View Full Version : Requesting an assessment of my rifle
I really wish I would've known about this site when I started putting together my first AR at the end of last year. The only experience I've had beforehand was my issued M16.
Last fall, I purchased a RRA complete lower with the standard carbine stock. In the spring, I found an upper at a gun show that caught my interest. The seller said it was a Bushmaster, and after talking about it with him, I took his word for it. It was a noob move, but it seemed like a nice upper after taking it apart and inspecting it. In hindsight, are there markings on the barrel that could identify it as a Bushmaster?
It's a 16" chrome-lined heavy barrel, with a 4-prong phantom fh. The twist is a 1 in 9". The previous owner installed a low profile gas block and one of the older mid-length Samson rails (looks exactly like a Troy). I don't know if this it's an add-on or is standard nowadays, but the bolt has what appears to be a 1-piece gas ring instead of the 3 we had on our M16s.
Whether I got fooled or not, she's a nice shooter for just plinking around. I'm getting quarter-size 3-shot groups at 100yds with irons and my Aimpoint CompM4 (4 MOA dot?). When I attended my first 3-gun in May, I was easily hitting 4" plates at 100yds in the prone from a chain suspended platform. I've put about 1,000 rounds through it, and the only malfunction was a failure to feed, resulting from a POS 20rd magazine.
I'd like to continue shooting 3-gun with it, and attend a Dynamic Carbine 1&2 class, when my knee's healed up. Possibly also get a good scope and mount so I can use it on prairie dogs.
What do you guys think? Decent enough for a first AR? I never really had a specified use in mind, just always wanted one of these. sorry for the long winded-ness
http://i287.photobucket.com/albums/ll129/bc310352/P3220016.jpg
BM barrels do have markings on them.
I woud check to see if the gas block is pinned. If not, see if there is any loctite on the screws holding it in place (by trying to remove one them). If not, remove one screw, degrease it and the hole and install with red loctite. Then do that other screw.
Check the staking on the gas key and make sure it is good. If it is a true BM barrel, that means that it is over gased so stick an H buffer in there (or an H2).
Check the extractor insert and if it is blue, change it to black and add a 5 coil spring.
Other than that, just shoot it! :D
C4
Pretty hard to argue with the performance you're getting from your AR! And the suggestions above should insure that it continues to function well.
Thanks for the replies, gents!
After reading this guy's thread, I might be making an order with BCM:
http://www.m4carbine.net/showthread.php?t=42353
Belmont31R
12-02-09, 18:16
You're shooting roughly 1" groups at 100 yards with a zero magnification optic and rack grade barrel? What ammo?
You're shooting roughly 1" groups at 100 yards with a zero magnification optic and rack grade barrel? What ammo?
Remington UMC fmj 55gr; only cheap stuff I could find when "the scare" was in it's peak.
This is only an estimate. Weather's crap this weekend, so I'll probably head to the indoor range and actually measure my groups. Hopefully I don't prove my guess was grossly inaccurate.
If I added an H buffer and a quality bcg, would this setup have a good chance at putting up with some hard use?
Belmont31R
12-02-09, 18:43
Remington UMC fmj 55gr; only cheap stuff I could find when "the scare" was in it's peak.
This is only an estimate. Weather's crap this weekend, so I'll probably head to the indoor range and actually measure my groups. Hopefully I don't prove my guess was grossly inaccurate.
If I added an H buffer and a quality bcg, would this setup have a good chance at putting up with some hard use?
Well shoot a few 10 shot groups, and see what it does. If its really an MOA gun with that barrel, ammo, and optics then that is one in a million.
A BCM BCG would go a long way to enhancing reliability as will any other BCG made to GI specs.
An H buffer will tame the gas system and smooth things out some.
As long as it runs well there isnt a need to buy another upper just because you have a BM. A few upgrades here and there along the way will do you just fine. The main short falling of most "cheaper" AR's is in the details....like properly cut feedramps, properly tested bolts, barrels with the right size gas hole, and then make sure its all put together properly. Skimping on those steps results in a cheaper gun to the end user but can lead to canted FSB's, BCG's that are not put together correctly (staking and testing), gas ports that are too large...et cetera.
Save your money down the road to buy something better if that is your inclination but dont be afraid to shoot what you have now.
Well shoot a few 10 shot groups, and see what it does. If its really an MOA gun with that barrel, ammo, and optics then that is one in a million.
Good call! I'll give that a try.
The main short falling of most "cheaper" AR's is in the details....like properly cut feedramps, properly tested bolts, barrels with the right size gas hole, and then make sure its all put together properly. Skimping on those steps results in a cheaper gun to the end user but can lead to canted FSB's, BCG's that are not put together correctly (staking and testing), gas ports that are too large...et cetera.
This sums up everything I'm learning on here nicely. Thanks again for the great advice!
It's a fun rifle to shoot, but with that HBAR, it's a heavy b!tch with my surefire mounted on there. In the near future, it'll probably be replaced; I'd like to get something I can have absolute trust in, and build my collection on that.
Good call! I'll give that a try.
This sums up everything I'm learning on here nicely. Thanks again for the great advice!
It's a fun rifle to shoot, but with that HBAR, it's a heavy b!tch with my surefire mounted on there. In the near future, it'll probably be replaced; I'd like to get something I can have absolute trust in, and build my collection on that.
You could always send it to ADCO and have them trim the fat off it.
Go Shoot the Gun! (http://tacticalyellowvisor.net/8343/126721.html) (it sounds like you're already doing this)
"Oh No! I Bought a BM/RRA/Stag Before I Knew Better!" (http://tacticalyellowvisor.net/8343/16001.html) (it sounds like you're on the right track with this)
I'd personally make sure everything is staked like it should be, witness mark all the screws on the rail and optic mount, and drop a complete BCM BCG in as the primary and save the one you're using now as the spare/backup.
(FWIW, you mention an Aimpoint M4 in your post, but your picture shows something else)
Go Shoot the Gun! (http://tacticalyellowvisor.net/8343/126721.html) (it sounds like you're already doing this)
"Oh No! I Bought a BM/RRA/Stag Before I Knew Better!" (http://tacticalyellowvisor.net/8343/16001.html) (it sounds like you're on the right track with this)
I'd personally make sure everything is staked like it should be, witness mark all the screws on the rail and optic mount, and drop a complete BCM BCG in as the primary and save the one you're using now as the spare/backup.
(FWIW, you mention an Aimpoint M4 in your post, but your picture shows something else)
You're right, I had it backwards; thinking the M4 was the older model. My dot is the M2. I got it before we deployed, since the word was we wouldn't be getting optics. Our CO said we could buy our own, within reason. Of course when we got there, they actually had ACOGs for the majority of us.
I did check my barrel markings last night: BMP 5.56 1/9 HBAR What does the P mean?
BMP is "Bushmaster, Magnetic Particle", which is true in the first part and a lie on the second part. Bushmaster marks all of their barrels as being MP, or magnetic particle inspected, when in fact they test random samples and not every single barrel.
The better makers test every single barrel. It is not the end of the world, and I would not worry about it if I were you since you already have the gun. If you were just starting out and looking to buy my advice would be to get one that MPIs all their barrels.
Bushmaster marks all of their barrels as being MP, or magnetic particle inspected, when in fact they test random samples and not every single barrel.
Son of a....
Well, I had to start somewhere, but learning about "the chart" was a helpful eye-opener for my next AR.
Son of a....
Well, I had to start somewhere, but learning about "the chart" was a helpful eye-opener for my next AR.
if this really is enough of an issue for you, you can get a sweet Daniel Defense barrel for only $169 from MidwayUSA.
http://www.midwayusa.com/viewproduct/?productnumber=461614&utm_source=froogle&utm_medium=free&utm_campaign=649
Well shoot a few 10 shot groups, and see what it does. If its really an MOA gun with that barrel, ammo, and optics then that is one in a million.
After starting this thread, I went shoot again to check my groups. My initial guesses couldn't have been more exagerrated. Actually I might've been thinking of the groups I had gotten out of my HB .22WMR...:eek:
It's taken me forever to post the results, but here they are. Hardly scientific...
Bushmaster 16" HB, Aimpoint CompM2, Remington UMC 55gr .223 FMJ, 100 yard zero
first three rounds at 25yds
http://i287.photobucket.com/albums/ll129/bc310352/25yd.jpg
next three rounds at 50yds, above the first group
http://i287.photobucket.com/albums/ll129/bc310352/50yd.jpg
three more at 100yds (piss poor group, flyer right in the middle)
http://i287.photobucket.com/albums/ll129/bc310352/100yd.jpg
I taped over the first 3 groups, then emptied the remainder of the 30rd magazine at 100.
http://i287.photobucket.com/albums/ll129/bc310352/RestOfMag.jpg
It shoots okay, but once some money frees up, I'm in the market for something I can take a class with.
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