School me on the 450 bushmaster

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[ARCHIVED THREAD] - School me on the 450 bushmaster (Page 1 of 2)

Posted: 3/26/2017 1:33:31 PM EDT

Thinking of a 450 bushmaster build what do I need to know?

what all parts are unique to the 450?

Who maks the best barrels?

16, 18, or 20in?

Thanks

Posted: 3/26/2017 7:56:53 PM EDT

[#1]

Well, one would need a barrel, gas port block, muzzle flash diffuser, and a bolt for the bolt carrier. The magazines need a single stack follower and you need to use metal magazines, no plastic ones.

Some people have used a heavier recoil spring and or a heavier buffer too. But they designed it to work with a stock 5.56 lower. This may be more related to the gas port and its hole size and where the gas port is located on the barrel.

That is about it for the 450 Bushmaster. One may find it more practical to get a upper kit or set of parts. That way all you have to do is swap out the upper to change calibers using the same lower.

The .450 Bushmaster also uses .452" diameter bullets, which are commonly found on the .45 pistols. Watch out for the .458" diameter rifle bullets though. You would have to swage them down to .452" to use.

As to best barrel? I think that all of the barrels are good. So no problem there. But maybe a chromed barrel is the way to go though.

My .450 rifle has a 20 inch barrel length. But one could go with a shorter one if they want to.

Posted: 3/27/2017 8:49:29 PM EDT

[#2]

Ruger seems to be all in on the 450 bushmaster game. They just added a gunsite scout model to go along with the american ranch. I think the cartridge is taking steps to becoming mainstream. This is good news for anyone getting into the cartridge in the AR platform. 16" really seems to be the new standard length and you shouldn't lose much velocity with that barrel length.

Posted: 3/28/2017 8:33:40 PM EDT

[#3]

Here is the dope card for Hornady factory ammo in a 16" barrel.

Posted: 3/28/2017 9:52:01 PM EDT

[#4]

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Here is the dope card for Hornady factory ammo in a 16" barrel.

http://i128.photobucket.com/albums/p172/bmosely/6668945f93c4f29437c51feb4a77ef42_zpsskaejh5y.jpg

http://i128.photobucket.com/albums/p172/bmosely/0de0d33a773ea87faf7746b5e70dde25_zps0scgm0i6.jpg

http://i128.photobucket.com/albums/p172/bmosely/1418f428c21f9012c681c9ba6c86833b_zps2wm9zj5m.jpg

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Are you sure on your listed 1705 FPS?

I got 2131 FPS average using 250 grain Hornady factory ammo from my 16" Bushmaster upper.

Here's my trajectory chart:

Posted: 3/28/2017 10:06:24 PM EDT

[#5]

Are you set on .450 Bushmaster? Have you considered .458 SOCOM

Posted: 3/28/2017 10:57:58 PM EDT

[#6]

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Quoted:
Are you set on .450 Bushmaster? Have you considered .458 SOCOM

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Pretty much set on the 450

Posted: 3/29/2017 7:44:39 AM EDT

[#7]

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Quoted:

Are you sure on your listed 1705 FPS?

I got 2131 FPS average using 250 grain Hornady factory ammo from my 16" Bushmaster upper.

Here's my trajectory chart:

http://photos.imageevent.com/brobert/ar15/websize/450B.jpg

View Quote

I did a bunch of research after missing some intermediate length shots. The box lists 2100 out of a 20" barrel. I assumed a couple of inches would cost some fps, but it seems significant on the .450. The 1750 came from several chronograph reports with Bushy 16" uppers from several people.
I typically carry this gun for 150 -175 yd or less engagements. My AR 10 .308 is set up for everything else out to 700 yds.

Posted: 4/2/2017 6:16:29 PM EDT

[#8]

I like my 16" 450 Bushy a lot.

Does anyone know if BM still makes a 20" upper and who keeps them in stock?

Probably shouldn't have put off getting one, as they seem to be scarce at the moment.

Posted: 4/2/2017 9:52:55 PM EDT

[#9]

Quote History

Quoted:
I like my 16" 450 Bushy a lot.

Does anyone know if BM still makes a 20" upper and who keeps them in stock?

Probably shouldn't have put off getting one, as they seem to be scarce at the moment.

View Quote

According to the email I just got from bushmaster who has nothingfar as uppers or barrels in stock they are only focused on building complete rifles

Posted: 4/3/2017 1:12:31 AM EDT

[#10]

1705 fps is way low for a 16" barrel. In my experience, 2100+/- is the norm for 16". The "Black" ammo is even faster, at least the lot I got was.

Bushmaster Support

What are the ballistic differences between the 16" and 20" barrel in .450 Bushmaster?

Since there is a complete powder burn in the 16" barrel there is very little, about 60 FPS, difference in velocities.

View Quote

Posted: 4/6/2017 9:27:38 PM EDT

[#11]

Check out the ballistics on a 12ga slug. Even a 20ga slug.

Not sure what you gaining at 150 yards??

Posted: 4/7/2017 7:08:42 AM EDT

[#12]

Quote History

Quoted:
Check out the ballistics on a 12ga slug. Even a 20ga slug.

Not sure what you gaining at 150 yards??

View Quote

How about a flatter shooting round, an adjustable stock, 16" barrel options, better optics mounting options, better triggers, mag fed, faster follow up shots and a much more configurable firearm.

Both work and they are all similar, but the 450 is flatter shooting and the real advantage is probably accuracy. It also basically an AR15 - which is just cool.

Posted: 4/10/2017 1:27:13 AM EDT

[#13]

I got lucky last week while cruising through my local Cabela's Bargain Cave and ran across a complete Bushmaster factory 20" .450 upper for really cheap. It was marked used but I looked it over thoroughly and didn't see any signs of use so I bought it. I put it on my .50 Beowulf lower and pulled a scope off of one of my other rifles and hit the range this weekend. After sighting it in, I have to say that I am VERY impressed at the accuracy of this rifle and round. I was using Hornady Black 250 grain rounds and my buddy and I were putting 3 round groups through the same hole at 50 yards and about 1MOA at 100 yards. We only put 20 rounds through it because that is all I bought when I purchased the upper, but I think this may be my go to hunting rifle this year. These pics are on a 7" target, the 2nd pic is at 50 yards (excuse the stray .223 round) and the 3rd pic is at 100 yards:

Posted: 4/10/2017 5:59:49 AM EDT

[#14]

My 20" Bushmaster target:

Attached File

Posted: 4/10/2017 9:45:57 AM EDT

[#15]

Looking at the different barrels available seems like the specs are all over the place far as twist, gas block diameter and muzzle threads even carbine mid length and rifle gas systems

Posted: 4/12/2017 2:05:13 AM EDT

[#16]

If you build one use a large port, big bore upper receiver.

Attached File

Posted: 4/12/2017 8:25:01 AM EDT

[#17]

You folks may find it of interest that Windham Weaponry will soon have a rifle available in this caliber. Also all of the parts for 450 Bushmaster will be available through us. We are calling the rifle the "450 THUMPER"

Posted: 4/12/2017 7:58:22 PM EDT

[#18]

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You folks may find it of interest that Windham Weaponry will soon have a rifle available in this caliber. Also all of the parts for 450 Bushmaster will be available through us. We are calling the rifle the "450 THUMPER"

http://i.imgur.com/9is18i8.jpg?2

http://i.imgur.com/hAWq6NH.jpg?2

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Nice thanks for the heads up

Posted: 4/12/2017 9:01:58 PM EDT

[#19]

Quote History

Quoted:
Nice thanks for the heads up

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Quote History

Quoted:

Quoted:
You folks may find it of interest that Windham Weaponry will soon have a rifle available in this caliber. Also all of the parts for 450 Bushmaster will be available through us. We are calling the rifle the "450 THUMPER"

http://i.imgur.com/9is18i8.jpg?2

http://i.imgur.com/hAWq6NH.jpg?2

Nice thanks for the heads up

+1

Posted: 4/13/2017 12:10:32 AM EDT

[#20]

Any pricing info?

I could be swayed in this direction for sure.

In for the group buy?

Posted: 4/13/2017 8:35:57 PM EDT

[#21]

I just ordered a Tromix barrel/bolt.

Posted: 4/13/2017 9:43:04 PM EDT

[#22]

Quote History

Quoted:
I just ordered a Tromix barrel/bolt.

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The ported barrel looks interesting but i dont want something crazy loud

Posted: 4/14/2017 5:57:04 AM EDT

[#23]

I didnt see they had a 450 ported barrel. I got the light weight one.

Posted: 4/14/2017 7:18:21 AM EDT

[#24]

Quote History

Quoted:
I didnt see they had a 450 ported barrel. I got the light weight one.
http://nebula.wsimg.com/8177e79afaa73aa4b4e8fbc4a00cf601?AccessKeyId=97B459EED18B9A18841F&disposition=0&alloworigin=1

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I was thinking of trident barrel. Looks good let me know how it shoots.

Posted: 4/14/2017 8:00:19 AM EDT

[#25]

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Quoted:
Any pricing info?

I could be swayed in this direction for sure.

In for the group buy?

View Quote

Not just yet. We will have pricing soon. The pictured rifle will be at the NRA show in a couple of weeks.

Posted: 4/21/2017 7:58:28 AM EDT

[#26]

Posted: 6/19/2017 10:40:24 PM EDT

[#27]

Quote History

Quoted:
I didnt see they had a 450 ported barrel. I got the light weight one.
http://nebula.wsimg.com/8177e79afaa73aa4b4e8fbc4a00cf601?AccessKeyId=97B459EED18B9A18841F&disposition=0&alloworigin=1

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Any update on how it shoots?

Posted: 6/20/2017 11:11:03 AM EDT

[#28]

So far I am loving 450 Bushmaster. My 450BM I put together a few weeks ago. 20 inch 450BM upper kit from Bushmaster. The lower is a DPMS A2 lower I had laying around.
Factory mags are only OK. I converted some standard straight GI 20rd and 30rd magazine using a 458 SOCOM follower from http://www.calegalmags.com/ and those magazines are excellent. Be sure to deburr the feed lips well.
I have my Dillon 650XL setup to reload 450BM. So far my favorite load is a 240gr XTP/MAG going ~2300fps (2818ft-lbs). I think I can get better accuracy out of some of the FTX bullet but I could still ring an 8-inch plate at 200 yards 4 out of 5 shots with it.
Midway has Hornady factory blemishes 300gr .452 muzzle loader bullet on sale cheap right now. I am going to try those. I have some 225 FTX, 250 FTX (bullet used in factor load) and some 225gr and 275gr Barnes I am going to try. Might even try some subsonics too.
Can't wait for deer season this year.

Posted: 6/20/2017 5:50:04 PM EDT

[#29]

Quote History

Quoted:

Any update on how it shoots?

View Quote

I had some problems and sent back a barrel and bolt to Tromix. The barrel extension was misaligned to the gas port, and the bolt wouldn't eject the case. When I got the new barrel installed the bolt still wouldn't work. I called again and he admitted he never checked the bolt. He sent me a new extractor and that finally got it working.

I went out a few weeks ago and finally got the 450 heated up. It shot fine, I got it sighted in off the seat of the 4wheeler. I did have one fail to feed, and to me the recoil is about like a Muzzleloader. Feels funny, because AR's don't kick. I got a quick sight in at 75 yards and then was able to hit steel plates at 150 yards.

Here is a pic, I may try my hand at painting this one. I still need to pick up a sling/swivel and probably a limbsaver.

Posted: 6/21/2017 10:55:01 PM EDT

[#30]

Quote History

Quoted:
Check out the ballistics on a 12ga slug. Even a 20ga slug.

Not sure what you gaining at 150 yards??

View Quote

I wrestle with that too. I hunt in Iowa and use a 20 gauge and am not delighted with its performance. My gun is a Savage slug hunter. I use the 3 inch Remington Accutips and am not impressed with them as far as penetration. Almost lost a 150 class big bodied buck due to no blood trail. The slug did not go through on a 80 yard shot.

Now that Iowa allows certain rifles (not certain whether the 450 is on the list or if it will be placed on the list) I am inclined to go with a rifle. I did shoot a deer at 120 plus yards with a 460 Smith in an Encore handgun and had complete penetration.

Posted: 6/22/2017 9:10:00 AM EDT

[#31]

Quote History

Quoted:

I wrestle with that too. I hunt in Iowa and use a 20 gauge and am not delighted with its performance. My gun is a Savage slug hunter. I use the 3 inch Remington Accutips and am not impressed with them as far as penetration. Almost lost a 150 class big bodied buck due to no blood trail. The slug did not go through on a 80 yard shot.

Now that Iowa allows certain rifles (not certain whether the 450 is on the list or if it will be placed on the list) I am inclined to go with a rifle. I did shoot a deer at 120 plus yards with a 460 Smith in an Encore handgun and had complete penetration.

View Quote

Remington's 450 Bushmaster ammunition shoots exactly the same 260gr Accutip bullet as is in the 20 Gauge Sabot. Be where the 20 Gauge version is ~1900 fps (2084ft-lbs) the 450BM launches that bullet at ~2180 fps (~2740 ft-lbs). If more penetration is what you want and you are a reloader you can get Barnes 275gr TSX or Hornady 300gr XTP/MAG or 300gr FTX bullets and probably get much better penetration. Supposedly Remington is going to release a factory 450 Bushmaster using the Barnes TSX.

Posted: 6/22/2017 10:18:05 AM EDT

[#32]

the rebated rim on the 450 bushmaster is still pretty big -- who makes a good bolt for the round? Do you have to actually open up the ejection port for the cartridge case or is it just a small amount of trimming? What mags work best for the cartridge? I imagine they are single stack but correct me if I'm wrong. Does anybody know if a balistics chart comparing a standard 450 bushmaster round fired from a 16" barrel, 18" barrel and a 20" barrel?

Posted: 6/22/2017 2:31:49 PM EDT

[#33]

Quote History

Quoted:
the rebated rim on the 450 bushmaster is still pretty big -- who makes a good bolt for the round? Do you have to actually open up the ejection port for the cartridge case or is it just a small amount of trimming? What mags work best for the cartridge? I imagine they are single stack but correct me if I'm wrong. Does anybody know if a balistics chart comparing a standard 450 bushmaster round fired from a 16" barrel, 18" barrel and a 20" barrel?

View Quote

I am running a Bushmaster bolt and it has been good so far. I am sure there are others.

As for magazines the factory magazines are only so-so, some are great some are not. I have had great luck with taking the NHMTG straight 20rd magazines, removing the floor plate and cut off the floor plate retention tab. I then replace the follower with a 458 SOCOM follower from http://www.calegalmags.com/ and use a standard floor plate from a 30rd magazine. I had a few left from when I put Ranger floor plate on some 30rds. These conversion hold 6 rounds and have been flawless for me even when feeding short and blunt Hornady 240gr XTP/MAG bullets.

As for velocity I don't think you loose much going from 20-inch down to 16-inch. With most loads you might loose 100fps between the two. Maybe a bit more with lighter bullets. That said i really like my 20-inch the extra weight is nice for recoil management.

Posted: 6/22/2017 9:09:44 PM EDT

[#34]

Quote History

Quoted:
the rebated rim on the 450 bushmaster is still pretty big -- who makes a good bolt for the round? Do you have to actually open up the ejection port for the cartridge case or is it just a small amount of trimming? What mags work best for the cartridge? I imagine they are single stack but correct me if I'm wrong. Does anybody know if a balistics chart comparing a standard 450 bushmaster round fired from a 16" barrel, 18" barrel and a 20" barrel?

View Quote

I got a Tromix bolt, on my 450b. Yes you will have to open up your receiver a little on the ejection port. There are instructions floating around if you feel like grinding. I had an older receiver not being used, so I just took a dremel tool and went to town. It took about 15 mins, but I also went pretty slow as to not take too much off. I converted a straight colt 20 round mag with the ebay single follower, I need to do more testing before I know it will work. Yes they are single stack, and from what Ive read they dont do well with the curve of the standard 30 round mags.

Bushmaster says 60FPS

Posted: 6/22/2017 11:14:17 PM EDT

[#35]

Quote History

Quoted:

I wrestle with that too. I hunt in Iowa and use a 20 gauge and am not delighted with its performance. My gun is a Savage slug hunter. I use the 3 inch Remington Accutips and am not impressed with them as far as penetration. Almost lost a 150 class big bodied buck due to no blood trail. The slug did not go through on a 80 yard shot.

Now that Iowa allows certain rifles (not certain whether the 450 is on the list or if it will be placed on the list) I am inclined to go with a rifle. I did shoot a deer at 120 plus yards with a 460 Smith in an Encore handgun and had complete penetration.

View Quote

Word is 450 will be on the list when the regs come out next month and is the reason I've been researching the hell out of it

Posted: 7/1/2017 7:53:42 PM EDT

[#36]

Quote History

Quoted:

I got a Tromix bolt, on my 450b. Yes you will have to open up your receiver a little on the ejection port. There are instructions floating around if you feel like grinding. I had an older receiver not being used, so I just took a dremel tool and went to town. It took about 15 mins, but I also went pretty slow as to not take too much off. I converted a straight colt 20 round mag with the ebay single follower, I need to do more testing before I know it will work. Yes they are single stack, and from what Ive read they dont do well with the curve of the standard 30 round mags.

Bushmaster says 60FPS

View Quote

How many 450 will a GI 20 and 30 hold?

Posted: 7/1/2017 10:49:31 PM EDT

[#37]

Quote History

Quoted:
How many 450 will a GI 20 and 30 hold?

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View All Quotes

Quote History

Quoted:

Quoted:

I got a Tromix bolt, on my 450b. Yes you will have to open up your receiver a little on the ejection port. There are instructions floating around if you feel like grinding. I had an older receiver not being used, so I just took a dremel tool and went to town. It took about 15 mins, but I also went pretty slow as to not take too much off. I converted a straight colt 20 round mag with the ebay single follower, I need to do more testing before I know it will work. Yes they are single stack, and from what Ive read they dont do well with the curve of the standard 30 round mags.

Bushmaster says 60FPS

How many 450 will a GI 20 and 30 hold?

With the 458 SOCOM follower I showed up thread I can get 6 round in a straight GI 20rd magazine. I can get a 7th round in the magazine but not enough room left to get it to lock into the rifle on a closed bolt. If I put that same 458 SOCOM follower in a standard GI 30rd magazine I can get 11 rounds in the magazine.

Posted: 7/20/2017 10:18:19 PM EDT

[#38]

Got a new 16" bushmaster upper switched out the rail for a kmr just got my ammo and mags and hand cycling the rounds they catch about halfway on the ejection port where you can see the edge.

Does this need trimmed more? Doesn't seem right to me but I never had a big bore upper.

Posted: 7/20/2017 11:24:31 PM EDT

[#39]

Quote History

Quoted:
Got a new 16" bushmaster upper switched out the rail for a kmr just got my ammo and mags and hand cycling the rounds they catch about halfway on the ejection port where you can see the edge.

Does this need trimmed more? Doesn't seem right to me but I never had a big bore upper.http://i.imgur.com/B56EDGp.jpg

View Quote

That looks just like my factory upper. Never have a problem with ejection when firing. Go shoot it don't worry about the hand cycling.

Posted: 7/20/2017 11:29:53 PM EDT

[#40]

Tag

I'm looking to get into the cartridge now that we can use it for deer hunting in Ohio.

I'm unclear on whether you need to buy a dedicated upper with a larger ejection port or a milspec sized 5.56 port will work. I've seen conflicting information on it.

ETA I guess I should have kept reading... that almost looks like something that could be done with a dremel

I don't know if I'll have the time and money this year but I should have one by next season

Posted: 7/20/2017 11:34:53 PM EDT

[#41]

Quote History

Quoted:
http://i.imgur.com/XfeLhlvl.jpg
So far I am loving 450 Bushmaster. My 450BM I put together a few weeks ago. 20 inch 450BM upper kit from Bushmaster. The lower is a DPMS A2 lower I had laying around.
Factory mags are only OK. I converted some standard straight GI 20rd and 30rd magazine using a 458 SOCOM follower from http://www.calegalmags.com/ and those magazines are excellent. Be sure to deburr the feed lips well.
I have my Dillon 650XL setup to reload 450BM. So far my favorite load is a 240gr XTP/MAG going ~2300fps (2818ft-lbs). I think I can get better accuracy out of some of the FTX bullet but I could still ring an 8-inch plate at 200 yards 4 out of 5 shots with it.
Midway has Hornady factory blemishes 300gr .452 muzzle loader bullet on sale cheap right now. I am going to try those. I have some 225 FTX, 250 FTX (bullet used in factor load) and some 225gr and 275gr Barnes I am going to try. Might even try some subsonics too.
Can't wait for deer season this year.

View Quote

@mcb

Which powder? How many have you tried? From what I've read Lil'Gun seems like the best fit.

Posted: 7/20/2017 11:44:27 PM EDT

[#42]

Quote History

Quoted:
Tag

I'm looking to get into the cartridge now that we can use it for deer hunting in Ohio.

I'm unclear on whether you need to buy a dedicated upper with a larger ejection port or a milspec sized 5.56 port will work. I've seen conflicting information on it.

ETA I guess I should have kept reading... that almost looks like something that could be done with a dremel

I don't know if I'll have the time and money this year but I should have one by next season

View Quote

You can mod a mil spec upper to work I think it was on 450bushmaster.net that I saw the instructions

Posted: 7/21/2017 12:47:16 AM EDT

[#43]

I have an upper that never gets used so if I could mod that with a new barrel and bolt, it would make it easier for me.

Posted: 7/21/2017 8:46:50 AM EDT

[#44]

Quote History

Quoted:

@mcb

Which powder? How many have you tried? From what I've read Lil'Gun seems like the best fit.

View Quote

Yes Lil'gun seems to be the best choice. I am using Lil'gun for bullet weights from 200gr-250gr. For the 275gr TSX Barnes and the 300gr XTP/MAG or FTX I am using H110. I am going to chrono a bunch of different loads this weekend. I have 200gr XPB, 225gr FTX, 250gr FTX and 275gr TSX loads ready for a range trip.

Posted: 7/21/2017 9:03:46 AM EDT

[#45]

Very nice... I already have a bunch of H110 for 44 mag.

Posted: 7/21/2017 1:15:35 PM EDT

[#46]

The beauty of the 450 is if you load for big bore pistols or PCR you already have most of the stuff. For me it is just needing some 450 brass and dies. I got both an AR upper and Ruger American. So far both are very impressive. I'm getting ready to load up some cast for the Ruger. I've read that the powder coated cast bullets can be used in the AR platform as well. These are dedicated and purpose built/set up for deer hunting.

Posted: 7/21/2017 1:40:39 PM EDT

[#47]

Quote History

Quoted:
I have an upper that never gets used so if I could mod that with a new barrel and bolt, it would make it easier for me.

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I moded my upper for 450. It was pretty easy with the dremil. Worst case upper receivers are cheap and easy to get should you mess one up.

Posted: 9/6/2017 9:20:20 PM EDT

[#48]

So far so good running e lander mags with the calegal 458 follower had no luck with GI mags feed lips just were not strong enough to hold.

50y target the bottom 3 shot ragged hole after I had it dialed in

Posted: 9/10/2017 12:22:42 PM EDT

[#49]

looks good. Anything you would change on the build now that you have some rounds through it?
I have also been looking to using the AR platform for deer hunting since the regulations changed. Was considering the .50 beuwolf, but .450 bushmaster seems like an excellent choice since it made it on the approved list.

Posted: 9/10/2017 12:24:33 PM EDT

[#50]

Any of you have a 450 in a non AR variant as well?

I know this is an AR forum but those Ruger American's look like it would be a good companion to my future 450B AR build.

[ARCHIVED THREAD] - School me on the 450 bushmaster (Page 1 of 2)

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