Your experience with Sierra .308 in 180gr & 190gr Match Kings?

VaniB

New member
Your experience with Sierra .308 Match Kings in 180gr & 190gr?

I'm trying to find the most accurate bullet for my 24" DPMS 308 LR rifle. So far I've found that the 175 Sierra Match Kings are more accurate then the 178 gr Amax or the 168 gr Match King.

Should I believe the 180 and 190's might be even better then the 175s? Seems I hear alot about the 175's being good, but not much mentioned about the 180's or 190's. Don't forget too that I am also limited to how far I can seat out the bullet before it does not fit in the magazine. So, I'm not sure if these longer bullets and their ogive will even load properly into these shorter overall length hand loads.
 
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The 190SMK in .308 is a great load with the right powder. I have used VV N550 and easily reached 2700fps. I would think that Alliant's new RL17 would also be a good powder.

Don
 
I would think that Alliant's new RL17 would also be a good powder.
Not in an AR-10. Semiauto rifle.
Stick with medium burn rate powders - something in the range between IMR-3031 and 4064 is acceptable for an AR-10. Faster, and the rifle doesn't cycle. Slower, and the rifle tears rims off the case instead of extracting properly. There are lots of decent powders in this burn range.

And if you're shooting less than 300 yards, stick with lightweight (sub-160 grain) flat based bullets. It is hard to beat the accuracy of such projectiles.
 
This thread sat for 7 days with no reply. I had a lot of time to read, sift through, and decifer all kinds of info in the searches.

JUST IN CASE anybody else cares to know:

The problem is that whatever works in a Remington or Savage bolt action often WILL NOT WORK the same in a semi-auto. If the .308 cartridge is made to an OAL of 2.04 to fit in a magazine, then there will be a lengthy jump for the bullet to reach the lands.

The general consenus is that the 155gr Sierra match kings, or the 155 grain Lapua Scenar bullets are the best candidates for jumping the gap into the barrel and delivering accuracy at shorter ranges. As for best accuracy in longer length bullets, it seems that the 175grain SMK has good potential, and the 168 has proved worthy too. I was informed that the 6 shot 9/16" group I got at 50 yards with the 175SMK might even get tighter at 100 yards due to a phenomena called epicyclic swerve

Semi-auto rifle or bolt action, it seems that the 180SMK is a dog. Haven't found anybody that likes it.

I also have an old May 2004 edition of the American Rifleman about the 24" DPMS which reports exceptional groups with the 167 grain scenar.

Rather then to delete my thread and sulk (like others have done) after 7 days of hearing nothing, I proceeded to do my own wash and sift through dozens of posts on numerous websights for the answer.
 
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VaniB,

Forgot you are dealing with an autoloader. With such a platform constraint, forget about the 190SMK.

Don
 
The general consenus is that the 155gr Sierra match kings, or the 155 grain Lapua Scenar bullets are the best candidates for jumping the gap into the barrel and delivering accuracy at shorter ranges. As for best accuracy in longer length bullets, it seems that the 175grain SMK has good potential, and the 168 has proved worthy too. I was informed that the 6 shot 9/16" group I got at 50 yards with the 175SMK might even get tighter at 100 yards due to a phenomena called epicyclic swerve

"Consensus" might be a starting point, but you cannot know what load your rifle will like the best, for the shooting contemplated, until you try various loads. For all-round simplicity, I think the SMK 175 is pretty good. Works well in MY rifles, at short and longer (to 1,000y) range. But your mileage may vary.

Try the Scenar. Try the 155 Nosler maybe, and the 155 AMAX. Try some Berger pills. Berger is firmly commited to making excellent products and supporting them, and they have quite a stable of top-level shooters and industry experts working for them.

The experimentation, and website searching, is supposed to be part of the fun. As to 50y groups, I would not waste my time at that distance with any centerfire rifle. Maybe one shot to prove the bore sighting was close enough, but no more. Save 50y for your .22 rimfire. :)
 
......The experimentation, and website searching, is supposed to be part of the fun. As to 50y groups, I would not waste my time at that distance with any centerfire rifle. Maybe one shot to prove the bore sighting was close enough, but no more. Save 50y for your .22 rimfire. :)



Do you test a brand new scoped rifle and hand-loads right off the bat at the 100 yard range? I always start at the 50 yard range. The idea is to test the initial sighting-in of the rifle, and to check the potential of the different 6 or 7 of the new hand-loads you brewed up. If the process is done properly, then I am also doing a day long bore preperation process at the same time too. This requires me to break the AR10 open and remove the bolt assembly after each of the first 30 shots. (YES, I do mean "a day long process")There is no reason to do any of this at 100 yards. If you prefer the 100 yard range...then I will simply say "to each his own".

So far I have bought 5 boxes of bullets from 2 different distributors (at $30 to $38 a pop, plus shipping).The majority of these trials resulting in 5 or 10 bullets from each box being fired, and the other 90-95 bullets being disqualified for poor grouping and temporatilly abandoned to the closet until maybe I discover another load to experiment with. If I find that one bullet delivers the kind of results that I am looking for, then normally the other 4 boxes get disqualified and forgotten about. As is often the case, I own no other rifle to utilize these other "disqualified" bullets.

How many of you shooters out there will go out and buy over $200 in bullets during a two week period like I did, for initial testing? I'll bet some of you do, but most of you DON'T. You have to draw a line somewhere.

My plan is that if I can't get one of these 5 quality bullets to group 3/4 MOA, then I'll rebarrel.
 
Welcome to the world of reloading - buying boxes of expensive bullets, only use a few. If it is any consolation, the .308 Win. is popular enough that you will almost certainly use those bullets in future tests.
A few questions about your rifle; Is the rifling rate 1/10 or 1/12, a faster twist will favor heavier bullets. Is the barrel standard production or premium, the production barrel may be a good barrel, but the tool marks may take a while to disappear, a hand lapped premium barrel will be good to go immediately. I have also read that the DPMS rifles take a while to break in. I also agree that 100 yds would give a better idea of the bullets performance, and shooting through a chronograph would double the data for your tests.
I have a Fulton Armory lower with a DPMS upper with a Shilen Select match barrel, since DPMS makes the lowers for Fulton, it is basically a DPMS rifle. I tried all the match bullets available in weights from 155grs. to 175grs. I settled on the 175 gr. SMK and Varget powder. If you factor the number of suitable bullets, powders, cases, primers, and seating depths available, you will see that you could spend the rest of your life, and certainly the barrel's life just testing. I believe that in a magazine fed rifle that requires a long bullet jump to the lands, the longer bearing surface of the 175 SMK prevents the bullet from tilting before engaging the rifling.
On another note, this really isn't the best forum for semi auto questions, there are too few participants and they only care about benchrest problems. You should post at The High Road or The Firing Line, and ask what luck other shooters have had with the same set up as your's. Good luck.
 
Do you test a brand new scoped rifle and hand-loads right off the bat at the 100 yard range?

Yes, or farther. And chances are that the bore prep process you mention is a complete waste of time.

Based on some of your posts, you march to the beat of a different drum, which is your prerogative.

Some of us use stocks that are already made and proven in competition, and some of us want something custom. Some of us buy hundreds and hundreds of dollars in bullets to work up loads (and later sell those which aren't the keepers), and some of us buy a couple hundred bucks worth, and others might buy a couple of boxes or a few bullets at a time.

That's what makes it a horse race.
 
Yes, or farther. And chances are that the bore prep process you mention is a complete waste of time.

Based on some of your posts, you march to the beat of a different drum, which is your prerogative.

Some of us use stocks that are already made and proven in competition, and some of us want something custom. Some of us buy hundreds and hundreds of dollars in bullets to work up loads (and later sell those which aren't the keepers), and some of us buy a couple hundred bucks worth, and others might buy a couple of boxes or a few bullets at a time.

That's what makes it a horse race.

Bill, other then the fact that many competitors singly feed each round into their AR chamber, but I don't because I'm not engaged in competition, (so I prefer to use the magazine as the semi-auto weapon it was was designed as) I'm surprised that I might be much different then other folks who shoot for accuracy. And, why shoot a new test load at a longer 100 yard distance.....the longer distance being a factor which tests your skill and leaves you more vulnerable to wind conditions, when all you're trying to do is check the potential accuracy of the hand load?

I have found (not surprisingly)that when testing hand loads for the first time at the 50 yard range which produced 1/2" tight clusters, this same hand load also produced tight clusters at the 100 yard range. At the same token, the other handload that produced 3/4" or 1" groups at the 50 yard range, did not suddenly get tighter at the 100 yard range so that it outshot the handload that gave me the 1/2" groups) I've never fired at longer ranges, so maybe 600-1000 yard shooting works differently.(?)....and this is perhaps why my 50 yard sight-in procedure isn't of any use to you. (?)

I really didn't think that my barrel prep regimen is so odd. It is recommended by the custom barrel makers too....even if directed in slightly different variations. (one particular manufacturer might recommend cleaning every 3rd shot after the frst 20, while I prefer to clean after every shot up to 30 shots) I believe this is escpecially suited for factory barrels like the DPMS 308 that don't have the ultra smooth bore and benefit of factory hand lapping.

I can't debate with you that some competitors will spend hundreds of dollars in bullets and other stuff seeking the ultimate winning formula. I draw the line at $150-$200 in bullets. Normaly, after studying dozens of threads, I can find a recommended winner. That is; if 3 guys say that Varget and 175SMK's work in their DPMS, it's a good gamble that some sought of variation with this powder and bullet will also work in my rifle. If not, then I try Varget and a 155 Lapua bullet. If that still doesn't work then I try still two more different bullets with 2 more differen't powders as mentioned by others. I would hope that I would find one bullet-powder combination out of the 5 which I bought, might produce satisfactory results. If not, I will try a different scope, or investigate other causes. Perhaps, I will buy a new custom barrel and dump the factory barrel.

I don't know where you are able to sell your open box of 91 bullets. Or do you know of some kind of web sight and clearing house to dump unwanted bullets? I'm not sure if you placed them on your bench during a match with a "for sale" sign, anybody would pay it much attention and you can actually get rid of it that way. I don't attend matches but know I've never witnessed that kind of activity at the public range. I know that if I paid $35 for it new, I would have to sell it for about $15-20 to keep anybody's interest.(....sought of garage sale priced.) Add shipping costs for web sales, and nobody would be interested. Is the time and trouble even worth it? I suppose it makes sense just to hold onto these excess boxes of bullets in case "I may be able to use it some day". I have rows of bullets in boxes stacked 4 and 5 boxes high on my shelf that I bought 30 years ago and up to yesterday which are still waiting for that "some day". I just prefer NOT to have to add more to this collection.

No debate here. It's more like you say....just a different "horse race" for ever individual. It's just that I am puzzled how different your sight-in procedure is, or your barrel prep regimen (or lack of it) can be. I assume that I am conversing with a serious match competitor and very experienced rifleman? Thus, it makes me scratch my head and wonder if I have it all wrong.
 
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