45-70 won't group

[The Cold Lake Kid]

I shoot a number of repro "Buffalo" gun single shot rifles, in .45-70, using cast lead bullets.
I found that some of my bullets were hollow and under weight. Further, you could not visually detect this, since the sprue cutter had pushed lead over the hollow.
For serious accuracy, I recommend weighing your bullets.
I use a bottom pour lead furnace and hold the mould under the spigot a bit longer to allow more lead to enter the mould as it cools and the lead shrinks.
I would clean any lead from your rifle's bore and slug it for size, then start sizing and lubing a bit more than the bore.
Your mileage may differ, but that's what worked for me.

 

[jethunter]

...I found that some of my bullets were hollow and under weight. Further, you could not visually detect this, since the sprue cutter had pushed lead over the hollow...

Interesting problem. That would be the mold temp being too cool and at the same time not letting the bullet cool long enough before cutting the sprue.

Most of these inconsistency problems are solved by casting hotter to raise mold temperature and make better fill-out, and then allowing the bullet to cool long enough. Heat and patience.

 

[jdschwass]

Heyall,
I hate to be that guy that starts a thread and leaves everyone in the dark... kids and life didn't allow me to get the 45-70 out since my last posts, until today.
Still using 405gr cast bullet from lee mold, unsized, alox lubed. I picked up a pound of IMR 3031 per recommendations on here. I loaded up 9 groups of ladders, 5 rounds per load. Starting at 34gr and moved up to 38 gr. in 0.5 gr increments This should put me roughly in the 1100-1352 fps range.

With respect to the gun itself, (Marlin 1895 SBL) i cleaned it up with a bore brush wrapped in copper mesh, also I saw recommended somewhere. It worked like a charm. It stripped out any of the fouling. Then I followed up with a normal cleaning.

I got out to the range today, and I have to say it was much better than my last session. I was shooting with the fore end supported on sand bags. Fairly stiff wind in my face. 75 meters. The bottom of my ladders (34 gr) was shooting about 6 inches. As the loads got hotter, the groups tightened up. Somewhere around 36-37 gr I was shooting a 5 hole group in about 2.5 inches. At least now I am in hunting territory. I was also running the brush through the bore between each set.

I am planning (when I can) to load up another batch of ladders, this time using smaller increments and honing in around the 36gr range. Aside from that, I am thinking I can start weighing and sorting bullets, but overall I am feeling much better about it. I have room for improvement... which is the name of the game.

Thanks for everyone's support.

Cheers.

 

[TrollGRG]

Once you are close to what you think is the right load, I would suggest that you start your range shooting by taking the first shot, do a quick clean of the barrel (this will also give the gun time to cool off) then take your second shot. Repeat for each round. If the impact is constant and your grouping is acceptable then start the next load combination.

Remember to clean and cool the gun after each shot. It does make a difference. If you don't see any - all the better - you at least have a good start..

If you are looking for a round for bear hunting then you are looking at a cold barrel, unless of course you are planning to put 9 or 10 rounds into him ;o)

 

[jdschwass]

Thanks, that is a good point. All of the ladders I did today were back to back shots with some cooling in between.
The most I have needed for a bear was 3... but those were piddly little .303 rounds...

 

[colt1851]

Some of those Lee molds are only 0.457 dia. Maybe you should get a different one and size to 0.459.

 

[yomomma]

Learn to powder coat. Reduces fouling and increases O.D.

 

[fingers284]

Heyall,
I hate to be that guy that starts a thread and leaves everyone in the dark... kids and life didn't allow me to get the 45-70 out since my last posts, until today.
Still using 405gr cast bullet from lee mold, unsized, alox lubed. I picked up a pound of IMR 3031 per recommendations on here. I loaded up 9 groups of ladders, 5 rounds per load. Starting at 34gr and moved up to 38 gr. in 0.5 gr increments This should put me roughly in the 1100-1352 fps range.

With respect to the gun itself, (Marlin 1895 SBL) i cleaned it up with a bore brush wrapped in copper mesh, also I saw recommended somewhere. It worked like a charm. It stripped out any of the fouling. Then I followed up with a normal cleaning.

I got out to the range today, and I have to say it was much better than my last session. I was shooting with the fore end supported on sand bags. Fairly stiff wind in my face. 75 meters. The bottom of my ladders (34 gr) was shooting about 6 inches. As the loads got hotter, the groups tightened up. Somewhere around 36-37 gr I was shooting a 5 hole group in about 2.5 inches. At least now I am in hunting territory. I was also running the brush through the bore between each set.

I am planning (when I can) to load up another batch of ladders, this time using smaller increments and honing in around the 36gr range. Aside from that, I am thinking I can start weighing and sorting bullets, but overall I am feeling much better about it. I have room for improvement... which is the name of the game.

Thanks for everyone's support.

Cheers.

You asked a question in the second last paragraph of your first post and I would suggest your expectations be realistic to the amount of effort you are putting into your cast slugs (no weight sort, no sizing, Alox lubing)...fact is you may have reached the summit of your slugs consistency... your rifle's as well, but without a "better example" to compare with, you may never know. Case in point is my own 1895 CB with 26" barrel...should be as good as anything with most any bullet...but it isn't , It will shoot most anything 450 gr or less, home cast or commercial hard cast, into 2-2.5 in" and that is what I expected from that rifle after many hundreds of test rounds from 1100 fps up to 1600 fps...until I got into powder coating and really stretched the envelope on a test I did with some commercial cast 250 gr .45 LC pistol slugs, I powder coated them up from .452 dia up to consistent sized .459 dia...that rifle will shoot those slugs into an inch group all day at 1200 fps.

The fact is that there have been thousands of home cast bullet shooters that have tried to overcome the odds & find a cast slug that will shoot jacketed bullet groups...a very minute', very lucky # have even come close . Fact is ,you have to go the extra mile to one extent or another to achieve the accuracy that Buffalo rifle shooters enjoy out too very long ranges at even 100 for us "mortals". Some of the gyrations they go thru to make "consistent ammo" is to the extreme sometimes, and you have to sort through it all to find what fulfills your expectations...if your expectations are to reproduce digitally produced "jacketed bullets", you are in for a loooonnngg learning curve that wont be a "rabbit hole"...more like a "crater".

Personally I have probably a dozen rifles in the herd that I shoot strictly home cast slugs through
that have varying degree's of "barrel fitness" from a lot of pitting-to some pitting-to new, modern productions and that 1895 with over sized pistol slugs is the only one that will shoot what we expect as a common jacketed group. All of them without exception, with unweighted, not sized, wax lubed slugs will shoot from 2.5- 4 inch groups, if I weigh the slugs & sort to a 4 gr. variance, size after casting to normalize, Powder coat to at least .002 oversize and give another trip through the sizer to normalize all at that .002 every one of those guns will shoot easily at 2-2.5 some consistently down to 1.5 (always the ones with a new, un-pitted barrel).