150gr. Will it do?

P

Pond James Pond

New member
As some may remember, I found a supply of affordable milspec .308 ammo. It was great in two respects.

Firstly, the components were brass case and copper jacketed (none of this steel nonsense ;)), and secondly it was boxer-primed mean I could actually reuse the brass.

I had decided to pull all the bullets and see if tweaking the powder charge and reassembling for uniformity would improve accuracy. It worked pretty well.

Cleaning out the tar sealant, setting a decent OAL for my rifle, neck sizing each case and a seemingly optimised powder charge meant that with some man-hours, but no extra cost I got these to shoot at about 1.5-1.8MOA compared to the 2.5MOA to begin with:
Works for me.

So now, as I struggle to get to grips with the infernal hunting regs here, I decided to apply the same logic to developing some hunting loads. The original FMJ bullets are about 147gr. I have since bought some Hornady 150gr SPBT bullets.

The plan is to use the same load work up as I did with the originals, so my question to you is, do you anticipate any problems in doing the same load work-up with a bullet of 150gr over 147gr?

That load work-up involved dropping the loaded charge by 7.5% and then working back up toward the original in increments.

I am mainly (although, not overly) concerned with the safety aspect that might arise from that small difference in bullet weight.
 
I'd do a ten round work up.

Weigh 10 powder charges from your deconstructed milsurp ammo. Calculate the average. Reduce that number by 10% and use that as your starting charge. Increase the powder charge in the case by 1% under each 150gr bullet. If there are no problems with pressure or extraction by the time you are done, you are good to go.

Bullets of different mass and construction can have wildly different friction coefficients going down the bore (for example the difference between a flat base and a boat tail, the flat base has a solid bit of copper resisting compression at the base meaning more friction).

Hope this helps, good hunting!
Jimro
 
150's will be fine. Three grains won't matter. THROW THE POWDER AWAY. You have no idea what it is and you cannot tell anything about it by just looking at it.
Assuming the stuff is NATO spec, every country uses different powders to get the NATO standard velocity. None of 'em publish what powder or how much is actually used.
Regular data with normal .308 Win powders for a 150 will work just fine. Think about 2733ish FPS. BL-C(2), IMR4064, IMR or H 4895 and a bunch of others do it.
 
Weigh 10 powder charges from your deconstructed milsurp ammo. Calculate the average. Reduce that number by 10% and use that as your starting charge. Increase the powder charge in the case by 1% under each 150gr bullet. If there are no problems with pressure or extraction by the time you are done, you are good to go.
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I've sort of done that bit already.

I've already established the average over about 20rds right at the beginning and I always check the powder used is the same (it's written on the boxes). Just to be sure, I'll weigh the first 10 to make sure they are the same.

Initially, I opted not for the OCW 10% drop, but 7.5% drop in case the actual charge in the case was not the max for that powder. OCW calculations are run from the listed max for a powder, but I can't assume that the charge in the cases is indeed the max, even if it is likely.

Assuming the charges are the same as those I first recorded, I should be able to use the same charge increment calculation.

I take your point about different frictional characteristics though. However, the originals are also boat-tails, so their profiles should not be all that different. Perhaps the bearing surface may be longer on one than the other, or perhaps one has a thicker copper wall, but I think I have chosen as closely to the original weight and shape that I can in a hunting bullet, given the local market choices.

THROW THE POWDER AWAY. You have no idea what it is and you cannot tell anything about it by just looking at it.
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Not quite.
I can't say which company it's from, but I do know which powder it is as it is printed on the boxes: "H102".
If I see the same code, I know its the same powder. If I also find the same average charge weight over the first 10 or so, then I think I can work on it being the same set up as that which I worked from initially.

The point of these cartridges and buying the Hornady's at a similar weight is that I can load cartridges for a fraction of the cost of what I might normally pay. Handloaded cartridges using a once fire case comes in at anything from €1 to €1.30. These cost me about half that including the Hornady's.

The only other variable that might change a lot is OAL, depending on the distance to the lands. Even this is limited by my mag length.
 
Going from boat tail to boat tail I expect no issues, a 7.5% drop in charge weight is more aggressive than I'd be, but the odds of having a problem at that starting charge are still very small.

Also check LOT numbers. Ammunition with the same LOT number should all have the same LOT of powder.

Once you change LOT numbers on your surplus, you need to assume that even if you are using the same type of powder that it will be different enough in burn characteristics that you'll need to normalize your data for the new LOT number.

I know that powder options in Estonia are limited and very expensive, so just be careful you don't mix lots and you'll be just fine.

Out of idle curiousity, is the powder graphite colored or straw colored? Stick or ball? I've had both come out of European ammunition. Straw stick from Serbia, graphite stick from UK, graphite ball from belgium, and of course the fine Scandinavian powders that cost such a pretty penny. Country of origin for your surplus could also tell you something. I know there was a powder works in the Czech republic, but only that Accurate Arms purchased a stick powder they marketed under the AA4064 label for a few lots before switching to another source.

Good hunting.
Jimro
 
Out of idle curiousity, is the powder graphite colored or straw colored? Stick or ball?
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Honestly, it looks exactly like the VV powder I've been using in all my other reloading!! The ammo itself is Brazilian, I believe.

I will have a look at the LOTs too, just to be on the safe side.

You really need to relocate to Texas.
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I think I wold have to reload more than I can realistically shoot to off-set the cost of moving to the other side of the planet....

That is why I like my mil-spec refurb' plan!!
 
I can't say for sure if the lot is the same as my initial trials, but what I do have now is all of the same lot. I have also measured the pwder charge from a random 10 cartridges and the average comes out at 43.8gn which is exactly what I had before as my starting point.

So, I will forge ahead with loading a 5-shot/group ladder with the 150gn Hornadys as well as loading a few of the load previously id'ed as the best load for this powder/bullet combo in my rifle at 43.0gn to see if they still group as well as they had previously.

For the Hornadys I will forego the higher charges as they had previously given me some stiffer extraction with the original bullets and I don't see slightly heavier bullets improving that situation.
 
Just an update for any who'd like to know. I pulled the originals and seated the Hornady's: 7 cartridges of 42.7, 43.1 and 43.6gn of the mystery original powder.

I finally found the time and weather to give them a go at the range. Rainy, mild cross-wind but still yielded results.

The walk-away winner was the 42.7gn charge weight (the same as the one that gave best results with the original bullets too). 1.17MOA at 100m with a 7-shot group.

Plenty for hunting, I think. Just need the licence now...
:)
 
Glad things have worked out for you and the search for a decent "cheap" hunting load.

I doubt you will be disappointed in the results with those Hornady bullets either. They usually work very well and especially at the velocity range your looking at. you should have no issues with separation or over expansion.

Good luck with the hunting and as mentioned now post up the final results of your efforts. A nice pick of your harvested critter, and the rifle.

Oh forgot to mention, pigs or hogs are a great test for your new loads if nothing else is available. ;)
 
2.5 inches is plenty for hunting, you are more than good.

I never did find an animal with a 1 inch square on it to check, but I suspect I would have been lucky to get within 3 or 4 inches of any I shot.

Behind the shoulder about the middle and not a specific aim point past that.
 
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