450Bushmaster.net

You'll love the 450 gramps.I live in zone 3 myself and been using an Encore ML with Blach Horn 209 and Hornady 250 sabots and its very accurate but the 450 is very accurate also in my AR.Sounds like MI is following IN.There isn't any difference in velocity and projectiles compared to ML's and the new shotgun ammo.I hope MI allows the 450.I would use it over anything else.It's easy to reload.

gramps wrote: ... If I'm following things right the 460 velocity is in the same ball park as the 450B and uses it uses pistol bullets!!! Help, now I'm really confused. Will the 450B and the 460SW at 2100 fps or more cause the bullet to go POOF in a 1-16 barrel? Reading here and on Calguns.net sounds like they may. HELP!! ...

Don-
A couple of points:
[1]
The 460 case capacity is slightly more than the 450B, and it has a higher SAAMI max pressure. I would expect the commercial 460 rifles that have been introduced recently to at least equal the 450 velocities with the same weight bullets. Because the 460 is a rimmed cartridge, it should be possible to crimp handloads really, really firmly.

[2]
I think that neither the 460 nor 450B will make pistol bullets go poof. The known exceptions are the plated 451 and 452 bullets that will toss off pieces of their plating when they exit the muzzle. I'm guessing it's a combination of high velocity, high spin rate, and the plating being cut by the rifling. As I recall, Hoot has had a chronograph whacked by the plating pieces.

You're right about the calguns thread raising the possibility of lighter pistol bullets coming apart at 450B velocities. Somewhere on that thread and in some 2009 threads in this forum I asked about this, and based on the answers decided to use the Hornady totally encapsulated 185-grain 451 bullets in my early experiments. I supposed that the heavy enclosure would prevent any disintegration in flight. There were no difficulties. You can read about the results in the first of several threads: 185-grain SWC trials - Chapter 1

Eventually, I was able to work up to about 3000 fps muzzle velocity with the 185-grain bullets. Here's a link to that thread:185-gr SWC, Chap. 8: 3000 FPS At Last. (Note that 3000 fps with 185-grain bullets is 300 Win Mag territory; recoil in a lighter rifle is noticeable.)

Based on the calguns warning, I decided to try to blow up some bullets. I purchased the Prvi Partizan soft points, and ran them at a muzzle velocity of 2900 fps. They didn't blow up on the way to the target. Full story on this thread: Trying to Blow Up a Bullet. T/wildcatter say's he's seen some bullets blow up from his early experiments with the cartridge, but he doesn't remember what bullets he used.

Your reservations about the use of pistol bullets are very appropriate when thinking about hunting. Hornady for good reasons only recommends their XTP Mag pistol bullets for reloading the 450B. Their non-mag pistol bullets are likely to go splat on game at 450B velocities.

[3]
I suspect that 1-turn-in-16-inches will be OK for most any bullet. John Barsness has a good article on "overstabilized" bullets in the latest issue of Handloader magazine. I selected the 1-in-24 twist for my heavy bolt gun simply because I wanted that part of its performance to equal that of the standard bushmaster barrels.

Keep us updated on your progress, and feel free to ask questions.

--Bob

Delete

Delete

I haven't failed--Just found one more way not to do something.

Welcome to the club!!
Still workin on the 450LM mag. here.

Any update on your project gramps?

B.

Delete

pitted bore wrote:

gramps wrote: ... If I'm following things right the 460 velocity is in the same ball park as the 450B and uses it uses pistol bullets!!! Help, now I'm really confused. Will the 450B and the 460SW at 2100 fps or more cause the bullet to go POOF in a 1-16 barrel? Reading here and on Calguns.net sounds like they may. HELP!! ...

Don-
A couple of points:
[1]
The 460 case capacity is slightly more than the 450B, and it has a higher SAAMI max pressure. I would expect the commercial 460 rifles that have been introduced recently to at least equal the 450 velocities with the same weight bullets. Because the 460 is a rimmed cartridge, it should be possible to crimp handloads really, really firmly.

[2]
I think that neither the 460 nor 450B will make pistol bullets go poof. The known exceptions are the plated 451 and 452 bullets that will toss off pieces of their plating when they exit the muzzle. I'm guessing it's a combination of high velocity, high spin rate, and the plating being cut by the rifling. As I recall, Hoot has had a chronograph whacked by the plating pieces.

You're right about the calguns thread raising the possibility of lighter pistol bullets coming apart at 450B velocities. Somewhere on that thread and in some 2009 threads in this forum I asked about this, and based on the answers decided to use the Hornady totally encapsulated 185-grain 451 bullets in my early experiments. I supposed that the heavy enclosure would prevent any disintegration in flight. There were no difficulties. You can read about the results in the first of several threads: 185-grain SWC trials - Chapter 1

Eventually, I was able to work up to about 3000 fps muzzle velocity with the 185-grain bullets. Here's a link to that thread:185-gr SWC, Chap. 8: 3000 FPS At Last. (Note that 3000 fps with 185-grain bullets is 300 Win Mag territory; recoil in a lighter rifle is noticeable.)

Based on the calguns warning, I decided to try to blow up some bullets. I purchased the Prvi Partizan soft points, and ran them at a muzzle velocity of 2900 fps. They didn't blow up on the way to the target. Full story on this thread: Trying to Blow Up a Bullet. T/wildcatter say's he's seen some bullets blow up from his early experiments with the cartridge, but he doesn't remember what bullets he used.

Your reservations about the use of pistol bullets are very appropriate when thinking about hunting. Hornady for good reasons only recommends their XTP Mag pistol bullets for reloading the 450B. Their non-mag pistol bullets are likely to go splat on game at 450B velocities.

[3]
I suspect that 1-turn-in-16-inches will be OK for most any bullet. John Barsness has a good article on "overstabilized" bullets in the latest issue of Handloader magazine. I selected the 1-in-24 twist for my heavy bolt gun simply because I wanted that part of its performance to equal that of the standard bushmaster barrels.

Keep us updated on your progress, and feel free to ask questions.

--Bob

Hey Dandy Don, It's good to see you thinking outside of the box. You'll find many here, that don't even know what a box is and PB is one of them. Trust his observations and advice. About the high light, I did in his post and for yous and everybody's consideration.. The 450b has a SAMMI standard of 38,000psi. The 460S&W has an operating pressure far in excess of that, in fact from Hodgdon's data is the following for a working load, not Sammi max..

460S&W

250 GR. BAR X Winchester-296 .451" dia 2.200"oal - 39.0gr 1985fps 43,500 PSI - 41.5gr 2133fps 56,800 PSI

Know that's data worth considering, for future projects and their effects on bullets..

..t

Hello Gramps,

Been away from the page a while...checked in today and read thru your questions and comments. First of all, WELCOME! you have definitely found the right group of people for some great information! I speak from experience because I read alot here and asked plenty of questions before I built my three 450B bolt rifles. I also used McGowen Barrels for mine. They do offer a 24 twist. You will either need to supply them with the reamer or do the chamber work yourself (as you probably will since you stated you are a machinist). Manson Reamers is where I purchased my reamer and go/no go gauges. Also, other posts here have indicated where you can rent them.

Virtually all the info on the three I built is on the site along with pictures. I used Savage 110 actions for the simple fact that this rifle is EXTREMELY easy to rebarrel and I am NOT a machinist so it saved me some money. All three rifles were originally 30/06, so the bolt head was the same as your Mauser 98, and action length pretty much the same (I am sure there is someone with more knowledge than me that would know how many thousandths they differ). Feeding problems with this combo varies....One of them has absolutely NO issues, the other two have no issue if the muzzle is elevated just slightly to keep the weight of the nose of the bullet from wanting to "fall" before reaching the chamber.

Recoil? I went with a varmint contour barrel, 24" long....our rifles scoped (unloaded) weigh 9.6 - 9.8 lbs. All have wood stocks. Recoil is comparable to say....a 50cal muzzleloader....Not near as sharp as my 30/06, and no where near a 12ga with slugs. Accuracy is incredible with these barrels!!!

I wish you luck, and I hope Michigan passes that law! I must admit, I actually thought they already had the 1.8 "straight walled" rule....but maybe that was a different region in Michigan?

P.S. I like the thought on using the 98 action! My first "custom" rifle was built on an Interarms Mark X action...chambered it for 25-06 Rem....that action is smooth as silk and that rifle will flat out drive tacks!

Good Luck!
Dogsniper