Is it accurate to say 450 Bushmaster mags are fussy ?

[dirtmcgirt76239]

I only know friends and family with Ruger 450 bolt actions.

https://www.ammoland.com/2018/09/450...#axzz5xqcsD1br

Curious if y'all agree with that article.

[BMT85]

I’ve seen that article before and a couple others from that author. I mostly disagree with him on this subject, and not a fan of his writing in general. I have a couple bushmaster 5rd mags, a few 9-10rd ASC mags, and some 5.56 that I modified. I tweak the feedlips and open the front a little bit on most of them. I usually do this to any mags that aren’t for 5.56. Only had feeding issues with one 5.56 mag I converted for 450B. I also have one 5rd 450b windowed so I can load longer, no issues.

While I’ve seen and heard about feeding issues with the 450B in an AR, I haven’t had it except for one steel mag I was converting. I took to the extreme to see what it would hold. It holds 11 (I believe), and is kind of sketchy. It worked fine at around 10 or so. I honestly don’t like converting 5.56 for 450B in general, I think those will give you the most issues. Though I haven’t tried lancers or the Tromix follower.

[Quads]

I 3D print mag followers for the Bownells 20rd milspec aluminum arf mags and they run fine without issue.
I've printed 20 or 30 followers for others and never heard a word of complaints or issues with them.

**EDIT** I'm using the 20rd straight mags.

[dirtmcgirt76239]

I 3D print mag followers for the Bownells 10rd milspec aluminum arf mags and they run fine without issue.
I've printed 20 or 30 followers for others and never heard a word of complaints or issues with them.

Interesting. But are there many off the shelf mags as reliable as 5.56, 7.62x51 etc

[Quads]

Interesting. But are there many off the shelf mags as reliable as 5.56, 7.62x51 etc

I believe there are, but they get something stupid like $30 bucks .ea for them.
Which, it's essentially a milspec mag with a follower and the front lip filed down with a rat tail file. (as shown in the authors last pic)

[Kev_lar]

I just bought two “factory” mags from Midway. The base plate is stamped .450. I am pretty sure they are actually Bushmaster brand. They both function flawlessly. In the field I have never had to fire more than 2 rounds in quick succession anyhow. At the range 5 in a row without a problem though.

[BMT85]

I believe there are, but they get something stupid like $30 bucks .ea for them.
Which, it's essentially a milspec mag with a follower and the front lip filed down with a rat tail file. (as shown in the authors last pic)

The 450 specific mags have "walls" underneath the feed lips to prevent the upper rounds from double stacking. With converted mags you can end up with the rounds trying to double stack, which could cause feed issues. Not saying it will happen, but there's a greater chance compared to the 450 specific mags.

IIRC, ASC makes the bushmaster brand and stoner brand 450 mags. I think CPD is now a different company and they are supposedly making 450 specific magsas well.

[BMT85]

I dug out my modded 5.56 mags to see what capacity's they had. I have a modded USGI that will hold 12 and works pretty well. The C-products I went extreme with and it holds 13rds. Its a little sketchy with 13, a bit better with 12. Rounds feeding up gets a little "sticky" around 3-4rd when stripping by hand, because of it trying to double stack. Might try to fix it. I played with my 10rd ASC 450 mags and one of them needs some work. Hard to load after 6rds and bad tilting after about 8.

Also I don't think anyone makes a 450 specific mags over 5rds anymore.

[Garymac]

As long as we're talking 450. I recently built a 450 AR upper and was able to get a couple 450 followers for the mags. I put the followers into some straight 20 round AR mags and hand cycled rounds through the rifle. They seem to cycle well but occasionally get caught up in the ejection port. It seems the more energetic I cycle the rounds the better they fly out. I thought I read somewhere where I might have to open up the ejection port to get reliable ejection (I used a standard AR upper). If so how large does the port need to be? I hopefully will get out this weekend to shoot it.

[BMT85]

The bottom of the ejection port has a slight lip. Usually you grind that out with a slight angle. I also went and took out the top lip in front of where the port door detent catches (also angled that a bit, too). If your real careful, or have access to a mill, you can take out the whole top lip, and still keep the spot for the detent to latch. 450 Bushmaster forums have a thread with pics.