.308 Win enigma

[Tom68]

So I've heard, if a rifle chambered in .308 Win that won't group with either Federal GMM or Hornady Match, then it's a lost cause. Or, at least words to that effect. Well, I have a rifle that breaks those rules, and has me completely stumped.

I bought a Mossberg ATR100 youth model for my son last winter. He had shot some Federal Fusion in 7mm-08 in the past, and had a particular affinity towards it, so with no time to work up a handload, I bought a few boxes to check it out, and dial in the scope for hunting whitetails. And...I was very surprised that this $319 package combo was printing 0.5" 3-shot groups with that particular cartridge.

My initial thought was that this particular rifle must be an exceptional example of a Mossberg budget gun, and that it may have tremendous potential. So, I thought, I could develop some really good loads for it using my experience and the vast array of compenents to arrive at the perfect soultion. (BTW, my experience is somewhere in the neighborhood of 3k handloaded rounds...not exactly a master yet.)

When I started working handloads for it this spring, I started with the bullet that I'd prefer...a 150 grain Nosler ballistic tip. I've tried Varget, IMR 4350, WC 846, and a few others... and none printed better than 2" for 5-shot groups at 100 yds. Then, I thought of the "rule" regarding the 168 grain offerings from federal (GMM) and Hornady...and the result was just as dismal as any handload I had assembled.

Thinking that maybe I had encountered a fluke "great" grouping from the initial Federal Fusion outing, I decided to try it again...and in three separate 3-shot groups, I averaged well under one inch. So much for the Match rule, huh?

So, I've decided to put this one aside, and let the boy hunt with the Fusions. I've got other projects to work on... another 7mm-08 that I've yet to shoot, plus two Mil-surp 8x57's an two .30/06 that I've not perfected; but, I hate to admit, that this Mossberg .308 has me beaten...for now!

[chiefr]

Not surprised at all of the Mossberg bolt gun. Although I do not own one, I have observed some remarkable groups with these as well as the Marlins at the range.

[deedude]

I have one in 30-06, and I have a handload with a 165gr nosler B-tip launched by H. Superformance. Group posted here. Mine also showed an affinity for fusions similar to yours.

Maybe your rifle will behave similarly.

[PawPaw]

So I've heard, if a rifle chambered in .308 Win that won't group with either Federal GMM or Hornady Match, then it's a lost cause

I bought a Mossberg ATR100 youth model for my son last winter. He had shot some Federal Fusion in 7mm-08 in the past, and had a particular affinity towards it

Please tell me that you're not shooting .308s through a 7mm-08?

On the other hand, I recently bought 500 pulled bullets that were billed as Federal Fusion bullets. I can't get them to group in anything. I've tried several .308 rifles and done ladder tests with them. Nothing better than 2" at 100 yards. I'm going to see if my .30-06 likes them, but I have no great expectation. I've heard great things about Federal Fusion, but so far my results are far from promising.

[Tom68]

no...not shooting .308 in a 7mm-08! Just referenced that he had used fusions in the other caliber and that he preferred them for some reason... so we tried them in the new .308. I should have made that reference a little more clear in my OP.

Anyway, I'm still puzzled.

[Mike / Tx]

I have a little Ruger COmpact, that is very similar to your Mossberg's preferred diet.

THe year I purchased it, I had little time to work on loads before hunting season was upon me. I found some Remington CL's on sale at a local store for about $10 per box and figured they would do fine for my intended use.

Well after the season was over I had only managed to shoot about half the box in sighting in and 2-3 more rounds on hogs at ranges less than 50yds. I decided to "work" up my own loads. Just like your experience, I have not yet been able to actually find a load which will top the accuracy of the factory cheap ol Core Lokt's. They will easily shoot around 1-1.5" at 100yds and with the little 1.5x6 power scope thats about as well as I can do with it anyway.

My best effort with handloads, aside from some reduced loads for my grandson which DO shoot 1" @ 50yds, has only come close to breaking 2" on a rare occasion. So I simply stocked up on the Remington factory stuff when I found it on sale and figured why fight it. I have also shot the Fusion as well , and it actually does shoot better than the Remington in all three, the 150gr 165gr, and 180gr loads.

Sometimes you just have to accept a loss once in a while I guess. LOL At least it's nice to know the thing WILL shoot, even if I am not the one building the ammo.

[WWWJD]

Are you ladder testing your loads? My .308 will shoot .3moa when the load's dialed in with the 168 SMK. I can also make it shoot 2" groups with the same bullet with the wrong powder charge. Judging by my limited experience, it doesn't take much of a change in charge weight to have a dramatic effect.

[Tom68]

WWWJD, I'm assembling 5-shot groups, starting with min load and working up in graduated increments (generally 1% of max)... Generally works out to about 7-10 groups. I generally write off the sets with no obvious potential, and then assemble another set of 5-shot groups centered around the ones that look good, normally in 0.5% increments.

I used to chrono while shooting for groups, but I've recently abandoned that idea as I felt that worrying about the chrono, lining up over the photo cells and such, was messing with my accuracy...getting into my head, I guess. Now I only chrono those promising loads in a separate step.

More of an enigma on this particular rifle, the Fusions clocked around 2760-2775 and printed good groups, while handloads with Nosler BTs printed poorly above, below, and at the 2760-2775 range. So much for finding a node, I guess...perhaps the rifle simply doesn't like Nosler BTs. If I get bored one day and run out of other projects, perhaps I'll try again using a different bullet.

[Unclenick]

Tom,

A couple of things. First, different powders can produce the same velocity but have different barrel times. A fast powder will get to that velocity with a higher peak pressure, but a lower muzzle pressure than a slow powder will use to reach it. The result is the fast powder does more accelerating earlier in the bullets bore travel, with its higher peak pressure, so it goes down the rest of the tube with a higher velocity than it is doing when the slow powder is driving it; that shortens barrel time. So your chronograph can't really tell you whether you are on a node or not. It will help you copy a load if you have the same powder and bullet and help you track performance.

1% is not expected to skip sweet spots, but you may get a clearer picture where they are located with Dan Newberry's 0.7% change. Also, when using a different bullet, some gun's throats are touchy about bullet ogive distance from the lands. See if you can copy that with your bullet choice.

It is unusual to see the Federal fail, but every gun is a law unto itself, so there are exceptions, as you've discovered.

[Jimro]

Tom,

4350 is a tad slow for 168 hpbt bullets. Varget or 846 are better choices. My experience with Varget was not good, I couldn't get it to group tighter than around 2 minutes in my Savage 10 Tactical, at least within the published starting and max charge weights.

I've never used 846 as a reloader (although I've shot plenty of ammo powered by 846).

I recommend H4895 or IMR4064 (one of my standby powders). H4895 will be a tad more temp stable, but the 20fps spread I've seen reported for IMR4064 is very good as well. Although Fed GMM used to be powered by 4064 (don't know if that's still the case or not) so you might want to try H4895 first.

Jimro

[Unclenick]

Jimro,

They switched to Reloader 15 after the military selected it for M118SB LR for snipers, so it is another good powder to try. I too, prefer IMR 4064 to IMR 4895 for accuracy in .308 (and .30-06), but all military M852 was ever loaded with was IMR 4895, so its still a very good choice.

The thing that turned me to IMR 4064 originally was John Feamster's experiment comparing it to IMR 4895 in the M14/M1A in the mid-90's. He loaded both powders under the 168 grain SMK to fixed velocities of 2200, 2300, 2400, 2500, and 2550 fps, IIRC. At the two low numbers it took more 4895 than 4064, indicating 4895 was the slower of the two powders at that pressure level, if you assume identical energy content per grain. At 2400 fps the charge weight was the same within 0.1 grains. At 2500 and 2550 fps the roles reversed, and it took more 4064 than 4895 to make velocity, indicating that at the higher pressures it was now 4064 that was the slower of the two. Taken as a slope of powder charge increase needed to increase velocity any given amount, the 4064 slope was the smaller (more gradual) of the two, suggesting it would be less sensitive not only to charge throw weight error, but to other factors that affect pressure, like barrel temperature or possibly even ignition variation due to primer variation or primer seating variation.

I've had very good luck with Varget in .308 and .30-06, both. I'm surprised you had trouble with it, but every gun…

[Jimro]

Unclenick,

It could have been the combination of Remington Brass and CCI-BR2 primers not working with Varget in that Savage. Or it could have been a hold over from the infamous "slow lot" of Varget as I bought the one pound I used at a mom&pop gun store that didn't move much product. Either way there are a lot of satisfied Varget users and it is still a good place to start.

Since then I've stopped using Remington brass for anything precision, and that has been a good choice. Not that it is bad brass, just that I am not going to spend the time to do the sorting and culling to make it accurate in my bolt rifles.

I think the real reason the current version of M118lr uses Re15 is that ATK won the bid to run Lake City Ammunition Plant. Not that it was a bad move, just that M118 has had a number of powders ran through it through the years (and it is on its second bullet as well). Probably the same reason that Federal (now owned by ATK) changed GMM to Re15 as well.

Jimro

[Unclenick]

Jimro,

I wondered whether you might of had that slow Varget. I got 8 lbs of it at one point and had to relegate it all to .30-06, as the extra case room worked well with it. Back then Brigadier 3032 was still available, and I was having good success with that in the .308 and decided not to change.

I've speculated about the role of ATK ownership in the switch to RL-15 in Federal GMM, but I note that they didn't switch from the Sierra MatchKings to the Speer match bullets, even though Speer is owned by ATK as well. Neither did Lake City. So I assume they tested the RL 15 and found no loss off accuracy with the powder in GMM or they would not have made the change, not wanting to lose the round's reputation. I assume they tested the Speer match bullet as well, but either found the Sierra outperformed it, or felt the Sierra name helped sell the ammunition. I don't know which. What Lake City would gain from RL-15 is higher bulk density than 4064, so you can get more velocity out of it. It's about like 4895 in that regard, but I don't know how the burn rate change under pressure compares to 4895 or 4064.

You can roll the old Federal load for yourself. I've pulled the 168 grain SMK GMM ammo in the past and found it used a slightly compressed load of 43.5 grains of IMR 4064. If you have Federal cases and the Federal 210M Primer, that will copy it. It would be about a grain more in the roomier Winchester case that Hodgdon uses in their load data. That's still just middle load range load, so you can work up from just 5% below instead of the usual 10%. It'd be interesting if that turned out to shoot in the OP's gun and the RL-15 version didn't, due to difference in barrel time.

[Jimro]

Unclenick,

Much easier to change powders than bullets for the .mil as a new match bullet would have to get yet another legal review for compliance with the Hague Treaty. Every couple of years a lawyer will find an old box of M852 with the "for competition use only" and flip out saying they are illegal hollowpoints. I had a lawyer tell me that HPBT bullets such as used in M118LR, M862 and Mk262 were not authorized except for those units that "had a special ROE just for them" which is utter BS. That briefing was in 2007, more than a decade after HPBTs were cleared for combat use.

My "accuracy loads" in 308 are pretty sedate, only 41.5 gr of 4064 under a 168 HPBT or 173 FMJBT. Velocity is low, but 600 and under no one notices. Any further than that I should really jump up to the 43.5 gr charge area, and in my testing I've gone all the way to 45 grains with no ill effects, but accuracy is my goal instead of velocity.

As far as Re15, it has a very good reputation for temp stability, so it should perform similar or better than 4064 with regard to charge density.

Jimro

[Bart B.]

The following's a good article on 7.62 NATO match ammo:

http://riflemansjournal.blogspot.com...nge-match.html

'Twas either Whelen or Hatcher that tried IMR4064 in .30-06 arsenal match ammo some decades ago. Weighed charges of it shot more accurate than weighed ones of IMR4895. But the high speed metering couldn't keep charge weight spread low enough, so the arsenals stayed with 4895.

[Unclenick]

Bart,

That whole history gets fuzzy. Hatcher says he ran two powders one year between the wars that were similar to modern 4320. One had short grains and the other had long grains. The arsenal loading gear would meter the short grains to within a 0.6 grain span while the coarse grains were only held to within a 1.7 grain spread. Nonetheless, ammo loaded on that equipment with the coarse grain powder was consistently more accurate than that loaded with the short grain powder, and the coarse grain powder was used in that year's NM ammunition. He said they had a know-it-all competitor at the national matches who brought a scale with him, pulled some, discovered the wide charge weight variation and pronounced it no good, but several records were set with it anyway. So, I would hope they would have tested the 4064 loads for accuracy rather than just for throw weight variance, but I suppose that would depend on who's in charge at the time.

The Federal GMM I pulled had a 0.4 grain span for 4064. I don't know if their equipment is just better than the LC gear or slower or a combination of the two? For present day manufacture, I wouldn't think it should be an issue. The last couple of decades have seen great advances in robotic high speed weighing and dispensing, so they could all get around the dispensing precision issue with any powder they chose if they decided to take advantage of that technology.


Jimro,

Didn't Black Hills roll the Mk262 with both Nosler and Sierra 77 grain bullets at different times?

[Jimro]

Unclenick,

Yes, Nosler supplied the original 77gr HPBTs for the Mk262 loading, known today as Mk262 Mod0. When Crane requested a cannelure Sierra originally said "no" and then someone realized that they would be missing out on literally millions of dollars in sales, and so they changed their answer to a "yes" and managed to nudge Nosler out of the contract for Mk262 Mod1.

For what it's worth I haven't shot an SMK out of my rifles in years. Nosler's Custom Competition line has been very good to me and my factory rifle barrels. So between Nosler CC, Hornady AMax, and whatever 75gr HPBT Wideners sells in bulk I've been pretty happy not paying Sierra's premium price tag. I'm not winning any matches (but the ammo I've loaded has in the hands of a better shooter).

Jimro

[Unclenick]

Sierra's certainly not the only game in town. Guys who've done ultrasonic void testing say they find Berger more consistent, but then you pay even more. At the other end of the cost spectrum, I have a Remington 600 in .222 that prefers 50 grain Hornady spire points at 100 yards over Sierra 52 and 53 grain MatchKings. The slightly shorter Hornady is more stable.

The Noslers I've used have either worked well or not. If I set one in caliper jaws sideways (base to tip aligned with jaws) and with the pressure ring at the heel outside the jaws and hold it up to the light, I see a small crack of light along the cylindrical bearing surface portion that grows toward the tip. In other words, they've had a very slight taper instead of a being true cylinder in that portion of the bullet, perhaps to make it easier for the punch in a forming die to push them out. Sierra and Berger and Hornady bullets I've measured have all had pretty parallel sides. It seems that some guns just love that slight Nosler taper and some can't make it shoot particularly well.

My suspicion is that in some throats it tends to help center the bullet better, but in others it allows the bullet to favor one side of the bore. But that's just a suspicion. I don't have a measurement to show that's actually the issue or if guns that don't like it are just exhibiting a variation of the more mundane random factors that always make some guns like one bullet over another. Anyway, the bottom line is always the same: you try different stuff to see what works best in your gun.

[Slamfire]

On the other hand, I recently bought 500 pulled bullets that were billed as Federal Fusion bullets. I can't get them to group in anything. I've tried several .308 rifles and done ladder tests with them. Nothing better than 2" at 100 yards. I'm going to see if my .30-06 likes them, but I have no great expectation. I've heard great things about Federal Fusion, but so far my results are far from promising.

I bought 500 pulled Federal Fusion's in 270 Win. Accuracy is mediocre, about 2”. Speer, Nosler bullets group inside what I get with the Federal Fusion bullets.

I have no idea why the OP’s rifle won’t shoot GM or any bullet than Federal Fusion.

My recommendation for him: buy a bunch of Federal fusion bullets before they go out of production.

[wncchester]

"So much for the Match rule, huh?"

Yep. I've been reloading since '65, have been told a lot of stuff by self styled "experts." Some of it's been true. Not a lot, but some. None of us honestly has a clue why some things do or don't work in ANY RIFLE; those who say they do will likely lie about other stuff too.

I've learned the best "match rule" for BS filtering is how certain the guy is; the more certain he is that his limited view is the only one, the more likely he's wrong. In fact, common sense gives us a clue; the more silly any such revelation sounds, the less likely it is to be true.

[Jimro]

Them "pulled bullets" were pulled for a reason. Sometimes it has nothing to do with the bullet itself, and sometimes it does.

Jimro

[SSA]

Tom68
I would try a flat base bullet. Speer Deep Curl, Hornady SP or RN, or a Nosler Partition.

[PawPaw]

Originally Posted by Slamfire

I bought 500 pulled Federal Fusion's in 270 Win. Accuracy is mediocre, about 2”.

I've had exactly the same experience with 500 pulled Fusion bullets I bought in .308. I can't get them to shoot in any of my .30 caliber barrels, and like you, accuracy is about 2". I use loads I've worked up with other bullets and I can't get them to fly.

Now, 2" is okay for short-range hunting and teaching grandkids to shoot, so I'm saving them for youth loads. They'll do just fine in that regard.