Need help with 450 Bushmaster loads.

[GunNut]

230 grn "varmet gernades" @ 3000fps! LOL!

[GunNut]

OH! BTW, I cut the 284 and 450 cases length wise. The 284s with LRPs are much thicker @ the base and the case tapper is on the outside, smooth bore on the inside. So, reaming the primer pocket on the 450B is for a much braver soul then me! Good luck to All! Be safe!

[Siringo]

OH! BTW, I cut the 284 and 450 cases length wise. The 284s with LRPs are much thicker @ the base and the case tapper is on the outside, smooth bore on the inside. So, reaming the primer pocket on the 450B is for a much braver soul then me! Good luck to All! Be safe!

What was the difference of the ID of the case neck of the 284 case versus the 450 case. Would a .451 bullet seated in the unreamed case chamber? Also, Montana Gold bullets measure .4505. Slash has shot a lot of these and I tried some also. Not the greatest accuracy, but they work. A montana gold (they do make a 230 gr) and the unaltered 284 case may be a safer alternative.

Keep in mind, that the 284 cases have a reduced case capacity and the loading data supplied by Hornady may be on the hot side when used with that case!

[450BOOMER]

What happens when you size a case; where does the brass go?
What happens to the brass when you expand the inside of the case with an expander die; where does the brass move to?

The way to do this right is re-size the case, shove the case on a mandrel (expander) the size of a bullet or slightly smaller in a lathe or case trimmer. With the inside of the case supported to keep the brass from moving away from the cutter and turn the case on the outside with the case supported by a tail-stock center in the flash hole. A lathe would be very handy for this but a case trimmer with a neck turning attachment could be made to work.



The case shoved on the mandrel will provide enough friction to hold the case for turning and you must alow for the case taper from case base the case mouth. This can be done by setting the lathe compound rest to the correct taper and turning the casses using the compound rest feed.

These concepts can be seen in this article: http://www.6mmbr.com/powerneckturn.html

Like I said before... Hornady brass is cheap at $39/50.

All of this has been gone over before in the first 5 pages of the thread.

Boomer

[GunNut]

What was the difference of the ID of the case neck of the 284 case versus the 450 case. Would a .451 bullet seated in the unreamed case chamber? Also, Montana Gold bullets measure .4505. Slash has shot a lot of these and I tried some also. Not the greatest accuracy, but they work. A montana gold (they do make a 230 gr) and the unaltered 284 case may be a safer alternative.

Keep in mind, that the 284 cases have a reduced case capacity and the loading data supplied by Hornady may be on the hot side when used with that case!

I don't recall the ID of the 284 case. But, If you just seat and light crimp a .451 bullet it will not chamber. A medium crimp and it will chamber. But, acts like a wedge anchor when fed from a mag. A heavy crimp takes care of the bullet jumping forward and acting like a wedge anchor. But, Damages the jacket and causes jacket separation like I was warned of by the Teck at Hornady"only use .452s Heaver jacket". Very scary When you don't know where they are going and the next on hits the dirt @ 25yds!! Time to releave some brass and go to a heaver jacket bullet. Like backing off from a max load! 2 ways to do this. Inside or outside. I chose to ream the inside to.452 and to the seating depth of my bullet a nice snug fit. A medium to heavy crimp should take care of the rest. As far as loads go. I was up to 45grs of Lil gun with factory cases. 41grs in the 284s seams hot enough for now and no over pressure signs. Will have to see what case life is looking like before going any further.

[GunNut]

284s

What happens when you size a case; where does the brass go?
What happens to the brass when you expand the inside of the case with an expander die; where does the brass move to?

The way to do this right is re-size the case, shove the case on a mandrel (expander) the size of a bullet or slightly smaller in a lathe or case trimmer. With the inside of the case supported to keep the brass from moving away from the cutter and turn the case on the outside with the case supported by a tail-stock center in the flash hole. A lathe would be very handy for this but a case trimmer with a neck turning attachment could be made to work.



The case shoved on the mandrel will provide enough friction to hold the case for turning and you must alow for the case taper from case base the case mouth. This can be done by setting the lathe compound rest to the correct taper and turning the casses using the compound rest feed.

These concepts can be seen in this article: http://www.6mmbr.com/powerneckturn.html

Like I said before... Hornady brass is cheap at $39/50.

All of this has been gone over before in the first 5 pages of the thread.

Boomer

When sizing, the brass seems to move forward about .002 to .005 depending on the load and how much sizing is done.
With the cases inside reamed to .452 and bullet is .4515 I don't need to use the expander or seating die. Nice snug fit. The tapper crimp will take care of the rest. This was proved to me when I was drilling them.
I don't have a lath. Inside reaming is comon with bottle neck cases and cheaper for me.
Turning the outside should improve chamber grip and reduce bolt thrust for awhile. fire forming would smooth them back out.
I have plenty of factory brass! But, No source for Small Rife Primers. Those I do have are for my AR15s
I can still get Large Rifle Primers for my AR10. Which brings us full circle as to why I started this project. Besides being fun creating custom ammo. Which is why I reload anyway.
Thanks Again to All of you!!

[pitted bore]

Bolt gun in 450 Bushmaster

I've had my .450 Bushmaster bolt gun since last January, but the winter has been hard. Last week the snow had melted and the mud had solidified enough to get into the local range to try it out.

Using factory ammo off the bench, I was on paper at 25 yards, and with some sight adjustments at 50, I tacked up the 100 yard target. The first shot was low and left, so after adjustments two more shots went down range. I was pleased. Bbl is 20" with 1:16 twist.
--Bob

[Siringo]

I've had my .450 Bushmaster bolt gun since last January, but the winter has been hard. Last week the snow had melted and the mud had solidified enough to get into the local range to try it out.

Using factory ammo off the bench, I was on paper at 25 yards, and with some sight adjustments at 50, I tacked up the 100 yard target. The first shot was low and left, so after adjustments two more shots went down range. I was pleased. Bbl is 20" with 1:16 twist.
--Bob

Whow! Nice job with the old '03. I have been comtemplating re-chambering an old Remington 760 pump.

[GunNut]

Really cool!

I've had my .450 Bushmaster bolt gun since last January, but the winter has been hard. Last week the snow had melted and the mud had solidified enough to get into the local range to try it out.

Using factory ammo off the bench, I was on paper at 25 yards, and with some sight adjustments at 50, I tacked up the 100 yard target. The first shot was low and left, so after adjustments two more shots went down range. I was pleased. Bbl is 20" with 1:16 twist.
--Bob

Now thats really cool! and just goes to show how acurate the factory ammo is!

[pitted bore]

Whow! Nice job with the old '03. I have been comtemplating re-chambering an old Remington 760 pump.

Siringo-
Last fall when I started this project, I found reamers to be uncommon. I had to order my own chamber reamer and headspace gauges from Dave Manson. My gunsmith has them now.

Would you rebarrel the 760, or have the barrel reamed and re-rifled?

--Bob

[Siringo]

Siringo-
Last fall when I started this project, I found reamers to be uncommon. I had to order my own chamber reamer and headspace gauges from Dave Manson. My gunsmith has them now.

Would you rebarrel the 760, or have the barrel reamed and re-rifled?

--Bob

I think I would go the reboring. I know quite a few that have had old rifles rebored with great success. I would like to have the barrel lopped to 18 inches.

[pitted bore]

Siringo-

A 760 in 450 Bushmaster would be an admirable rifle for hunting in a state like Pennsylvania which does not permit semi-auto rifles for hunting. Like pump shotguns, it could be operated about as fast as a semi-auto.

--Bob

[Wildcatter]

I've had my .450 Bushmaster bolt gun since last January, but the winter has been hard. Last week the snow had melted and the mud had solidified enough to get into the local range to try it out.

Using factory ammo off the bench, I was on paper at 25 yards, and with some sight adjustments at 50, I tacked up the 100 yard target. The first shot was low and left, so after adjustments two more shots went down range. I was pleased. Bbl is 20" with 1:16 twist.
--Bob

Hey Way-To-Go Pitted Bore and Welcome aboard Sailor! I think you may be more like a Pit Bull instead..wink. I assume you reload and you've got a digital camera there, if you've got some great micrometers then you "MIGHT" be able to show these gents where the Bear squats in the buck wheat.

Being able to take and post close-up pics of the primers and then mike-ing the case bases, before and after and then staying under .0015" (one and a half thousandth) expansion on the case head, which is in the 55,000psi "AREABUT", only if your experience level is up to it.

Either way I applaud your work and good go old man, it's going to be great to read your future post, along with the other giants that are already writing here!

Safety First..t

[pitted bore]

Wildcatter-
Thank you for the welcome, and I do appreciate your enthusiasm. Your note makes pretty heady reading for a simple backwoods Yooper.

When building the rifle, I had not thought about high speeds with lightweight bullets. I was thinking more about the Elmer Keith end of the spectrum, rather than Jack O'Connor's. However, it would be fun to take this to the Salt Flats to try for a new land speed record.

As you note, finding acceptable light bullets with jackets that will hold up to the stress of relatively rapid twist at relatively high velocity may be a problem. I've no light bullets on the shelves right now, so obtaining suitable possibilities will be an early priority. Please offer your advice. (Other posters are welcome to jump in also.)

Hornady, Magtech, Nosler, Remington, Sierra, and Speer, all offer 185-grain jacketed hollow points. I've no idea which of these manufacturer's products might be more likely prospects for this project.

Hornady, Sierra, Remington and Speer offer 185-grain full metal jacketed bullets, if these are likely to be better at tolerating rotational stress.

From a position of zero experience, I'd guess solid copper bullets would be able to withstand most any stress. Barnes offers these in 160- and 185-grain weights; Magtech's are 165 grains and 185 grains. At about 80 cents each, Barnes' are about 33% more expensive, and will cause greater stress on the available project bankroll.

After a suitable bullet or two has been selected for the speed trials, we can talk about powder and primers.

Thanks.
--Bob

[BD1]

I'm not sure that I see the twist as being an issue as much as bullet construction, or maybe some factor not yet considered? 230 grainers at 3,000 fps out of pitted bore's 16 inch twist are only spinng at 135,000 rpm. This is only getting to the top end of cast bullet accuracy rpms. There are all kinds of folks winning bench rest & high power matches, or popping PDs with jacketed bullets spinning over 200,000 rpms.

The only time I ever experienced the gray dust cloud, and no holes in the target, was trying a handful of varmit grenades out of a 8 twist .220/06. They were spinning well over 300,000 rpm before going "poof".

Could it be that the average 230 grainer, designed for .45 acp, just can't handle the pressure? I'm also wondering if the self defense designs, with the big hollow points and striated jackets might be more prone to coming apart than a regular cup and core hunting construction bullet? It wouldn't take but one little petal going just a wee bit out of concentricity to make a flyer.

I finally got my lower in and by the weekend I'm hoping to run some 250 grain Sierras to break in the barrel a bit. I don't think I'm gonna hit 3,000 fps though

BD