Leading?

[bigcountry]

So, I do shoot a bunch of CB in pistols under 1300fps.

So, started casting bullets for my 45-70. Had a microgroove, and had obvious leading issues and accuracy issues. Got rid of that gun, and have a newer with ballard rifling. below are my loads

RCBS 300gr FN GC Lyman #2 sized to .459 and std ideal lyman lube
IMR3031 55gr
IMR4198 44gr

So here is my question. After shooting 20 rounds (10 of each), it took me significant amout of effort to get brown/black fouling out. About twice as much as a hornady jacketed bullet loads. Using shooters choice and lead remover. Ran a brush thru about 10 times twice. So is this leading? Is this normal? I was getting 3MOA at 100 yards, even on my last 5 shots. The picture is at 50 yards.

I know with my microgroove, with severe leading, accuracy went to crap.263451

[454PB]

You can usually see lead on the cleaning patch. If all you saw was fouling, and no flecks of lead, I doubt you have a leading problem. My Marlin Guide Gun in 45/70 has Ballard rifling, I size to .4585", and get zero leading.

[knifemaker]

My Marlin 1895 preferred cast sized to .460 and I got one inch 3 shot groups at 100 yards using my Ranch Dog 350 gr cast with 43gr. of IMR-4198 powder. When talking to other marlin 1895 users in my area, they all said they got best results sizing to .460.

[bigcountry]

Problem is coming out of the mold they are only .458 or maybe .459.

[bigcountry]

You can usually see lead on the cleaning patch. If all you saw was fouling, and no flecks of lead, I doubt you have a leading problem. My Marlin Guide Gun in 45/70 has Ballard rifling, I size to .4585", and get zero leading.

Yea, I don't see slivers of lead like I did with microgroove. Just some brown and black. Do you think its the lube that is making so dirty?

[MT Chambers]

That 300 gr. rcbs is undersized for my Marlin, inaccurate and will cause leading in my gun. I shoot the 457122 gould hp no problem, and all other heavier cast boolits.

[Bird]

Your target groups look very consistent. I would expect groups to open up if leading was occurring. What lube are you using?

[bigcountry]

Lyman Ideal lube. I have never used anything else. recommend something else?


Your target groups look very consistent. I would expect groups to open up if leading was occurring. What lube are you using?

[bigcountry]

So, took a bore scope to this barrel. The barrel is rough as a cob. I found some jacket material. Minor lead. So I don't think my load is leading. I just think this barrel is so rough. I only have like 50 rounds thru it. Maybe more.

I slugged the barrel, and its .458" and .452" on grooves. 6 grooves. I expected ballard to be deeper.

I am considering lead lapping but I know the lands will probably open up to .459 at the best. And I am not sure I want that. I can't find a .460 lube sizer to fit my lyman lube anywhere. Biggest they make is .459"

[Bird]

I think Buffalo Arms make a .460 die. You will need to make sure a 0.460 seated bullet will chamber in your rifle. In my 1886 miroku/winchester , it would be a tight fit.
If you are not leading the bore , then your lube is not a problem, but it may be causing some discoloration of your cleaning patches.
It may help group size if you load to lever action pressures, at the cost of more recoil. Those 300g cast bullets actually may be 325 grains with lube and gas check fitted, and type of alloy used.
Try shooting a couple of hundred jacketed bullets down the bore, cleaning every 10 or so shots.

[sigep1764]

If the bore is rough, you can fire lap it with JB Bore Paste. It'll smooth up in a few shots. I just put it on a patch for pistols and run it thru the barrel on a jag, but longer barrels get the fire treatment.

[454PB]

It's relatively easy to open up a Lyman sizer die .001". I have a lathe to do that, but it can be done with an electric drill and a split arbor of some sort (even a wood dowel will work) and some fine emery clothe. You don't say what alloy you are using, but adding some antimony will increase as cast diameter.

[bigcountry]

If the bore is rough, you can fire lap it with JB Bore Paste. It'll smooth up in a few shots. I just put it on a patch for pistols and run it thru the barrel on a jag, but longer barrels get the fire treatment.

I fire lapped a competition rifle about 18 years ago with tubbs fire lapping bullets. It rounded over all the rifling. Cost me 500 dollars to rebarrel. Ever since then, I have been hesitate. I realize Jb's is not near as aggressive, but I have lead lapped hand lapped. Long process.

[salvadore]

I have an AR-15 that would take forever to clean the copper out of the barrel. It was a days long ordeal with green patches the rule. Anyway, when I finally got it clean I used a product called dyna tek. When I range tested it the groups improved and clean up was swabbing the barrel, twenty times with the bore brush reswab and I was done. Just a thought.

[Ozark mike]

Probably the bbl.The quality of marlin is crap at best i have a 95 that took a considerable amount of work to be a ok gun. I've seen chattered bbls sights not straight loose wood rough actions and much more best advice i have is find a henry or japchester if you don't have a interest in a kit gun