I was recently assigned a Bushmaster 308, AR platform rifle with the hopes of turning it into a precision gun. I had a Troy 13.8" rail, Magpul PRS, Versapod, and Bushnell 6-24x50 ffp put on it. Much to my dismay, and my Captain's it will not group better than 2" at 100 yards and even then it may group high right in one string of 5, then turn right around and group low left the next string. I have shot it as have 3 other snipers and we all have these issues. Our best guess is to swap the scope and see if there is an issue with the optic. Does anyone have any expeience with how this particular gun handles, what might be wrong or if we are just barking up the wrong tree and got a turd of a rifle to start with? I am brand new to Sniping, but just finished a 1week Basic school taught by the FBI. Thanks in advance for the help guys.
- Thread starter sputnic81
- Start date
Re: Bushmaster LR-308
sounds like an optics problem, ensure its mounted correctly.
sounds like an optics problem, ensure its mounted correctly.
Re: Bushmaster LR-308
-could run a q-tip back&forth in the end of the barrel and see if any of the strands catch, its not out of the question that it could be an f-d up crown.
-the scope would be the first variable I'd check though.
-are you all used to shooting semi's
-try taking off the versapod and shooting it off a bag.
-could run a q-tip back&forth in the end of the barrel and see if any of the strands catch, its not out of the question that it could be an f-d up crown.
-the scope would be the first variable I'd check though.
-are you all used to shooting semi's
-try taking off the versapod and shooting it off a bag.
Re: Bushmaster LR-308
Aside from scope or gritty trigger issues you just might have a bad barrel? My shooting buddy wanted to see if he could make a semi-auto shoot as good as a bolt gun. He bought a DPMS LR-308 and then a JP .934 adjustable aluminum gas block & a DPMS barrel extension then gave it all to Mark Chanlynn at Big Horn Arms to have him re-barrel it (24" 11 twist barrel). When my buddy got it back and developed a load for it using IMR4895/SMK175/Fed210/Win case - it shoots scary little groups, 1/2 moa.
Mark just did another LR308 for a buddy of mine and it's being broken in by me right now. One shot & clean for 10 rounds. We'll see how his shoots in a week or so.
I've got a custom build AR308 as well going right now on a MEGA receiver set and I'm having Mark do the barrel just like the others - will be done in a month or so - just waiting for the MEGA stuff.
Aside from scope or gritty trigger issues you just might have a bad barrel? My shooting buddy wanted to see if he could make a semi-auto shoot as good as a bolt gun. He bought a DPMS LR-308 and then a JP .934 adjustable aluminum gas block & a DPMS barrel extension then gave it all to Mark Chanlynn at Big Horn Arms to have him re-barrel it (24" 11 twist barrel). When my buddy got it back and developed a load for it using IMR4895/SMK175/Fed210/Win case - it shoots scary little groups, 1/2 moa.
Mark just did another LR308 for a buddy of mine and it's being broken in by me right now. One shot & clean for 10 rounds. We'll see how his shoots in a week or so.
I've got a custom build AR308 as well going right now on a MEGA receiver set and I'm having Mark do the barrel just like the others - will be done in a month or so - just waiting for the MEGA stuff.
Re: Bushmaster LR-308
What ammo?
How do you shoot with a bolt gun?
Who swapped the forearm out?
How did it shoot prior to forearm swap?
Do you know how to properly eliminate parallax?
Eliminate variables one by one.
I would start with quality ammo same lot and scope.
If you are not confident in the rifle it will continue to shoot shit for you. I find it best to allow an experienced shooter to print good groups with a rifle witnessed by the owner.
What ammo?
How do you shoot with a bolt gun?
Who swapped the forearm out?
How did it shoot prior to forearm swap?
Do you know how to properly eliminate parallax?
Eliminate variables one by one.
I would start with quality ammo same lot and scope.
If you are not confident in the rifle it will continue to shoot shit for you. I find it best to allow an experienced shooter to print good groups with a rifle witnessed by the owner.
Re: Bushmaster LR-308
BTW, I continue to see Depts buy nice rifles but skimp on accessories like scopes and mounts. Tell the Capt. to come off the wallet.
I know of a SO Swat Operator who has a Tru Glo red dot on a Suppressed HK UMP 45. Silly
BTW, I continue to see Depts buy nice rifles but skimp on accessories like scopes and mounts. Tell the Capt. to come off the wallet.
I know of a SO Swat Operator who has a Tru Glo red dot on a Suppressed HK UMP 45. Silly
Re: Bushmaster LR-308
I would like to see a picture of said rifle with the rail. I wanted a rail and ended up with a dpms free float handguard due to running out of funds.
I own the same and so far she is not a precision rifle. Granted I only intend to hunt deer under 150yds with mine and refuse to feed it expensive ammo.
I would like to see a picture of said rifle with the rail. I wanted a rail and ended up with a dpms free float handguard due to running out of funds.
I own the same and so far she is not a precision rifle. Granted I only intend to hunt deer under 150yds with mine and refuse to feed it expensive ammo.
Re: Bushmaster LR-308
Hooper:
I shoot Federal Sierra Match King, 168 gr BTHP. The Department is on contract for that ammo so I am locked into it.
I shoot MOA to slightly sub-MOA with a bolt, but I really don't have a ton of experience on one, the one I shot was a GA Precision.
All the work on the Bushmaster was done by Ty @ MidwestPX, and I am confident that he did a clean job on it.
I can't really speak well to how it shot prior to all the modifications. I had only put about 100 rounds through it and had no bi-pod and only a fixed 6x scope that was not properly mounted (someone threw it on just to test out the gun). It seemed to shoot ok given all of that, I was able to pass an ASA qual course with it if that says anything.
As far as the parallax settings go this scope is marked for yardage, I have just been setting it near the desired yardage and then fine tuning once I'm on the scope. The old scope had no parallax adjust. I am open to any learning opportunity, so if you have a tried and true technique I am all ears.
Another more experienced sniper is taking it out later this week with a different scope to see how it functions. Then we are doing just like you said, one variable at a time until we get it done.
I am working on the purse string issue and trying to convince him if he wants this rifle operational and me behind it I am going to have to have more work done before I will be comfortable calling this a precision gun.
Thanks for all the help guys, and I will try to get some pics of it up once I get these issues resolved.
Hooper:
I shoot Federal Sierra Match King, 168 gr BTHP. The Department is on contract for that ammo so I am locked into it.
I shoot MOA to slightly sub-MOA with a bolt, but I really don't have a ton of experience on one, the one I shot was a GA Precision.
All the work on the Bushmaster was done by Ty @ MidwestPX, and I am confident that he did a clean job on it.
I can't really speak well to how it shot prior to all the modifications. I had only put about 100 rounds through it and had no bi-pod and only a fixed 6x scope that was not properly mounted (someone threw it on just to test out the gun). It seemed to shoot ok given all of that, I was able to pass an ASA qual course with it if that says anything.
As far as the parallax settings go this scope is marked for yardage, I have just been setting it near the desired yardage and then fine tuning once I'm on the scope. The old scope had no parallax adjust. I am open to any learning opportunity, so if you have a tried and true technique I am all ears.
Another more experienced sniper is taking it out later this week with a different scope to see how it functions. Then we are doing just like you said, one variable at a time until we get it done.
I am working on the purse string issue and trying to convince him if he wants this rifle operational and me behind it I am going to have to have more work done before I will be comfortable calling this a precision gun.
Thanks for all the help guys, and I will try to get some pics of it up once I get these issues resolved.
Re: Bushmaster LR-308
Is the barrel free floated? If not shoot with just the magazine on the ground to see if the groups get better.
Is the barrel free floated? If not shoot with just the magazine on the ground to see if the groups get better.
Re: Bushmaster LR-308
Aren't Troy rails free float?
Aren't Troy rails free float?
Re: Bushmaster LR-308
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LSMarksman</div><div class="ubbcode-body">Hooper:
I shoot Federal Sierra Match King, 168 gr BTHP. The Department is on contract for that ammo so I am locked into it.</div></div>
Good, that is great ammo
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LSMarksman</div><div class="ubbcode-body">
I shoot MOA to slightly sub-MOA with a bolt, but I really don't have a ton of experience on one, the one I shot was a GA Precision.</div></div>
Most will tell you it takes some getting used to vs a bolt action. Judging by your comment "The one I shot" tells me you need some time behind a long gun with a shooting partner that can help you. 2 MOA with no experience on the system with a crappy scope is not really odd.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LSMarksman</div><div class="ubbcode-body">
All the work on the Bushmaster was done by Ty @ MidwestPX, and I am confident that he did a clean job on it.
I can't really speak well to how it shot prior to all the modifications. I had only put about 100 rounds through it and had no bi-pod and only a fixed 6x scope that was not properly mounted (someone threw it on just to test out the gun). It seemed to shoot ok given all of that, I was able to pass an ASA qual course with it if that says anything.</div></div>
If you passed ASA and now after changes to rifle it shoots like shit, most likely it is <span style="font-weight: bold">NOT</span>the rifle but the changes made.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LSMarksman</div><div class="ubbcode-body">
As far as the parallax settings go this scope is marked for yardage, I have just been setting it near the desired yardage and then fine tuning once I'm on the scope. The old scope had no parallax adjust. I am open to any learning opportunity, so if you have a tried and true technique I am all ears. </div></div>
Parallax adjustment 101: Professor Hooper... Venue: Hide Auto Rifle Forum 1500 hrs.
On a static 100 yd range:
1 Unload rifle
2 Scope properly installed, level, torqued
3 set rifle on bipod or bags facing target
4 present crosshairs behind bullseye as if you were shooting(if there is little contrast, a corner of a piece of paper will suffice as the bullseye)
5 set the rifle to where it will stay on target without your help. Bags work great.
6 step out from the rifle and turn the parallax adjustment to the closest setting.(If it is marked in yds, turn it to the turn stop past 100 yds. Closest distance)
7 without touching the rifle, and it centered on a fixed aiming point, look through the scope and center your head as if taking a shot. It should be out of focus. Now move your head side to side without touching rifle. The reticle should move all over the aiming point.
8 Adjust the parallax while moving your head side to side until the reticle does not move.
Now you should have a clear image or close to it. Move it past the adjustment of no parallax. The reticle should dance again.
9 Move the Parallax adjustment back to zero stop.
10 repeat steps 7-9 until you verify the 100 yd parallax adjustment. Mark this spot with a sharpie or tape on scope .
11 compare new mark to the mark already on the scope for the 100 yd "Focus" setting. It most likely will be close. But use your newly found setting.
12 repeat this process for each yardage in 100 yd increments out to the capability of the rifle.
Remember to always go to your setting from a closer yardage. In other words, if you have the rifle set @ 800 yds, and want to now shoot @ 200 yds, go past the 200 yd setting down to about 100 yd, then go to the 200 yd parallax setting. This makes sure you avoid any slack in the system and assures a consistant setting.
This process will help to eliminate any problems associated with inconsistencies in your cheek weld.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LSMarksman</div><div class="ubbcode-body">
I am working on the purse string issue and trying to convince him if he wants this rifle operational and me behind it I am going to have to have more work done before I will be comfortable calling this a precision gun.</div></div>
Great. A decent scope/mounts is a good start. Get a side parallax adjustment.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LSMarksman</div><div class="ubbcode-body">Hooper:
I shoot Federal Sierra Match King, 168 gr BTHP. The Department is on contract for that ammo so I am locked into it.</div></div>
Good, that is great ammo
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LSMarksman</div><div class="ubbcode-body">
I shoot MOA to slightly sub-MOA with a bolt, but I really don't have a ton of experience on one, the one I shot was a GA Precision.</div></div>
Most will tell you it takes some getting used to vs a bolt action. Judging by your comment "The one I shot" tells me you need some time behind a long gun with a shooting partner that can help you. 2 MOA with no experience on the system with a crappy scope is not really odd.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LSMarksman</div><div class="ubbcode-body">
All the work on the Bushmaster was done by Ty @ MidwestPX, and I am confident that he did a clean job on it.
I can't really speak well to how it shot prior to all the modifications. I had only put about 100 rounds through it and had no bi-pod and only a fixed 6x scope that was not properly mounted (someone threw it on just to test out the gun). It seemed to shoot ok given all of that, I was able to pass an ASA qual course with it if that says anything.</div></div>
If you passed ASA and now after changes to rifle it shoots like shit, most likely it is <span style="font-weight: bold">NOT</span>the rifle but the changes made.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LSMarksman</div><div class="ubbcode-body">
As far as the parallax settings go this scope is marked for yardage, I have just been setting it near the desired yardage and then fine tuning once I'm on the scope. The old scope had no parallax adjust. I am open to any learning opportunity, so if you have a tried and true technique I am all ears. </div></div>
Parallax adjustment 101: Professor Hooper... Venue: Hide Auto Rifle Forum 1500 hrs.
On a static 100 yd range:
1 Unload rifle
2 Scope properly installed, level, torqued
3 set rifle on bipod or bags facing target
4 present crosshairs behind bullseye as if you were shooting(if there is little contrast, a corner of a piece of paper will suffice as the bullseye)
5 set the rifle to where it will stay on target without your help. Bags work great.
6 step out from the rifle and turn the parallax adjustment to the closest setting.(If it is marked in yds, turn it to the turn stop past 100 yds. Closest distance)
7 without touching the rifle, and it centered on a fixed aiming point, look through the scope and center your head as if taking a shot. It should be out of focus. Now move your head side to side without touching rifle. The reticle should move all over the aiming point.
8 Adjust the parallax while moving your head side to side until the reticle does not move.
Now you should have a clear image or close to it. Move it past the adjustment of no parallax. The reticle should dance again.
9 Move the Parallax adjustment back to zero stop.
10 repeat steps 7-9 until you verify the 100 yd parallax adjustment. Mark this spot with a sharpie or tape on scope .
11 compare new mark to the mark already on the scope for the 100 yd "Focus" setting. It most likely will be close. But use your newly found setting.
12 repeat this process for each yardage in 100 yd increments out to the capability of the rifle.
Remember to always go to your setting from a closer yardage. In other words, if you have the rifle set @ 800 yds, and want to now shoot @ 200 yds, go past the 200 yd setting down to about 100 yd, then go to the 200 yd parallax setting. This makes sure you avoid any slack in the system and assures a consistant setting.
This process will help to eliminate any problems associated with inconsistencies in your cheek weld.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LSMarksman</div><div class="ubbcode-body">
I am working on the purse string issue and trying to convince him if he wants this rifle operational and me behind it I am going to have to have more work done before I will be comfortable calling this a precision gun.</div></div>
Great. A decent scope/mounts is a good start. Get a side parallax adjustment.
Re: Bushmaster LR-308
BTW, you may want to trade the LR308 for a Remington 700 Police in 308. Have the barrel cut to 18 or 20 inches, scope it up and call it a day. The advantage of an autoloader is fast follow ups. Rarely in LE shootings do you need follow ups.
You eliminate a lot of variables accociated with an autoloader and it will shoot sub moa without a lot of trouble.
This is actually what my advice would be if your Captain called and asked me.
BTW, you may want to trade the LR308 for a Remington 700 Police in 308. Have the barrel cut to 18 or 20 inches, scope it up and call it a day. The advantage of an autoloader is fast follow ups. Rarely in LE shootings do you need follow ups.
You eliminate a lot of variables accociated with an autoloader and it will shoot sub moa without a lot of trouble.
This is actually what my advice would be if your Captain called and asked me.
Re: Bushmaster LR-308
Well I shot it yesterday with a different scope and had the same problems. I got two rounds touching right on the bull, then two rounds touching 2" low and 1.5" left then one round centered and 2" low. Two others shot it and got basically the same results. Now it will just be a matter of seeing if the brass I'll call it a loss and get me a bolt gun or if he is going to double- down and keep trying to polish this turd. I really appreciate all the ideas you guys have thrown at me, especially the parallax lesson as I will be able to take that with me to any rifle. I will keep you posted as this thing progresses.
Well I shot it yesterday with a different scope and had the same problems. I got two rounds touching right on the bull, then two rounds touching 2" low and 1.5" left then one round centered and 2" low. Two others shot it and got basically the same results. Now it will just be a matter of seeing if the brass I'll call it a loss and get me a bolt gun or if he is going to double- down and keep trying to polish this turd. I really appreciate all the ideas you guys have thrown at me, especially the parallax lesson as I will be able to take that with me to any rifle. I will keep you posted as this thing progresses.
Re: Bushmaster LR-308
It could be as simple as the gastube being in a bind.
It is easy to have a gastube off center when changing a forearm if you are not meticulous upon reassembly.
Bolt gun would be a great idea.
It could be as simple as the gastube being in a bind.
It is easy to have a gastube off center when changing a forearm if you are not meticulous upon reassembly.
Bolt gun would be a great idea.
Re: Bushmaster LR-308
For the time being I have been re-assigned to a "Rock" bolt gun. Took it out today to qual with before going to Camp Dodge. It was nice to have the round hit right where I wanted it to. I think one would have to work at missing with this thing. I guess the brass is open to possibly re-barreling and new trigger for the semi...I am going to push for just sending it to GA Precision and letting them work it over if we are dead set on being able to field the gun.
For the time being I have been re-assigned to a "Rock" bolt gun. Took it out today to qual with before going to Camp Dodge. It was nice to have the round hit right where I wanted it to. I think one would have to work at missing with this thing. I guess the brass is open to possibly re-barreling and new trigger for the semi...I am going to push for just sending it to GA Precision and letting them work it over if we are dead set on being able to field the gun.
