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Posted: 2/6/2002 5:31:19 PM EDT
Ever since I got my AR from Bushmaster I have not been totally enthused
with the accuracy. They insisted that it requires a break-in period. Well after about 1000 rounds I decided to take it out for some serious shooting and here are the results.

My reason for not being totally happy is due to some inconsistency. With my Remington 700, I can consistently get good groups but with the AR, its too sporadic.

The test was done with about 6 different brands of ammo and most were tested with 2 different 3 shot groups. The AR is a Bushmaster flat-top (post-ban) with a Leupold scope, the DCM trigger and was shot using a sandbag.

The dot on each image is the point of aim.

Let me know if I should give it another try before sending it back to Bushmaster for maintenance or if this is typical grouping.

Since I have not been able to figure out how to incorporate images into a post, you can see the targets are the following URL:
http://ddi.digital.net/~seb/TargetPage.html
Link Posted: 2/6/2002 5:37:34 PM EDT
Here is what you were trying to display before you edited your post.

[I sent you a message, hope you got it!]











continued...
Link Posted: 2/6/2002 5:42:48 PM EDT
NOTE: JThompson indicated previously that the red dot was the point of aim.










Link Posted: 2/6/2002 5:44:09 PM EDT
I don't think this is typical accuracy. You didn't mention what yardage(I assume 100yds) or what barrel you are using. You should be getting better groups that this though. If this is a chrome lined barrel then there is really not a break in period. My 20" Bushmaster shoots 1.5" groups at 100 and I consider this bad because the stock trigger is horrible and I can't ever tell where it is going to break. Also, all the punctures look the same when I shoot(PMC 55gr), but some of yours look kind of ragged, like maybe the bullet isn't stabilized. I may be mistaken in this but its just a guess. I'm don't know how much help this is but its all I know, some of the other guys should be able to help you out more.
Bill3508
Link Posted: 2/6/2002 5:49:35 PM EDT
Link Posted: 2/6/2002 5:59:13 PM EDT
A few important notes I forgot to include:

- the smaller squares are 1/2 inch and the larger red squares are 1 inch.

- this was shot at 100 yards

- this Bushmaster is only about 1 year old and is the 20 inch chrome barrel
Link Posted: 2/6/2002 6:00:51 PM EDT
Yah, that looks just about right. Assuming you are shooting 100 yards. I had Bushmaster 16" post ban upper and I was totally disappointed with the way it shot. I tried shooting with bipod, sandbag, and rifle rest.
I had about 1000 rds through it too. So this AR became my least favorite gun to shoot. Then I bought Fulton Armory Gen II upper w/ match barrel and it shot way better than the original Bushmaster. This was using American eagle .223 too. One thing to remember is that AR has high cap magazine and its a semi auto. Barrel heats up very quickly as your finger goes nuts on the trigger. Use a timer or something so you leave enough time for the barrel to cool down before the next shot. Also you need to put in consideration, wind, and temperature. I don't know what distance you are shooting but wind might be affecting this. Also, you might need some fouling shots before you get more consistent pattern, depending on when (warm barrel? cold barrel?) you zeroed your scope.
Too much lube inside the barrel cause inconsistency too. Another thing you should look out for is how the scope is mounted. Make sure the scope is securely installed. Also make sure that your head location is same for each shot. If you find yourself moving your head up n' down or left and right to get clear picture from the scope then you need to fix that by raising the scope higher or lowering it. You might have to move the scope closer to the front or back.
Link Posted: 2/6/2002 6:07:14 PM EDT
I assumed the squares were 1 inch. Your a little over 1 inch average seems pretty good with the stock barrel then. I would be happy with that. I don't think there is anything wrong with your weapon. If you want better accuracy you need to go to a premium unchromed barrel-Douglas, Krieger,etc.
Bill3508
Link Posted: 2/6/2002 9:16:03 PM EDT
[Last Edit: 2/6/2002 9:53:06 PM EDT by Vinnie]
Looks like you could take down a man sized target to me. If you want "more accuracy" then get their chrome moly Nat. Match Civialian Marksmanship Program barrel.
Link Posted: 2/6/2002 9:33:15 PM EDT
didn't say if you were using iron sights or not. also using 6 different kinds of ammo is going to put your groups all over the place. i'd say pick the best out of your groups and stick with that, maybe it will tighten up. still i don't think it's that bad for 100yds, unless it's a dcm barrel or something.
Link Posted: 2/6/2002 9:49:18 PM EDT
I own a postban Bushmaster V-Match with standard trigger. I shot 50 rounds of Black Hills BlueBox 55 grain PSP's and 50 rounds of UltraMax 55 grain PSP's. The UltraMax's shot into 1 inch, the BlackHills shot into 3/4 inch. These were 5 shot groups. Then I threw my favorite handload. Mix & Match brass from all over the world, Detailed, 26 grains of VV N-135, Federal Small Rifle Match Primers, Moly coated 40 Grain Hornaday V-Max's. This load will shoot 1/4 inch groups about 25% of the time. The rest of the time 3/8 inch. I shoot this same handload in my other 2 AR's with the same results. This load also shoot the same in 5 other AR's that don't belong to me but shoot this load.
Link Posted: 2/6/2002 10:21:38 PM EDT
I would suggest using a heavier grain. Like 62 Grain. I had the same problems with mine (I was using 55 and 52 grain rounds) until I read that with a 1-7 inch twist I should use 59-65 grain round. So I got about 500 rounds Wolf 62 Grain FMJ. I now get 3-shot groups within a silver dollar area at 100yrds. Try it out, can't hurt nothin'
Link Posted: 2/7/2002 8:10:53 PM EDT
If it has a chrome lined barrel like you say, that's the best you will get. Some barrels will print better, but usually a chrome lined one acts just like yours. Also, there is almost no break in required for a chrome lined barrel. What you get in corrosion resistance and long barrel life are trade offs for less accuracy. It is almost impossible to lay down a uniform thickness of chrome lining along a 20 inch long hole that is less than a quarter of an inch wide.
Link Posted: 2/7/2002 9:19:05 PM EDT

Originally Posted By ArmyOrdGuy:
If it has a chrome lined barrel like you say, that's the best you will get. Some barrels will print better, but usually a chrome lined one acts just like yours. Also, there is almost no break in required for a chrome lined barrel. What you get in corrosion resistance and long barrel life are trade offs for less accuracy. It is almost impossible to lay down a uniform thickness of chrome lining along a 20 inch long hole that is less than a quarter of an inch wide.



Tell that to Fulton Armory. Their Police Sniper, equivalent to the PSS, is chrome lined.

It's not that it is almost impossible... its that current issue barrels that are chrome lined are typically NATO spec chambers... and these were never designed to be match barrels.

But it's not the lining.... it's the entire package.
Link Posted: 2/8/2002 3:23:23 AM EDT
For Christmas I received an Oly PCR-1 Ultramatch, 20" SS broached barrel, chose it because I wanted tight groups at 100 yds.
I have less than 100 rounds through it so far,
and using cheap AE 55gr. FMJBT, so far my best 5 shot group had 4 touching, and 1 out 1/2 inch.
I bought some better ammo, and hope to do better, when the weather breaks.(all 5 touching?)
Since I wanted small groups, I am glad I didn't buy a BM.
You might consider an Oly barrel for your BM.
Lance
Link Posted: 2/8/2002 5:02:36 AM EDT
Still too many variables to adequately assess rifle vs shooter technique vs external factors.

What do your Rem 700 groups look like? (same day, same bench technique)

Does group contain 1st shot from cold barrel?

How long between shots?

Do you have free float tube? If not, is sling tension constant?

Is sandbag at tip, middle or mag end of handguard?

Sandbag for buttstock too?

Sandbag touching magazine?

Wind/gusts that day?

Has the Leupy shot well on other rifles?

Was barrel fouled when groups were shot?

Were long strings shot with same ammo? (fouling patterns change with each type of ammo and can effect group size)

These are a sample of some of the things to assess during your next range session.
Link Posted: 2/8/2002 6:41:44 AM EDT
One more variable to consider is the shooter. All in all, though, that looks like pretty decent results to me. If you want them all touching you're going to need a different gun.
Link Posted: 2/8/2002 6:59:14 AM EDT
Shots landing within 1" of each other at 100yards? In a chrome lined bore with a military throat and factory ammo using either soft point or FMJ bullets. Be happy bud. A lot of people wish they could get this level of performance from basic ammo.

Now if you had a good match barrel with handloaded ammo using match bullets, carefully prepped cases and the like, we could start asking more of the rifle...
Link Posted: 2/8/2002 7:08:10 AM EDT
That looks about like the groups my BM Shorty shot at 100yds in the hands of a far better shot than mine out of box. The unmodified AR15 is a fighting rifle, and while it is very accurate, it's not a sub-MOA sniper. If you want laser fine accuracy, you'll need to tweak it some.
Link Posted: 2/8/2002 7:23:34 AM EDT

Originally Posted By Kadar:
I would suggest using a heavier grain. Like 62 Grain. I had the same problems with mine (I was using 55 and 52 grain rounds) until I read that with a 1-7 inch twist I should use 59-65 grain round. So I got about 500 rounds Wolf 62 Grain FMJ. I now get 3-shot groups within a silver dollar area at 100yrds. Try it out, can't hurt nothin'



There are alot of variables here....
this may not help but as my own rule of thumb:

I would recommend that you use a minimum of 65gr for a 1:7 twist. A minimum of 55gr for a 1:9 twist.
Link Posted: 2/8/2002 8:22:55 AM EDT

Originally Posted By Rancid:

You might consider an Oly barrel for your BM.
Lance



Rancid's right.

Some how I always forget Oly as a manufacturer of fine match-grade barrels. The few professional types I know never forget though.
Link Posted: 2/8/2002 9:16:40 AM EDT
Sell it and get a colt!!!
Link Posted: 2/8/2002 11:11:07 AM EDT
Looks about right. Best groups out of my Colt 1 in 7 HBAR pre-ban EVER with hand loads and testing galore was about 1 inch. The Olympic Stainless Ultra Match will do better, and a Krieger will do even better. You can switch out the barrels easily enough.
Link Posted: 2/8/2002 11:35:01 AM EDT
those are good groups for a chrome bbl that's not floated. don't send it back.
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