Discussion in 'Ammunition and Reloading' started by Toetagger, May 5, 2015.
Just picked up a 308 mvp patrol yesterday and looking for powder preferences for 150 gr bullets.
Varget is great. I also like benchmark, IMR 4895, and IMR 4064.
My pet load is 41.3gn IMR 4064, LC brass, CCI #34 primer, Hornady 165 SST. It's accurate and powerful but a good way from max. Deer/pig/bear killin' machine and works fantastic up to 1000yrds as a target load.
IMR 4895 and IMR 4064 are both good. Try some H335 also.
41 gr w/H335.
42.5 gr IMR 4895 with Hornady 150 is good.
I use Varget and IMR (or H) 4895. Both are good, consistent, relatively slow powders. I use 42gr of the Varget and 40gr of the 4895 under 168 HPBTs when shooting my service rifles. I used the same loads for M14 .308 and M1 Garand 30-06.
IMR 8208 XBR. I get great results with it.
Don't forget IMR 3031, a fast powder for a short barrel.
Editorial comment about my admiration affection for the .308 cartridge....
Rhetorically: Is there any other cartridge with as many or more powder/load options than the .308?
I love this cartridge!
150 grain JACKETED in the Lee 2nd Edition; *=Loads I've used
Want a sweet .308 plinking load?
110 grain speer (SPBT) with 53.2c of Win 748; specs-out at 3,300 feet per second...
I have had good results with Hodgdon BL-C(2) and 150 grain bullets in my MVP Scout. It meters well and I have read it is one of the original military powders developed especially for the .308.
BL-C(2), Varget, IMR 4064, IMR 4895. BL-C(2) is the best metering of all of them.
IMR3031 works great in the short barreled Patrol(16").
Figured this may be a good thread to ask in.
I'm looking for how much free bore to set using the Hornaday HPBT 168gr. Starting with 748 or 760 for now until I can get some 4895 or 3031. This will be going into a MVP Thunder Ranch 308. I've set a few @ .090 for now to test but thought some of you wizards may have better ideas on what to set it at. I know most loads have a OAL but that is a general and not per bullet mfg. etc. I would be looking more for consistency. I noticed that some factory loads are all the way out to 0.120 free bore. To me that seems excessive. But being new to 308, maybe that's where it's supposed to be. I know the closer you get to the lands the higher the pressure....Is there any formulas anyone is aware of for powder adjustments as you get closer to the lands/leades?
Thanks in advance!
I use that bullet in my Savage when I can't get the Interlock's or SST's. My usual load is to just touch the ogive to the lands. Gives me .5-.7" groups with max-charge minus 1 grain. More jump will more often make for less consistency than less jump. I start with zero jump and then if pressures are too high before I get the velocity I'm looking for I'll seat a few thou deeper, cut off a couple tenths of a grain in charge weight and try again. I take pains to make sure that the heel of the bullet base doesn't go past the base of the shoulder on the case if at all possible. Seems to help. Most of my loads are so long that the bullet base is usually in the base of the neck.
I use Hornady 150 gr. Interlock, Boat-Tail, Ballistic Tip bullets ahead of 46.5 gr. of Hodgden BL-C(2) set to an OAL of 2.7810" in a full length resized and trimmed case. I full length resize because I use the same ammo in my semi-auto rifles. I also trim to the SAAMI maximum case length of 2.015". A good way (which you may already know) to set OAL is to seat a bullet into an unprimed case and chamber it. The lands will contact the ogive and push the bullet back into the case. You can then carefully remove the cartridge and measure over all chamber length with a caliper. You can then back off from your chamber measurement for bullet jump. Remember that the closer the bullet to the lands may cause an increase in pressure so for loads right up to the lands, I would back off my powder charge a couple of tenths of a grain to compensate. I would also check my cases for signs of excessive pressure after firing.
The above method works better with non cannelured bullets because a longer OAL may place the cannelure above the neck of a freshly trimmed case. That can be remedied however by trimming the cases longer but still under maximum OAL.
The cannelure on my Interlock loads ends up about 3/8" forward of the case mouth. This does drive up pressures too high if I use too fast of a powder. As a rule I tend to use heavy bullets and slowish powders. I wish IMR would make a short cut 4064. That stuff is perfect for mid weight bullets in .308's but it meters very poorly by my standards.
I weigh my charges of 4064. S-l-o-w and b-o-r-i-n-g on a balance beam scale but it works.
I used a balance and beam scale for years. It is an old, old, Lyman/OHAUS scale that to this day is spot on with the various RCBS check weights. As wood chucker stated it is slow and boring, but it does produce accurate loads. I just purchased this past fall, an RCBS Chargemaster 1500 combo. I still use a single stage press for my rifle loads and the new Chargemaster has sped things up quite a bit.
It has a feature named auto dispense where one enters a charge weight and pushes enter. The unit will dispense the charge into the pan and I will take the pan and pour the charge into a funneled, ready case. When I return the pan to the platen, the unit automatically dispenses another charge while I grab another case and position the drop funnel on it. I then dump the charge into that case and repeat the process. I have been checking the RCBS charge weights against my balance and beam scale and they are zero on. I can truly say that the Chargemaster has been a time saver for loading .308.