450 Bushmaster feeding issue

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Chaparral

New member
I have a 450 Bushmaster that is from Bushmaster Arms. And I only have 1 magazine that came with the rifle that is a Bushmaster magazine. Folks this is sadly a great single shot. I can not get this gun to cycle. If I put rounds in the mag it will chamber the first round when I chamber the round. I fire the gun. The second round will stack up in the chamber with the empty casing. If I cycle 1 round and fire it; the chamber stays (locks) open and there is the empty casing just laying in the chamber. I want to keep this rifle. It is super accurate and I love the round.
 
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langenc

New member
Id be on the horn w/ Bushmaster and suggest they fix it.

I wish 450 would have come along a little sooner cause Id probably have one, at least an upper for my gun. I bet yours is a terrible black gun, also.
The only 'problem' Ive heard is they bark pretty loud but have a great small group bite out to over 200 yards.
 
C

Chaparral

New member
langenc said:
Id be on the horn w/ Bushmaster and suggest they fix it.

I wish 450 would have come along a little sooner cause Id probably have one, at least an upper for my gun. I bet yours is a terrible black gun, also.
The only 'problem' Ive heard is they bark pretty loud but have a great small group bite out to over 200 yards.
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Yeah that was one of my considerations. After obtaining the rifle I started seeing on the internet where people were having this issue with the 450 Bushmaster no matter who the maker is. I've seen everything from file this down, bought a new BCG, bought new mags, bought new spring, bought different buffer, etc etc etc. And they said the same thing in that " very accurate rifle, but........"
 
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stagpanther

New member
When you say chamber is left open--do you mean the bolt locks back after firing? I don't have a 450m bushmaster--but do have a 458 socom which I chose over the bushie specifically because it has a shoulder.
 
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stagpanther

New member
Ok--if it's locking back but leaving the case in the receiver or double stacking when there's another cartridge in the mag, my guess would be there's an issue with the bolt's extractor and/or ejector. How does your spent brass look?
 
C

Chaparral

New member
stagpanther said:
Ok--if it's locking back but leaving the case in the receiver or double stacking when there's another cartridge in the mag, my guess would be there's an issue with the bolt's extractor and/or ejector. How does your spent brass look?
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I thought the same exact thing today. When I was at the range my 1st thought was to order a new BCG. The brass looked great after I retrieved it from the open chamber. I got home and started reading online and realized this is a common issue with this caliber. And numerous brands of uppers were mentioned including Bushmaster. It seemed like 90% of the people blamed the magazines. I read where one guy said he replaced the heavy buffer tube spring with a light .223 spring. He said it fixed the problem of not ejecting immediately.
 
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stagpanther

New member
Before starting "buffer/spring musical chairs" (that's what I call it because it seems that's what many people jump on when they have a cycling issue) I'd strip and clean everything--including the bolt's ejector and extractor. If the 450 is anything like the 458 (I would imagine very close) it probably has a heavy duty bolt with "extra power" springs in the ejector and extractor. The reason I asked about the brass is that often there are tell-tale dents, scratches etc that can help diagnose what's going on. Sometimes the process of feeding from the magazine can also cause issues--if you have other mags I'd try them. I often will slow cycle by hand dummy cartridges and try to see if anything is going on with the position of the cartridge as it is fed from the magazine. Just out of curiosity--does your magazine use a single stack cartridge follower?
 
9

9x19

New member
YOu say it feeds fine, but doesn't eject the brass...

Check your bolt, make sure the extractor moves freely. If it has too much tension, look and see if it has an added o-ring to increase spring tension, you can remove the o-ring and try again... also check to make sure the ejector spring is present and the ejector moves freely.

Good luck
 
C

Chaparral

New member
stagpanther said:
Before starting "buffer/spring musical chairs" (that's what I call it because it seems that's what many people jump on when they have a cycling issue) I'd strip and clean everything--including the bolt's ejector and extractor. If the 450 is anything like the 458 (I would imagine very close) it probably has a heavy duty bolt with "extra power" springs in the ejector and extractor. The reason I asked about the brass is that often there are tell-tale dents, scratches etc that can help diagnose what's going on. Sometimes the process of feeding from the magazine can also cause issues--if you have other mags I'd try them. I often will slow cycle by hand dummy cartridges and try to see if anything is going on with the position of the cartridge as it is fed from the magazine. Just out of curiosity--does your magazine use a single stack cartridge follower?
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Yes single stack. The only time I saw any scratches or dings on casings is when I loaded a loaded magazine and the next round coming out of the magazine piled up on the empty casing.
 
C

Chaparral

New member
9x19 said:
YOu say it feeds fine, but doesn't eject the brass...

Check your bolt, make sure the extractor moves freely. If it has too much tension, look and see if it has an added o-ring to increase spring tension, you can remove the o-ring and try again... also check to make sure the ejector spring is present and the ejector moves freely.

Good luck
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I appreciate your suggestions greatly. I will do this.
 
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stagpanther

New member
I think what 9 x 19 is probably referring to is if your extractor is overpowered (or extractor is underpowered) it might be "hanging on" to your spent case rather than ejecting it.
 
T

TRX

New member
Does the magazine use the standard 5.56 follower (with the half-cartridge molded on one side), or does it have a proper single-stack .450 follower?

For my .50 Beowulf, even "correct" Alexander Arms magazines refused to feed until I installed some .450 Bushmaster single-stack followers and ground a half-moon out of the front of each mag so the case mouth wouldn't catch on it.

If you paint a couple of your .450s all over with black Magic Marker, carefully insert them in the mag so they don't get scratched, and then cycle the action, the scratch marks can tell you a lot about what's going on in the feed path.
 
B

bullspotter

New member
Dose it have an adjustable gas block? I had a issue like this also. I got proper gas, and also found the brass was hitting the upper exit window on the way out and bouncing back into the upper above the magazine. Found some specs online and did some file work, Runs 100% now for the last few hundred rounds.
 
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CarJunkieLS1

New member
Yeah this is an extractor and or ejector problem. Of course clean and lube everything up real nice. Completely disassemble your rifles bolt and make sure your extractor isn't chipped or broken and your ejector has a spring behind it. Shoot I've seen it before even in a factory rifle but is it possible you have the wrong extractor in the bolt.

If at all possible just get a 450BM/458Socom complete bolt rebuild kit and replace everything.
 
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GeauxTide

New member
I also have a Bushmaster factory rifle. With Hornady FTX ammo, it shoots 1/2" and I've had no issues. I'd also look at the ammo, since the headspace is on the case mouth.
 
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