Rosco barrel accuracy expectations/problems

J

Joshua1:9b

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Minuteman
Jan 11, 2020
65
26
#1
I switched my barrel to a 16 inch Rosco stray dog 1/7 socom profile barrel.

I had been running an hbar 1/9 twist bushmaster barrel that came with the rifle originally

My groups went from roughly 1 in to 2 inch plus groups.

I even bought some match grade 77 grain Hornady ammo to compare to the other ammo I was shooting, and even that was only shooting one and three-quarter inch groups.

Is this the best I should be able to expect from a Rosco barrel. I have never had a rifle that I could not shoot 1 MOA with.

The barrel has some visible defects, just passed the chamber.
6771AF89-FA82-43B4-9C3E-ED4CE464D8F9.jpeg
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#3
I think you are expecting too much from a Rosco. Actual experience varies, but they make a rock solid infantry grade 2 MOA barrel. Colt uses a lot of Rosco's with Chrome Lining, and they are fantastic at what they do, but it is not a match barrel. Yes, moving to a heavier bullet can help. And maybe you have some hot lapping you can do. Just because you moved from 1:9 to 1:7 does not mean your 77 Grain is now going to shoot great out of an average barrel.
 
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#5
longshot2000 said:
I think you are expecting too much from a Rosco. Actual experience varies, but they make a rock solid infantry grade 2 MOA barrel. Colt uses a lot of Rosco's with Chrome Lining, and they are fantastic at what they do, but it is not a match barrel. Yes, moving to a heavier bullet can help. And maybe you have some hot lapping you can do. Just because you moved from 1:9 to 1:7 does not mean your 77 Grain is now going to shoot great out of an average barrel.
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this

end thread
 
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#6
JS8588 said:
Reach out to Rosco. I suspect they'll take care of you if you're unhappy.
Click to expand...
what? take of him for what; a rack grade barrel that shoots better than the standard? they will laugh at him

If he had a lothar, CLE, craddock barrel sure but this is a rosco production rack grade and getting 2ish moa. that's a good barrel for what it is

OP, those older Bushmaster barrels are fking lasers
 
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#8
RUTGERS95 said:
what? take of him for what; a rack grade barrel that shoots better than the standard? they will laugh at him

If he had a lothar, CLE, craddock barrel sure but this is a rosco production rack grade and getting 2ish moa. that's a good barrel for what it is

OP, those older Bushmaster barrels are fking lasers
Click to expand...
Exchange it for something else. Either one that doesn't have the defects he observed past the chamber or possibly that K9 16 which should give 1 MOA-Ish accuracy based upon the specs.
 
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#9
So I threw on the Nightforce Atacr 4-16. Got out the rear bag cleaned the barrel good and tried a fresh day. Trying to take out as must human error as possible. Here are the results.
3DED4CD5-C413-47A5-A881-0E751301794A.jpeg
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3D4231EF-9B74-42A2-87AA-ECE3F158E134.jpeg
 
#12
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#18
I have one Roscoe barrel, bought on the recommendation of @TonyTheTiger. I had robbed the scope from that rifle for another project, but this thread inspired me to mount a scope and head to the range. Full disclosure, the rifle was built for run and gun competitions, and is an 18" rifle gas length barrel, on an Aero M4E1 Enhanced upper/lower set. It is from Roscoe's Pureblood line, and came as a package with their bolt and carrier. The rifle has a magpul PRS Lite stock in the rear, and a MDT GRND pod in the front. It has an SLR gas block, but I did not touch the settings for this outing. On top, the rifle wears a Vortex Viper PST Gen ii 5-25x scope. Gisele SD-E trigger.

I shot a few rounds to get the optic zeroed (you can see the impacts spread across the upper part of target 1, and then settled in to groups. I shot the groups at a reasonable pace(3-5 sec between shots), and only paused between groups long enough to load the next magazine. The ammunition chosen is just what I happen to have on hand. Groups are all 5 shots.

tempImaged9aE7t.jpg


Screen Shot 2024-09-16 at 11.35.09 AM.png


For the cost of the barrel, and for the shooting that I do with it, none of these groups are going to hold me back. The said, if I were taking it to the deer blind, where I typically look for head/upper neck shots, I would be sourcing more of that Fiocchi ammo. As a matter of fact, I'll be doing that just 'cuz...

The moral of the story is that sometimes you need to find the ammunition that the gun likes...
 
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#20
I contacted the customer support and they were extremely helpful.

Going to help me send in the barrel either for a swap or an upgrade. I’ll pay the difference, of course.

So, as long as I am looking at changing.

any recommendations. I know the purebred line is going to be the most accurate, but I don’t know how it will hold up to duty use that maybe I should lean toward something with a nitride treatment.
 
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#21
hlee said:
I have one Roscoe barrel, bought on the recommendation of @TonyTheTiger. I had robbed the scope from that rifle for another project, but this thread inspired me to mount a scope and head to the range. Full disclosure, the rifle was built for run and gun competitions, and is an 18" rifle gas length barrel, on an Aero M4E1 Enhanced upper/lower set. It is from Roscoe's Pureblood line, and came as a package with their bolt and carrier. The rifle has a magpul PRS Lite stock in the rear, and a MDT GRND pod in the front. It has an SLR gas block, but I did not touch the settings for this outing. On top, the rifle wears a Vortex Viper PST Gen ii 5-25x scope. Gisele SD-E trigger.

I shot a few rounds to get the optic zeroed (you can see the impacts spread across the upper part of target 1, and then settled in to groups. I shot the groups at a reasonable pace(3-5 sec between shots), and only paused between groups long enough to load the next magazine. The ammunition chosen is just what I happen to have on hand. Groups are all 5 shots.

View attachment 8502964

View attachment 8502983

For the cost of the barrel, and for the shooting that I do with it, none of these groups are going to hold me back. The said, if I were taking it to the deer blind, where I typically look for head/upper neck shots, I would be sourcing more of that Fiocchi ammo. As a matter of fact, I'll be doing that just 'cuz...

The moral of the story is that sometimes you need to find the ammunition that the gun likes...
Click to expand...
Thank you for the write up. I have only been able to test four or five types of ammo so far and none of them did as well as your worst group almost.

Also, we have to use ranger 64 Grain Winchester ammo for work. And it seem to hate that the most.
 
#24
Looking at the stainless steel with the nitride finishes, so they’re a little more durable

will they be substantially less accurate than the chromelind without the nitride

Specifically kind of looking at the barrel and hatchet edition 16 inch with the intermediate length gas
 
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#26
hlee said:
I have one Roscoe barrel, bought on the recommendation of @TonyTheTiger. I had robbed the scope from that rifle for another project, but this thread inspired me to mount a scope and head to the range. Full disclosure, the rifle was built for run and gun competitions, and is an 18" rifle gas length barrel, on an Aero M4E1 Enhanced upper/lower set. It is from Roscoe's Pureblood line, and came as a package with their bolt and carrier. The rifle has a magpul PRS Lite stock in the rear, and a MDT GRND pod in the front. It has an SLR gas block, but I did not touch the settings for this outing. On top, the rifle wears a Vortex Viper PST Gen ii 5-25x scope. Gisele SD-E trigger.

I shot a few rounds to get the optic zeroed (you can see the impacts spread across the upper part of target 1, and then settled in to groups. I shot the groups at a reasonable pace(3-5 sec between shots), and only paused between groups long enough to load the next magazine. The ammunition chosen is just what I happen to have on hand. Groups are all 5 shots.

View attachment 8502964

View attachment 8502983

For the cost of the barrel, and for the shooting that I do with it, none of these groups are going to hold me back. The said, if I were taking it to the deer blind, where I typically look for head/upper neck shots, I would be sourcing more of that Fiocchi ammo. As a matter of fact, I'll be doing that just 'cuz...

The moral of the story is that sometimes you need to find the ammunition that the gun likes...
Click to expand...
( No Offense intended at all... ) But, no fair with the Fed TV 50gr load... that stuff flat out shoots well in every barrel I have seen it fired from.

Darned near a perfect 100yd factory load... cheap, ( $5.29 / 20rds back in the day ) , crazy consistent.. just above 1 MOA, all day long.

Why Fed discontinued it ( and never listed it in a catolog / webpage ) is beyond me.
Pic is from my 20" SS FN CHF PSA upper. 100yds , scoped, benched... 20rd group, left hand upper corner is kinda like Molon's "Quarter MOA" target ( 10 quarters, 2 rows of 5 across a 8 1/2" x 11" sheet of paper.
The white dots and orange dot is 1".

Thank You for all the info !

And for the OP... sorry about the thread drift.... but I sure do miss that specific ammo.
 

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#27
Aaros143 said:
For what its worth I have the 12.5 K9 barrel and it shoots amazingly well with my 75 grain duty ammo.
Click to expand...
The stray dog I have is a mass production barrel. they mentioned the k9 barrels being button rifled and nitrided instead of chrome. I like their 12 five and 13 nine options I just don’t have an SBR lower and don’t want to pin in the weld at this time.

Good to know someone’s having good luck with the K9 series though.

Anyone else have groups the show from their k9
 
#28
bfoosh006 said:
( No Offense intended at all... ) But, no fair with the Fed TV 50gr load... that stuff flat out shoots well in every barrel I have seen it fired from.

Darned near a perfect 100yd factory load... cheap, ( $5.29 / 20rds back in the day ) , crazy consistent.. just above 1 MOA, all day long.

Why Fed discontinued it ( and never listed it in a catolog / webpage ) is beyond me.
Pic is from my 20" SS FN CHF PSA upper. 100yds , scoped, benched... 20rd group, left hand upper corner is kinda like Molon's "Quarter MOA" target ( 10 quarters, 2 rows of 5 across a 8 1/2" x 11" sheet of paper.
The white dots and orange dot is 1".

Thank You for all the info !

And for the OP... sorry about the thread drift.... but I sure do miss that specific ammo.
Click to expand...
Yeah, I picked it up on a whim and it was the best out of the gun I was shooting at the time. I kept looking for more and never found any. And, the fiocchi exacta rifle match is also discontinued. FML. I need another reloading project. 😫
 
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#29
Joshua1:9b said:
Looking at the stainless steel with the nitride finishes, so they’re a little more durable

will they be substantially less accurate than the chromelind without the nitride

Specifically kind of looking at the barrel and hatchet edition 16 inch with the intermediate length gas
Click to expand...

If it were me I'd tell them I wanted to exchange it for a regular stainless barrel not nitrided etc

I used to worry about barrel life but it's kind of a joke tbh, that 200$ stainless barrel will potentially last through 2000$ worth of ammo as long as you don't overheat it or physically damage it with a cleaning rod
 
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#30
Joshua1:9b said:
Looking at the stainless steel with the nitride finishes, so they’re a little more durable

will they be substantially less accurate than the chromelind without the nitride

Specifically kind of looking at the barrel and hatchet edition 16 inch with the intermediate length gas
Click to expand...
The barrel and hatchet is what I'd go for. Nitride isn't going to make the barrel less accurate, it will just make it last longer and Rosco does nitride as well or better than anybody else in the industry.
 
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#33
I received the k9 16 inch barrel and hatchet barrel. Extremely happy with the accuracy increase. Also the gas’s system produces noticeably less recoil. I did not notice any group size, increase or point of impact shift when shooting the barrel hot or cold.

The weight is shifted to the rear with the profile design and the barrel even matched up to the receiver better.
 
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