Question about working up a load for a new rifle

[TimK]

Need a sanity check here. The rifle is a 700 in .308, new to me. I've settled on Varget (because I have a lot of it) and 168g SMK's. Brass is new Lapua.

My plan is to load up 5 rounds each at the starting charge of 42g of Varget, one at 0.005" off the lands, 0.010, 0.015, and 0.020". Once I discover which of those shoots best, then I'll go after working up the charge 1/2 grain at a time until I find the best of the best. Does that make sense or do I have my head up my arse?

 

[deadly0311]

Re: Question about working up a load for a new rifle

i would settle on the powder charge first. Find the speed and accuracy node you are looking for first. Once you have that settled then start playing with your seating depth. Loading 1 round up at different depths isnt going to tell you anything.

 

[jdel]

Re: Question about working up a load for a new rifle

search for OCW (optimin charge weight) Practical Riflery Forum has lots of info on testing loads. Once you find a sweet spot with the charge then you can play with seating depths. I did this myself once but found no noticable difference bettween depths, of course I was only shooting at 100yds.

 

[TimK]

Re: Question about working up a load for a new rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: deadly0311</div><div class="ubbcode-body">i would settle on the powder charge first. Find the speed and accuracy node you are looking for first. Once you have that settled then start playing with your seating depth. Loading 1 round up at different depths isnt going to tell you anything. </div></div>

Must not have been clear in my first post, I'll be loading 5 rounds of each length, then shooting them for group.

My Lyman manual makes the claim that the best distance from the lands, once determined, never changes regardless of other variables. That's what got me thinking to get it sorted out first.

 

[deadly0311]

Re: Question about working up a load for a new rifle

Even if you are going to play load 5 up of different charge weights and seating depths. I would seat them at all the same length. Because you may find an accuracy node and you cant be to sure wether its the powder charge or the seating depth. I would seat them all at the recommended OAL with different powder charges underneath them. Once you find a good charge weight that gives the accuracy and speed you want, then start messing with the seating depths

 

[sniperdude]

Re: Question about working up a load for a new rifle

I always try not to have too many variables when working up a load. Varget is pretty good. I would safely work up a good velocity and grouping. then play with the seating. Most 308's are good just touching the lands to 010 off.

 

[BobinNC]

Re: Question about working up a load for a new rifle

Tim,

First determine you optimum max seating depth COAL. The will be the lessor of either your max mag box length (minus 0.010"), or if your using a very short bullet, the COAL length that keeps at least one bullet diameter (for 308 then at least .308" of bullet in your case) or if the bullet hits the lands (meaning your neck to lands distance is less than your MAX mag box length).

Now you know you cannot seat your bullet any longer (without changing your mag. box length, or the bullet). Then starting at the minimum charge weight, work up in 1/2 grain increments, loading 5 at a time with each charge weight.

So if the powder and bullet combo says the starting load is at 41 grain of X powder, and the max is 45 grains.

I would load 5 each of 41, 41.5, 42, 42.5, 43, 43.5, 44, 44.5, 45, and 45.5 (yes, over max). That's 50 rounds.

I watch the pressures signs as I go up, and keep a written record. If is see pressure signs, I stop. So if I see pressure signs @ 44.5 grains, I stop shooting and pull the
45 and 45.5 grain loads.

Remember MAX loads are tailored for your rifle only. The book may say 45 grains is the MAX. But your rifle may MAX out at lower or higher powder levels (I've seen it both ways). But be safe and be prudent.

I don't dink with seating depth again until I find my sweet spot as to powder charge (note you cannot make the seating depth longer). And if the accuracy is there with a good load I've found, I won't mess with seating depth at all.

Note: I'm not shooting benchrest where 1/10" one way or the other has any meaning. I hunt and do some tactical comps. out to 1K yds so velocity that keeps my round supersonic, accuracy is my next goal at my desired velocity.

Also note: I never do load development from a squeaky clean barrel. I fire 5-10 rounds ( make some extras of your starting load for example) to foul the bore first. Then run the test loads.

And even though I reload, I like to fire at least one box of factory loads (if avaliable) to establish an accuracy and pressure baseline with that rifle. It helps.

There are new methods like the Audette ladder. But I have been approaching rifle loads this way for 35 years, and it works for me.

Bob

 

[81Z4ME]

Re: Question about working up a load for a new rifle

Can't say it any better than BobinNC. Almost sounds like I wrote it.

The way I found out what my seating depth was for my M1A (like you, trying to get the bullet out there right next to the lands but not quite touching) was to see one as long as possible that fit in the mag and then slowly chamber it. You've got to be really feeling it when you slowly slide that bolt up near lock up. Then eject the round and check for rifling marks. If you have them seat the bullet a little deeper and polish the marks out with some real fine steel wool (OOOO steel wool) and try it again. Keep doing it till you get it where you want it.

I've got some Varget, too, but haven't tried it yet in the rifle (M1A). Since you're shooting a bolt action rifle you might want to check out some slower burning powder. The best groups I ever got out of my M1A was with Sierra 180 grain matchkings and IMR 4350 powder - and yes, it did eventually crack the op rod - that was in 1980 when I had no clue slow burning powders were "bad" for my M1A. Back to the load, can't remember the powder amount but I know it was a compressed load.

Good luck with your rifle/load and be careful.

 

[Cologgi]

Re: Question about working up a load for a new rifle

Great info Bob, That really helps! I am also getting ready to work up a load for my 308. I only have exerience with pistol cartridge reloading thus far and will use your advice. I have a good load that came with the rifle but I am about out of that surplus of ammo. I plan to copy that recipe and then load it up a little hotter for longer distance. It currently uses 178 amax with 43 grains of varget on a 1/11 twist 24" barrel on my GAP. last time out it was shooting around 1" at 300 meters but am a little concerned it is not going to be enough powder for 600 to 800 meteres. Most of the people seem to be running right at 45 grains. Is my assumption correct?

 

[TimK]

Re: Question about working up a load for a new rifle

Thanks for the replies. I borrowed a stoney point gage and can't figure out how to use it accurately, so I think I'll just set the COAL to some established number and play with charge weight as suggested.

 

[BobinNC]

Re: Question about working up a load for a new rifle

Tim,

If your shooting a stock Rem 700 barrel with the normal long throating you will never reach the lands unless your running a Wyatt mag box or a Seekins DBM system, just to name a few.

With the stock mag box, and barrel your COAL will be 0.010" less than your magazine box length or around 2.815" I think. I don't have a standard Rem mag box to measure, so that's from memory, but just measure yours, and set your bullet seating 0.010" less, reload and go shoot.

Bob

 

[filefish]

Re: Question about working up a load for a new rifle

have you considered the 168 A-max bullets? they have a better BC, which should keep them SS longer, I am new at this and trying to figure out a a load myself

 

[TimK]

Re: Question about working up a load for a new rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 7.62x51</div><div class="ubbcode-body">have you considered the 168 A-max bullets? they have a better BC, which should keep them SS longer, I am new at this and trying to figure out a a load myself </div></div>

I didn't consider them. I made my choice because the SMK's are popular and well regarded, and because there is factory match ammo available loaded with them. Gives me something to compare to. If they don't shoot well, I'll be looking at other options.

 

[BobinNC]

Re: Question about working up a load for a new rifle

Tim,

And the 168 SMK's are not a bad choice for ranges under 800 yds.

As you may not be aware, because they are not sold everywhere, HSM has a very full line of match 308 ammo. It is sold by Mele over @ Sniper Central.

Link: HSM Ammo

For example they are offering a match 308 loads with the 155, 168 and 178 A-Max's aboard, at very nice prices. The 168 A-Max HSM loads sell for $19.97 a box. The many $ cheaper than the Federal GMM stuff usually goes for.

Just saying, to keep your options open.

Bob

 

[TimK]

Re: Question about working up a load for a new rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BobinNC</div><div class="ubbcode-body">Tim,

And the 168 SMK's are not a bad choice for ranges under 800 yds.

As you may not be aware, because they are not sold everywhere, HSM has a very full line of match 308 ammo. It is sold by Mele over @ Sniper Central.

Link: HSM Ammo

For example they are offering a match 308 loads with the 155, 168 and 178 A-Max's aboard, at very nice prices. The 168 A-Max HSM loads sell for $19.97 a box. The many $ cheaper than the Federal GMM stuff usually goes for.

Just saying, to keep your options open.

Bob

</div></div>

Good to know Bob, thanks for the info. In my case, the Federals I have were free...hard to beat that price.