Home Forums Reloading Big Game Rifles Help “balancing” when changing primers

Hello. I know I’ll need to start low and work up, do a bit of trial and error, but am hoping some more experienced hand loaders can shorten the process. I’ve shot 140 grain accubonds and ballistic tips in my 7-08 for years. 44 grains of Reloader 15, Federal GM205M primers in Lapua 308 srp brass for 2890.

Family is going to Zimbabwe soon and we’re taking one of the kids’ 7-08s. I had to buy some Alpha munitions brass that is stamped 7-08. Is there a guesstimate of nature to account for changing from small rifle primer to large rifle primer? Suggestions on which to use? I’ve got
CCI
CCI Large Rifle No 200
Federal Large Rifle Match GM210 or LRP 210
Winchester standard rifle WLR
CCI large rifle magnum No 250
CCI large rifle magnum No 450
Federal large rifle magnum GM215M

Thanks

Along with primer type, how does the capacity of the Alpha compare to the Lapua?

I'm not a 7-08 expert, but the load you listed looks pretty stiff to me. Please be careful changing things.

Agree, suggest he go to Nosler and look at the data. Personally wouldn’t change brass or primer without backing way off.

Thanks. I did check Nosler and this load is quite a bit over max. I was given the rifle (and load data) about 15 years ago and haven’t changed it. I’ll start from scratch with the new brass and primers.

RL 15 is a stick power.

Switch to the CCI 200's, back off a bit and work up, don't look back.

For reference, I use 44 gr of RL-15 with 120's, 42 gr with 140's, Fed-210's in Winchester & Starline brass.

Do what AS said to be sure & safe.

MM

1/2 grain over taint bad, but 2.5 over isnt the territory to be playing switcheroo with components.

^^This.
Changing from SRP to LRP is a big change to begin with, and hot loads may make for a bigger change.

All of those primers will work, but I'd use the CCI200's, as that is what I generally use. Even when running ball powder in the 7mm-08. You could possibly try the CCI250's, if using big game or Hunter, or other ball powders. I've never had issues using standard large rifle primers with RL15 though. According to the Nosler load data, you are already over max with that powder though. So, you want our opinion? Try some Big Game powder, and please reference the Nosler load manual, or their online data. It's free!!

Since you asked, this is how I'd do it:

1. Primer: CCI250
2. Starting load of 45gr of Big Game and work up 1/2 grain at a time, until I reached book max of 47.5gr's or I saw obvious signs of pressure.
3. Shoot some 5 shot groups, with the varying charge weights, as I worked up. Look for OCW and good accuracy nodes.
4. Load those bullets at .020" off the lands, or mag box length: if that is shorter than .020" off the lands.
5. After finding something that shoots sub moa, retest/confirm. If they are consistent, load more, to suit your needs.

This is what I'd do, regardless of what brass I am using.

Your load you have currently is fine, if switching to LR primers then do a full work up.
Years ago when Hornandy had the " Light " magnum ammo I bought a box because they claimed 3000 fps with there 139 SST and sure enough my chrono said 2999FPS. I was using 4350 with 140NP and could only get 2850 and ran out of powder room and so I pulled apart a factory round and it had ball powder so I switched to 760 powder, CCI 200 and sure enough 2950 with a 140 NP using Rem 7mm-08 brass in a Rem 24" barrel
Hornady factory ammo today claims 2950 with there 139 in a 24" barrel so if that length is what your running i wouldn't worry about the speed your currently at.
Just be careful with 15 its not that stable I would do load development with as close to the same temps in Zimbabwe if you stick with it.

Comparing a Nosler bullet to a Hornady bullet is quite stupid. Just because one gets a certain velocity with a certain powder, does not guarantee another will with the same pressures. The powder he's using is way over book max, and also over book max velocities. I'd be careful about suggesting what is "fine". The OP also should not just assume a load is safe because someone else worked it up in said rifle. That is also unsafe, and not a general practice that most handloaders do. If I were given a rifle and handloaded ammo for that rifle, I'd pull the bullets, dump the powder, and start from scratch. That is something any real handloader would do. There are no "shortcuts" to this process, unless you are looking for something to bite you in the azz..

The Lapua SRP brass is what is allowing the higher powder charges and velocities that are concerning others IMO. I suspect it can easily handle sustained loading at close to 70 ksi. Switching to LRP eliminates that safety margin and I would certainly do a full workup and try to match temperatures like sherm_61 suggests.

Problem is his loads are probably even hotter. Although he’s using a single base powder hot weather and a hot load isn’t a good thing.

Pretty sure he'd get ejector marks if he was hotter than that. Maybe he is?

Reloder 15 is a double base powder.

I’m a believer in always working up.

You’re right, it is double based. Don’t know why I was thinking otherwise.

Lapua seems to be darn strong brass, particularly when newish.

No worries!

I have about 400 pieces of Lapua SRP .308 brass I am cycling thru with more in reserve. Most is on it's 13th firing and both my summer and winter loads with N135 are more that 4 grains over their "Book Max" for LRP cases. Of course not all barrels and reamers are the same, and the VV manual does not list pressures. Rest assured I started low and worked up though, and this same load is used by more than one member of the US Palma Team.

Thousand yard 308 shooters load hot? Who would have thought?

I appreciate everyone’s suggestions and am starting from scratch with the new brass and primers. As I stated initially, I am a relatively novice handloader. My late father in law gave me this rifle and load. He shot a lot of bench rest and prairie dogs (and was a pretty remarkable knife maker on top of that). When he helped me set up my reloading bench, I was not in a position to tell him he was wrong. I’ve loaded what he showed me for 15 years and managed to kill a bunch of whitetail, aoudad, and even 2 once in a lifetime NM animals, an on range oryx in 2010 and a desert bighorn a few years ago.
I do know that he “ran his 7-08 hot” per his gunsmith. I haven’t seen any reason to tinker with it, but may reconsider.
Thanks for the feedback, I’m hoping to put a few together today and give them a spin.

You should see what the long range .223 guys are loading.😲