Bullet change and more copper fouling

[Tac-O]

I have about 500 rounds shot through my stainless Tikka. I broke it in with 20 rounds of Winchester power points. The shoot, clean, shoot, clean method.

After that, I was shooting handloads of .30 Cal Sierra 150gr bullets with staball 6.5 powder. I would have very little, if any copper after 20 rounds. Usually none. I'd clean with wipe out foam every 20-25 rounds. I did this to about the 200 rd mark. Then quit cleaning it completely until the 475 rd mark.

I cleaned to steel, gave the first 3-6 inches a go with JBs. Still didn't seem to get that much copper built up.

Switched over to 180gr Speer hot cors and h4350 powder. Shot 15 rounds and holy moly there was a lot of visible copper fouling starting to build up near the muzzle already.

I know the staball has a decoppering agent, but I wouldn't think it would make that big a difference. I'm talking almost no copper after a couple hundred rounds vs a ton of copper.

Could it be the different bullet manufacturer with more bearing surface since they're 180gr vs 150gr?

Could it be the decoppering agent?

Could the staball powder not getting a complete burn have scratched my bore?

I just find it odd there was that big of a difference.

 

[Bob Wright]

Tagging

 

[Tac-O]

Anyone? Ideas?

 

[cohunt]

hot-core's seem to be a whole different animal, they seem to have drastically different reload data for them in certain cartridges, I think its due to the type of "bonded hot poured lead core" they use and the different allow of copper jacket for the hot-cores--I would suspect the bullets first--- always clean between different bullet types so clean it again and try a different bullet, or same bullet with other powder and see what happens--each rifle is different too

 

[CVCOBRA1]

Clean well, load 20 rounds with the Hot Core bullets and Staball powder and you will answer your own question. Bullets or powder? I'm sure you can find some kind of load for 180's and Staball.

 

[Tac-O]

I don't think I like that staball powder. Insanely dirty.

I do have 12 or 13 Sierra bullets left. So maybe I'll just load some of those with h4350 and see what the fouling looks like. Or Maybe I'll do the staball and speers.

I thought I read somewhere that speer jackets were a softer alloy than some others, but I'm not sure.

 

[MagnumManiac]

Speer jackets are sticky and leave lots of deposits of copper behind.
I used a lot of them in my 25-06 and 300WM years ago and had to use tonnes of Sweets getting them clean. Very good accurate bullets so I put up with coppered up bores.
Those 120gr Hot Cors outta my 25-06 were dynamite on Wapiti sized deer in New Zealand, nothing penetrated like them, not even Partitions!

Cheers.

 

[Tac-O]

Speer jackets are sticky and leave lots of deposits of copper behind.
I used a lot of them in my 25-06 and 300WM years ago and had to use tonnes of Sweets getting them clean. Very good accurate bullets so I put up with coppered up bores.
Those 120gr Hot Cors outta my 25-06 were dynamite on Wapiti sized deer in New Zealand, nothing penetrated like them, not even Partitions!

Cheers.

Thank you! That's good to know.

I have shot a box of Speer boat tails out if my kids' savage 7mm08. It was a reduced charge load and shot wonderfully! It did lay down a lot of copper but I just attributes that to the savage bore. Maybe it was just as much the speers as it was the bore.

It took me a couple rounds of soaking to get all the copper out out of my tikka after shooting the 25 rounds the other day. I don't mind it, as long as it shoots and performs on the animals.

 

[Tiny Tim]

Gilding material used in bullet jackets can vary greatly from manufacturer to manufacturer. Also the "hot core" process may have an annealing effect on the jacket as well. You could try another bullet with the same powder, or the same bullet with another powder to see if it is a component or combination issue.

 

[LoneTraveler]

The Speer Hot core Bullets seem soft compared to other bullets.
I wonder how the cooling process is done after the hot core is installed, If the copper content in the gilding metal is cooled quick the jacket will be soft.
Sort of like annealing case necks and the copper content of brass softening from heat and quick quinching.

 

[Dirtrax]

I don't have any experience with the Speer Hot-cor but what has been said seems reasonable enough. I did run RL-23 for awhile when I couldn't find H-1000. RL-23 does have a de-coppering agent and I could really notice a difference. So all you can do is run the Speer bullets with Staball and see what happens.

 

[Tac-O]

Here is an update on this issue.

The first 25 rounds with the Speer hot cors created a lot of copper fouling, which I thought seemed very odd for my gun because it's always taken a LOT of shooting to pick up copper. These rounds were also the first firing on some virgin starline brass, which I haven't used before. I cleaned to steel after this.

On the second 25 rounds of hot cors, I resized the starline and shot it again. Same powder and charge weights as before. No visible fouling near the muzzle!! I cleaned to steel again.

On the third round of 25, I used virgin starline again. TONS of copper after 25 rounds again.

I'm thinking it's got to be something about the virgin brass. Thoughts??

 

[Mikecr]

Whatever you're closing in on, it's very interesting.

 

[Tiny Tim]

What brass were you using on the second batch? Was it the same starliner brass, just not virgin? I guess I'm missing something.