[spearehead]

I bought a new Ruger American 450 Bushmaster recently and when I tried to sight it in the cartridges would not feed from the magazine into the chamber. After examining the magazine I noticed that the back of the Platform ( or follower ) in the magazine ( or clip ) was sticking along the back wall. I disassembled the magazine with a small screwdriver by prying the bottom plate rearward. I sanded about 1 mm (1/32”) from the back edge of the Platform and rounded off and smoothed the edges. I bent the back of the platform up a little and reassembled the magazine. IT WORKS PERFECTLY. Here’s some photos.

Sent from my iPhone

 

[onlinebiker]

New rifle. Some assembly required...

 

[Tilden Hunter]

I'm glad you're handy. It looks like Ruger sold you a rifle kit.

 

[Chessieman]

I noticed on one of my same clips that the shells are moving forward. I do not know if it was the one that came with the gun or the extra I bought. This would be a jam just waiting to happen. Sure would be a messed up situation being I am loading the gun in the dark. I guess I will have to take it apart and stretch the spring a bit after a little comparing.

 

[spearehead]

After receiving the replacement magazine from Ruger I noticed that the platform was reversed from front to back. (The bullet shape is facing backwards) Take the magazine apart and reverse the bottom plate on the spring.

 

[Chessieman]

Mine mold indent is in the correct location in relation to feed direction.
I think that a little bending the feed plate pushing the end will fix it.
Just watch out for it any of you Rugar owners.

Just a heads up also, for the shells that you chamber in before inserting your clip. I shot the two that were chambered from the pervious season first when sighting in at one session. Those shots were way out probably do to casing wear. On now only chamber the same shell for the first season and will utilize a new one for our second season.

 

[Bucman]

Mine mold indent is in the correct location in relation to feed direction.
I think that a little bending the feed plate pushing the end will fix it.
Just watch out for it any of you Rugar owners.

Just a heads up also, for the shells that you chamber in before inserting your clip. I shot the two that were chambered from the pervious season first when sighting in at one session. Those shots were way out probably do to casing wear. On now only chamber the same shell for the first season and will utilize a new one for our second season.

So chambering a multiple times round can affect the accuracy?

 

[bowhunter426]

So chambering a multiple times round can affect the accuracy?

Only if there is an issue with your gun that is cutting the case mouth shorter of damaging the brass.

 

[Chessieman]

Yep, hard to believe. I was firing at my range with new loads all the rounds hitting in a 1" group. I had three shells in a plastic bag marked as used last year for chambering. I was at another friends range and shot those three first and they were 8" all around not consistent. Fired new rounds again was back to the 1" group. Could it have been moisture or Brass deformation, I do not know but the Brass had a lot of witness marks. The new shells in my two mags that were carried for the month shot fine. Ah, the mystery's of life!

 

[Chessieman]

Only if there is an issue with your gun that is cutting the case mouth shorter

Hum, I shall have to see, presently I am only chambering one shell 9 times a week. I guess the only way to check it would be magnification. Thinking about it I should break out a new shell, my big buck critical shot time of year is coming up!

 

[Bucman]

Hum, I shall have to see, presently I am only chambering one shell 9 times a week. I guess the only way to check it would be magnification. Thinking about it I should break out a new shell, my big buck critical shot time of year is coming up!

Personally being anal of this type of situation I would never chamber a round twice for hunting unless I figured out the issue. 🤷🏻‍♂️that's just me.

 

[Chessieman]

I am going to get the Vernier's out later and check, I do not have the deep 0 to 1" deep Mics so will have to guess on the tenths. I figure those wild shells what were chambered at least 40 times last season. Since I drop in the shell only the extractors really touch the casing so it must be head compression that should be easy to measure. I replace the shell every five times out now.

 

[bowhunter426]

I am going to get the Vernier's out later and check, I do not have the deep 0 to 1" deep Mics so will have to guess on the tenths. I figure those wild shells what were chambered at least 40 times last season. Since I drop in the shell only the extractors really touch the casing so it must be head compression that should be easy to measure. I replace the shell every five times out now.

not loading from the magazine could be the issue. If the extractor doesn't pop over the rim you will jam your case mount into the Lands, potentially changing the neck tension/ crimp pressure

 

[spearehead]

Now I’m worried if my rifle is really sighted in. With the original magazine not feeding a cartridge into the chamber I sighted in the scope by inserting one cartridge at a time by hand. I didn’t fire it again until I hunted with the new magazine and recovered a nice buck that went 30 yards but thought the shot hit lower than I aimed. Back to the range. Thanks for all the input guys.