.308 Copper Monos

[oxn939]

Have a Howa 1500 in .308 Win that likes Hornady 165 grain GMX factory stuff pretty well, and planning to load up a few rounds to attempt to duplicate or improve this performance. Question is this- since a 165 grain copper (or "gilding," in this case) monolithic bullet takes up so much volume, is it worth loading into a case with capacity as low as .308? I'm not looking for a barrel burner load by any means- just something MOA or better in the 2600 FPS range- but apparently guys are getting compressed loads with as little as 42 grains of Varget.

Any experience or input appreciated!

 

[VikingsGuy]

Go with 150 grain mono in .308, it is a great round.

 

[oxn939]

What I tried initially. This rifle didn't seem to like the 150 grain TTSX much (2.5 MOA) and only liked Hammer hunters somewhat better (1.3 MOA) so I figured I'd try a projectile that it did well with using factory ammo. The new Hornady CX stuff seems to jump, in .308 cal, from 110 grains to 165 grains as well

 

[marksjeep]

Does it matter if it's slightly compressed, so long as you can load it consistently? I would try a few and see how they shoot.

Here's a note from Hodgdon's web site about it:
A full case, or lightly compressed charge is an ideal condition for creating loads with the most uniform velocities and pressures, and oftentimes, producing top accuracy

I don't have a Hornady book in front of me. Barnes lists 44 grains of Varget as max load for 165 grain monos, so 42, even slightly compressed, would put you right in there.

 

[oxn939]

Does it matter if it's slightly compressed, so long as you can load it consistently? I would try a few and see how they shoot.

Here's a note from Hodgdon's web site about it:
A full case, or lightly compressed charge is an ideal condition for creating loads with the most uniform velocities and pressures, and oftentimes, producing top accuracy

I don't have a Hornady book in front of me. Barnes lists 44 grains of Varget as max load for 165 grain monos, so 42, even slightly compressed, would put you right in there.

Check. Will see if I can find a Hornady loading manual around. Stability calculator says they should be fine with 1:10

 

[VikingsGuy]

What I tried initially. This rifle didn't seem to like the 150 grain TTSX much (2.5 MOA) and only liked Hammer hunters somewhat better (1.3 MOA) so I figured I'd try a projectile that it did well with using factory ammo. The new Hornady CX stuff seems to jump, in .308 cal, from 110 grains to 165 grains as well

Did you give the monos .050 jump to the lands?

 

[Dougfirtree]

I wouldn't rule out 130's either.

 

[Caseknife]

I just loaded up some 130 TTSX in .308 for my hunting partner, AR-Comp and good jump to the lands, just over 3000fps and 3/4" groups. Speed kills in monos.

Don't be afraid of loading compressed loads. In actuality you are not compressing the powder, just the air between the individual kernels. Yes, it does crunch a bit but that is just the grains conforming to the open pockets. If you take the time to tamp the cartridge case a few times on the bench prior to seating the bullet, you will get less crunch noise. In my years of reloading, I have found that loads that fill the case completely seem to have better consistency, the powder is always in the same position/density no matter the aspect of the case.

 

[oxn939]

Did you give the monos .050 jump to the lands?

Yep, always start there. Looking back at my reloading book, I had one good group and then one that was 3 inches.

I wouldn't rule out 130's either.

This is going to be specifically for Alaskan game, and 130s would be a little small for moose. 165s doing 2700, though, would be a different story.

If you take the time to tamp the cartridge case a few times on the bench prior to seating the bullet, you will get less crunch noise.

I've noticed this too. Think I'll see how fast I can get them using this technique- will report back on this thread what I find. I do recall that the factory stuff was lackluster, doing only about 2550 FPS. Like I said, if I can get a load to carry that kind of energy at or past realistic shooting ranges, I'd be happier about my life

 

[VikingsGuy]

As for compressed loads - I like a load that has a bit of compression seems to aid precision. When I am getting near compression loads I use an 6" drop tube when loading powders. Not sure exacty why but it does seem to create a better natural packing of the powder and most loads no longer "crunch". Of course, too much compression can lead to inconsistent seating depth and bullet creep if not crimped.

 

[wsco3506]

I have been able to get great accuracy with 168 grain TTSX with my 308. Velocity is just a hair over 2700fps. I use IMR 4064 compressed slightly.

 

[BRI]

I picked up a Ruger American in 308 at a price I couldn't pass up. I developed a really accurate load with 152 grain hammers, RL15 at 2820 fps. Have yet to shoot an animal with it but looking forward to doing so this coming year.

 

[oxn939]

I have been able to get great accuracy with 168 grain TTSX with my 308. Velocity is just a hair over 2700fps. I use IMR 4064 compressed slightly.

That's exactly what I'm looking for. Evidently, Varget is listed as the most accurate powder in Hornady's loading manual and I miraculously managed to come across a few pounds of it recently, so hoping I can come up with a 1" load doing around that velocity.

 

[Dougfirtree]

Yep, always start there. Looking back at my reloading book, I had one good group and then one that was 3 inches.



This is going to be specifically for Alaskan game, and 130s would be a little small for moose. 165s doing 2700, though, would be a different story.



I've noticed this too. Think I'll see how fast I can get them using this technique- will report back on this thread what I find. I do recall that the factory stuff was lackluster, doing only about 2550 FPS. Like I said, if I can get a load to carry that kind of energy at or past realistic shooting ranges, I'd be happier about my life

Fair enough. I'd want bigger for moose, as well. One related morsel of info: I once spoke with a guy at Barnes bullets, who explained to me that each specific weight/caliber of TTSX/TSX is designed to open at different velocities. He said that with TTSX's, the .308 168 grain bullet is designed to open well at lower velocities than the 165. This is specifically because of use in the .308 win cartridge. So, if you're open to trying Barnes, you might try the 168 instead. Or, it might be worth asking Hornady if they do something similar.

 

[oxn939]

Fair enough. I'd want bigger for moose, as well. One related morsel of info: I once spoke with a guy at Barnes bullets, who explained to me that each specific weight/caliber of TTSX/TSX is designed to open at different velocities. He said that with TTSX's, the .308 168 grain bullet is designed to open well at lower velocities than the 165. This is specifically because of use in the .308 win cartridge. So, if you're open to trying Barnes, you might try the 168 instead. Or, it might be worth asking Hornady if they do something similar.

Great SA on this! I had heard the same thing. I'd love to try those 168s, actually- if anyone has a few extra laying around, shoot me a PM and I'd be happy to take them off your hands! Haven't seen them in stock at any stores I've been to recently.