Any thoughts or experiences from shooters that have used both rounds? I'm looking for a comparison.
Range Report .308 155 Scenar vs 175 SMK
- Thread starter usmcmk12
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I've shot both through a bolt gun. I liked the 155 Lapuas because of the velocity that i gained, basically the same BC. what's not to like.
xdeano
xdeano
Lets nail this down a bit further.
In my 24" tube getting the 155s moving 2935 was an easy task.
I"m going to say that comparitvely 2700 FPS is also as easy. I could go faster with 155 you could probably push the 175 a little harder.
155 @ 2935 FPS @ 1000 yards = 8.9 mils 320.7 inch drop 0.3 mils per mph 9.4 inches per mph of wind Time of Flight is 1.556 seconds
175 @ 2700 FPS @ 1000 yards = 10.7 mils 385.6 inch drop 0.3 mils per mph 10.4 inches per mph of wind Time of Flight is 1.701 seconds
I think the answer is crystal clear to me. 1.8 mils less drop and 1 inch less drift per MPH of wind.
You can change the numbers put in your atompsheric conditions but I think you would be hard pressed to find the 155 not beating out the 175.
Up to about 600 yards the 155 scenar at a good speed (2900+) will match a .260 or 6.5 Creedmoor in ballistics and actually be slightly better @ 300 yards.
In my 24" tube getting the 155s moving 2935 was an easy task.
I"m going to say that comparitvely 2700 FPS is also as easy. I could go faster with 155 you could probably push the 175 a little harder.
155 @ 2935 FPS @ 1000 yards = 8.9 mils 320.7 inch drop 0.3 mils per mph 9.4 inches per mph of wind Time of Flight is 1.556 seconds
175 @ 2700 FPS @ 1000 yards = 10.7 mils 385.6 inch drop 0.3 mils per mph 10.4 inches per mph of wind Time of Flight is 1.701 seconds
I think the answer is crystal clear to me. 1.8 mils less drop and 1 inch less drift per MPH of wind.
You can change the numbers put in your atompsheric conditions but I think you would be hard pressed to find the 155 not beating out the 175.
Up to about 600 yards the 155 scenar at a good speed (2900+) will match a .260 or 6.5 Creedmoor in ballistics and actually be slightly better @ 300 yards.
Wind drift is the only major difference. They will shoot lights out until you hit heavy wind. 175 SMK charges forward in the wind. I personally really like 155 Palma Match bullets until I get in wind over 10 MPH I also have good luck with 168 AMAX bullets. The 155 will shoot flatter and a real tack driver out to 700-800 yards. My buddy shoots 155 Palmas out of his 18.5" Obermeyer that has a Palma Match chamber he really goes to pound town on 12"x20" ISPC plates out to 900.
Only real reason I don't shoot them all the time is for having a 18.5" barrel I don't get the screaming velocity like guys with 24"-26" barrel. I can get mine up over 2800 FPS but I quit trying to push them faster the accuracy is phenomenal.
Only real reason I don't shoot them all the time is for having a 18.5" barrel I don't get the screaming velocity like guys with 24"-26" barrel. I can get mine up over 2800 FPS but I quit trying to push them faster the accuracy is phenomenal.
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He's got the hard facts and it's kind of a no brainer 155 bullets once you build a load is hard to beat.
Cant argue with the data.
I shot them both, but unless you can push them over 2900 fps, your actual BC will vary. I was shooting out of a 20" tube and did not have a chrony, my calcs put me at at approx 2830 fps with 46 varget, compared to a 178 Amax at 2650 fps. The 155 shot flatter, but the 178 faired better in the wind.
Out of a 30-06, the trajectory of the 155 Scenar mimics a 162 Amax out of my 7mm mag to 700Y. Its just like magic.
I shot them both, but unless you can push them over 2900 fps, your actual BC will vary. I was shooting out of a 20" tube and did not have a chrony, my calcs put me at at approx 2830 fps with 46 varget, compared to a 178 Amax at 2650 fps. The 155 shot flatter, but the 178 faired better in the wind.
Out of a 30-06, the trajectory of the 155 Scenar mimics a 162 Amax out of my 7mm mag to 700Y. Its just like magic.
If cost is no option then go 155. Otherwise 175 SMK or 178Amax is your answer. Dont discount the 168 Amax as well depending on your usage.
Thanks for the info. I use the Accuracy First Wiz Wheel so I'll have to order another wheel for the different load. The flatter trajectory definitely makes a case for the smaller bullet.
I'm a huge AMAX fan shoot 105 AMAX in my 6mm AI, 168 and 178 AMAX in my .308, 80gr AMAX in .223 and 208 AMAX in my .300 Win. Good luck with all of them and they all have a high BC. They also make a 155 AMAX.
Assuming both the 155 gr Scenar and 175 gr Matchking can be made to shoot equally well out of your rifle, the simplest answer for these two bullets is that velocity is going to win the day, both in drop and wind resistance. No ballistic calculations are really necessary in this particular example because the BCs are very close (0.236 vs 0.243 G7 BCs). With BCs that close, the Scenar is going to outperform the Matchking because it can realistically be pushed in the neighborhood of 200 fps faster, regardless of barrel length. The same would be true for the Berger 155.5 Fullbore (G7 BC 0.237), or any other 155 gr bullet with a BC that is within 2-3% of the Scenar. When the BCs are close, higher velocity = better performance.
However, when you pick a bullet with a markedly better BC for comparison, it's a much different story. At 0.236 and 0.243, respectively, neither the Scenar nor the Matchking have particularly high BCs. In the case of the Scenar, it's a lighter and smaller 155 gr bullet, so the lower BC is not a design issue, it simply comes with the territory. In the case of the heavier 175 Matchking, it's an older design that is simply not as ballistically efficient as some of the newer high BC designs in that weight range that are currently available. Not trying to disrespect the Matchking, it's been a workhorse and proven performer in 30 cal shooting for a long time. But if you compare the 155 Scenar at 2900 fps against something like the Berger 168 gr Hybrid (G7 BC of 0.266) at 2800 fps, then you start to see what a heavier high BC bullet can buy you in terms of performance at long range. In this example, although the drop is a bit more, the Berger 168 would enjoy a 1" less drift per mph wind advantage over the Scenar at 1000 yd. I personally think wind resistance is much more important than drop. Further, both those velocities are readily achievable from rifles with barrels in the 24-26" range. Bottom line is that once the BC of one bullet exceeds that of another by something like 7-9%, it will generally start to outperform the lower BC bullet under realistic conditions without having to push it to unsafe velocities.
In terms of some guidelines as to which bullet to pick, I would suggest the following:
1) First and foremost, can the bullet be made to shoot well out of a given rifle? If not, it's not worth the trouble no matter what the BC is.
2) How difficult is it to find a good load for it? Some bullets are easy to load, some require much more effort to load consistently (for example, VLDs can sometimes be pretty finicky because of the secant ogive). Part of that is also dependent on how the rifle chamber was cut. Knowing your chamber specs and what bullet they're optimal for is really useful info for selecting the right bullet.
3) Does it need to be loaded to mag length? Some of the really high BC bullets have very long bearing surfaces and noses. Loading these to mag length may take away much of their ballistic advantage if they can't be pushed to a sufficient velocity when case powder capacity becomes limited.
4) Finally (and possibly the most important), are they readily available in the current market? How much do they cost? If you can't find the bullet and/or the right powder necessary to push it when you need them, it really doesn't matter too much how good the performance is. If you can't get it, you can't shoot it.
There are a lot of good choices in 30 cal out there and the good news is that with a little patience and diligence, it's usually possible (even in the current climate) to find what you're after.
However, when you pick a bullet with a markedly better BC for comparison, it's a much different story. At 0.236 and 0.243, respectively, neither the Scenar nor the Matchking have particularly high BCs. In the case of the Scenar, it's a lighter and smaller 155 gr bullet, so the lower BC is not a design issue, it simply comes with the territory. In the case of the heavier 175 Matchking, it's an older design that is simply not as ballistically efficient as some of the newer high BC designs in that weight range that are currently available. Not trying to disrespect the Matchking, it's been a workhorse and proven performer in 30 cal shooting for a long time. But if you compare the 155 Scenar at 2900 fps against something like the Berger 168 gr Hybrid (G7 BC of 0.266) at 2800 fps, then you start to see what a heavier high BC bullet can buy you in terms of performance at long range. In this example, although the drop is a bit more, the Berger 168 would enjoy a 1" less drift per mph wind advantage over the Scenar at 1000 yd. I personally think wind resistance is much more important than drop. Further, both those velocities are readily achievable from rifles with barrels in the 24-26" range. Bottom line is that once the BC of one bullet exceeds that of another by something like 7-9%, it will generally start to outperform the lower BC bullet under realistic conditions without having to push it to unsafe velocities.
In terms of some guidelines as to which bullet to pick, I would suggest the following:
1) First and foremost, can the bullet be made to shoot well out of a given rifle? If not, it's not worth the trouble no matter what the BC is.
2) How difficult is it to find a good load for it? Some bullets are easy to load, some require much more effort to load consistently (for example, VLDs can sometimes be pretty finicky because of the secant ogive). Part of that is also dependent on how the rifle chamber was cut. Knowing your chamber specs and what bullet they're optimal for is really useful info for selecting the right bullet.
3) Does it need to be loaded to mag length? Some of the really high BC bullets have very long bearing surfaces and noses. Loading these to mag length may take away much of their ballistic advantage if they can't be pushed to a sufficient velocity when case powder capacity becomes limited.
4) Finally (and possibly the most important), are they readily available in the current market? How much do they cost? If you can't find the bullet and/or the right powder necessary to push it when you need them, it really doesn't matter too much how good the performance is. If you can't get it, you can't shoot it.
There are a lot of good choices in 30 cal out there and the good news is that with a little patience and diligence, it's usually possible (even in the current climate) to find what you're after.
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155 Scenars really shine if you can get them in the 2900-3000fps range and they transition well in the transonic window. That said, some rifles just don't seem to like them whereas I haven't come across a rifle that didn't shoot 175SMK like a champ.
Southwest Ammo will reload there brass in 155 Scenar and it's only a couple of cents more than the 175s so that's a pretty good deal. Where are you guys getting your AMAX ammo from?
Sounds like I should test them out in my rifle before making a big purchase.
I have shot a lot of both. The 155s are very accurate, but as Dog says you have to get them moving with lots of powder if you want to see consistent results out to 1k. If you don't want to worry about it as much the 175 is going to be more consistent. But this is also dependent on what your particular barrel likes. I have been lucky, most of my 308's have liked both particular bullets.
The question arises if you have an autoloading gun or a magazine fed rifle that needs the ammo to be a specific length. OAL will play a role in what round you may choose and the scenars are long, especially if your doing custom loads and pushing the projectile closer to the lands and groves. I have had issues with AI magazines and scenars.
All this said if I had to shoot to 500-999y I would probably use 155 scenars, the 155 is awesome in that zone. If I was pushing past that then 175s.
Same here shot them both. I honestly prefer the 175gr bullets though. I never ran SMKs i ran berger BT LRs which have a G7 of .264 and am now running Hornady 178s which have an acclaimed G1 of .530 i can't remember what the G7 is (.259?). Either way i've always chosen higher BC rather than velocity sure they go hand in hand but windage goes to the 175 & 178s once you get out there (of the ones i've shot anyway). Though it depends on the consistency of velocity of the 155s over the 175s as mentioned. It will vary from rifle to rifle say your gun groups best with 175s/178s @ 2550 but does just as well with 155s at 2900. Well no comparison there as the difference between velocity is too great.
I always loved this article by Bryan Litz http://www.appliedballisticsllc.com/index_files/30cal_fullVersion.pdf Really addresses the .30 caliber bullet and how it's real heavyweights with proper BCs are the much heavier bullets. Which by then require too much powder/barrel life to run. Admittedly i've always wanted to have a .30-.338 or .300RUM to try and push some 220gr-240gr SMKs out of a 26-28" tube and see what i could get. Somewhere along the lines of a poor man's .338LM.
Always followed this analogy: German Salazar put it aptly: “Muzzle velocity is a depreciating asset, not unlike a new car, but BC, like diamonds, is forever.”
Though at this point it's just preference really both will perform. I just prefer/like the heavier pills. Hell they both shot out of my rifle.
11 shot group of 155gr scenars
5 shot group with my Hornady 178s
155 scenars are awesome. But I still stick with 2 bullets for my 4 308's 168 AMAX and 175 SMK. I can have others but I get consistency from both not only on the range but at the checkout line too. That's more important to me. If I cant learn a bullet I don't want it.
As a rule, the better your barrel's twist is matched to the bullet, the better your accuracy will be. I've compared the best 100 yard loads between the Scenars versus 175 Matchkings and 178 AMAX's from my 10 twist barrels... and at longer ranges, the heavier bullets still shoot better. A bit more drift (maybe)... more elevation needed to get to target (definitely), but the heavies just work better from the 10 twists. With a 12 twist, it may be a toss up.
I'm shooting an Auto so it sounds like the Scenars may not even fit into a PMAG. Thanks for the great advice.
Mine were loaded to 2.800" a COAL of 2.8 won't fit in a PMAG for an AR-10?
When I first got my GAP 308, I broke in the barrel and worked up loads with both the 175 smk, and the 155 scenar. Went to the range and ran them both out to 1k. The 155's almost felt like they turned the 308 into a different caliber. There really was no comparison. I had some crazy groups with them. I have since sent it in and it's getting a makeover to 6.5 SAUM. This is just my opinion though, but seems most agree.
Alan
Alan
One thing I didn't see mentioned is the recoil difference, shooting 60 -70 rounds of 155 to me is a lot less pounding then the 175's. Shot 185 Bergers one season of F-class and got some of the best scores I've had, but the recoil turned me off them and went back to the 155's.
I haven't shot the 155. But my gum loves the 175smk. 26" tube with a 1:12 twist
The best I could do out of my factory 308’s and a custom with the scenar 155 was in the neighborhood 2850fps without pushing into the unknown. While 175’s were easy getting to near 2700fps and in one rifle a little more. The only advantage I saw with the velocities I could obtain was bullet drop. Since I have a laser and I am not shooting unknown distances at matches that advantage doesn’t mean as much. Wind drift does and 175’s were working better there for me. Now I am exploring the 168 berger hybrid’s that perform better than both of the others in the wind. The berger classic hunter (which is a hybrid design) has a little higher BC .496g1 to the 175’s .475g1 and the scenars .462 and the target hybrid, which I have yet to use, is .519g1 which would be a significant advantage to all of them.
So for me it boils down to cost. I use 168 & 178 a-max when a deal can’t be had on 175’s and when the task is important to send the very best (my opinion at the moment for a dual purpose target and hunting bullet) I send the 168 berger classic hunter.
So for me it boils down to cost. I use 168 & 178 a-max when a deal can’t be had on 175’s and when the task is important to send the very best (my opinion at the moment for a dual purpose target and hunting bullet) I send the 168 berger classic hunter.
Niles did you ever get the 168 hybrids to shoot? I ended up selling mine because i was switching to a cheaper load all together.
If cost a concern it's hard to argue with SMKs or hornady's new HPBT match. The Hornadys usually have a tad higher BC than the SMKs as well. The highest BC bullet that i've ran was berger 175 BT LR (.515G1/.264G7) they performed great just hard to keep rolling at 50$/100ct.
If cost a concern it's hard to argue with SMKs or hornady's new HPBT match. The Hornadys usually have a tad higher BC than the SMKs as well. The highest BC bullet that i've ran was berger 175 BT LR (.515G1/.264G7) they performed great just hard to keep rolling at 50$/100ct.
with my factory Sako TRG 22:
175 SMK at 2730
155 scenar at just over 2900.
I prefer the 175's myself. inside 500 yds the 155's are lasers but way out there at 1000-1100 I had better luck with the 175's.
CJG
175 SMK at 2730
155 scenar at just over 2900.
I prefer the 175's myself. inside 500 yds the 155's are lasers but way out there at 1000-1100 I had better luck with the 175's.
CJG
