The 1:12 shoots 175gr bullets extremely accurately. There is 0 need for a faster twist IMO

 

This has been my experience as well. I have taken my 16" barreled 17 out to 1000 yards with excellent results.

 

How well do you think my Scar 17 will shoot these various choices of ammo others in my family like in their bolt guns?

Sellier & Ballot 190 grain HPBT .533 BC:
Product detail 308 WIN. (V341132) ? Sellier & Bellot

Hornady 178 grain ELD-X .535 BC:
Hornady Manufacturing Company :: Ammunition :: Rifle :: Choose by Caliber :: 308 Winchester :: 308 Win 178 gr ELD-X™ Precision Hunter™

...

 

I've had GREAT results with 175 M118LR. I've had terrible results with 180 grain hunting loads from 3 or 4 different manufactures. If you stick to a match/target load, 175s will work great in the SCAR 17.

Interesting info: 147 grains are faster at 100 yards, but 175 grain stays supersonic past 900 yards (980 I think) where the 147 grain goes subsonic in the 840 yard range. This is mainly due to the 175 having a better shape for long distance. Numbers may not be exact, bit the 175 is better for long range.

Edit note: data is probably for 24 inch barrels, but the 175 will still perform better at longer ranges than the 147s.

 

I'm sorry, I have no answers for you, as I am just a lurker in the SCAR world. But I wanted to tell you I really like how you defined the problem. Or lack thereof. And your logic behind solving it. Or the lack thereof. :biggrin:

 

I'm thinking that a 16" that is as close of a copy of the FN Scar 17 barrel in every way that can be achieved except that it has a faster twist of 1:11 or 1:10 for the purpose of being optimized for shooting 175 grain and up projectiles would, dare I say it, be an improvement for civilian enthusiasts in that it would arguably improve accuracy though more accurate projectiles without adding weight or upsetting the awesome balance of the Scar 17.

Your thoughts?

The SCAR 17S, SCAR 17, Mk17 & Mk20 all share the same 1:12 rate of twist.

They all shoot M118LR and Mk316 Mod0 exceedingly accurate from short distance to long range. Heavier weight projectiles will reduce launch velocity, increase recoil forces imparted on the shooter, and will not outperform the lighter aforementioned projectiles when fired from the SCAR 762X51 platform.

A faster rate of twist would not be conducive to accuracy at longer ranges, when loading projectiles heavier than the 175 grain SMK projectile as muzzle velocity drops to a level which is unrealistic in offering better performance.

Some people argue for a heavier profile barrel. Some people desire longer barrels for increased range. Some people want a 13" barrel. Then you get THAT one guy who wants to neuter the weapon by shoving a sh*tty steel cased AK cartridge up the SCAR's *ss like an anal laxative, reducing the weapon's effectiveness at every possible level.

People want. That's for sure. Don't be THAT guy. :th_thumbsup:

 

Haha... Thanks. THAT guy always gets all of the attention and is a prime motivating force for both good and bad. Bad that he leads so many of the ignorant astray, and good that he forces those with real knowledge to educate those who seek to overcome their ignorance and position themselves on higher ground.

My question arose from a recent family firearms discussion that paralleled Einstein's scientific quest for the "unified field theory."

It began with how successful my family came together after the 2012 ammunition drought to obtain ample supplies of .22LR where we all lacked sufficient quantities to just go plinking anytime we felt like it. Prior to that most recent ammunition drought, we would often stop on the way to range to buy ammo or we would buy the ammo from the range when we checked in. .22LR was cheap and so plentiful that we just took it for granted it would be on the shelf any particular day we might on the spur of the moment decide it was a good day to go shooting. .22LR has an important role in that anyone who can shoot can shoot it, from grandma to to grandkids, in pistols, bolt rifles and semi-autos. And $20 used to buy enough .22LR to consume an hour or so in a lane.

Our .22LR solution was to buy a considerable portion of a pallet of 36 grain copper plated hollow point .22LR that would perform adequately in all the pistols and rifles and divide it up so that each of us had a couple of bricks of it. This served to reduce the cost per round, but more importantly, it reduced any one individuals cash outlay and demand for storage space. Any one of us could have lost our own couple of bricks of .22LR to fire, flood, theft or whatever, but because everyone in my family had a reasonable personal supply distributed all over the State of Georgia, as a family we could continue to shoot .22LR without the need to scour the shelves and the internets and pay exorbitantly inflated prices for it.

5.56 was pretty much the same way in that everyone in my family owns some kind of .22LR and some kind of 5.56, except there was already an abundance 5.56 on hand in my family so there was no need to acquire and divide a bulk purchase.

Most other rifle calibers in my family are not owned by more than one or two of us. I gave up on shooting my .300 Blk during the ammo drought just as other family members suspended shooting their less mainstream and less universal calibers. There is no family "solution" for these calibers because no one else in my family likes .300 Blk and I don't like rimmed centerfire calibers, 30-06 and some other classics, so we will never agree on any common needs there, except maybe for .308.

I'm the .308 newbie in the family as others have been hunting with it in bolt guns for years. I don't own a .308 bolt gun and frankly I don't need to when there are several I can borrow. But I have been shooting more .308 than any of them since I got my Scar 17. And that is what "triggered" this discussion (if you can pardon the pun) of whether we could decide on a .308 ammo selection that could perform adequately enough that at least several of us could agree on it for use in these different platforms that we could justify a bulk purchase to divide up

I have only shot 147's and 168's in my Scar. Somewhere between 1,100 and 1,200 rounds IIRC. And I will continue shooting these loads for at least the next year or two because the ammo drought taught me to plan ahead... well ahead. I have saved maybe 2/3 of that brass and plan to reload someday when I get the time to invest in learning that process.

My 147's and 168's are a big step down for those who run much heavier weight hunting bullets in bolt rifles. Yes, it is better to over stabilize a lighter projectile than to under stabilize a heavier one. But none of them are ever going to agree to downgrade their ammo preference to these choices unless they are starving to death and that is all that is available to hunt deer with. Their problem is that would probably be the case in our family if it happened today because their 20 round box or box and a half of .308 ain't gonna last forever. Even in a seldom shot bolt gun.

So this is a consideration as I start buying .308 ammo this year for shooting starting around 2017 or 2018 when I start running low on what I already have. It would be nice if I can find a selection that works as good or better in my Scar 17 than the 147's and the 168's and also will perform adequately in .308 bolt guns. I do plan to test several brands and choices of 175's with the idea of moving in that direction. That has got to be an improvement for both requirements.

But I doubt I could convince anyone who swears by hunting with 180 grains and up to lighten up and split a bulk quantity .308 purchase with me that we both can use.

Which is what gave me cause to ponder the idea of a barrel for my Scar 17 with more twist so that I could move up in projectile weight to meet them rather than forcing them to move down in projectile weight to meet me. I did not consider the gain in recoil that I surely will not like, nor did I realize that a faster twist 16" barrel will cause heavier projectiles to loose considerably more velocity than I had initially "assumed" thereby negating any gains and perhaps causing a loss of accuracy. I get your point that we are on the 1:12 twist for a reason and if a faster twist were better, FN would not be using the 1:12.

In a perfect world, I want one rifle that does everything and one size of ammunition that does everything. And I want world peace too. That's the just idealist daydreamer in me. But I also realize and accept that while these are worthy goals, it is unrealistic to actually expect any of these wishes to come true any time soon.

It is just as important to me to learn why something does not work or why it is a bad idea as it is to learn why something does work or is a good idea.

 

The 308/7.62X51 round loses a lot of it's ballistic performance above a 180 grain projectile
Most 1:12 barrels handle up to 180 grain accurately
Where was I going with this ?
They didn't pick the twist rate out of thin air
130-175 grain, we're GTG

 

"I have not failed. I've just found 10,000 ways that won't work."
-Thomas Edison

 

I see where you are coming from.
All my family uses 308 for hunting
150/165 is adequate for all the big game we hunt, which is mostly deer and black bear
I personally think 180 gr is too heavy for deer, but fine for elk, moose, bear
We recently did some testing and purchased a bulk supply of ADI ammo with 165 Sierra gameking bullets.
Works decent in all the rifles and a few love it
I also want the 308 to be compatible with all the 308 semi rifles out there, which also eliminates the heavy weight loads
BTW: I have a Rem 700VS 308 1:12 that shoots my Sierra 180 MK reloads into small groups
Good luck on your project

 

Most 300WM hinting cartridges use 180 grains. It's a bit heavy for 308 hunting IMO, bit you know how opinions go

 

First off, excellent thread mityno1, very good read, and you seem to have excellent reasoning in this quest for the perfect ammo solution in "group" usage amongst various types of rifles. A common bullet to share among all of you could be tough it seems. I don't envy you having to try to convince someone to try a different bullet weigh out. When one finds a great bullet match they like with their rifle that is affordable and performs well, it's usually a keeper for life lol. For myself, I'm pretty much just a hobbyist too. I haven't gone on an extended camping trip in Utah for a couple years now...was laid off from a 16 yr job, and the new job threw me off my game a bit...but I digress. My main usage and desire for a rifle is kind of a do all things with one gun too. I grew up using lever and bolt guns mostly in Texas. Hardly a deer hunting trip went by without scoring a wild pig or two. I've never been charged by a wild animal, but have heard the who knows how much embellished stories. And I've seen a couple packs of wild pigs while solo in the woods, while nothing exciting happened, it is what made me go to the world of 308 battle rifles, and it's the world I will stay in it seems. My shooting fun is most enjoyed at rapid firing, or at least as fast as I can accurately at I'd say man sized targets at like 25 to 75 yards out. I enjoy ranges out to 200 yards too, but rapid firing close in is just fun to me. I'm not real picky about bullet weight, as for self defense inside a hundred yards, anything will really work. For long distance fun, yes the optimum load is needed. I laughed when I saw the "THAT" guy mentioned, that's me I think lol. I worry about barrel overheating while going nuts shooting at close ranges, although in real life the 17's pencil barrel will surely take care of anything I need. But I feel that heat from the barrel after a three or four mags of quick shooting, and it makes me desire a heavier profile barrel. Now I'm certainly not expecting the military to ask for a barrel designed for my needs, but the SCAR 17 has become a popular rifle, and aftermarket companies are flourishing with stuff for us. My dream barrel for the SCAR 17, and 16 for that matter, would be an 18 inch medium profiled chrome lined barrel. Twist rate not a big deal, but I'd make it one in eleven twist if given my choice. I'll get a 20 inch barrel no doubt when it comes out. I doubt I'll chop it to 18 inches. I'd be VERY happy with 20 inch too. I do wonder if longer barrels in same pencil weight profile will shoot less accurately when heated up though. It seems like more flex would occur. But I don't think there is anything wrong with a hobbyist looking for a barrel that suits his specific wants. What a gun enthusiast wants may not be what's best for everyone, but nothing wrong with having fun trying different things. That's what's so cool about the SCAR, it's a rifle everyone can love...from the serious military applications, to the range time target shooters, the hunters, and the SHTF preppers. The military has chosen what works best for them, and it works well for me too. But as I said, the aftermarket world of companies seem to be liking the SCAR design too. It offers something new besides the flooded market of the AR platform to design for. So the SCAR and it's shooters have a bright future I think.