In the Nosler manual, the best velocities for 120g and 140g bullets was obtained using N-560. Worked out to 100% loading density with one of these bullet weights but can't remember which. Should work well.......but then I would have figured Hunter would work great.

Varget may be very accurate but too fast to obtain the best velocities shooting 120g - 140g bullets.

milanuk:

Sorry milanuk, I have been very busy and not on this site or any others much here of late. It wasn't a cock-a-mamie idea just the velocity expectation is a little high. There are quite a few shooters shooting the 123 out of the 6.5-08 / 260 Rem. at 600 to 1000 yards @ 2900 to 3050 fps with excellent results. That bullet at that velocity is a serious long range load.

But seriously the 142 MK is by FAR the most popular bullet in 6.5 mm cartridges at long range matches, in the non moly coated version. Again I really believe your velocity expectations of 2850 to 2900 fps are just a little high for the 140 gr. class bullets with 6.5-08 for the 140 gr. class of bullets. The most frequently used powder with the 140 gr. class bullets is H4350 EXT @ some where between 41.8 gr. and 42.6 gr. with a CCI BR-2 primer in Remington or Lapua brass. Velocity runs in the 2750 to 2825 fps range with excellent accuracy. Another powder that works well is the one I use with the 142 MK is H4831 SC @44 gr. with a Federal 210M primer. Velocity runs 2745 out of my 25" Krieger barrel and that load shoots well enough to to be able to clean a target at 1000 yards with a good X count when I am on my game. I finished second in the Kentucky long range championships (I missed three condition changes in the second relay) with that load. It shot plenty good enough to win, I just missed the condition changes and I lost by 3 points with a 396-14X. Enjoy the 6.5-08 for what it is a very efficient long range performer with modest powder charges, good barrel life and excellent accuracy.

If there is anything I can do to help just let me know.

Hold into the wind my friend..........RiverRat

For what's it's worth, QuickLoad estimates 3000-3050 is all you'll safely get. It figures a ball powder similar to 4350 is about right.

Personally if a powder with the burning rate of 4350 in that mediun size case shows pressure you are at the end of the road. The additional velocity generated by that additionall 4" should be rather small with the fast twist.

It seems that the fast twist indicates that you want to stabalize long heavy bullets. Yet if you don't have a long action and a deep throat the longer bullets are going to be eating up your powder space. The lighter bullets are being handicaped by the force necessary to overcome the fast twist and the limited amount of slow burning powder that will fit in the case. Am I missing something here. Talk about leaving oneself open. roger

I don't think I've ever heard of someone putting a .260 in a long action... doesn't mean it might not have merit, just not something most people that shoot them do... ever.



The relation btwn bore diameter and powder capacity in this case end up leaving a person w/ a *lot* of air space w/ medium burn rate powders. A *very* heavy load of RE-19 or Hunter behind a 123gr Scenar barely comes to the bottom of the case neck, and w/ the bullet seated out towards the lands, it ain't coming close to impinging on the powder capacity. A stiff load of 4350 or Varget behind a 142gr SMK (about 4 grains less) leaves even more space. Also, FWIW, the Lapua 123gr Scenar is longer than some other 'light' bullets, hence it's rather hefty B.C. (0.547). The idea (in general) was that while normally speed doesn't make up for a lack of B.C., a bullet w/ a pretty good B.C. going 300-400 fps faster than a bullet w/ a really good B.C. would come out ahead, shooting flatter, needing less wind correction, etc. Looks good on the ballistics software, just trying to make it work in real life is proving aggravating.



About the only person I've ever heard of actually running out of space in a 6.5-08 was/is running 50.5gr H1000 behind a 142gr SMK... has to trickle thru a drop tube, tap it some, and then crunch the powder some to get it all in there. All for a whopping 2850fps. Of course, he also holds a range record in LR Prone w/ it at one of the more treacherous ranges around here (Rattlesnake, sits up on top of a plateau, lots of strong switching winds). Oh, and he had to use Winchester cases (thinner, lighter, slightly more capacity) to do it. Hmmm... might be onto something there



I'm a little short on time here (match coming up on next Saturday), so I'm giving the 47.0gr Hunter load a little wringing out. Switched to a cooler primer, CCI BR2, that I have more faith in. Gun still seems to like the 123gr Scenar 15 thou off the lands, just wish the mirage would either die off or blow off so I could see the target well enough to be sure of my hold. Otherwise, I've got some H4831SC and H1000 sitting around here somewhere...



Thanks,



Monte

Go slower, Monte. That's what all that barrel is for. And with faster powders, things like high temps or whatever are going to have a FASTER and more pronounced effect on these powders.

Definitely shy away from the pressure signs your getting.

Try 4831 is my suggestion and work your way up.

I`ve got my highest velocity in my 260 rem with R19 useing 129 gr Hornadies. I know this isn`t the same bullet but the wgts are similar. I don`t know if a slower powder would help, I`ve used H1000 under a 140 Sierra and was doing some major chrunching with out reaching vel I got with R22, H4831. There just isn`t enought space in the 308 case for real slow powders with the heavier bullets in this caliber. I use R22 and get velocities that satisfy my needs with the 140 but I`m not going for the warp speeds you want.

Ah, Hunter may yet work quite well... more of an issue of stupidity on the part of the loader... left the bullets jammed into the lands by accident.

Monte

Ok, here's the scenario:

Rem700SA, 30" PacNor 1-8" twist
Winchester .308 brass necked down to 6.5mm, either CCI or MagTech primers
Lapua Scenar 123gr moly-coated (home done)

Based on what I dug up before I got this gun, I was hoping to be able to push said bullet in the range of 3200-3250fps from the 30" barrel, as people had claimed 3075-3150 from 26-28" barrels.

First load when I started out w/ the gun was naked 123 Scenars ahead of 47.5gr RE-19 at around 3125 w/ very good accuracy. Because of other considerations, I went to moly, and 120/142gr SMKs for a while. Now that I'm revisiting this experiment, I'm trying Ramshot Hunter (supposedly right btwn H4350 and RE-19 in burn rate). Did a ladder test today, and have a big fat 'node' btwn 46.5 to 47.5gr, running about 3170fps. Problem is that I'm starting to get some healthy pressure signs at the upper end... sticky bolt lift, slight ejector wipe, one leaky primer (abnormally high velocity on that round - 3199). 48gr... 3200fps, but more pressure signs and very definitely pierced a primer (ow!). Granted, the conditions were about as non-friendly to testing as could be... 95-100 degrees, no shade, hazy, dry, and the barrel pretty much stayed hot btwn 3 shot strings even though I was driving down to the target 300yds away (further w/ the goat-trail two-track road from the firing point to the butts) btwn strings.

Now I'm starting to think I'm probably not going to safely make it to the speed I want w/ powders in this range, from the looks of things thus far. So the question becomes, before abandoning the effort entirely, which way to go for more speed? For a 140 class pill I'd guess a slower powder like H4831SC, H1000, RE-22, maybe Magnum. For a lighter bullet like the 123 Scenar... should I start looking faster, like Varget, RE-15, Big Game? Or go w/ slower as well?

Thanks,

Monte

Sorry, QuickLoad isn't accurate enough to predict what a particular powder will do. It will give a good idea of what a class of powders can do, but it can't reliably tell you what one particular powder will do. Many powders, such as 3031 and 4064, are not well represented. The mathematical representation of burning powder has, in this program, several shortcomings. This prevents the program from giving exact results. Some powders will be close, some too hot, others too slow. To the author's credit, he lists all the shortcomings in his notes and his manual.



QL predicts about 2750 for the medium speed powders under the 142 gn bullet, this with a charge near 38 gn. (The agreement with your numbers is partly luck, or course.)



Again, do NOT put too much faith in QuickLoad numbers. The writer John Barness has written that the program can be off 10,000 psi. I'll note he has access to a piezo bench to test loads, so I trust his word on this.

milanuk:
For whatever it is worth, IMHO you are trying for a velocity figure that is not attainable with a 6.5-08 even with a 30" match barrel in necked down Winchester brass. I know of no body that has attained 3200 to 3250 with barrels up to 30" long. With out fail pressure issues start to show up at around 3150 fps. It might not be a sticky bolt but loose primer pockets show up very quick as a minimum with only 2 or 3 shots at that velocity.

The following observations are based on 1200+ rounds through my 6.5-08(260 Rem.)at then bench in load developement and in long range competition, and findings from other knowledgeable and sucessful long range shooters (several more thousand rounds at the bench and long range) using barrels that vary from 25" to 30" with the various bullets including the 123 Lapua Scenar. And various powders for the 123 Secenar. With the 123 in a 25 to 26" barrel the accuracy node seems to be very consistent around 2900 to 2950 fps. With the 28 to 30" barrels it seems to be very consistent around 3000 to 3050 fps. Powders of choice with the 123 seem to be N 140, H4350 EXT, and RL-19. Varget may work, I just don't know of anyone that has used it with the 123. I know that IMR 4064 works very well with a 120 gr. Sierra Pro Hunter from my 24" barrel 260 hunting rifle. Velocity runs an average of 3017 fps from the 24" Krieger tube. Accuracy in the mid .4's to the mid .5's. N560 does make good velocity with the 140 gr. class bullets but the extreme spread has always been too high to be useful at long range in competition with N560.

Seriously, the 123 at 2900 to 3050 fps makes a very competitive combination if the rifle and shooter are up to it. Velocities are well above transonic at 1000 yards.

Sure don't mean to rain on your parade but, I though I would pass this on to you. Hope it helps some.

Hold in to the wind my friend.......RiverRat

RiverRat...

Dang it, man. Where *WERE* you when I dreamed up this cock-a-mamie idea of 3200fps last fall

Actually, I asked around on a couple HP shooting boards (www.floridahighpower.com and www.long-range.com) to get what little information I do have in the way of powder charges, etc. Surprisingly few people use the 123gr Scenars at all (or at least that were willing to talk) as compared to the apparently growing number that are using the 139gr Scenar as an alternative to Sierra MatchKings.

Guess I'm still a little befuddled as to why people can start encroaching on 6.5x55 and 6.5-284 territory (142 SMK @ 2850-2900) w/ a 6.5-08 and a long enough barrel, but can't seem to get much more than 3100fps w/ said barrel and a 120 class pill.

In any case, I re-visited the most promising N160 load from the other day... definitely less impressive this time around. Called Russ Haydon's and a box of 500 142gr SMKs should be here tomorrow or so. Just enough time to moly them up, clean the snot ouf of my barrel, re-acclimate it to H4350, and get my zeros hammered down before Saturday.

Thanks,

Monte

Have you tried N-560?

HogWild

Hmmm... figured 2700-2800 is what I hear most often reported from 26" barrels. My barrel w/ 42.2gr H4350 and a moly 142gr SMK does right at 2800 w/ that load, w/o even straining.

The real 'weird' part of that load development was that I was testing from 42.0 thru 44.5gr H4350, @ 300yds w/ 3-shot 0.5 increments. Didn't bother to go down to mark individual holes, as I figured there would be substantial vertical stringing, at least to start off. After firing all rounds, I went down, and found one 'group' about 2.5" high by 4.5" wide, w/ all the shots in it. WTF? This gun, for whatever reason, doesn't play nicely w/ the ladder test theories since I started using moly. Especially weird since the velocities ranged from just under 2800 thru 2940fps. Pretty much the same thing w/ Hunter and N160; all the bullets went into one area, all almost exactly the same height, only the width of the group varying at all (minimal wind).

FWIW, I'm not arguing that 2850-2900 is probably a bit ambitious on the whole; just that my gun (and others w/ 30" tubes) has reached that level, albeit w/ some pressure signs. I'm starting to get the idea that maybe a 26" barrel really is about all that is useable in a 6.5-08. Ah, well. That's why I'm looking at building a LR Prone rifle in 6.5x55 or 6.5-284

I guess at some point I need to just need to find one load and call good 'good enough'. Not sure why I have a hard time accepting that. W/ an AR, I don't feel the need to twiddle as much as I do a bolt gun; as long as the bullet goes down range in a reasonable fashion and doesn't do anything unexpected, I'm happy w/ it from an AR. W/ the bolt gun... I keep wanting to push the envelope, for some reason. The stinker of it is that it keeps me busy twiddling w/ loads rather than focusing on shooting. Too much 'varmint hunter' left in me, I guess

Interesting. I really need to get me a copy of that

What does it have to say about Varget? I only ask because we have several High Master ranked shooters who swear by 38.0gr of Varget behind a 142gr SMK for 600yds, and then the same charge behind a 120gr SMK for a reduced load for 200/300yds. I missed a chance to chrono it, but I think its a tad on the slow side, perhaps 2700-2750fps.

Sounds like I'll probably be back to a 120 class bullet for 200/300 and a 140 class for 600+. Bummer. But, if it works, it works.

Thanks,

Monte

QuickLoad figures you'll loose about 150 fps going from 125 gn to 140 gn. The Powley computer figures the same fps loss. For the 4831 class powders and slower, QL figures you'll likely need a compressed load to deliver little better performance than the 4350 class.