1 in 12 twist / 155 Scenar stabilize?

Dacam

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Oct 16, 2012
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Hey guys,
I have a 20" 1/12 twist barrel. Will it stabilize a 155 Lapua scenar or am I totally off base here.
Correct me if Im wrong but isnt the scenar longer than a typical 155 grain bullet? Would I need a faster twist?
I am shooting 168 grain to 800yds no problem but I would like to push it to 1000yds. I tried 175 grain but
my rifle doesnt like it at all, 1.3" groups at 100yds.
 
my 20" 1:12 does shoot the 155's, but close to max load of varget. 175-178 fine with 44.1-44.4 varget. (approx .75 moa, but consistant)

The 155 is flatter than the 175 (in my rifle), but little tougher to correct in the wind. I gave up on the 155's in my 308. I now use them in my -06, a 1:11 clocking 2900+ and they really shine.
 
I'm not real sure but I believe the Palma guys mostly run the 12's. They fire at 800,900 and 1000. Limited to 155's and iron sights. They do use the really long barrel lengths (26 to 30!).
 
My FN SPR with 1:12 doesn't like the scenars at all. Looks like a buckshot pattern at 100y. However the 155 berg hybrids shoot incredibly good and flat running 2920fps
 
My FN SPR with 1:12 doesn't like the scenars at all. Looks like a buckshot pattern at 100y. However the 155 berg hybrids shoot incredibly good and flat running 2920fps

I too have a FN SPR (a5m). It really doesn't like FGMM 175g factory ammo. I am gonna start loading up some 175g handloads and see how it performs. I'll try some 155g scenars as well.
 
My old FN SPR A3G with 1-12 twist shot the 155 Scenar nicely.

12 twist is plenty for the 155s, which is not to say they'll always shoot well from all/any 12 twist barrel (hopefully that's obvious).

A fellow at the gunclub shoots 208amax and 208hpbt Hornadys from his 12 twist Steyr 308 with good results.
 
I shot for Lapua for many years in F TR. I have shot many thousands of 155 Scenars through a 308 running between 2800-3100 fps muzzle velocity

What I found is the 155 Scenar is same length as a Sierra 175 but it requires more spin to stabilize at long range

With a 12 twist I would shoot great to 700 running the slower side and 900 yards pushing super fast

I switched to 1/11.25 and groups at 1000 shrank dramatically

Now the Berger 155.5 stabilized in the 1/12 to a 1000 no problem
 
Hi there and thanks for the reply. I am a Palma shooter from Australia. Very little info regarding these projectiles.155 scenar L). I have shot these projectiles for about 8 years with good effect but not brilliant. I am now after brilliant, these bullets are by far the best when you compare them to other 155’s eg weight, length. We need 3020fps,iam running 45.0 grains of Adi 2206h.
Again Thankyou for replying.
Regards Paul
 
Hi there and thanks for the reply. I am a Palma shooter from Australia. Very little info regarding these projectiles.155 scenar L). I have shot these projectiles for about 8 years with good effect but not brilliant. I am now after brilliant, these bullets are by far the best when you compare them to other 155’s eg weight, length. We need 3020fps,iam running 45.0 grains of Adi 2206h.
Again Thankyou for replying.
Regards Paul
Switch to 155.5 Berger Full Bores. They are brilliant
 
Switch to 155.5 Berger Full Bores. They are brilliant
Hi there again , yes you are right they are very good I have used hybrids and full bore both are excellent projectiles without doubt and easy to get the best out of them. But when you measure them up against lapua they are not as good. The question is how to get them to shoot as good as they look?
They have a better BC ( only marginal) when you compare against Berger full bore 155 and they are clearly superior in all facets . The big difference appears to be the longer bearing surface. Finally they are made by a huge company with unwavering commitment to produce quality. Also I have 5 thousand of them lol. I have received a new barrel just today 33inch Border, 1/11.25 throated out .145 thou. Well thanks again for the reply and if anyone else would like to chime in feel free I’m just going to put my head down the rabbit hole again and be off.
 
Hi there again , yes you are right they are very good I have used hybrids and full bore both are excellent projectiles without doubt and easy to get the best out of them. But when you measure them up against lapua they are not as good. The question is how to get them to shoot as good as they look?
They have a better BC ( only marginal) when you compare against Berger full bore 155 and they are clearly superior in all facets . The big difference appears to be the longer bearing surface. Finally they are made by a huge company with unwavering commitment to produce quality. Also I have 5 thousand of them lol. I have received a new barrel just today 33inch Border, 1/11.25 throated out .145 thou. Well thanks again for the reply and if anyone else would like to chime in feel free I’m just going to put my head down the rabbit hole again and be off.
I shot for Lapua for many years. Great company. I shot many thousands of 155 Scenars. I won a bunch of matches with them.
If that’s what your set on here is what worked for me
30” 1/11 Bartlien
95 Palma chamber reamer
Load them so they are just touching lands
46 grains Varget
Lapua LP case
Fed Match Primer

I left the rounds loaded way long and just before matches I would clean then set seating depth of rounds. About every five hundred rds they would need to be slightly longer to keep getting the one hole groups
 
Hi there and thankyou for the reply,I think the common idea is to drive them fast and that is what I have been doing for years(3030-50fps). Now it appears harder because our powder appears to be much slower than before. We obviously need 2950 to stay supersonic @1000YDS so I’m thinking 2970-2980 may be worth trying.there is a lot of thought about slowing them down.
 
If you slow them down the groups will open up at a 1000 yards. I shot F TR which has an X ring half the size of the Palma target so you may see great scores still but your X or V numbers will suffer

I found 3000 plus feet per second to
Be the answer. Varget, H4895SC or N140 will all do that
 
Many Palma guys gave up on the 155 Scenar because it really needs more spin because it is longer. Since I was sponsored by Lapua it was the bullet I used so I built the rifles around it

In 2009 Worlds Berger was the Team USA sponsor so I shot those instead. 155.5 Fullbore

Since then I have found BC between 155 Scenar to be basically the same as 155.5 Berger but the Berger’s are far easier to get to work well. They don’t care if they jump.

Berger is now owned by Lapua
 
Many Palma guys gave up on the 155 Scenar because it really needs more spin because it is longer. Since I was sponsored by Lapua it was the bullet I used so I built the rifles around it

In 2009 Worlds Berger was the Team USA sponsor so I shot those instead. 155.5 Fullbore

Since then I have found BC between 155 Scenar to be basically the same as 155.5 Berger but the Berger’s are far easier to get to work well. They don’t care if they jump.

Berger is now owned by Lapua
Hi there and thanks for the reply, I have always shot reasonably well with these projectiles but I think that they are capable of a lot more and that is what I’m trying to work out. as I’ve stated I’ve just got a new barrel a couple of days ago a one and 11 1/2 and if I can’t get them to shoot with that, maybe I need to go one in 10 maybe as you stated spin a little bit faster maybe that might be the best.
 
How did you go? I'm about to build a 308 barrel setup for these projectiles fired from an accuracy international AT. I have a 1-12 barrel knocking around but I'm looking at an 18" ish barrel (plus brake) and I wonder if I'd need a different twist rate for these projectiles.
 
How did you go? I'm about to build a 308 barrel setup for these projectiles fired from an accuracy international AT. I have a 1-12 barrel knocking around but I'm looking at an 18" ish barrel (plus brake) and I wonder if I'd need a different twist rate for these projectiles.
Hi there,
I’m still chasing my tail atm and have not been able to find something that makes me happy. I use 33 inch barrels over here so that will speed things up a fair bit. I will get back to you as I go.
 
Hey guys,
I have a 20" 1/12 twist barrel. Will it stabilize a 155 Lapua scenar or am I totally off base here.
Correct me if Im wrong but isnt the scenar longer than a typical 155 grain bullet? Would I need a faster twist?
I am shooting 168 grain to 800yds no problem but I would like to push it to 1000yds. I tried 175 grain but
my rifle doesnt like it at all, 1.3" groups at 100yds.
I've shot 17,000 rds of match grade 155 Lapua Scenars to 1400yds 25 yrs ago.

All 12 twist barrels, dropped the 20" barrel in favor of 26" and 27" for added velocity at long range. In practical shooting the extra barrel lenght made a difference.
Varget was $112 for 8 lbs, 155 Lapua's were cheaper in 3000 pc lots around 25 cents ea.
Shooting began at 800 yds everything else was too easy.
And barrel changes were at 8,000 rds per barrel, velocities were 2975 to 3020 fps depending on barrel...some loads were 1 gr above max depending on the loading manuals. 2 OZ Jewell trigger.

One thousand yards with a 308 is fairly easy with 155 Scenar.
And much better today with all the new high BC bullets.

Here is a 1400 yrd groups about fist size.

Notice the 155 Scenar stuck at a steep downward angle in the rock.

Group at 1000 yds, 308 155 Lapua, Lapua brass, Fed Match primer...and why you can shoot eggs at 1000 yds with the 308.

The egg wrapped tight in plastic has two hits at 1000 yds one center and one low left.
But you have to be very dedicated to shoot your 308 and 155s like this. Only the last barrel had a muzzle brake...
You have a practice schedule, you alway practice. Mine was 85 rds per practice session several times a week...weather just another variable, until the falling snow completely obscures the target.

You only need a range finder, the rest will come naturally through your senses, and observations, as you practice with purpose.
 

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So you can answer the question for yourself. (y)

Thanks, I’ve seen varying opinions on whether a 1-12 works for 155 especially with a shorter barrel. Higher speed seems to help, I’d welcome peoples real world experiences.
 
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I took a 308 12 twist barrel that had 8000 rds on it, and it shot very well with 155 Scenars.
Cut it down to remove most the firecracking & make an AR 15 in 30 RAR out of the old barrel.
The newly chambered 30 RAR on an old 308 Win barrel really shot good with 155 Scenars ...same as when it was chambeted in 308. Only running a little over 2400 fps the little 30 RAR AR 15 shot nice groups at 100 yds.
Point is, I agree with the velocity being around 3000 fps for 1000yds...but if you're only gonna shoot 500 is, lower velocities "may " work.
I have a 11.25 twist that likes Sierra 155 Palma better.
There are general observations made by many who shot the 155 Scenar successfully, but trying one of the other 155s available from other makers might be more accurate in your barrel.

I remember some 308 30" plus barreled Palma shooters running 1-13 twist back in the day...probably the SMK for bullet.

Pics are 30 RAR AR 15 155 Scenars at 2415 fps average in 12 twist.
They can shoot well in short barrels and low velocity.
I never tried them at long range to see how they do, because that's not what this AR 15 was designed for.
 

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