Questions About Developing my Load

[MShanahan15]

Hi everyone, I'm just getting into reloading, and I have a few questions; I have the basics down, and I've loaded and shot a few rounds, but I have stayed within a grain of the starting charges, because I have been afraid to push the envelope, but now that I am having trouble finding loaded ammo, I'm looking to create a load that is competitive with factory loadings with regards to muzzle velocity and energy, and am posting here to be absolutely sure that i do it right, so please feel free to infodump all you know about building up a load. however, to narrow it down a bit, I am loading for both a .308 AR and a Savage Model 10 rifle, in .308, and would like to be able to use the same rounds in both. I'm using Winchester brass, CCI large rifle primers, Varget powder, and 178 Grain Hornady A-Max bullets, and I know that the starting load (10%) below indicated max load is 38.9 grains, so my questions are as follows:

-Is 38.9 grains a good start point (10% below.the max load listed in Hornady's reloading manual)? And if not, what should my starting powder charge be?

-How many rounds at each powder charge should I make and shoot in each rifle, to test for pressure signs?

-What should my increments in powder charges be when building up the load?

-What specific methods should I employ, if any, to ensure this round's safe functionality in both my bolt gun and my gas gun?

-Lastly, as I have never come close to encountering pressure signs, I was also wondering if any of you could list pressure signs that I may encounter, such as flattened primers, case-head separations, neck splitting and whatever else I should be looking for, along with pictures, so that I can better identify them?

Thank you all for your time. I just want to do this right, and I really appreciate your input.

 

[Joop]

The first thing I would suggest, is that you take some time, a lot of time, and read, read, read. Then, read some more. These forums are full of great information. There are a lot of different methods/opinions on load development, but if you read for a while, you'll start to get an idea of where you should start and what may suit you best.

Personally, I think 38.9 grains is pretty low for a starting point. Not saying that it's wrong, though and it will certainly be safe. I use the 178 A-Max with Varget and I would probably start at around 41.0 grains for a new to me rifle. That's bolt actions. I don't have a .308 AR, so that could be very different and some of the guys here can surely send you in the right direction on that one. With that in mind, I'm going to suggest that you focus on the two different guns as two different reloading projects. In a perfect world, you could come up with one load that's perfect in both guns. In reality, that doesn't often happen. Especially, when one is a semi and the other a bolt. I would separate my brass for each gun, accordingly and start my load development from scratch, for both guns, as if they were two completely different calibers. That's just my opinion, though.

John

 

[shootist2004]

do you own a chronograph? its kinda inportant to working up loads.....

 

[MShanahan15]

do you own a chronograph? its kinda inportant to working up loads.....

No, i do not have a chronograph, but I was figuring that once I built up to the max load in the manual, or until I saw pressure signs (and then backed off to the last safe charge), whichever comes first, that THEN, I would make arrangements to use my friend's chrono, to log the FPS for the purpose of ballistic calculations and whatnot. If there's a flaw in that plan, please let me know, but so far, I can't see why that wouldn't work, but, again, I'm new to this, so I know that I could be missing something here.

 

[fireEMT5]

Check out Dan Newberry's OCW method for working up a load - OCW Overview - Dan Newberry's OCW Load Development System Read it until you understand it, then give it a try. You'll be on your way to a load your guns like, although you may find that a bolt gun and a gas gun like different recipies.

FWIW - after doing the OCW method for my Savage 10PC .308, I ended up over the published book max load using Varget and a variety of Horandy bullets - 150 SST's, 165 SST's, and 168 HPBT's. I followed the steps outlined by Dan, and as long as whatever charge I was on didn't show or exhibit pressure signs, I felt safe moving up to the next charge weight in powder. It did take some trail and error and several trips to the range to confirm what I found, but I found my recipies.

I'm far from a reloading expert, so take it for what it's worth, but it's been my experience that when using Varget for the .308, you'll probably end up close to a full case of powder (leaving room for the seated bullet of course) - maybe even boardering on slightly compressed. That's where I found the load that works best for MY GUN. You of course will want to work up to this point for safety reasons.

You might also consider buying yourself a 2nd set of .308 dies also, just to save yourself the time of adjusting between your bolt brass and AR brass - no doubt they will require different sizing settings.

If you can borrow your friend's chrono when you run your OCW test, you'll be able to write down some important data and know where you are at when you get "that group".

 

[MShanahan15]

Thanks for the link; I'll start reading now. And pardon my naivity, but I've been using a full-length Lee resizing die for my low-powered loads for both rifles, and had had no issues. Should I change that when i step up pressure? And if so, why? I am really hoping to develop a load that works in both. I know it will have to be a compromise, but I just want something like M118LR (which I am having a hard time finding, but shoots great out of both guns). I know that the M118LR uses SMKs of the 175 grain variety, but with components scarce, the closest i could get were 178 grain A-Max bullets, but the M118LR inspiration still remains in that I am really hoping to make a round that performs adequately and safely in both my autoloader and my bolt gun.

 

[fireEMT5]

I only mentioned having a second set of dies, or at least a 2nd sizing die, because if you check your fireformed brass - brass from your bolt gun, and brass from your AR, you will find that they are different sizes. More than likely your AR will show you it needs brass with more head space and the Savage bolt gun will likely be tighter, needing less.

It's up to you if you want to size your brass each time all the way back to specs - this will ensure that you can use it in either gun, however you will be overworking your brass, and thus shorten it life. Your best bet will be to get a headspace guage and figure out the headspace for each gun. Then you can still use a full length sizing die, but set it so that only sizes back until it works in your gun. If you had 2 dies, you'd have one set up for the Savage and one for the AR, and you wouldn't have to fiddle around when loading for one or the other. It's up to you, but components being hard to come by, why overwork your precious brass? You don't need to, but having dies set up saves time. Or, you can adjust your sizing die when doing bolt brass, then again when doing AR brass, or just size it all the way back to SAMMI specs so it works in either. Toatally up to you.

The brass I get out of my AR vs. my Savage bolt gun varies serveral thousands of an inch - that's why I used decicated brass for each and only size them back enough so they work reliably in each gun.

 

[MShanahan15]

Yeah, I think I'll just stick to fully sizing it back to SAAMI specs each time, I know it puts more stress on the casing, but it ensures that it will work in any .308, and I really like that aspect. As I said, the inspiration here is the M118LR, which can be used in an M14, M110, or M40 safely and accurately, a group that obviously includes not just a bolt gun and two autoloaders, but two different types of semi-autos, one being short-stroke piston driven, and the other being DGI. I'm looking to make a round that has that kind of versatility; a homemade equivalent of a full-power factory loading; sure it won't be custom-tuned to any one gun, but by the same property, it won't be restricted to just one. Am I making sense? Unlike most people here, I'm not looking for a laser trajectory, or one-hole groups at insane ranges, just instructions on how to build up to a recipe for something I can load, zero my rifles with, and use whenever I go shooting, that has comparable power to factory rounds that I could pick up off the shelf.