Range Report Some help on where to go with 308 load dev

[RobG]

I am developing a load for my stock Rem LTR, 20" .308. I tried to stay "standard" and went with Win brass fully prepped, Varget, Fed 210M primers, and 175 grain SMK's loaded to 2.805. I started at 43.5 on up to 45 grains in .5 increments. I first shot one of every load and all impacted with 4 inches of one another at 200 yds. I then shot 4 more of each (I only loaded 5 of each load) to check grouping and chrono speed. I achieved the following:

At 43.5: 2450, 2430, 2450, 2450, 2442, ES 20, SD 8.7, ave 2440
At 44: 2473, 2501, 2525, 2473, 2510, ES 52, SD 23, ave 2496
At 44.5: 2530, 2525, 2575, 2554, 2539, ES 50, SD 20, ave 2544
At 45: 2599, 2564, 2583, 2578, 2583, ES 35, SD 12, ave 2581
Groups at 200 yds from 43.5 and up, 1.2", 2.0", 2.75", 3.2".

The more velocity, the larger the group. So what I am looking for is advice to go from here. I have only worked up one previous caliber (7MM RM) and it was very easy, taking only a few tweaks to get it shooting well. Should I tweak the powder charge, change powders, or ?? I cannot lengthen the load much and still be able to fit the mag well. Again, I am pretty new in regards to this stuff so any advice is appreciated.

Thanks

 

[bjordan]

Re: Some help on where to go with 308 load dev

I pretty much had the same results as you until I tried Reloader 15. My gun does not like varget at all. I'm shooting a remmy xcr LRT with a 26" barell. try some reloader 15 and see where that gets you.

 

[ChadTRG42]

Re: Some help on where to go with 308 load dev

I would try R15 or H4895. H4895 would be my first pick.

 

[RobG]

Re: Some help on where to go with 308 load dev

Thanks guys. Think I'll try those powders and see what I come up with.


Thanks

 

[skep_tic1]

Re: Some help on where to go with 308 load dev

I've had very satisfying results with IMR 4895

 

[jeepwilson]

Re: Some help on where to go with 308 load dev

Powder is one thing to try but OAL can change everything.After you try the other powders I would come back to whatever shoots the best and start playing with OAL.I usually start loading about .030 off the lands and go to .020 off then .015 and .010.I load 5 of each,then I will shoot 5 of one let barrel cool and maybe clean then to the next 5 and so on.You may be very suprised what can happen.A lot of people thinks longer is better but that is not the case let the gun pick.

 

[RobG]

Re: Some help on where to go with 308 load dev

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jeepwilson</div><div class="ubbcode-body">Powder is one thing to try but OAL can change everything.After you try the other powders I would come back to whatever shoots the best and start playing with OAL.I usually start loading about .030 off the lands and go to .020 off then .015 and .010.I load 5 of each,then I will shoot 5 of one let barrel cool and maybe clean then to the next 5 and so on.You may be very suprised what can happen.A lot of people thinks longer is better but that is not the case let the gun pick. </div></div>

Unless I want to single load, and I don't, the closest I can get is about .100 from the lands. I will just have to work with what I got I suppose.

Thanks

 

[bjordan]

Re: Some help on where to go with 308 load dev

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: RobG</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jeepwilson</div><div class="ubbcode-body">Powder is one thing to try but OAL can change everything.After you try the other powders I would come back to whatever shoots the best and start playing with OAL.I usually start loading about .030 off the lands and go to .020 off then .015 and .010.I load 5 of each,then I will shoot 5 of one let barrel cool and maybe clean then to the next 5 and so on.You may be very suprised what can happen.A lot of people thinks longer is better but that is not the case let the gun pick. </div></div>

Unless I want to single load, and I don't, the closest I can get is about .100 from the lands. I will just have to work with what I got I suppose.

Thanks </div></div>

I'm in the same boat but I got excellent accuracy loading them to mag length. Try some reloader-15 and go from there. My gun literally shoots twice as good with reloader 15 than varget. Primers made a noticeable difference in my groups too.

 

[armymedic.2]

Re: Some help on where to go with 308 load dev

don't forget the old standby imr 4064



best part is, since apparently im the only one ever using it, it is always in stock!

i have found it to be acceptably temp stable as well.

 

[1fstTA]

Re: Some help on where to go with 308 load dev

R15 all the way

 

[wyobill]

Re: Some help on where to go with 308 load dev

a friend and i have several 308s and imr 4064 shoots very well with 168 and 175mk in all of them.fed gmm or m118lr would probably give you a good bench mark.

 

[rezmedic54]

Re: Some help on where to go with 308 load dev

I have several ..308's and reload for all of the unlike you I'm not limited to length as much as I have an internal box mag. I load to .003 off the lands with 168 Bergers over 43 gr. of IMR-4320 and my speeds are right at 2700. I load my 168 Bergers to .006 off the lands and that's over 43.6 gr. of IMR-4320 my speeds are right at 2710 to 2735 max . I also use CCI BR2 primers for both. Mt rifles are all Savages 2 Mod-12s and a Weather Warrior Mod 16 all shoot sub 1/2 groups at 100 yds.

 

[RobG]

Re: Some help on where to go with 308 load dev

I got some R15 to try with much better results, groups tightening as the charge was increased. The best so far:

43.7 grains, 175 smk, 210m, at 2.840 (longest I can get in mag)

2450, 2402, 2419, 2446, 2469, ave 2437, es 67, sd 26

5 shots at 200 was .846

Grouping was good but I would like a touch more velocity, something in the mid to high 2500 fps range and I will be satisfied. I am going to work up a few more loads and see how it all works out.

Thanks for all the info.

 

[TDaly25]

Re: Some help on where to go with 308 load dev

A couple things:

I shoot 3 different bullets out of my .308s. I shoot 155 gr. AMaxs over 43.8 grains of IMR-4831, 168 gr. AMaxs over 42.8 grains of BL-C(2), and 178 Gr. AMaxs over 44.7 grains of H-380. I would start by setting your seating die so you are seating .010" off the lands. I would then run 3 shot groups of H-380 in increments of .3 grains, begining at 44.4 grains, up to 45.6. After these groups I'd pick the best one and load two more sets of 3, varying the load you selected and adding .1 grain and decrementing by .1 grain just to see if you can eek out any incremental improvement. Once you've selected the best load then I'd play with seating depth. I'd load a set seated down to the lands and then load a set at .020" and see if either of those perform better than the .010" set. Good luck!

 

[Desert-Rat]

Re: Some help on where to go with 308 load dev

I ran horny 168 match's w/ 45.5 of target in a 1:12 twist and shot 18 of 20 FTR X rings at 500

Stabilized well, vie never been able to load 175's fast enough to flatten out for me. I'm a light and fast loader!

I run my Palma loads at 46g w/ 155g scenars at 3000 fps and they are super flat, that's a 1:13 twist krieger

 

[blakheaven]

Re: Some help on where to go with 308 load dev

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: armymedic.2</div><div class="ubbcode-body">don't forget the old standby imr 4064



best part is, since apparently im the only one ever using it, it is always in stock!

i have found it to be acceptably temp stable as well. </div></div>
I have always have at least a lb of 4064 myself. It is a great powder for 308 Winchester but for the 175smk's you might wanna try IMR 4895. It is one of the two propellants the USMC uses on the M118 (173gr bullets but close enough) and trust me they have done all the load testing for you already! and they have to fit in the badger M5 mag too so this might be what you need.
Also what is the twist rate in your barrel? And how much bullet jump do you have on those bullets (I know its different for every bullet cause of different ogives)
Also might wanna give a look at Tres Mons ladder test thread, its a sticky in the reloading section

 

[Greg Langelius *]

Re: Some help on where to go with 308 load dev

I'd stop for a moment and do a little measuring.

The loads you're shooting should show more grouping variance and at least one of them should be dead-nutz. 45.0gr of Varget is a very commonly effective generic load for the 175. Another is 42.2gr of IMR-4064.

I'm suspecting some ergonomic mismatch between your stock and your body.

I'd measure LOP and comb drop as a comparison between the .308 and the 7mag. I suspect you'll find some significant difference between the two, and there's where the issue could lie. I'm tall, and I typically employ a Limbsaver slip-on recoil pad to gain some LOP. Stock packs can add to comb rise, as can neoprene foam and contact cement. Some craft foams, like Foamies, come with peel-off adhesive.

If I'm wrong, examine the .308's crown under some magnification. It needs to be absolutely symmetrical.

If that's all good, do the usual checks for loose optic/bedding.

Greg

 

[Kosovojoe]

Re: Some help on where to go with 308 load dev

im getting a lil under sub moa at 100 yards with my rem sps 700 308 tactical using PMC brass (i know its cheep brass but i have a lot of it) win large primers 168 SMK HPBT and 42.0 gr. of varget,and OAL of 2.800. its hard to find places to shoot over 100 yards in socal, so i used some BLM land and with just using mil dot and a good guess on size was able to ring a 10" plate at 200, and one at 350, with a +15* angel. off a millet TRS-1 at 10x. anyone with a good load for this rifle let me know, but so far this one works, do plan on ditching the pmc bronze and gettin a few bags of win brass. im new to reloading dont shoot!

 

[LawnMM]

Re: Some help on where to go with 308 load dev

I've found that 44 grains of Reloader 15 yields good speed for me (2560's) and I had three rounds through one ragged hole at 290 yards. Haven't tested how it groups at 100 yet but that may be part of your issue. It may not group the best at 100, try to do your load development around 300 yards so the bullet has some time to stabilize.

Seen many here show less than great results at 100 but it really tightens up down range. Do you need sub MOA accuracy at 100? Its nice and all but I'd rather have it group better at extended ranges where my own shortcomings are magnified instead of minimized and I need all the help I can get.

 

[okiefired]

Re: Some help on where to go with 308 load dev

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">I'd stop for a moment and do a little measuring.

The loads you're shooting should show more grouping variance and at least one of them should be dead-nutz. 45.0gr of Varget is a very commonly effective generic load for the 175. Another is 42.2gr of IMR-4064. </div></div>

Not sure I'm following Greg on the "grouping varience" comment but he's spot on in the rest.
Your problem is not with the powder. Varget will perform well with damn near any 308. I spent half yesterday printing .5 moa groups with my own factory barreled LTR useing 178 Amax's, 45 gr Varget, 210m's in FGMM brass at 2.810 OAL. Everyone always wants to say "the powder dosn't work" when there are many other variables to consider first. Besides what Greg mentioned, whats your reloading pratice? Whats your neck tension and runout? Does your bolt close easily, are your sholders bumped back properly? Your ES and SD's are nothing to brag about and IMO your speeds are a little slow. Are you getting any presure signs yet? These people asking how far you are off the lands have obviously never loaded for a factory Remington chamber

. If your feeding from the mag, which I think you're dumb if you're not, you're JUMPING, thats what you do with factory chambers. Find a bullet and load that will do it acceptably so you can use the rifle as intended. If you want ultimate accuracy from a factory 700, get a single feed 40X, the action will be stronger. Dont know what your load developemnet habbits are but if you hav'nt already, look at OCW and ladder testing. Choose the one you're comfortable with and do it right. If you get talked into absolutely changing powders then RL15 is a good one but I promise you it shouldnt make much if any improvement over Varget in that rifle, I never could get it to make an improvement in mine and I tried. I think you've definately got something else going on besides the powder. Good luck.

okie

 

[Nebraska123]

Re: Some help on where to go with 308 load dev

tag

 

[RobG]

Re: Some help on where to go with 308 load dev

Thanks guys. Heading out tomorrow for some more testing, finally. Damn rain.

 

[Leaddog]

Re: Some help on where to go with 308 load dev

43.5 looks like a winner for you. Good numbers. With that 20" barrel and only shooting mid-range you are good to go with that load. For LR (600+), I'd think about a longer barrel.

 

[RobG]

Re: Some help on where to go with 308 load dev

I ran some more loads through working up to 44.9 grains of R15. Ave speed was 2495, sd 11, es 28. I think I "overloaded" one round as the first 4 ave 2490, sd 2.5, es 5 with 3 out of the 4 reading the same velocity, 2492. That "fast" one was 2515. Accuracy was good, right around an 1" at 200 for 5 shots. No pressure signs at all. It strung horizontally, I am thinking the bipod was hopping on the concrete bench?? (my 7mm did the same thing) Probably should have used a bag or something under the feet. Not really gaining any more speed with the powder increases, the short barrel can only use so much powder I assume. I may try the 4895 you guys recommended as it has a faster burn rate.

Thanks for all the help guys.