Anyone Cast for the 450 Bushmaster?

hrpenley

Active Member
I need some advice, I am trying to cast for the 450BM but am having feeding issues, I cast for a lot of calibers but this one still haunts me, I am shooting with AR style, I can load Flex tip, FTX, Deep Curl, 330gn cast HP, but I can not get it to feed 235gn cast RN, 250gn RN, or 300gn FP. I have played with the seating depth and bullet size, am I barking at the moon here or doing something wrong any help would save me and my checkbook a lot of heartache.
 

Joshua

Taco Aficionado/Salish Sea Pirate/Part-Time Dragon
Not chambering or not cycling your action? What powder/s are you using? What’s your powder charge? Are these light loads when compared to your jacketed loads? What is the length of your gas system?
 

CWLONGSHOT

Well-Known Member
I shoot the 450 BM quite a bit. But only reciently picked up a Barre and built a upper. I Have been shootIng my Ruger Bolt.

I shoot two bullets Both Lyman molds the 457 121 & 122. The 122 is my "deer bullet" pushed with 5744 and the 121 is my sub bullet using Unique or Herco. I know the sub will not Cycle I have t tried the 122 HP. But both profiles are very close.

I al still just starting with the AR and using the 300g FTX. Cause I bought a bunch in clearance.
CW
 

hrpenley

Active Member
No problems cycling, carbine length GS, mid/upper mid loads. I can put the round in the gun it fires and ejects fine, good chamber drop, they just don't want to feed. Never really had issues with RN feeding in any other caliber. .308 feeds fine with RN, I can understand the flat point, not much of a point closer to WC if you ask me but lee call's it FP. My cast 330g HP's feed fine, the over the counters feed (Flex tip and Horn XP's) don't use standard 45 cal tips as they are not really raited for the pressure and velocitys but I am tempted to try them to see if any RN's feed. Just looking to see if just me or anyone else has had this issue. ramps polished burs removed gun is clean.....
 

Ian

Notorious member
What exactly is happening to stop the feeding? Cycle by hand in slow-motion and post a photo of the stoppage please.
 

hrpenley

Active Member
I will see what I can do about a vid next time I go out shooting, The round jam's 1/2-3/4 way in, scrapes up the pc dented the brass a bit (pretty good actually). I haven't really done a bunch of troubleshooting as well, I am a tight a** and 450 brass is a bit salty and I really get ill when it gets damaged. So was looking for all advice I can get before I damage more and feel worse.... I've adjusted the seating depth with no change, doesn't make a lot of sense.
 

Ian

Notorious member
If you make a dummy cartridge and let the bolt down on it by hand, slowly, we can all see the stoppage point and it won't kill a case. Odds are the more abrupt ogive of the cast bullets is tipping the nose up too far on the feed ramp and binding against the feed lips. Figuring out where the new release point needs to be and flaring the feed lips to match is likely going to be your solution, though a more thin nose profile would be a better solution.
 

Missionary

Well-Known Member
This is a good read ! We bought a 450 B this past February.. I was figuring to be loading and shooting it by now but not to be this year..
 

popper

Well-Known Member
Check your mag lips. Basically noses up and hits or doesn't release back soon enough. Basically trying to put a round peg into a hole the same size. Gotta be 'just right'. Had to file the lips and front mag ramp on some Pmags for BO to get them to run right and if change profile, start over. Cycle slow by hand and see what happens. Oh, always rap the mag on case side to make sure rnds are at the back. They can walk forward & cause problems. I seat short so the nose has some 'running' room to feed.
 

hrpenley

Active Member
Ya I thought maybe it was due to the short seating with the small size, I stretched them out past the first grease groove and it didn't make any dif, but the feed lips may be something to look at,
 

popper

Well-Known Member
The lips don't have to be parralel. They hold the case in the mag but have to release the nose at the right time to get it pointed up (aided by barrel ramp), then the base so the case pops up parallel with the bore.
 

CWLONGSHOT

Well-Known Member
I had feed issues with mine. Found the follower I had to be large culprite.

Is your upper built for the 458/450?? Mine wasnt, I had to open up the ejection port.

CW
 
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Ian

Notorious member
My Tony Rumore .458 barrel has a modified feed ramp, too: the M-4 ramps are blended together to make one big trough and the bottom locking lug is shortened. I opened the ejection port per a drawing on the 458 boards, there's a way to do it where dust cover will still work.
 

CWLONGSHOT

Well-Known Member
My Tony Rumore .458 barrel has a modified feed ramp, too: the M-4 ramps are blended together to make one big trough and the bottom locking lug is shortened. I opened the ejection port per a drawing on the 458 boards, there's a way to do it where dust cover will still work.
YUP...

E3F6A1D5-61C7-4298-8E33-EF764263B7F0.jpeg8521C5C0-F21F-4ECA-8542-DF9ECCE39E98.jpeg
The 350 Legend barrel I have is the same single wide ramp.
CW
 
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hrpenley

Active Member
I had feed issues with mine. Found the follower I had to be large culprite.

Is your upper built for the 458/450?? Mine wasnt, I had to open up the ejection port.

CW
It was my first big bore and my buddy had just built his 50 beo and had those same issues (had to mod the eject port, play with the gas system ect. and he was not happy) so I opted to buy the upper this time. It feeds a lot of the rnds with no problems just seems to hate RN style, those usually feed the best for me in pretty much all other calibers.
 

CWLONGSHOT

Well-Known Member
I opened mine up on a bridgeport.

BEFORE;

D61B21DB-D1B0-421C-B312-4FBFD8C84C38.jpeg

AFTER;

75C0E0D7-AD28-4065-88F8-BB0A88ADFEA1.jpeg
477C8A90-B6B3-40EA-94F9-7BF81B340CBC.jpeg9178F022-EC44-4356-AF98-73394A3D9FA3.jpeg

(I only had a 458 as a reference to show size.)

I also decided to omit the door so I also removed the bosses.

CW
 

RBHarter

West Central AR
Now I have to go look at the ARP M4 I don't think it's cut that deep and a lot more polished and "defarbed" . The Mossy/Wilson seconds looked that but rougher .
 

popper

Well-Known Member
You're welcome. Had to find out about the mags as my DPMS 308 had problems. CS said send em back or tweak to get them to work. BO mags can be temperamental too.