Help with .308 154gr Scenars

Dave42

Dave42

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I'm currently working up a load for these bullets and am not getting them to shoot all that well. The gun is a trued up 700 w/ a shillen match barrel skim bedded in an HS stock. The gun shoots fine with the nosler 168's (1/2 to 3/4MOA) and I never really did any load development.

I have heard these bullets can be tough to get working so I'm looking to see what others have tried and are using in the way of powders, powder weights, and seating depths.

I'm currently using Lapua brass, Varget, and CCI LR primmers. My best load so far is about 3/4MOA at best, using 45.8gr varget and .010" off the lands. I've tried changing the seating depth but my velocity's are jumping up as I move the bullet in.

Thanks in advance for any help.

Dave
 
Well, looks like your going through what i just went through.

I started load development with my accuracy international AIAWP and 154 Lapua scenars. Once I figured out where my pressure limit was i started working up ladder tests. They all shot like crap. The best groups I could get @200m were MOA at best, some were over 3". I used the same components as you but Fed 210M primers. I repeated tests with IMR 4895. ES with IMR was way less than with varget but still shot like garbage. Believe me, I've never fought with a rifle to get it to shoot like I did with this combination. I was ready to grow hair just to pull it out.

I moved them closer to the lands (I can jam them and still mag feed as the AIAW mags are really long). I moved them .010 off and started again. Groups tightened way up with one being under 1/2MOA @ 200m. I then tried adjusting neck tension, that tightened it up a touch more.

Best groups were .010 off in the 2950fps range. 3 thou neck tension (mag fed gun).

It took 135 rounds of testing various powder charges (running 5 shot groups in .3 grain incriments), types of powder, seating depth, neck tension, etc, to get the 155 to shoot well. Of course the chamber in the AI is likely more generous then yours and not so conducive to tuning tight groups with picky bullets.

I got the 175 Sierra match kings shooting well in short order. Even as far off as .040 they shot. My 2cents would be if your pressed for time to stick to the match kings for now.

Take care and good luck.


Dave42 said:
I'm currently working up a load for these bullets and am not getting them to shoot all that well. The gun is a trued up 700 w/ a shillen match barrel skim bedded in an HS stock. The gun shoots fine with the nosler 168's (1/2 to 3/4MOA) and I never really did any load development.

I have heard these bullets can be tough to get working so I'm looking to see what others have tried and are using in the way of powders, powder weights, and seating depths.

I'm currently using Lapua brass, Varget, and CCI LR primmers. My best load so far is about 3/4MOA at best, using 45.8gr varget and .010" off the lands. I've tried changing the seating depth but my velocity's are jumping up as I move the bullet in.

Thanks in advance for any help.

Dave
Click to expand...
 
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I had the same problems w/ the lapuas. Tried the 155.5 bergers and havn't looked back. 175 smks were easy to get shoot as well- just like Blackcloud says.
 
mpwolf said:
I had the same problems w/ the lapuas. Tried the 155.5 bergers and havn't looked back. 175 smks were easy to get shoot as well- just like Blackcloud says.
Click to expand...

With a 15% better B.C. and 20% less cost than the Bergers, I'll stick with the Scenars for now. As for the Sierra, it may be easy to get shooting but even though they have the same B.C. as the scenars the extra wieght slows them down a lot. I'd be lucky to see 2700fps without pushing max pressure.

I know they'll shoot 3/4 to 1/2 MOA or better, just need to find the right combo. I still have a week or so before I'm screwed and need to try a different bullet. Thanks for the help so far guys.:D
 
I've been using H4895 with the Scenars. I also jammed the Scenars into the lands about 30 thou. Lapua brass, CCI BR2 primers. When I used Varget I was using between 46 and 47 grains. For my rifle, jamming the Scenars worked nicely. BTW, the rifle is a 700VS with a PSS barrel.
 
I would have to agree with Terry with jamming the Scenars I have 20 thous jam using Varget CCI primers and Norma brass works for me. I have found that the Scenar’s being the longest 155 need to be seated out to avoid the bullet being pushed into the shoulder neck junction, seated to deeply and accuracy falls off accordingly. YMMV

I would also suggest a proper ladder test to see where the node is for your rifle most folk find a node around 46.


This is not mag length is single loading
 
Thanks for the help guys.

I need this load to mag feed or at least really want it to considering there is an AI mag system on the gun. I just got back from the range where I did a little more playing with the OAL. I rechecked my seating length in the gun a few more times and found that my original ladder test was about .007 off the lands not .010. I decided to go in .005 increments to see if there was a sweet spot. At .012 off the group was around 1" at 100m. At .017 it was around .75" and at .022 was what I was waiting for. Can't believe that such a small change in OAL made such a big difference. Just need to reprove the load tomorrow and make sure there was not some other factor involved.

Here's the last two groups.:D

Dsc07624.jpg


They are both five shot's, double tapped the top right hole on the large group and not sure where the fifth shot is on the other:confused: Maybe I missed the target:D.

Dave
 
with the 155's i bought off you Dave. in load development .020 off and i got .5moa with 45 gr blc2 and averaged 2930fps. with varget 45 gr i got another solid .5 moa and avg speed of 2960. no pressure signs with any loads.
 
HI Dave, nice to see you're making progress.

What overall length are your rounds? (I'm trying to figure if you've got a long or a short throat).

You don't want a load that is super-sensitive to any one parameter (charge weight, bullet seating depth, etc). Since you seem to be able to shoot them well with some jump, I would suggest that you try shooting them with a "lot" more. I would suggest trying .040" jump from the lands. If this shoots well, also try .060" and .020". If all three shoot well, then use .040" as your nominal loading depth (knowing that if one round is a bit more, and another is a bit less, then you'll still have something that shoots well).

Oftentimes it is difficult to determine the point of rifling engagement with any accuracy. So if you are either "well clear" or "well into" the rifling, you can avoid this uncertainty. And if you can possibly get a "well clear" load to shoot well for you, you definitely want that (e.g. you know you can always unload an unfired round, without fear of the bullet sticking in the throat and the case dumping powder into your action and trigger!)
 
I'm jumping my moly'd scenars about 0.040" ... 46.2gr H4895 in Winchester brass @3000fps, 2.840" OAL and M852 chambered. Working quite well! Also good with magazine length (2.810") in Norma brass and using IMR3031 @2940fps.
 
Intitially, those shooting the GB491 used about a grain less powder than the amount used with the Sierra 155 MK due to larger bearing surface. The above contributors and others have shown very high pressures can produce accuracy. For sure is that these bullets are the equal of any as regards quality control - jacket uniformity. Alain Marion measured thousands on a Juenke and all were BR level. It is also fair comment that they may be particular to OAL and may not work in all rifles. Many top shooters use these bullets to win matches and we'll have them in stock mid-June, along with.308 brass.

Regards,

Peter Dobson
www.hirschprecision.com
 
If your not getting results with the 155's, and you are with other sizes why are you messing with the 155's, shoot what your rifle likes. I've had better results with 4064 than varget. I've seen some of my friends 308's that just don't like 155's, but when 168's shoot under .3 consistantly who cares what works if it works, use what works.

M.
 
Dave42 said:
I'm currently working up a load for these bullets and am not getting them to shoot all that well. The gun is a trued up 700 w/ a shillen match barrel skim bedded in an HS stock. The gun shoots fine with the nosler 168's (1/2 to 3/4MOA) and I never really did any load development.

I have heard these bullets can be tough to get working so I'm looking to see what others have tried and are using in the way of powders, powder weights, and seating depths.

I'm currently using Lapua brass, Varget, and CCI LR primmers. My best load so far is about 3/4MOA at best, using 45.8gr varget and .010" off the lands. I've tried changing the seating depth but my velocity's are jumping up as I move the bullet in.

Thanks in advance for any help.

Dave
Click to expand...

what is the twist rate on your shilen barrel?
 
While I agree in general with Ice-Pick's advice, experience has shown that performance of the 168 gr Sierra is not good at ranges greater than 600 m, even though it has produced excellent results from 100 to 600 inclusive.

Past 600, other bullets with higher BC's than the 168 gr must be used.
 
My PGW Coyote.308 24" barrel 1:10 twist likes the 155 Scenars seated @ 10thou off with 46.6gr Varget,Lapua brass,Fed Match primers.
Sud .25" groups all day long.

Pete
 
The barrel is a 1-10 twist.

Could not repeat the group from my earlier post, so I've been back at it and with no luck. Tried into the lands and the ES was better than off the lands but groups were still around 3/4. I'm pretty much done trying now and going to get some heavier bullets. I've had the 168 noslers shooting just fine so I'll go back to them first and then maby try some Bergers after.

I'm sure the 155's work great, just not in this gun or at least not with the powder / primmer / brass combo I'm using. I'm going to try one last ditch effort with them tonight to finish off the box but I'm not expecting anything spectacular. Just seems like the gun spits them out at 3/4MOA and thats it.:( I did learn alot about what seating depth can do so it was not a total loss.:)

It happens, thanks for the help guys.:D

Dave
 
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