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That means you are close to 2725 fps when fired from a 24" tube. How fast does Hornady's maximum load travel with Varget and 178's? Your load seems fast to me. I don't run any 168 or 175 SMK's faster than 2600 fps from my 24" .308 barrels. I haven't loaded any 178's so take that into consideration. I suspect you are pushing it. My M1-A 168 grain loads run 2500 fps actual velocity from a 22" when using military brass and published maximum "service rifle loads".
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Hey op, I worked up some 178 amax for my 308 and tested this morning. Did .2 increments up to 43.2. They got better as I approached 43.2 and I was able to get .5 inch sized grouping at 100 yards. Hornady manual says 43.2 is max. I have, however seen others load upwards to 44.3 grain loads. My loads seemed tight and maybe compressed. I didn't see any pressure signs, what's typical for a 178 amax and should I go up a little more?
If you're at the bullet manufacturer's maximum load and getting 1/2" groups, why would you want to go higher? Without a chronograph to compare your velocities vs. Hornady's published speeds I would be happy and stop. You may be over pressure now and not know it. You may a have a tiny amount of wiggle room to go higher, but your accuracy is great. I wouldn't change anything if I was getting 1/2" groups.
Who said I didn't have a chrono. Avg speed 2625 fps out of a 20 inch barrel. Reason I want to go higher is that the groups didn't tighten down until my last set of 5 at 43.2 grains. Just curious to see when they start to tighten or spread so I have a range
That means you are close to 2725 fps when fired from a 24" tube. How fast does Hornady's maximum load travel with Varget and 178's? Your load seems fast to me. I don't run any 168 or 175 SMK's faster than 2600 fps from my 24" .308 barrels. I haven't loaded any 178's so take that into consideration. I suspect you are pushing it. My M1-A 168 grain loads run 2500 fps actual velocity from a 22" when using military brass and published maximum "service rifle loads".
Just got home and looked at my Hornady manual. Was at the lease this weekend, so did a lot of reading about this combo this weekend. Hornady says 43.2 is 2500 FPS at 43.2 grains. No pressures given. So, I consulted my Lyman 49th. It gives 44 grains max 2661 FPS pressure 60,500. I do agree that I'm at max according to hornady and near max according to Lyman. This weekend, my chrono errored on two of five shots due to the sun. But I did get 2655,2527,2694. Avg 2625
Reason I want to proceed a little more is that my grouping with other factory ammo is better, Nickle sized in a 150 grain bullet. I'm great with that as its a hunting round. I'd like to get the 178 to do a little better. From most of my reading what others have gotten, 43.7 was average. So, I'm thinking of trying 43.2 again for repeatability and then 43.4, 43.6, 43.8 to see what that does. My 168 SMK groups Nickle to dime sized with 42 gr RL15. I'd like to try getting this 178 amax up to that if I can.
I do need to be practical though. If consensus is that I'm as high as I should go, I'll leave it. I'm just feeling out some responses on the forum. The 168 seems to shoot best. I'm working with the 178 for distance shooting. Going to try to learn and practice longer shots.