First time reloading .308.  I'm starting to work up some loads for my Remington .308 SPS Varmint 26" barrel. I will be using Sierra 168gn Matchking and IMR-4895 powder.

There is conflicting load data between Sierra's and IMR's data.

Sierra Min  = 38.2gn
Sierra Max = 41.3gn

IMR Min  = 41.0gn
IMR Max = 45.4gn

What grain would you start at?

Starting at the min, what increments of grain do you increase?

Thanks for the help

To be the most conservative, and for reloading you ought to be, start with the low end of the range.

Load 5 rounds at each charge weight, and see how they chrono. Also check for signs of overpressure (flattened primers, ejector marks, etc) as you go.

I did 0.1 grain, but if you have a lot of weight range to cover, maybe go 0.2 grains.

In 308 I generally increase by .3gr increments.

.1 isn't enough of a change when you talk about 40+ grains per charge.

As mentioned, look at various sources and start low, work up.

I've heard people discuss Sierra data is notoriously conservative. I personally have a load that is several grains higher than Sierra's Max and doesn't show any signs of pressure for me.

Pay attention to COAL, choice of brass and choice of primer cited in the load data.  See how the components and parameters chosen for the testing compare to what you plan to use.

When researching a starting point for my .308 loads, I found similar to what you describe.  I ended up going with a starting point on the lower end of all the various data.  I worked my way up to an accurate load that is about 80% of the way to the maxi max published load, putting me near max for some of the loads that start with less powder so their max is less.

Never anything wrong with starting low and working your way up.

Between .3 and .5 grains.  If I'm planning to do a larger spread I may load in .5 gr increments, then whichever load seems to shoot the best, do a second loading centered around that charge but varying by .3 grains up and down.

I always wonder how to adjust a load I look up to take into account using different brass...  I like it when the recommended max load is compressed (as the IMR data reports for this bullet/powder combination) because I feel that I can reasonably use a high load density, non-compressed load safely.

My routine is to determine seating depth for the bullet in question and mark a wood dowel (that will fit in the case mouth) to show the seating depth.  Then, using the powder and cases that I will be using for the load in question, I determine the case capacity (100% load density) at the seating depth thru trial and error...  add powder to the case until the witness mark on the dowel is at the case mouth when you dip stick the case with the dowel.  Then pour the powder on your scale and measure the weight.  Do this several times using different cases - you should get good agreement between the case capacities...  If so, call the average (100% load density) your maximum load realizing that there is a little room above this "max" that should be an extra safety margin.  For a starting load, I usually use 90% of the max.  I use Varget in 308 - the max load is slightly compressed according to the Hodgdon website.  My final loads usually end up right around 97% load density (1 to 2 grains below "max").

When I load a ladder for testing, I usually use 0.2 or 0.3 grain increments.

P.S.:  Kind of hard to believe that there is only 0.3 grain overlap between the 2 charge ranges!!!  You could use Sierra's max as a starting load!  I never use Sierra's load data.  I usually use Hodgdon's or IMR's websites pages as a starting point for load development

I talked with a bullet manufacturer about a similar "discrepancy".

Bullet manufacturer told me to ALWAYS use the powder manufacturers data over theirs, if there was a difference.

I would certainly use that lower data for the starting load, but as has been mentioned, a load that is safe/works in one setup may not in another.

That doesn't mean I'd limit myself to the lowest upper limit, but I'd certainly be cautious. if I even had a need to go to "max".

I don't know what brass you are using, and I've never used IMR4895 . . . my own loads use N140 and 167gr Scenars. Were I trying IMR4895, I'd see what you saw in your research and if I had no other reliable data I'd start at 41.0gr and increase by 0.3gr per charge looking for pressure signs. Fortunately, I do have some other info so my actual plan would be different.

Quickload says 45.3gr of IMR4895 with a 168gr SMK at COL=2.800 is a 100% fill load in a Federal case with 56.0gr water capacity, produces safely below max pressure for 308, and a muzzle velocity of 2827fps from a 26" barrel. While internal ballistics software is never perfect, this would confirm the general safety of IMR's data in my mind. IOW, while a 45.3gr load could possibly show pressure signs using my chamber, it would not be damaging or dangerous in any way.

I'd fill my own case with 45.3gr and see if it was close to a 100% fill were a bullet seated to 2.800". If the powder level looked either low or close to 100% fill I'd be ready to go forward. If it looked too full, that would indicate to me that my case capacity is smaller than IMR's Winchesters were and I'd reduce what follows by perhaps ~0.5gr.

I had found that FGM 308 factory ammo (168gr Sierra, Federal components, IMR4064 powder) shot very well from my 308, and had an MV of ~2710 from my 26" barrel. My own 167gr Scenar loads shoot very well at that ~MV. So I'd want to make sure to include that velocity in the range that I test. Quickload says that 43.0gr of IMR4895 might well yield ~2700fps.

So I'd start at 42.7gr and increase my 3-shot loads by 0.3gr up to 45.1gr. As said above, if my cases show to be "smaller" I'd reduce that range by 0.5gr.

Where I went next would depend on my target results, chronograph readings, pressure signs, and my goals for the load.

This is what I did, and though I don’t use 168gr pills I load a 178gr Amax with 42.3 grains of h4895 using a Winchester case and a WLR primer. I’ve gotten stellar accuracy results with this load.

Unfortunately I can’t find Amax bullets anymore so I have had to change to the ELD M pills.

#1 Pay attention to the components used to generate the data!
I.E.  in 308 Sierra uses Federal Brass to generate their data.  Whereas, Hodgdon (IMR Distributor) used Winchester Brass to generate their data.  Their respective internal case capacities are different hence the pressure differences and powder charges.

#2 All bullets are not created the same.  Case in point Barnes solid copper projectiles are different breed vs their Match Burner bullets which are a conventional jacked and lead core bullet.  Usually Barnes solid copper bullets are longer then say their copper jacket/lead core weight equivalent. And, so goes the same for Swaged, Hard Cast (coated or non-coated), Plated (are swaged bullets with varying thicknesses of copper plating, Jacketed (some plated bullets i.e. Speer gold dots, tmj, etc are heavily plated to create much thicker jackets than say a Berry's bullet in same weight.

#3 In pistol calibers charge weight increments will be small due to the low charge weights, but in rifle load work ups I think a 1% increment will work just fine.
So if a max charge is 50gr of XYZ powder.  And, I was going to do a load work up.  My increments would be 1% of 50gr, or 0.5gr.

#4 Where to start.  Well, look at the data details.  If you are using the same brand (headstamp of brass as the data source) then simply do the old standby routine of reduce the max load 10% and work up looking for accuracy, reliability, and safety in your firearm.  If you are not using the same brand of brass, then scan several data sources take the smallest max charge weight and reduce 10% and work up.

Thanks everyone.  I'm using once fired Federal brass btw.

I will go with IMR's recommended starting load and work my way up.  I don't have a chronograph yet so I'll just be going with what is grouping good and pressure signs until I can afford a chrono.

I appreciate the input

.308 has the widest specs regarding powder charges because the military brass (surplus) is completely different than commercial cases.

41.5 grains of IMR-4895 is a known accuracy load when using commercial .308 brass.

40.5 grains of IMR-4895 is a maximum load using Lake City or IMI (Israeli military industries) 7.62x51mm brass.

.5 grain increments equals 30 fps +/- in .308 ammunition.

You will not get in trouble and have been good results with the loads I posted. I suggest you try 40.0 grains of IMR-4895 in military surplus brass first before trying 40.5.

Look for accuracy, not velocity.

All guns are different, but I use 45grs IMR 4895 with 168's and h-4895 @ the same amount in 2 of my 308's. It's a pretty hefty load, but works good.

The 3rd one don't like 168's it likes 130's-150's with about that much 4895, and cfe223 even better.

As far as you I would start around 41, look at the primer, case etc. and go from there. I bet you get close to 45grs.

Have found federal brass to brittle for reloads so shoot only Hornady brass. Varget is probably the best powder for longer barrels from the years of my reloading for 308. Your safe to start in the middle of min/max published data to save on powder. I used to do .2 increments but changed to .3 to save a little more powder. BUT, when I got close to max published data, switched to .2 increments. Just make sure the powder your going to use is not temperature sensitive. Good luck.

I haven't found Federal brass to be too brittle.  I have 10 firings on 40 pieces of Federal brass that I use for load development, I have never annealed it, and it is still going strong...  just 1 man's experience, YMMV...

I don't have any problem with 308 federal brass either.

Federal brass is not brittle.  Brittle means hard.

Federal brass is soft.

Many reloaders do not bother with Federal because they only get a few firings before discarding the brass for reasons such as the primer pockets open up and won't hold primers or perhaps case head separations from stretching.  This is traceable to its being soft and expanding on firing.

Personally, I use it.  It's fine for "plinking" loads.  I won't put a lot of work into it but I also won't throw it away.

Federal .308 brass needs to be treated like Lake City if you want more than one reload from it.

You might get away with .5 grain higher charges, but why bother. Try 40.5 to 41.0 grains of IMR-4895 or 41.5 to 42.0 grains of IMR-4064 with 168 SMK's and you should get a couple of loads before it's toast.

I like Winchester brand .308 brass because it's tough, allows higher charge weights before reaching peak pressure and doesn't cost too much. Lapua is the very best and you'll pay accordingly.

dryflash3;

It is comments/observations like yours that makes me wonder why your experience and my experience with Federal brass seem to be so much different.

One possibility is that your experience happened years ago and mine is more recent...  it is possible that Federal has changed how they make their "FC 308 WIN" brass.  Maybe a different alloy, different specs, etc...  Another possibility is that you might be more demanding of your brass (loading for a semiautomatic rifle) than I am (loading for a bolt action rifle) and that the brass specs have not changed at all over time.

My question is - do you have any insight as to which of the 2 is at work here or is there a 3rd possibility that I haven't considered?

Dryflash's web dimensions probably make more sense if you read them as .185"

.175"

.163"

Lots of well meaning advice here.

The .308 has enough case capacity to allow 1gr increments when doing initial work ups. Going with less is simply a waste of components.

Your accuracy nod will be more pronounced using 1 full grain increments. Any decent .308 like your Rem. is should maintain 100 yard group size with a +/-.5gr change in charge weight. Mine always did and does.

Find the nod first then fine tune. It will save you a lot of components.

Motor

Years ago I ran into FC 223 brass that was crap, primer pockets would expand by the second firing so bad they wouldn't hold a primer.

I had 2 case separations before I figured it out, ya I'm a little slow, ah

So I like you didn't like them, but I used them for hunting coyotes, fox and whatever, because I let the cases fly and didn't bother to look for them.

But now I don't have a problem with them, but I have not measured them like you have, so there's that. I will check them out better next time.

In 308 I have not had any problems in 2 different bolt actions and one semi-auto. And I have a lot of FC brass in 308, and 30-30.

In my bolt guns, one of them gets loaded hot, it likes em hot, no problems, could it be FC has several different plants making brass, because on some you

notice the headstamp is a little different, they all will be stamped  FC 223 rem  all 3 words spaced the same distance apart, and then

there are some stamped with the same lettering, BUT the FC stands alone and on the bottom  223 rem  are tight together. It's the same with 308, and 30-30 brass

which I use a lot of in that caliber. I think the FC brass where the words are not spaced equal around the head of the case and the FC

stands alone is better, and the equally worded one is older. If you have a bunch try and find both headstamps, it's easy to see. Just look at the case with  FC  to the top.

So my brass is from boxes of Federal Premium Gold Medal Sierra Matchking that I had shot.  The back of the box says "Match Grade Federal Brass".  Also says Benchrest Quality Gold Medal Primers are in it.

Does Federal have 2 types of brass for hunting cartridges and a type of match grade brass?

I guess maybe that could explain different experiences with Federal.  Idk

You mean like this? >>>


< This is one of the cases I have been using since I have been getting "back into reloading" after a long hiatus.  I bought a case of FGMM 168s and shot them saving the brass for reloading. >

I’m no expert but doesn’t that case show a couple signs of over pressure?

Good call!  There is some primer "cratering" that in this particular case is not a pressure sign but it frequently is (essentially every case that comes out of the rifle that shot that case shows "cratering").  Primer (Fed GM210M) is not flattened.  There is a light ejector recess impression at ~6:00.  The charge was 45.9 grains of Varget under a 180 grain bullet with a COAL of 3.00".  This case was from the highest charge weight in an OCW ladder...  The chrono showed a MV of 2,724 fps out of a 20" barrel.

That photo was from load development...  the final charge for that 180 gn bullet worked up to be 43.8 grains of Varget.  There were no ejector marks at that charge weight but the primers still cratered!...  

The trouble with FC brass was in .223 NOT .308 Win. Even at that many people don't have any complaints with FC .223 brass.

BTW: The case pictured above does not show any higher than normal pressure signs. Look at the radius around the edge of the primer. It is still fully round and there is no primer cup flow.

The crater around the pin strike is either because the pin bore mouth is slightly deburred or the primer flowed back over the pin while the case was struck forward in the chamber by the initial pressure rise.

The ejector bore marks are also very common these days because to cut manufacturing costs they don't deburr it cleanly.

Motor

Ya, that's one where the FC stands alone like I was saying, and the 2 other words at the bottom close to each other.

The other type they are all equally spaced apart. If you have the FC on top, the other word/ numbers whatever are at 12,4 and 8 o,clock.

I think they are from different plants, but what do I know?

I don't have much of a problem with federal any more, it's some of my better brass in 30-30, and you talk about loading cases where you can get case stretch.

I did the same with some federal gmm. A lot of work and got one load and tossed them in the scrapyard bucket.

For commercial brass you should find a nice load anywhere from 41 to 43 grains.   For m14 loads I like to say 40-41.

In my experience, this is all 100% correct.
40.5 grains of IMR4895 (both mil spec and commercial brass)  with 168 grain SMK’s is a lights out accurate in every rifle I’ve shot it in.