A few years ago after playing with the Talon Tips inserted into the big bore Raptors, we discovered that we would actually gain anything from 125-150 fps with the Talon Tips installed over not having them. No surprise right, BC is greatly improved over that big flat HP.
Standard Raptors have a nose projection above the top band of .700 inches. Installing a tip in those, you cannot run them thru the magazines of the standard B&Ms or the longer 500 MDM. You can single shot them first round up, but everything in the magazine requires no tips to function.
Now the Lever Raptors are different, they have very short nose projections of .350 to .400 above the top bands, so you seat those deep in the case, and add tips for the bolt guns and you are set to jet. However, you take up a lot of case capacity and limited to lighter bullets.
Fortunately I had plenty of the long RUM Winchester actions to play with, I had put several aside for 500 MDM builds. This is the 3.6 inch magazine, and rifles built for 300 RUM. They are very highly modified to work with the fatter RUM case.
I decided to play with a 2.5 inch RUM case. Cut an RUM case down to 2.5 inches and size for .500 caliber. And then later look at 458 caliber as well. With the shorter case I would be able to load the longer Safari Raptors, insert Talon tips, and gain velocity at 50 yards with the tip. My thoughts were, that at 50 yard impacts the 2.5 inch case with tipped Raptors, would be close to the same impact velocity as the longer 500 MDM with the same Raptors, but no talon tips. Indeed the theory was very close to being correct.
I called the .500 the 500 B&M. As opposed to the 50 B&M 2.25 inch RUM and the big 500 MDM at 2.8 inch RUM. It was dead in between, but used the same action as the 500 MDM.
There were only two rifles built in 500 B&M. Mine, and then another B&M fan had one built as well. These guns came in 18 inch barrels. And were very close to the same size as the regular 50 B&M which uses a WSM action. I also went with the same barrel contour as the 50 B&M, which is much lighter than the bigger 500 MDM. The 500s are pretty spiffy. Later in life, the other fellow with the 500 B&M decided he can no longer handle the big bore guns, so I bought his barrel from him, and it laid here for a few years. Last year I decided to put another one together. I now have the only two 500 B&Ms ever built. These are not part of the regular B&M Lineup. Personally I like working with them much better than the bigger 500 MDM however. They are much easier to make brass for, they are easy to load, and not really far off the mark with the 500 MDM. The guns are shorter as well.
At one point a friend of mine in New Jersey built a 500 MDM. But the stock was short for him. He needed a longer LOP. I agreed to take his stock, while he had another one built for him. This stock was cut for a 500 MDM with the heavier barrel profile. I decided to make the 2.5 inch 458 version with this stock, so it would have to have the larger barrel profile of the 500 MDM and not the regular 458 B&M. I knew the gun would come in a pound or so heavier than I wanted, and in 458 I would need a 20 inch barrel to get up to spec. My goal was to equal 458 Lott with the 20 inch barrel.
I went to work doing load data and pressure data in July 2015. I finished the heavier bullets in September 2015. Later I revisited the 458 B&M EX in 2016 with loads and data for the 250 Socom. In the end, the goals were meant, to equal 458 Lott with the shorter RUM case, and most important the 20 inch barrel. At this point I actually was bored with it, and it was put away until the last couple of weeks.
Standard Raptors have a nose projection above the top band of .700 inches. Installing a tip in those, you cannot run them thru the magazines of the standard B&Ms or the longer 500 MDM. You can single shot them first round up, but everything in the magazine requires no tips to function.
Now the Lever Raptors are different, they have very short nose projections of .350 to .400 above the top bands, so you seat those deep in the case, and add tips for the bolt guns and you are set to jet. However, you take up a lot of case capacity and limited to lighter bullets.
Fortunately I had plenty of the long RUM Winchester actions to play with, I had put several aside for 500 MDM builds. This is the 3.6 inch magazine, and rifles built for 300 RUM. They are very highly modified to work with the fatter RUM case.
I decided to play with a 2.5 inch RUM case. Cut an RUM case down to 2.5 inches and size for .500 caliber. And then later look at 458 caliber as well. With the shorter case I would be able to load the longer Safari Raptors, insert Talon tips, and gain velocity at 50 yards with the tip. My thoughts were, that at 50 yard impacts the 2.5 inch case with tipped Raptors, would be close to the same impact velocity as the longer 500 MDM with the same Raptors, but no talon tips. Indeed the theory was very close to being correct.
I called the .500 the 500 B&M. As opposed to the 50 B&M 2.25 inch RUM and the big 500 MDM at 2.8 inch RUM. It was dead in between, but used the same action as the 500 MDM.
There were only two rifles built in 500 B&M. Mine, and then another B&M fan had one built as well. These guns came in 18 inch barrels. And were very close to the same size as the regular 50 B&M which uses a WSM action. I also went with the same barrel contour as the 50 B&M, which is much lighter than the bigger 500 MDM. The 500s are pretty spiffy. Later in life, the other fellow with the 500 B&M decided he can no longer handle the big bore guns, so I bought his barrel from him, and it laid here for a few years. Last year I decided to put another one together. I now have the only two 500 B&Ms ever built. These are not part of the regular B&M Lineup. Personally I like working with them much better than the bigger 500 MDM however. They are much easier to make brass for, they are easy to load, and not really far off the mark with the 500 MDM. The guns are shorter as well.
At one point a friend of mine in New Jersey built a 500 MDM. But the stock was short for him. He needed a longer LOP. I agreed to take his stock, while he had another one built for him. This stock was cut for a 500 MDM with the heavier barrel profile. I decided to make the 2.5 inch 458 version with this stock, so it would have to have the larger barrel profile of the 500 MDM and not the regular 458 B&M. I knew the gun would come in a pound or so heavier than I wanted, and in 458 I would need a 20 inch barrel to get up to spec. My goal was to equal 458 Lott with the 20 inch barrel.
I went to work doing load data and pressure data in July 2015. I finished the heavier bullets in September 2015. Later I revisited the 458 B&M EX in 2016 with loads and data for the 250 Socom. In the end, the goals were meant, to equal 458 Lott with the shorter RUM case, and most important the 20 inch barrel. At this point I actually was bored with it, and it was put away until the last couple of weeks.
