I got to the range today to test the 450BM and the SOCOM:
Same lower with both uppers.
Scope is a Leopold 30MM Eurpean Varible 1.25-4x. Switched between guns
Trigger was the suck ass single stage regular AR trigger, damn it was terrible- Geisselle on order.
458S- 16" Marty built SS match barrel, don't know manf of barrel
450B-CL 16" barrel-standard config
Bench was a fold up picnic table with a bag front and back.
Chronograph Chrony Beta model 10' from gun
3000 elevation/ 45 degrees, slight 2-5mph wind, right to left
Socom was shooting 405 gr SP's plinking loads- 30.1+/-.3 grns H110
450BM Hornady Factory 250gr SST/FTT-don't know what it was loaded with?
1.5" group (.5"/4)
Recoil: the 450B was basically a bigbore AR15, nothing spectacular, a little less than the 405gr Socoms. The 405grs in the SOCOM was definatly, more with the bigger bullet but with the same gr bullet I would say you would not be able to tell.
Scope dope: Scope was zeroed for the 458, switched it between the upper and the BM shot exactly level, but 6" to the left. HMMMM?
458 accuracy: I have shot a .5" group with this thing, It will shoot regular 1" groups with my match loads. 1.5" with my plinking 405's is standard. I could test factory ammo as i will not bring myself to pay those prices when I can load a $0.25 shot.
Mags and the BM: Basically the options suck. You can only get 4 in a 30rd aluminum mag. You can Get 10 in a HK steel mag, but it won't feed 10-5. You basically are limited to 5 no matter what you use. I also had 1 FTFeed (2nd round) with the HK mag. The follower was not modded (single stack) but it seemed to feed the last round fine just like the SOCOM. After loading the 5th round, the feed lips spread causing the nose of the bullet to get lifted too high, causing a FTFeed.
Groups: The good part. The 450BM shot a 1.2" right out the door-no cleaning the barrel-nothing. With my crappy scope and trigger defiantly impressed. The second group was even better with 4 at .5" with a flyer bringing it out to 1.5" (1st shot, top left, you see was before the FTFeed- messed with the gun then started over)
Overall I really like the performance, BUT I hate that the bullets/powder won't be available, and brass is hard to find. If you don't reload, then this is the gun for you. If you do, get the 458. Mag options suck IMO. Not a concern if you just want a 5 round mag to hunt, with but I would like to use all 10 rounds.
second group there are 308 mixed in there, with 3 close touching, top left was not part of the group
One quick question. I saw in my BM catalog that the 450B comes with a chrome lined barrel? Is yours in that configuration?
I do think that BM has the chrome process down very well, as my two 20" BM chormed lined 556 barrels shoot lights out.
And thanks for the testing and update. It does seem at this point that the big bore crowd here is a little more "user friendly" than the 6.5/6.8 crowd, and I hope we can keep it that way.