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No, a Bomar is an adjustable site. It also looks like the machinist missed on a couple of measurements as well. The actual dovetail cut looks like a relatively good fit though.

Rick
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  #3  
Old 09-26-2008, 11:41 PM
DOUBLE DOG DARE DOUBLE DOG DARE is offline
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It is a Bo-mar cut in the slide, but the sight is no Bo-mar. Got a picture of the other side? Just to see if it's a straight cut or delux cut.
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  #4  
Old 09-27-2008, 12:27 AM
Det. Charlie Det. Charlie is offline
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I know the sight is not a Bomar. It's not adjustable, except for windage via a set screw in the dovetail cut. I want to replace the sight with an adjustable unit and want to confirm that this is a Bomar cut before I order (and pay for) an adjustable rear sight...probably from Caspian, the outfit, I beieve, is the original maker of the frame and slide.
I've never hear of a straight or deluxe Bomar cut. Any explaination would be welcome
Thanks to all.
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  #5  
Old 09-27-2008, 01:00 AM
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John Harrison John Harrison is offline
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Quote:
Originally Posted by Det. Charlie View Post
Is this a BoMar cut?



Many Thanx.
That is definitely not a Bo-Mar cut. The dovetail is too far to the rear. It might be a cut for an LPA sight, like Springfield or Para use.
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  #6  
Old 09-27-2008, 03:06 AM
maximus83 maximus83 is offline
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Just for comparative purposes, here is a side profile of the LPA-style sight cut (which looks extremely Bomar-ish, but is not the same) used in some of the Springfield pistols. I own a custom version of this pistol, the Loaded model, and it has the LPA sight that is made for Springfield.

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  #7  
Old 09-27-2008, 04:02 AM
DOUBLE DOG DARE DOUBLE DOG DARE is offline
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I looked at my Bo-Mar cut 1911's and I still think it's the same type of cut, but noted it my have been set back a little further than what would be normal for an adjustable type Bo-Mar position. Where on the slide the cut is positioned and for what style sight to be used in the cut can vary. The sight on that side may have required a Bo-Mar type cut made to fit that sight and the smith who cut it that way knew it wasn't an adjustable Bo-Mar he was installing but that sight in the picture and he just put the cut where it would work best for that sight. This is only an observation on my part as I had quit a few Bo-Mar's on most of my Colt's and have seen some vary in how far up or back their put on the slide. Some hang off the end so much they all but block the hammer and some were way forward. In any case to answer Det Charlie's question, I'd scrap that cut and start over. You can always buy the sight and try the fit but anything that goes on a gun almost always requires fitting/cutting/filing etc... and that would put you back at the start. I guess the point Im tying to make is there are some differences in Bo-Mar type millings, different cuts for different sights.
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  #8  
Old 09-27-2008, 09:39 AM
Greg Derr Greg Derr is online now
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The image of the SA sight looks like the BMCS-2 which has a slightly different location for the davetail. From the breechface .500 back instead of the .555 back for the BMCS. The-2 sight had the self contained elevation screw and a thicker body. John Harrison is well versed, making a fixed sight design to fill the BoMar cut.
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  #9  
Old 09-27-2008, 10:09 AM
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Ricky T Ricky T is offline
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Quote:
Originally Posted by John Harrison View Post
That is definitely not a Bo-Mar cut. The dovetail is too far to the rear. It might be a cut for an LPA sight, like Springfield or Para use.
Is the adjustable sights on the Kimbers LPA? That sight in the first picture looks like the #356 Heinie for the Kimber adjustable.

http://www.heinie.com/357big.php
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  #10  
Old 09-27-2008, 10:37 AM
JBnTX JBnTX is offline
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How can you tell what type sight cut it is
without knowing the measurements?
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  #11  
Old 09-27-2008, 10:53 AM
d90king d90king is offline
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Quote:
Originally Posted by JBnTX View Post
How can you tell what type sight cut it is
without knowing the measurements?
Trust me if John Harrison says it you can cash the check. He has seen one or two. Considering he created a fixed sight option for a "Bomar" cut that should tell you all you need to know. He is a master smith......
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  #12  
Old 09-27-2008, 11:44 AM
log man log man is offline
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Maximus, good intensions, but that isn't an LPA cut you can see the elevation screw isn't going into the dove tail as it does on the LPA, which I believe is what the OP has. This is an example of the LPA from Springfield, zoom in for a comparison.

http://www.springfield-armory.com/armory.php?model=9

LOG
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  #13  
Old 09-27-2008, 11:57 AM
maximus83 maximus83 is offline
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Quote:
Originally Posted by log man View Post
Maximus, good intensions, but that isn't an LPA cut you can see the elevation screw isn't going into the dove tail as it does on the LPA, which I believe is what the OP has. This is an example of the LPA from Springfield, zoom in for a comparison.

http://www.springfield-armory.com/armory.php?model=9

LOG
You could be right. I can see the difference between that one and mine, definitely. The one you linked to has a 45-degree angle on the upper part of the cut, whereas mine is a 90-degree angle. Springfield TOLD me mine was an LPA-style when I asked last year, because I was thinking about replacing my rear sight (but I never did, and it's a good thing, if they were wrong about the LPA cut). What style cut IS my rear sight, then?
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  #14  
Old 09-27-2008, 12:13 PM
log man log man is offline
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I'm not sure but it is the same as a Bo-Mar in dove tail set back and elevation screw, however the relief for the windage blade is larger due to the tritium inserts. I have that sight also in a full rail Operator and believe these sights where made by Champion. Wouldn't it be great if there was a graph with all the known front and rear sight configurations on the same page with dimensions and pictured in the same scale, I'd buy it.

LOG
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  #15  
Old 09-27-2008, 12:14 PM
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John Harrison John Harrison is offline
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Quote:
Originally Posted by maximus83 View Post
What style cut IS my rear sight, then?
Your's is a BoMar cut on your Springfield. The LPA cut has the dovetail much farther back from the front of the sight than the BoMar does. Look at the sights in the attached links and compare to yours. A BoMar dovetail is about half way down the main flat of the cut. The LPA dovetail is about 3/4 of the way back.


Also compare the dovetail location to the pic that Det. Charlie posted and you'll see the LPA is closer in location of dovetail than the BoMar.

I've attached a standard BoMar cut and a deluxe BoMar cut so you can see the difference.

I don't think the original picture is of a Kimber sight, as their dovetails are real close to the front, like 1/4 of the way down the flat.

I think you may find that the original sight in question is a one-off that someone made and that the cut may be non-standard in dimensions.
Attached Thumbnails
LPA cut and sight.JPG   BoMar BMCS standard cut.jpg   BoMar BMCS deluxe cut.JPG  
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  #16  
Old 09-27-2008, 12:41 PM
maximus83 maximus83 is offline
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Thanks John, that's really interesting and I'm glad to finally find out what kind of sight I have on the rear.

That deluxe Bomar is kind of different looking, with that little raised edge at the rear of the cut. Why do they cut it that way? Seems like it's just making the cut very complicated, and I don't see what advantage that gives.

One other thing I noticed: Some bomar cuts I've seen, seem to have a rounded style of cut in the rear portion of the cut where it forms a right angle. Other bomar cuts seem to just have a perfect right angle there, with no rounding. Is the rounding just a matter of style and preference?
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Last edited by maximus83; 09-27-2008 at 12:44 PM.
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  #17  
Old 09-27-2008, 01:01 PM
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John Harrison John Harrison is offline
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Quote:
Originally Posted by maximus83 View Post
Thanks John, that's really interesting and I'm glad to finally find out what kind of sight I have on the rear.

That deluxe Bomar is kind of different looking, with that little raised edge at the rear of the cut. Why do they cut it that way? Seems like it's just making the cut very complicated, and I don't see what advantage that gives.

One other thing I noticed: Some bomar cuts I've seen, seem to have a rounded style of cut in the rear portion of the cut where it forms a right angle. Other bomar cuts seem to just have a perfect right angle there, with no rounding. Is the rounding just a matter of style and preference?
The deluxe, or pocket cut is done for several reasons. It protects the rear of the sight to some degree and because it is more difficult to do, is sort of an upgrade to the standard cut.

The standard cut can be preformed with a radius at the front of the windage relief section, or it you don't want to go to the trouble to change cutters, you can cut it square. The "prefect right angle" comes from just using a standard milling cutter all the way, rather than going the extra mile and changing to a ball nose mill to finish the cut.
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  #18  
Old 09-27-2008, 11:47 PM
lilricky2 lilricky2 is offline
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Like I said, it's not a Bomar. I've milled out a few myself.

Rick
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