30-284?

I honestly don't know. I've never shot long strings of em consecutively except when developing loads... and that was a while back.
I only shoot those when hunting so never noticed.
 
How did you notice? Borescope?

I'd get a lot of bad fliers and was able to see it really easily looking in the muzzle. Then with my bore scope could see how very gloopy it is. The Sierra copper fouling was pretty light and easy to clean. This stuff looks super gloopy and is hard to clean off.

I'd still get good accuracy in the '06 but the fouling also wasn't near as bad.
 
Wow... that's interesting.
Leade angle maybe?
A really good smith (precision rifle builder) here says leade angle must match the angle of bullet from the straight wall bearing surface to ogive for maximum precision. He also said that if they do not, and the leade angle is a sharper (higher degree of angle) than the bullet angle, then accuracy can go ary. Interestingly though... after 100-200 rounds... the bullet will actually pound and push out and change the leade angle to match the bullet that keeps slamming into it and accuracy settle down.
 
That's certainly interesting! Leade angle in this barrel is pretty low... Either 1.5 or maybe lower. The leade in my old Tikka '06 barrel was pretty steep. I don't know what Tikka uses, but 3 degrees is pretty standard for a factory barrel, right?
 
Many modern chamber Leade angles are 1 degree 30 min. I had to look for quite a while to find one that was 2 degrees, the 300 H and H.

The print for the 30-06 does not use a 3 degree leade angle.

The 35 Whelen mag uses a 2 degree 30 min angle.

Finally on page 112 the 338 Lapua looks like it uses a 3 degree leade angle. I didn't find any others but there are many chamberings listed on Sammi's site:


 
Or...Perhaps simple science ... the softer copper jacket of the Hot Cor is getting caught up in the machine chatter marks upon initial engraving from rifling.
 
Or...Perhaps simple science ... the softer copper jacket of the Hot Cor is getting caught up in the machine chatter marks upon initial engraving from rifling.

That's kinda what I was thinking. It just goes to show how nice the Tikka chamber and bores usually are.

Many modern chamber Leade angles are 1 degree 30 min. I had to look for quite a while to find one that was 2 degrees, the 300 H and H.

The print for the 30-06 does not use a 3 degree leade angle.

The 35 Whelen mag uses a 2 degree 30 min angle.

Finally on page 112 the 338 Lapua looks like it uses a 3 degree leade angle. I didn't find any others but there are many chamberings listed on Sammi's site:


Duh... I guess I could have just looked at saami prints!! I didn't think about all the mfgs using the same angle due to saami
 
Here's a big question... I've shot 40 of these hot cors with no accuracy that I'd want to rely on hunting. And I've got no other hunting bullets and things are scarce.

Since I've got some accurate loads with the Sierra 175 MK, what do y'all think about hunting elk with them for broadside behind the shoulder shots only? Any experience? I wonder how frangible these are in comparison to say the Berger's that everyone loves
 
I can't elaborate on the Sierra SMK being acceptable for elk.
I've read that they may work great on one shot and pencil on another due to it's structure.
I do know that my buddy took some double shoulder shots on whitetail with Nosler RDF @ 100-200yds and had beautiful golf ball exits.
We do understand that he may have expansion issues farther out and not hit bone. He was "testing what he read" as someone commented RDF being good for hunting.
 
Here's an update. I had another thread going trying to figure out my fouling issue. https://www.longrangehunting.com/threads/copper-fouling-location-in-barrel.278407/post-2280097

No resolution. It's a heavy fouler with Hornady and Speer cup and core bullets.

I think I've found this barrel and Speer HC shoots best when loaded with copper. I initially did a seating depth test to start and it seemed to like being 0.020 off, but also had a nasty flier in that group and quite a few in the others. The fouling was heavy, after 20, so I figured it was likely that. I then tried a 20 round test on a clean barrel to find best charge. Lots of fliers, decided to try a different bullet.

I thought I heard Hornady jackets were harder than speer, so decided to give the Hornady 165gr BTSP a try. The fouling was much worse and got nowhere trying to develop a load because I'm just not going to clean a barrel every 5 rounds.

Tried some Tubbs TMS bullets. Visibly, it smoothed out the awful reamer marks in the throat quite a bit, but there was no significant change in fouling or groups with the Hornady 165gr after.

So I went back to the Speer. I loaded 30 of the best seating depth hot cor load today, rather than try to continue development on a clean barrel and chase my tail, to see if it got better as fouling increased. After 30 shots, the lands are coated nearly solid with copper for the last half of the barrel. Not in the grooves though, like the interlock did. Near the muzzle, it may look a little less gloopy than it did before the TMS bullet treatment.

30 rounds
Virgin Peterson brass
56.5gr h4350
Cci200
Speer hc 180gr ~0.020" off lands
2861 fps avg
9 SD
20 ES

There were a several fliers 1.5" away in the first 20 rounds and then the last 10 were acceptable. I used a new rear rest that took some time to get the stability during trigger break figured out, so I had some definite misses in the first 15 shots that screw with my overall results. But, given the last 10 shots, this will do for hunting. I'm going to just do a light clean on the bore and chamber with hoppes and see how far it will go before copper buildup becomes a problem.

I think this cartridge has a great potential. My '06 would take this same load to about 2850 fps, but it used 58.8gr of h4350 as opposed to 56.5gr this one uses. I can get this cartridge and bullet to at least 58.5gr without any pressure signs so it has to be pushing 2925 or 2950 with that charge. I unfortunately didn't have my Chrono that day so I don't know for sure. That's on a 22.5-23" barrel and with a very poor shooter!

I'm sure if some of you guys took on this cartridge, you could really make it shine.

I need to get with a good smith and have a reamer designed for myself.

IMG_20210906_144250944.jpg
 
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That is definitely a hunting capable group!
I will be working on a 30-284 before long if I can find a reamer.
That's definitely a brown pounder with a 180 @ 2850+FPS!
 
That is definitely a hunting capable group!
I will be working on a 30-284 before long if I can find a reamer.
That's definitely a brown pounder with a 180 @ 2850+FPS!

Yea and I'm sure if someone went after it has that more options for components than me or if a person had the quickload software, they'd be able to finish ND the best combo. Maybe 4831 or rl23 would really get them screaming.

I think a 30-284 shehane would probably be the absolute ideal non magnum 30cal round. But, I don't want to have to buy a hydroform die or waste primers doing that much fireforming.

Are you thinking of renting or buying a reamer?
 

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