Let's Talk About The 458 B&M

[Wheels]

I read quite a bit about the B&M's a few years ago when they were developed/introduced, and was very impressed. If I was a re-loader and starting over, the 458B&M is probably the way I would go, for an all around African rifle.

@michael458 it is always enjoyable to read what you write. The amount of time you spent developing the B&M's and your knowledge always shines through.

Toby, good job in resurrecting an old topic that needs revisited every couple of years.

 

[TOBY458]

Good morning all, Where do I start with my adventure with the 458 B&M. @PHOENIX PHIL and I were discussing double rifles. (We have successfully added him to the double club) and he brought up a handy little rifle that he had called a 458 B&M after our conversation I looked up the B&M lineup and contacted @michael458 and we worked out a plan to get a 20in version in the synthetic built for me (Read alaska wet). I have had the rifle for a little while and it shoot most anything I have shot in it WELL. Have several loads for the CEB 450gr that I like. I am currently getting it ready for a alaska spring black bear hunt. Shooting the barnes 300gr SOCOM bullet on this hunt. I will post a report when we get back. Very handy rifle that packs a punch far larger than is size

What you described is exactly what I would want. A stainless/Synthetic version with a 20" barrel. If you dont mind me asking, what bells and whistles did you get, and how much did it cost? Feel free to PM me if you would like to discuss in private. Thanks!

 

[TOBY458]

Toby..... With todays premium bullets in 458 caliber, both 458 Winchester and 458 Lott are enhanced, there is absolutely zero reason to go to 500 gr or heavier in .458 caliber, regardless of cartridge capacity. When you exit broadside elephant, how much more do you want? For absolute zero doubt, in 458 Winchester capacity, 450s will do anything you want and then some.....

The North Fork and Cutting Edge Solids are SUPERIOR to the banded FN Barnes solid. I have tested both of course, and have used both in the field. If I could not get North Forks or CEBs, then I would go to the Barnes FN Banded..... FN ONLY..........

Talking 416s... I have a little 416 B&M 18 inch gun, again same story, 6.5 lbs... short and handy, very much a pleasure to carry around, and will do anything you want to do with 416 caliber....

Michael, have you ever tried the 458 Win Mag in a 20" barrel? If so, how does the velocity/recoil comparison work out against the 458 B&M?

 

[michael458]

Michael, have you ever tried the 458 Win Mag in a 20" barrel? If so, how does the velocity/recoil comparison work out against the 458 B&M?

Oh yes, all the first guns were 20 inches and that is what is standard. You only get a 18 or 19 if you request it. Velocity difference depends on various powders, but for the larger weight bullets it is normally 40-50 fps total difference between 18 and 20 inches........

The rifle I use to take pressures is 20 inches, so all pressure data is with that..........

Wheels...... Thank you.

Anything I can do to help, or answer any questions just let me know.............

 

[TOBY458]

Oh yes, all the first guns were 20 inches and that is what is standard. You only get a 18 or 19 if you request it. Velocity difference depends on various powders, but for the larger weight bullets it is normally 40-50 fps total difference between 18 and 20 inches........

The rifle I use to take pressures is 20 inches, so all pressure data is with that..........

Wheels...... Thank you.

Anything I can do to help, or answer any questions just let me know.............

Have you ever tried the 458 Win Mag in a 20" barrel? If so, how does it compare velocity and recoil wise?

 

[TTundra]

I'm curious as well....how does a 20" 458 Win mag compare to a 20" 458 b&m

 

[PHOENIX PHIL]

I'm curious as well....how does a 20" 458 Win mag compare to a 20" 458 b&m

Have you ever tried the 458 Win Mag in a 20" barrel? If so, how does it compare velocity and recoil wise?

Go here for ballistics info: https://www.b-mriflesandcartridges.com/upload/Gen Load Data 458 BM 3262013.pdf

Hard for me to give a recoil comparison as I've not shot a .458 Win. But I was shooting my .458B&M off the bench with full power 500gr loads without issue. It's stout, don't get me wrong. But the use of the much higher burning powder and with the way the AI stock distributes the recoil, it's reasonable.

Then I started using a sling, military style to reduce muzzle jump, makes a huge difference. Load development is done for you guys. Follow that PDF above and you're there. I used H4198 with the 250gr SOCOM from CEB and AA2520 for the big boys, took no time at all.

 

[Milehighshooter]

Man I remember the B&M and bullet testing threads on AR when they were only 3 or 4 pages long HAHA!
Always wanted one, never got around to having one built. Bit out of my price range. But man did I have a hankering for a 475 or any of the super shorts. I still keep an eye out for deals on WSSM crf actions, just in case

 

[michael458]

I'm curious as well....how does a 20" 458 Win mag compare to a 20" 458 b&m

I can't tell you for sure to be 100% honest. Doing pressure work and load data on both, the 20 inch 458 B&M is overall equal to a 24 inch 458 Winchester, with the same bullet, same velocity at or near the same pressures. The RUM cases that the B&Ms are made on can run slightly more pressure than the basic H&H case, by just a few 1000PSI....... However, I do not run full 65000 PSI in the B&Ms anyway. Depending on bullet, load, mission, and other variables top loads run from 58000 to 62000 PSI.....and the same in 458 Winchester.

I never much bought in to that "EFFICIENCY" junk with shorter/fatter cases being more efficient than equal capacity cases being longer and slimmer. And still do not, at least in lesser calibers. What I did learn in our endeavors is that as you increase caliber, you do start to see that efficiency begin to work. Within the B&Ms, and the 2.25 inch RUM cases, .500 caliber is extremely efficient, you are wasting time, energy and metal going beyond 18 inch barrels. With inside diameter at 1/2 inch, you are burning every bit of powder you can stuff in the case inside 18 inches of barrel. I have had 20 inch guns, and no, zero, velocity gain...... Waste of metal. As caliber begins to drop, but your case capacities are the same, then you have less internal burning area, and begin to loose some velocity with shorter barrels. 458 is more efficient than 416 and 416 more so than 9.3.... and so forth............

I never messed with a 20 inch barrel 458 Winchester. I do have a 22 inch 458 Win, and I was basically loosing around 60 fps from a 24 inch gun. If that held up down to 20 inches, then one would loose around 120 fps from 24 to 20............ In 450 weight bullets I did fairly extensive Data with the CEB and North Forks in 458 Winchester some years ago. I topped out with 458 Winchester 24 inch barrel with 450 gr bullets between 2275 and max 2300 fps. If you drop 120 fps going to 20 inches, then you would be at or around 2155 to 2180 fps with the same loads at max 458 Win pressures. Just slightly less than 458 B&M at 18 inches. However, still very effective, with properly designed bullets. I most certainly would have zero issues going to the field with 450 gr proper bullets, CEB and North Fork, at 2150 fps........

 

[michael458]

As for recoil it is hard to say really. I have shot 1000s of rounds in both 458 Win, 458 Lott and 458 B&M. I would have to say honestly that the 458 B&M is easier to shoot, and one would not think so. All my wood stocked B&Ms are with Accurate Innovations stocks. Has the full length aluminum chassis all the way up into the fore arm. There is no doubt in my mind that this absorbs and distributes a tremendous amount of the felt recoil. In addition with the straight in line stock with the bore, this keeps muzzle flip, and felt recoil, and perceived felt recoil way down.

Now if you put any of these guns in that very light Winchester Ultimate stock, dropping weight 1.5 lbs, then you will feel a little more recoil with the heavier bullets, but you would have this in 458 Win as well. But the worst part is with heavier bullets, the trigger guard just knocks the hell out of my knuckles and fingers. So bad, that I used to wrap my trigger finger in duct tape when I had to test those guns with heavy bullets. Lighter bullets, no issues, but heavy bullets would begin to hurt! LOL..............

You may get benefit from the shorter barrels and recoil, getting the bullet out faster, but that is just conjecture and another possible. It is mostly I believe in the stock design........

The B&M website used to be pretty good, lots of things over there. I suppose it still is, but I have not updated it in a long time, there are many areas I need to get over, and update some of that data....... I have been pretty damn lazy for the last couple of years with some things.........

 

[michael458]

Man I remember the B&M and bullet testing threads on AR when they were only 3 or 4 pages long HAHA!
Always wanted one, never got around to having one built. Bit out of my price range. But man did I have a hankering for a 475 or any of the super shorts. I still keep an eye out for deals on WSSM crf actions, just in case

Hey Milehigh..... Good to hear of you. Yes, long time ago for sure........... As you know, I quit AR many years ago, just way too much argument and disagreeable folks there at that time.....I have not posted on a public forum very much since then. This is the only public forum I have posted on at all, and you see, it has not been a lot. Member since 2010 and I see above 17 posts, and this one 18 I suppose. However, I think the folks here are a much better quality group than most........

Here is another 458 B&M of mine, this I consider my "Alaska Rifle"...... Yeah, I know, the snow camo is a bit much, but it is just so different, I love it. I had Virginia Hydro do quite a few of those Ulitmate stocks, many recently. This is one they did some years ago, and had them do the scope as well. Some of the more recent Snow Camo they did looks way better than this one does, and I changed the stock to one of those...........Yet again, another 18 inch 458 B&M Stainless gun............

This is the New Va Hydro Stock on the 458 now..........

 

[AZDAVE]

@TOBY458 PM sent

 

[AZDAVE]

Here are a couple pics of my 458, 20 in barrel and factory stock, with a bit of pad and spacer to get it to the correct LOP.

 

[TOBY458]

AZDAVE Now you're just being rude! Don't you know it's not nice to taunt people?

 

[TOBY458]

I can't tell you for sure to be 100% honest. Doing pressure work and load data on both, the 20 inch 458 B&M is overall equal to a 24 inch 458 Winchester, with the same bullet, same velocity at or near the same pressures. The RUM cases that the B&Ms are made on can run slightly more pressure than the basic H&H case, by just a few 1000PSI....... However, I do not run full 65000 PSI in the B&Ms anyway. Depending on bullet, load, mission, and other variables top loads run from 58000 to 62000 PSI.....and the same in 458 Winchester.

I never much bought in to that "EFFICIENCY" junk with shorter/fatter cases being more efficient than equal capacity cases being longer and slimmer. And still do not, at least in lesser calibers. What I did learn in our endeavors is that as you increase caliber, you do start to see that efficiency begin to work. Within the B&Ms, and the 2.25 inch RUM cases, .500 caliber is extremely efficient, you are wasting time, energy and metal going beyond 18 inch barrels. With inside diameter at 1/2 inch, you are burning every bit of powder you can stuff in the case inside 18 inches of barrel. I have had 20 inch guns, and no, zero, velocity gain...... Waste of metal. As caliber begins to drop, but your case capacities are the same, then you have less internal burning area, and begin to loose some velocity with shorter barrels. 458 is more efficient than 416 and 416 more so than 9.3.... and so forth............

I never messed with a 20 inch barrel 458 Winchester. I do have a 22 inch 458 Win, and I was basically loosing around 60 fps from a 24 inch gun. If that held up down to 20 inches, then one would loose around 120 fps from 24 to 20............ In 450 weight bullets I did fairly extensive Data with the CEB and North Forks in 458 Winchester some years ago. I topped out with 458 Winchester 24 inch barrel with 450 gr bullets between 2275 and max 2300 fps. If you drop 120 fps going to 20 inches, then you would be at or around 2155 to 2180 fps with the same loads at max 458 Win pressures. Just slightly less than 458 B&M at 18 inches. However, still very effective, with properly designed bullets. I most certainly would have zero issues going to the field with 450 gr proper bullets, CEB and North Fork, at 2150 fps........

Thanks so much for this info! The main reason I asked about 458 Win Mag, is I have a really nice stainless New Haven rifle in 7mm Rem Mag that I'm considering converting to either 416 Taylor Or 458 Win Mag. I already have a Ruger Alaskan in 416 Ruger, so I'm leaning towards 458 Win on this project. I've also been leaning more and more toward a shorter set up for all my DG rifles. I have a Winchester 70 416 Rem Mag that shoots great, but is heavy and long to drag through the thorns. Your rifles seem perfect for this...

 

[AZDAVE]

@TOBY458 There are several nice people on AH that have accused me of being a bad influence, so I guess it is your turn for me to assist in selecting a new big bore or 2. I say get both the 458 B&M and the 458WM. The B&M for long walks and the WM for sitting in a blind. Once you have done that we can sit down with a beer and start talking double rifles

 

[TOBY458]

@TOBY458 There are several nice people on AH that have accused me of being a bad influence, so I guess it is your turn for me to assist in selecting a new big bore or 2. I say get both the 458 B&M and the 458WM. The B&M for long walks and the WM for sitting in a blind. Once you have done that we can sit down with a beer and start talking double rifles

Been there and done that on Double rifles! (May do it again)......lol!

 

[PaulT]

but is heavy and long to drag through the thorns.

Toby, I can assure you that there are some awesome rifle/cartridge platforms.

Having witnessed most of the B&M range from 9.3 up to .500 being used on buffalo in conjunction with the CEB projectiles,
I'm sure you will find some handy little packages with plenty of "knock-down" power and penetration.

My own personal choice for both back-up stopping and recreational hunting has been the .500 mdm ultramag.

An 8.5lb .50 sledge hammer that is comfortable to shoot AND carry .

 

[TOBY458]

Toby, I can assure you that there are some awesome rifle/cartridge platforms.

Having witnessed most of the B&M range from 9.3 up to .500 being used on buffalo in conjunction with the CEB projectiles,
I'm sure you will find some handy little packages with plenty of "knock-down" power and penetration.

My own personal choice for both back-up stopping and recreational hunting has been the .500 mdm ultramag.

An 8.5lb .50 sledge hammer that is comfortable to shoot AND carry .

Is that 8.5lbs with or without a scope?

 

[PaulT]

8.5 without scope.