.308 and IMR 3031

[762frmafr]

So, I am brand new to reloading. In fact I just received my last shipment of equipment earlier this week. I am going to be reloading the .308 win primarily at first then progress from there. Here is my question/concern. My cousin has been reloading for years and has a remington 700p in .308 the he worked up a load for. it is 175gr smk with 40.2 grains of IMR 3031. now i know i am below a novice, but i can read. in the sierra book that i ordered with my equipment, it shows the max load for 3031 as being somewhere around 39 grains. i do not remember exactly as it is at home and i am at work. also the c.o.a.l. of his reloads was longer than recommended in the book. so is there a better powder for the .308? i have been shooting this load out of my LR308 for sometime and accuracy is so-so. i had some M118lr that shot better, but that is neither here nor there. the primers in his loads show some slight cratering after being shot from my DPMS. I would like to stay with the 175 smks. but i am open to different powders and seating depths. i will be getting my .308 bolt gun back from the smith sometime this week and i really want to work up a load for it. thank you in advance and sorry for the rambling.

 

[Queequeg]

Re: .308 and IMR 3031

Sierra and Hornady manuals are both fairly conservative. There are other manuals, such as Hodgdons, Lyman or Lee that show considerably higher, yet still very safe, loads.

For example, Hodgdon shows a range of 38 (min.) to 41.3 (max) grains of IMR3031 under the 175 SMK at a coal of 2.800". I usually load mine to 2.825" max oal for my SPS and Savage, or just long enough to still fit the mags for my AR-10; 2.810".

The magazines are what limits the OAL as the cartridges won't fit if too long. There are other examples of this load inconsistency, which is an excellent reason for owning several manuals for cross reference purposes, in addition to damn enjoyable reading!

There are better powders for accuracy and consistent velocity than 3031 in the various bullet weights commonly used in the .308win. Varget, RL-15, RL-17, the 4895s, IMR4064 and several others are suitable. I've also used BLC-2, and H335 when using my Dillon powder dispenser.

There are some excellent threads that answer all of your concerns in this particular forum. Check the depot above and prepare to be stunned!

Be safe.

 

["Partridge"]

Re: .308 and IMR 3031

probably would be worth a look at varget

 

[vinconco]

Re: .308 and IMR 3031

I use 3031 in my 7600 carbine 18" barrel. Less muzzle flash and blast with decent velocity.

 

[buffybuster]

Re: .308 and IMR 3031

3031 is a bit on the fast burning side with 175gr's bullets. A slightly slower burning powder (Varget, 4895, R15, 4064) would give you better load density and higher velocities.

 

[762frmafr]

Re: .308 and IMR 3031

ok so here is what i have found. i bought an rcbs precision mic for the .308. i measured the freebore in my dpms. it was -.064. i measured my cousins reloads and they were +.015 which tells me that they were .079 into the lands. could explain the cratering no? so when i use his powder load and my seating depth .010 off the lands the powder is compressed. no shakey shakey. which i do not believe is good. needless to say i only loaded 3 cartridges and stopped. i am going to pull the bullets and start over i believe. i have 2 pounds of 3031 so i'd like to stay with that but if it's not the right powder then i guess i'll have to switch. im thinking of going with the accuracy load velocity which is 2400 fps. then translating that to 3031 powder which is 37.3 grains. which would be 2.9 grains below what my cousins load was. then work up from there i guess. thoughts? suggestions?