155g Lapua scenars load dev

[joshmartin8]

Now i have got to grips with the short-medium range (600) ability of my 308 AI AE mk111 using 155amax i would like to look into pushing out to the 1000yard mark on gongs and paper a little more,

 

I have done this with the 155Amax but after a lot of reading and advise there is a lot better options for the 1000y performance i want to achieve, I looked into heavier bullets but for the weight and higher bc tbh there was not a lot in it, i compared a 178g amax to my 155 and for the extra weight and bc it wasn't achieving hardly any benefit as they had to be launched at lower speeds,whereas the 155scenar achieves close to .500 at a lot faster speeds i.e. 2900ish

 

So i then went back to one of my loads i had written down and tried when i first purchased the gun and that was 155 scenars, with 46g of v n140 they were grouping very well .5moa or less and were achieving a respectful 2850fps, no pressure signs as yet and they are seated quiet long at OAL of 2.860,

 

All this is great and on my ballistic app it shows they will stay supersonic at 1000 happily- 1350fps,

I have not done an OCW test on 46g+ up towards 47g, as the OAL is quiet a lot i am led to believe i think i can still safely get some more out of these bullets as there is no signs of pressure yet

 

MY QUESTION IS- do you helpful folks think i should try this and see if i can improve on velocity and possibly group size or stay at a mild load and run with it, if so would .2g increments be a good starting point or should i got to .1g increments,

 

Secondly- should i consider a different bullet in the first place as i have missed something i should have thought about before..... any advice welcome thank you,

[Davy]

I shot an AE Mk1 with the 155 Scenar for many years, mostly with N540 up to around 47.8 grains without any issues however that was my rifle.With N140 like you I was around 46.5 grains with reasonable results. OAL was 2.890" I would say go up in .2 grain increments however this is as much down to range access as a desire to find the most accurate load quickly. I used to have a 110 mile round trip at the time when I first started my load development. A simple ladder test at 200-300 yards should give you a better idea of where to concentrate your development.

 

I found the 155 Scenar worked best for me with a jump of around .012" and pointing the bullets was a step change with a gain of just under 1MOA in verticals at 1000 yards and general tightening of groups. You should be able to comfortably get to 1100 on a warm day with the 24" barrel and Scenars however 1200 is always going to be sketchy regardless of what you do due to the MV limitations of the barrel length and cartridge.

 

The important thing is to work up carefully regardless of how robust the AI action is perceived to be and drop back .5 grains at any sign of heavy bolt lift/primary extraction issues.

 

I forgot to add, the 170 Lockbase was staggeringly good in my AI.

[gbal]

Josh,the 308 is a very fine medium range cartridge-as you have found...say to 750.Let's see what it needs to be competitive with some others at say 1000y.

 

A very good yardstick for 1000y competition shooting has been the 6.5 (x284) so lets take that:

 

6.5 calibre 142 bullet BC .565 @ 2950

 

to match the wind drift from that ,the 308 needs:

 

308 calibre BC .627 @ 2650 and Bullet of 220 g

 

That's 220 g-some have tried,recoil is punitive,up nearly half,and that affects performance,for most shooters.

You can't get parity with the 6.5s as velocity has its limits,unless you go high BC/Bullet weight.

 

That's really why the 30 cals are very much in a minority,as shootable accurate 1000y cartridges-and they are not much fun either,you will be stuck with the barrel a while,if that is any consolation .

 

That said,the 155 lapua is a good light weight 308 bullet-and you should be pleased with it's performance.Don't get too carried away with a 100 fps or so-it helps,but is not the holy grail except for really experienced shooters,at the cutting edge-because others will be pushing their velocities,to get an edge( or just like buying new barrels!).

Remember too,in very light wind,most will shoot the small but efficient 6BR class better than a heavy-they are just more shooter friendly.Big isn't better,efficient and high BC is.

Things change...a 1/7 243 with 115Dtac bullets is a very much superior long distance performer than a standard 243 restricted to say 90g bullets-good stalker,yes...Long Range,no.

 

(just for fun,at the other end a 224 cartridge needs 90g,BC .502,and an unfeasible 3270fps to compete),which is why,with some laudible exceptions,they don't. Gong plinker,OK.

 

So 155 scenars are just dandy for decent performance,within the marginal 'competitive' envelope the 308 now finds itself in-not a major concern for the non competitive-just don't expect world class performance.

Varminters often like to see the strike-or splash-another reason disruptive recoil is to be avoided.OK for gongs-they clang and swing for a bit.

 

gbal

[Brillo]

Here's my take on it based on performance of my AW (almost like-for-like) and my Sako TRG-22.

First of all, I think the Scenar 155 is a superb bullet and gives excellent performance in both rifles. Initially the Scenar would not work in the TRG until I discovered that it like a really big jump. Seated to 2.860", like yours, this gives a 0.055" jump. On the other hand the AW throat is shorter and best performance is at 2.830" which gives a 0.010" jump.

 

Like Davey, I found best MVs and groups were achieved with N540. However, I'm sure this is responsible for the excessive throat wear on the TRG and as such I stopped using it.

 

Since then I've started using RS52 and with the Scenar 155 and Berger 155.5 and hybrid 155 bullets the results so far have proved outstanding by comparison to N140. By that I mean MVs are up considerably with no pressure signs and with loss of, or even improved accuracy.

You may not be seeing any pressure signs just yet with 46 grains of N140 but QuickLoad suggests this is already gives too high a pressure so I suspect that you'll see signs not far from your current load.

 

With the 155 Scenar and 45.1 grains of RS52 the AW MV is ~2950 fps and I'm happy with this from a 26" barrel.

[Biathlonjimmy]

I was pondering the same recently and found the Hornady 208 AMax with BC of .648 looked promising.

http://www.hornady.com/store/30-Cal-.308-208-gr-A-MAX/

 

No experience of it on the range and I'm not sure of its availability. If you get hold of some I'd be very interested to hear how you get on.

 

 

Best,

 

 

J

 

[Davy]

(just for fun,at the other end a 224 cartridge needs 90g,BC .502,and an unfeasible 3270fps to compete),which is why,with some laudible exceptions,they don't. Gong plinker,OK.

 

So 155 scenars are just dandy for decent performance,within the marginal 'competitive' envelope the 308 now finds itself in-not a major concern for the non competitive-just don't expect world class performance.

Varminters often like to see the strike-or splash-another reason disruptive recoil is to be avoided.OK for gongs-they clang and swing for a bit.

 

gbal

Unfeasible, well not really. The 90 grain SMK with a load of H4831SC or N560 in a 22-6,5x47 can be run very comfortably to 1000m/sec to keep within MoD range restrictions and has the advantage of utilising the .308BF will magazine feed and offers superb accuracy and reasonable barrel life. Pointed they are even better and you will see similar results with the 80g SMK even on a blowy day plus you have the fun of shooting a rifle that comfortably punches above its weight.

 

The other bullets to consider in the 155 family are the SMK #2156 which has a proven record within T/R and if you take time out to batch them by weight and boat tail base to upper edge of the bearing surface length they give superb long range results for F/TR plus there is the the 155HBC which again works well and has seen good results in the league.

[dannywayoflife]

I was pondering the same recently and found the Hornady 208 AMax with BC of .648 looked promising.[/size]

http://www.hornady.com/store/30-Cal-.308-208-gr-A-MAX/[/size]

 

No experience of it on the range and I'm not sure of its availability. If you get hold of some I'd be very interested to hear how you get on.[/size]

 

Best,[/size]

 

J[/size]

I use the 208 in my dta srs covert mate. I was shooting it at 900 on Sunday my accurate load is doing 2250 from the 16" stump of a barrel. I have had them up to 2350 but that was single loading and they wouldn't fit in the mag(I may mod the mag to rectify this however!) They now seem very hard to find but I love them. I'm now developing a short range 1-800yd load to save them for 800-1000 yds.

[gbal]

Unfeasible, well not really. The 90 grain SMK with a load of H4831SC or N560 in a 22-6,5x47 can be run very comfortably to 1000m/sec to keep within MoD range restrictions and has the advantage of utilising the .308BF will magazine feed and offers superb accuracy and reasonable barrel life. Pointed they are even better and you will see similar results with the 80g SMK even on a blowy day plus you have the fun of shooting a rifle that comfortably punches above its weight.

 

The other bullets to consider in the 155 family are the SMK #2156 which has a proven record within T/R and if you take time out to batch them by weight and boat tail base to upper edge of the bearing surface length they give superb long range results for F/TR plus there is the the 155HBC which again works well and has seen good results in the league.

 

Davy,yes my error -when changing to a generic 224,(in line with 30/6.5 etc) rather than the intended 223rem-) "other end of scale," also too vague,I just wanted to reduce the 'my 223 does 1000y" ambitions,) but it is misleading and I meant the attempt to get the 223rem to so perform-Laurie apart- was likely to be an exercise in relative frustration....A bigger case will of course get the numbers,though hot 224s are not much used-too much of a challenge/handicap or even allowed in 308/223 restricted comps,which is popular format/preserves the venerable-take your pick!

Some of the oldies might well work too,given these new fangled BC bullets -the 22 Clark (necked 7x57).

 

 

But thanks for the clarification-anyone wanting to do it knows what not to use,and what to try!...and the numbers needed to get amongst them.

 

gbal

[Ballistic Hamster]

Jos

Being I shoot a AX MC in .308 l shoot 155 scenars with n140 46 .3 g and ogive is different with all barrels and bullets , they perform well past 1000 yds when I do F class FTR and extreme long range , just up bit by bit and see, asking people who shoot this combination will give you the best advice, so just go out and learn by what your do, write it down and keep targets and repeat when it looks good and close the book and enjoy.

[joshmartin8]

thanks for all the great replays guys and some good info there, as for playing with 224bullets i have a AR15 which really likes the 80gsmk with good velocity which i am currently doing load development for now also with n140 and tac, both with great results of sub .5 moa consistently, so will do a load write up and post/pics of how i get on with that at a later date for shits and giggles and how they perform down range, i know when i was trying to look into other peoples results regarding similar bullets it was quite hard to find a much info or results so if it just gives one person an idea where to start or interest then thats great, ,

 

back to the 308 in question, i think i am going to defiantly run with the 155 lapua scenars, and as they are up near the max load already i think i am going to do .2g increments and do 5 loads up to 47g n140 as i know the previous owner did go that high with not many issues. i do quiet enjoy chasing the perfection and trigger time in general so its not like this is a chore for me, will also give feed back on the OCW results and with the best loads push them to 300 on a still day or down a hedge row to see how they perform further out, and then to 600 and then 800, 1000....

 

totally agree that the 308 is going to be close to its limits at 1000 and can see the advantage to dropping to a 6.5 but until my barrel is burnt out on my AI i am going to run and have fun pushing it and learning more and more about this addictive hobby. I'm away working for a couple weeks at the min so no progress for a day or two I'm afraid till i return home, lets keep the good discussions coming thou guys and any input is never bad input,

 

josh

[brown dog]

Josh, you're at 2850fps and accurate.

Before you chase your tail trying to take it 90-100fps faster; have you stopped to consider/quantify what extra performance that extra 90fps will bring?

Have a play with the numbers and put some values on it - such as % change to deflection, and see if you still think it's worth the bother.

 

Also be aware that the scenar is a great paper-punching bullet, but, for other purposes, it shares none of the terminal ballistic charateristics of the a-max.

[gbal]

Josh, you're at 2850fps and accurate.

Before you chase your tail trying to take it 90-100fps faster; have you stopped to consider/quantify what extra performance that extra 90fps will bring?

Have a play with the numbers and put some values on it - such as % change to deflection, and see if you still think it's worth the bother.

 

Also be aware that the scenar is a great paper-punching bullet, but, for other purposes, it shares none of the terminal ballistic charateristics of the a-max.

 

 

+1

Most of us have room for 100% better wind reading,and wind is in a different league to 100fps as a hit/miss factor.

g

[joshmartin8]

Josh, you're at 2850fps and accurate.

Before you chase your tail trying to take it 90-100fps faster; have you stopped to consider/quantify what extra performance that extra 90fps will bring?

Have a play with the numbers and put some values on it - such as % change to deflection, and see if you still think it's worth the bother.

 

Also be aware that the scenar is a great paper-punching bullet, but, for other purposes, it shares none of the terminal ballistic charateristics of the a-max.

 

yeah i did the numbers today and even if i could get an extra 100fps the is no major advantage like you say I'm, mainly going to to a few loads slightly hotter just so i know where the nodes are and where the pressure signs start to come in just for my own knowledge really, not fussed if i don't mange to get extra velocity as the 2850 is fine and accuracy is great so just going thou the process for my own knowledge,

 

+1

Most of us have room for 100% better wind reading,and wind is in a different league to 100fps as a hit/miss factor.

g

yeah totally understand gbal, just need to get home now and get some trigger time in

[joshmartin8]

well got back home yesterday for the day and loaded up 46, 46.2, 46.4, 46.6, V N140 purchased a chrono for myself as I've always borrowed one in the past got in the field and shot these 4 groups,

 

46g,=2846fps avg and .211'' group 4 shots, ragged hole

46.2= 2867fps avg and .312'' group 4 shots, larger ragged hole

46.4= 2884fps avg and .347'' group 4 shots, same again

46.6= 2891fps avg and .509'' group 4 shots lateral diffence in wind, would have been .2 group if wind diddnt push this group,

 

none of these groups were showing pressure signs or sticky bolt so going to keep going up till i do get some slight signs, if the groups get worse i will stick with the 46g of V N140 as its not a bad speed and will prolong brass life and is consistent,

[Brillo]

Interesting and not unexpected results.

 

Running these results through 3 ballistics programmes show the difference between your 46 gr and 46.6 gr load represents a gain of only 1.25 MOA (12") elevation at 1000 yards, a velocity gain from 1360 fps to1385 fps at the same distance and only a 0.1 MOA advantage in windage (assuming a direct 3/9 o'clock, 10 mph wind.

[The Gun Pimp]

Interesting and not unexpected results.

 

Running these results through 3 ballistics programmes show the difference between your 46 gr and 46.6 gr load represents a gain of only 1.25 MOA (12") elevation at 1000 yards, a velocity gain from 1360 fps to1385 fps at the same distance and only a 0.1 MOA advantage in windage (assuming a direct 3/9 o'clock, 10 mph wind.

ONLY - what a great word Brillo. How many times do we hear the words "If ONLY that line-cutter 4 had been a 5."

 

Today, F Class comps are won by odd points and that one-tenth MOA less wind-drift at 1000 yards could mean that your four could have been a five.

 

Of course, it's not quite that simple and the wind blows 'em in as well as blowin' 'em out! But, that's why all competitors strive for maximum ballistics - especially the FTR guys who are stuck with the 308.

[Brillo]

ONLY - what a great word Brillo. How many times do we hear the words "If ONLY that line-cutter 4 had been a 5."

 

Today, F Class comps are won by odd points and that one-tenth MOA less wind-drift at 1000 yards could mean that your four could have been a five.

 

Of course, it's not quite that simple and the wind blows 'em in as well as blowin' 'em out! But, that's why all competitors strive for maximum ballistics - especially the FTR guys who are stuck with the 308.

Ah yes, I agree Vince, but my point is that the accuracy of the lower velocity load should more than compensate for the 0.1 moa wind drift.

I think it fair to assume that the group size would open up with distance and arguably the higher MV group will be poorer at 1000 yards than the one 45 fps slower. Equally the reverse could be true and the proof of the pudding will be testing these at longer ranges. ONLY the OP can find this out

[joshmartin8]

very good points and considerations guys, i would only consider the higher velocities over my 46g load if they could match the accuracy of it, i will be back out in the field next week to do further testing, might push out to 200 for further testing if the wind is good.

[joshmartin8]

very good points and considerations guys, i would only consider the higher velocities over my 46g load if they could match the accuracy of it, i will be back out in the field next week to do further testing, might push out to 200 for further testing if the wind is good.

[Chickenthief]

Josh,the 308 is a very fine medium range cartridge-as you have found...say to 750.Let's see what it needs to be competitive with some others at say 1000y.

 

A very good yardstick for 1000y competition shooting has been the 6.5 (x284) so lets take that:

 

6.5 calibre 142 bullet BC .565 @ 2950

 

to match the wind drift from that ,the 308 needs:

 

308 calibre BC .627 @ 2650 and Bullet of 220 g

 

That's 220 g-some have tried,recoil is punitive,up nearly half,and that affects performance,for most shooters.

You can't get parity with the 6.5s as velocity has its limits,unless you go high BC/Bullet weight.

 

That's really why the 30 cals are very much in a minority,as shootable accurate 1000y cartridges-and they are not much fun either,you will be stuck with the barrel a while,if that is any consolation .

 

That said,the 155 lapua is a good light weight 308 bullet-and you should be pleased with it's performance.Don't get too carried away with a 100 fps or so-it helps,but is not the holy grail except for really experienced shooters,at the cutting edge-because others will be pushing their velocities,to get an edge( or just like buying new barrels!).

Remember too,in very light wind,most will shoot the small but efficient 6BR class better than a heavy-they are just more shooter friendly.Big isn't better,efficient and high BC is.

Things change...a 1/7 243 with 115Dtac bullets is a very much superior long distance performer than a standard 243 restricted to say 90g bullets-good stalker,yes...Long Range,no.

 

(just for fun,at the other end a 224 cartridge needs 90g,BC .502,and an unfeasible 3270fps to compete),which is why,with some laudible exceptions,they don't. Gong plinker,OK.

 

So 155 scenars are just dandy for decent performance,within the marginal 'competitive' envelope the 308 now finds itself in-not a major concern for the non competitive-just don't expect world class performance.

Varminters often like to see the strike-or splash-another reason disruptive recoil is to be avoided.OK for gongs-they clang and swing for a bit.

 

gbal

No it isnt.

22-243 AI and a 26" barrel will do @3300fps with a Sierra 90gr.

Barrel burner yes, but it will get you there if desire strikes!

[Chickenthief]

Oh and a 223 WSSM will duplicate that result!

[gbal]

No it isnt.

22-243 AI and a 26" barrel will do @3300fps with a Sierra 90gr.

Barrel burner yes, but it will get you there if desire strikes!

Chickenthief,yes -see similar post 8- it's just possible-if the Sierra is a genuine .5 BC-see recent discussions-even if it wasn't, the Middlestead is a great varminter,if a bit bypassed by the 55/58g 243 these days,as an easy varmint number.

 

I was careless in moving from the 224 calibre maths,to the 'just for fun' point that I meant to make-the 223Rem cartridge is 'unfeasible'...so anyone trying 223rem at 1000y should not expect to be competitive,due to lack of fps. Of course,'get you exactly where' at 1000y is more variable-markable on a 6x6 foot target,yes...in a 5 inch group....not so regularly as the better 6.5/7s in wind.

Some other wildcats might be marginals too....224 Clark,30-06 saboted....above and beyond normal desire !

 

gbal

 

(Actually my use of 'unfeasible' was deliberate...it's a weasel word,not in the dictionary....though 'feasible' includes "probable.desireable,likely,practicable...from the latin 'facere' to do)...I wanted to avoid 'can't be done',more as above,to clearly indicate there were alternate routes to compete with the 6.5 ,and that even the 30 calibre was more 'feasible' (despite recoil).

You are right of course about short barrel life in any 224 at those velocities-I was also thinking of

 

pressures and indeed bullet failure...one reason back in the day I didn't have a Middlestead.

 

The BCs quoted are adjusted for the midlevel velocities that the bullets will actually follow,and not the maxima for the bullets (which are highest at muzzle),a point that needs careful consideration,but has been built in here -the 142 eg has BC .595 max,so reduced a fair bit,I'm assuming 224 pro rata....(just in case anyone thinks the 224 .502 is a bit low,and with a higher BC (MV one) the velocity could be a bit less...and therefore a bit 'more feasible'.... No free lunch....as the WSSMs testify....best save for another barrel...

 

Complicated,ain't it !

 

g

[joshmartin8]

well I've not had chance to do any max load development yet but decided to go out today with some previous loaded 46g n140 and got this 3shot group at 130y,(small pinky for size comparison) so for what I'm going to gain in velocity I've thought is not worth trying to just get an extra 100fps, don't think i can achieve any better than this and at upto 2850fps I'm hoping they are going stretch out to 1000y, JUST maybe if I'm lucky, now to go back and step it out 100 at a time from 600 and see how it performs , wish me luck