Magazines

Talk about the AR15 style rifles chambered in 450 Bushmaster.

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Re: Magazines

Postby Hoot » Thu Apr 11, 2019 10:46 am

plant_one wrote:i hate it when i see folks holding "mil spec" to such a gold standard.


in reality.... Mil-Spec = lowest common denominator

remember mil-spec on ammo = 3-4 MOA just as one example....

just saying...


That's a broad brush stroke. They can be quite stringent. For 15 years, I worked for a company that made onboard computers for the F-18 Hornet and F-14 Tomcat. Believe me, the military can be very anal about minuscule specifications! :roll:

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Re: Magazines

Postby Snapdragon » Tue Jun 11, 2019 11:45 am

I am new to the game with 450 Bushmaster in an AR. I have several dedicated 450 magazines that seem to work OK so far. I tried a 20 round P Mag with the 223 follower yesterday and had no problems with it feeding 450. It held 8 rounds. I ran only 2 magazines through the rifle which is certainly not a definitive test.
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Re: Magazines

Postby Hoot » Tue Jun 11, 2019 9:42 pm

Snapdragon wrote:I am new to the game with 450 Bushmaster in an AR. I have several dedicated 450 magazines that seem to work OK so far. I tried a 20 round P Mag with the 223 follower yesterday and had no problems with it feeding 450. It held 8 rounds. I ran only 2 magazines through the rifle which is certainly not a definitive test.


Welcome Aboard Snap!

Did that accomplishment somehow involve dancing nude in the blue moon light, around an inverted cross, covered in goat's blood? ;)

I must confess, I too have been pretty lucky with magazines though I admit, I never pursued a high-cap solution. If I can't get it done with 5 shots, my time would probably be better spent fishing. :lol:

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Re: Magazines

Postby Snapdragon » Fri Jun 14, 2019 6:03 pm

Well, my goat blood lost its power. I took the rifle back to the range and could not get through one of my four dedicated 450 magazines without a jam. The top round would strip out of the magazine and the second round would go far enough forward to jam the bolt before it returned to battery completely. I did not have a P-Mag with me to try one of them. These were the same magazines and the same ammo that worked perfectly last week. The rifle was well lubed, and the magazines were dry.

edit: I left out the nude moonlight dancing this time. Perhaps that is the cause.
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Re: Magazines

Postby Hoot » Fri Jun 14, 2019 9:44 pm

Snapdragon wrote:Well, my goat blood lost its power. I took the rifle back to the range and could not get through one of my four dedicated 450 magazines without a jam. The top round would strip out of the magazine and the second round would go far enough forward to jam the bolt before it returned to battery completely. I did not have a P-Mag with me to try one of them. These were the same magazines and the same ammo that worked perfectly last week. The rifle was well lubed, and the magazines were dry.

edit: I left out the nude moonlight dancing this time. Perhaps that is the cause.


Take some turns off the bottom of your magazine springs. They tend to have way too much lift force. Normally that is counteracted by the staggered feed of a 5.52 round but with a straight lift inline feed like the 450b it presses the top round up too hard. Now we're getting into remedies that are more often discussed around these parts. Polishing the bottom edge of the lips where the cases drag as they are stripped has merit as well. Everyone has their talisman for reliable mag function. I remove as many spring windings as will still allow a little upward pressure with the last round. Certainly not suitable for plunging the works in rice paddy muck and still being able to rely upon that last 5.56 round to save my life but I don't hunt under those conditions. Some, possibly many will differ with me on the following: If I get a magazine and it has those thin sheet metal plates on either side wall near the top, apparently to aid in centering the rounds, I yank them as well. The convex underside of the lips will serve to center the rounds as they lift into place. Using the proper follower also aids in centering. IMHO, those tabs drag on the rounds not only going up but also when you need that top round to bob down a little so that it doesn't drag against the bottom of the bolt or the preceding round that is trying to strip, or when the bolt is on the way back. Don't forget to grind off any remaining spot weld pips left behind if you yank them, though they usually are not an issue. A lighter spring lift and a little top round bob keeps everything fluid and able to more adequately yield the to the right of way.

That's my magic incantation for reliable magazines. If after having done those common sense preparatory steps, if my mags still are the source of a cycling issue, then I say "I have a mag problem."

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Re: Magazines

Postby Snapdragon » Fri Jun 14, 2019 10:19 pm

Thanks.
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Re: Magazines

Postby Snapdragon » Sat Jun 15, 2019 8:01 am

The reloads I was shooting have a COAL of around 2.02. The Winchester factory loads I have are around 2.22 if I remember correctly. Anyway, my reloads are about 0.2 shorter with the bullets I have on hand. Is it likely that the recoil is causing my reloads to jump forward in the magazine while the Winchester rounds would just hit against the front of the magazine and stay in their correct position?
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Re: Magazines

Postby Hoot » Sat Jun 15, 2019 9:48 am

Snapdragon wrote:The reloads I was shooting have a COAL of around 2.02. The Winchester factory loads I have are around 2.22 if I remember correctly. Anyway, my reloads are about 0.2 shorter with the bullets I have on hand. Is it likely that the recoil is causing my reloads to jump forward in the magazine while the Winchester rounds would just hit against the front of the magazine and stay in their correct position?


I've personally have never had an issue from recoil affecting my rounds in the mag but that's just my experience.

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Re: Magazines

Postby Snapdragon » Sat Jun 15, 2019 1:05 pm

I just tried a little science experiment in which I smacked the magazine against my leg to get the rounds as far forward as the magazine allows and tried to feed the rounds. Several jammed. I will try shooting the remaining factory rounds next week to see if they jam the same way.
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Re: Magazines

Postby Snapdragon » Thu Jun 27, 2019 12:02 pm

I did some more tinkering and got the rifle to run 100% with 4 different magazines for 50 rounds. The shorter hollow point bullets seem to be the problem. Evidently they would creep forward during recoil and cause the feeding problem. I put them in a P-Mag with the 223 follower and with the ridge down the middle of the front. They fed with no problems. I also have some 250 grain Hornady bullets made for the Bushmaster round that are more pointed and have a longer COAL. They fed without problems in 4 dedicated 450 magazines of two different brands. The longer length evidently keeps the rounds in place so they do not affect the feeding of the round above them. I will do it again next week to see if it still works.
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