458 B&M Norma RUM brass Testing

[Michael458]

Everything B&M with the exception of the B&M Super Shorts is based from Remington Ultra Mag brass. As many of you may or may not know, the last RUM brass that I was able to purchase from Remington was 2013, its just not being made any longer by Remington. While I don't know the inside scoop, I can imagine that Remington doled this out to Hornady, Nosler, and Norma. I show my first tests of this brass back in 2015 with Norma and Hornady RUM. 2017 with Nosler RUM. At that time I found Norma and Nosler to be far ahead of the Hornady brass. The Norma and Nosler RUM tested even better than the Remington, giving higher velocity and lower pressures, a very pleasant surprise.

Last week I found myself loading some 458 B&M for a friend of mine in CA. He already has a 500 MDM and a 416 B&M from some years ago, and recently had a 18 inch 458 B&M Built. My friend Andy is wrong handed as well. While Andy is a proficient handloader, I decided to help him with his brass and loads. He purchased 150 pieces of new Norma RUM, I cut, trimmed and formed it for him and while I am at it I might as well load it and send the whole package. My job was to check his rifle for feed/function, and sight in the irons for him. He had planned to come visit for a few days and we do this together and have some fun, but COVID-19 nixed that plan.

Last week I loaded some test loads of my own brass to sight in and test the gun. Loaded 450 CEB Solids with standard load of 76/TAC. Normally in 18 inch gun this would test out at 2225 fps or so, that would have been with the old Remington RUM. I had not really fired any Norma in any 18 inch guns. I found velocity running 2280+ fps with the same load? I had also opened a new Keg of TAC. This extra velocity was an immediate RED FLAG.

I came back in the loading room, and proceeded to load up some more 450s with some New Norma formed brass, this time it was going through my 458 B&M that I do the pressure work with. This is a 20 inch gun.

In 2015 I had tested the Norma brass with the same load, same gun, and averaged 2287 fps at 58500 PSI with the 450 and 76/TAC. Remington brass would give the same basic velocity, but at higher pressure of 62000 PSI. Last week 450 #13 Solids and 76/TAC gave me 2328 fps at 58300 PSI with New Formed Norma Brass. I tested Fired Norma brass next, same load, and hit 2313 fps at 56800 PSI. This is common with most big bores from New Formed brass to Fired brass. Mostly because of slightly increased case capacity.

I was very pleased with the pressure tests, and even more so with Andy's 18 inch gun which was averaging 2290 fps with the same load. This exceeds what can be done in 458 Winchester with 24 inches of barrel, and still at lower pressures.

 

[Michael458]

Today I finished up the test work with the Norma brass, but using the 420Raptor, which is a match to the 450 Solids, just with a hollow point. These are primarily for first shots on buffalo, which then would be followed with the Solids. Also loading and testing the 250 Socom Raptors, which will handle all other game less than buffalo, all plains game antelope, moose, bears, lions, basically anything considered thin skinned game.

Concerning the 420 Raptors, they are the same bullet as the 450 Solids. Raptors produce tremendous amounts of Trauma. Since they are the same bullet as the solid, loaded the same, they are in the same hole at 50 yards as the solids. This way, you have the best of both worlds, without a change of POI. They are designed this way. When we designed the solids, we needed a serious trauma inflicting bullet to match. Most companies try to match "WEIGHT" to make the Expanding/trauma bullet equal the solids and same POI at 50 yards, or close. I had a theory that if you had the same length, and bearing surface, that you would get the same POI, regardless of weight. This proved to be true, and in fact a great advantage for the lighter Raptor. Weight equal pressure, so running the same velocity, the Raptor would be considerably less pressure, you could up the velocity of the Raptor, which increases performance, and still not have to be concerned with pressures. POI does change some, you can normally increase the velocity of the Raptors and POI will be 1/2 inch higher at 50 yards than the solids, with zero change in windage POI. This is very acceptable, and of zero consequence.

To make everything consistent, I decided to test the 420 Raptors and the 250 Socom Raptors in the new and fired Norma brass.

420 Raptors 77/TAC gave 2353 fps at 54000 PSI with New Formed Norma brass and 2330 fps at 51500 PSI with Fired Norma.

The 250 Socoms are loaded with 77/H-4198 giving 2932 fps at 50600 PSI with New Formed Norma and 2942 fps at 50900 PSI with Fired Norma brass. Not much difference between New Formed and Fired Norma brass with the much faster powder. And FAR below max pressures of 65000 PSI. One could probably find a bit faster powder and increase performance, but I have shot a lot of critters with these 250 Socom Raptors at 2900 fps, and you don't need anything more than that, everything I have shot has been DRT, including some rather large animals.

This is what I have been up to for the last couple of weeks. Now I have to get back in and load the rest of these for the guys and get them sent out.

Next week I will be working on a chaps 50 B&M Alaskan lever gun and some 350 and 420 Lehighs...................

Some photos from today.....

 

[Michael458]

 

[Michael458]

And this is my friends 18 inch 458 B&M, Wrong handed Winchester M70................. Accurate Innovations Turkish Walnut................

Pleased to report it feeds/functions 100%......... And I have the irons sighted in for him at 25 yards........... All shots right of the two in the center is where I started walking it over. Last two rounds are the ones in the center........

 

[Michael458]

I am headed back in to finish up the 458 loading project.........

Any Questions? Thoughts? Remarks? Comments? Anything?...........................................