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450B upper build question

PostPosted: Wed Aug 25, 2010 3:27 pm
by Clipity
I have been going back and forth on building a 450 bushmaster but can't figure out something. I have seen that a few people have built these, but what I haven't seen what kind of upper is being used other than someone said they used a DPMS. So what works A3 with A3 feed ramp, A3 with M4 feed ramp or A2? I have read that when building a 50 Beowulf they say not to use uppers with the M4 feed ramp anyone know why?

TIA Clipity

Re: 450B upper build question

PostPosted: Wed Aug 25, 2010 10:35 pm
by 2zero6
Clipity wrote:I have been going back and forth on building a 450 bushmaster but can't figure out something. I have seen that a few people have built these, but what I haven't seen what kind of upper is being used other than someone said they used a DPMS. So what works A3 with A3 feed ramp, A3 with M4 feed ramp or A2? I have read that when building a 50 Beowulf they say not to use uppers with the M4 feed ramp anyone know why?

TIA Clipity

The Barrel extension is ground down to center the rounds fed as the projectile is much larger in diameter. If you use a Mil spec upper receiver you will need to enlarge the ejection port. There is a very well put together how to by the the_mad_rshn found here: http://450bushmaster.net/viewtopic.php?f=2&t=132 .
There is also another good thread found here: http://450bushmaster.net/viewtopic.php?f=2&t=104
Bushmaster's part number for their upper receiver less barrel/extension and BCG is: VUR-45 is for a .450 upper reciever (includ. forward assist, factory .450 laser printing, and dust cover) price $190.00 before shipping.I believe MGI also sells .450 parts as well, Even the barrel is Bushmaster stamped. That thread can be found here: http://450bushmaster.net/viewtopic.php?f=2&t=887. Hope all this helps. :D

Re: 450B upper build question

PostPosted: Wed Aug 25, 2010 11:26 pm
by Mike
Another option on the ejector port is to send it to me with enough money for me to ship it back and Ill mill the port out for you. I personally like the lopro slick side uppers as they lack a forward assist which keeps you from turning a bad situation into a worse situation.

Re: 450B upper build question

PostPosted: Wed Aug 25, 2010 11:48 pm
by 2zero6
Unless you want the forward assist to close the bolt a little quieter in certain hunting situations. Mike, didn't you use some MGI parts?

Re: 450B upper build question

PostPosted: Fri Aug 27, 2010 9:54 pm
by Mike
Quite a bit ........ Just got a couple more sumthin sumthins from them ......Man I wish they sold a 20 ".


2Zero- Just for you Im gonna do a side charger next go round. That would be the best of both. You think I should go left or right side???? I just need to find a teeny tiny skull to fab into the charging handle, Titanium preferably, but Ill settle for steel.................. LMAO

Re: 450B upper build question

PostPosted: Fri Aug 27, 2010 10:19 pm
by 2zero6
Mike wrote:2Zero- Just for you Im gonna do a side charger next go round. That would be the best of both. You think I should go left or right side???? I just need to find a teeny tiny skull to fab into the charging handle, Titanium preferably, but Ill settle for steel.................. LMAO

I would love to do a left side bolt/right side ejection side charger (like the LWRC REPR) to be able to keep firing grip maintained. I always thought that layout made much more sense ergonomically and tactically. On a lighter note you could always make a trip to the local auto parts store and get those little skull tire valve stem caps or skull lock knobs. :D

Re: 450B upper build question

PostPosted: Sat Aug 28, 2010 7:37 am
by Mike
Holy Crap that would be worth doin just to have the pictures. Ill get the ones with the internal battery and LED eyes that light when its in motion. that would be hot.

I couldnt agree with you more on the lefty charger. You got any parts to donate to your cause? Spare upper? carrier?

Speaking of carriers- does anyone make one anymore without the dust cover recess? I know they are makin them wthout the FA serrations, But the ones Im finding still have the recess.

I cant remember where I saw one, but my latest attempts are turning up with nothing.

Re: 450B upper build question

PostPosted: Sat Aug 28, 2010 12:06 pm
by 2zero6
Closest thing I remember seeing is JP Enterprises low mass bolt carrier . I would actually keep the recess as to help channel out dirt and contaminants (in theory). :D

Re: 450B upper build question

PostPosted: Sun Aug 29, 2010 10:45 am
by Clipity
Loving the thread jacking going on here.

Re: 450B upper build question

PostPosted: Sun Aug 29, 2010 11:21 am
by 2zero6
Clipity wrote:Loving the thread jacking going on here.

Sorry, won't happen again. :oops: As far as the feed ramps go, if you are modding your own extension you will need to grind down the lower part of the extension where the feed ramps are and make it into a larger single feed ramp. Hope that helps.