Velosity over 2500ft/ sec?

[DCB]

When I get lined out on the boolit alloy for the 270 I want to try some loads over 2500f/s
Ill powder coat the boolits and work up from about 2000f/s. Lyman 3rd edition list 2 powders Imr 3031,WW748. for the boolits, I cast 280412 and 280473 136grGC and 126grGC
Has anyone tried to push the rifle cast boolits that fast?
What hardness would you recommend for the rifle boolits?

[Winger Ed.]

I don't go much over 2000 fps with cast & a GC.
I cast .30-06, .30-30, and .308 with a 170RN and 190SP. They'll go faster, but I don't shoot much over 150 yards,
and the accuracy was falling off as I went on up past the mid-upper 'teens'.

I do get some leading with hard boolits and Orange Magic lube after 15-20 shots, but it comes out easily with a brush.
You should get better results than I did at the higher speeds just from using a good quality powder coat.

If ya really want to get the speeds up---
Check out some youtube videos of guys that have switched over to casting Zinc.
They come out at about 60% of the weight a Lead boolit does, and you can gas them up to jacketed speeds.

You'd probably be disappointed at their expansion, but they should do OK as a redneck version of a Barnes solid.

[popper]

I push cast to 2700 in my AR10 24" barrel. Used an alloy (WD) with copper in it. The rpm is primarily the problem. GC of course & PCd.

[Silvercreek Farmer]

I’m at 2300 with 9 ish bhn in the the 358 Winchester (1-12) and getting around 1.5 MOA. Your twist rate might hold you back a bit, but depending on the accuracy you require, some impressive velocities are being posted with PCed boolits. Water dropping wheel weights (even blended with pure) hardens it up very well.

[DCB]

Thanks, What is WD with copper? The AR10 is it 308, 243 ?
2700 would be a goal. I think I can get 126grPC. within a couple hundred feet of that
I have a bucket of wheel weights but have not got them sorted out.
If get a batch of alloy to 17,18,19 bhn do you think it will be to brittle ? gas checks and powder coated

[charlie b]

Complex question because the 'limits' of PC bullets are not fully explored. Several of us have pushed them a bit and found they can be stable at a bit higher speed than with conventional lube. How much more is not clear yet just because so few of us have documented them fully. I know I can push them (Lyman #2) about 10% faster and not lose any accuracy but 20% higher and groups start to open up a little (<1.5 MOA to ~2MOA).

[popper]

I use copper sulfate in the alloy to toughen it (~0.5% works). There is a sticky on it. WD is water dropped. AR10 is 308W 1:10. 24" barrel. I used H4895. ARcomp is another good powder - can't find it now. LC brass that was MG fired. Adding a tad of chilled shot will get alloy harder quickly, not really needed but helps some. I run ~4% Sb with no tin.

[DCB]

Thanks Charlie At what range do you test your loads. I am thinking 100yrds to start. I make up 10 rounds for start to get on target. Ill shoot across a chrony to get basic velocities.
i will load 5 in each weight and shoot for groups and clean after 5 shots.
That should give me a pretty good Idea how fast I can go.
Ill have 20 rounds diffrent powder weight with a boolit at 130grs PC+GC.
'''''''''''''''''''''''''''''''''''''''''''''''''' '''''''''''''''''''''''''''''''''''''''''''''''''' ''''''' 140gr PC+GC.
Ill check for leading after each 5 shots.
what else should i look for.
Thanks

[rockrat]

I usually run about .2% copper and I use #3 babbit and water drop. Don't know the BHN, but they are hard!! Think I did the chart to calculate BHN and it came out around 24, IIRC

[Silvercreek Farmer]

Any reasonable load with a properly sized PC boolit shouldn’t lead the bore. In my experience, a clean bore will take around 10 shots to “season” and start shooting it’s best. Can’t say for sure how many rounds accuracy will hold up for, but, in my rifles, it certainly seems to be 100 rounds or more. A light cleaning might be in order if a load doesn’t burn well and leaves a bunch of soot, but you probably won’t run into that if you are pushing for 2700 fps…

[charlie b]

^^^this. I shoot at least 5 before I do anything serious.

My cast bullet rifle is a Savage 12 in .308, 1:10 twist. It has over 3000 rounds through it, about half jacketed. Yes, I will shoot jacketed and cast in same session. Jacketed first. The gas checked bullets have a tendency to 'scrape out' the copper fouling from the jacketed bullets, which is nice when it comes to cleaning the bore. Also takes about 5 cast bullets to "settle down" after the jacketed. My favorite cast bullets are the Acc 31-210E and NOE 165 XCB.

My development shooting starts at 100yd just to see where the different loads land. I narrow down a bit and move to 200yd for the rest of the development work. When I am 'having fun' I am shooting at soda cans on the 300yd berm and a 5" plate at 500yd. No, I don't hit the plate every time, usually only half the shots hit :) But, I have had a 4 out of 5 day :) (no wind at all)

When developing a load I look for accuracy first and then low extreme spread and SD in velocity. The velocity thing is important cause if the spread and SD are low then you should be getting small groups. If not, then it is you, the rifle or the bullets :)

With PC I do not get any lead fouling. I will get a few, very small, 'flakes' of lead on the first couple of patches when cleaning. I don't clean every session and have found I maintain accuracy for 100-150 rounds (I always shoot jacketed out of a clean bore).

[DCB]

Thanks for the information. Ill be ready when the weather breaks.

[waco]

https://www.youtube.com/watch?v=l9VDouNYi7A
.308 with 1/10" twist
165gr bullet 90/6/4(Pb/Sb/Sn) water dropped for 18bhn
2500+ lube with an overcoat of BLL for a velocity of 2600fps
10" steel plate at 500 yards.

[DCB]

waco thats good shootin. loads are right there with jacketed bullets

[JWFilips]

I have shot PC coated & Gas checked 105 gr. NOE 246-105 In my Ruger 77 V With loadings of 2400 and RX-7 @ 2200 fps successfully ( wheel weight alloy air dropped) No fouling and super accurate@ 100 yards

[dverna]

https://www.youtube.com/watch?v=l9VDouNYi7A
.308 with 1/10" twist
165gr bullet 90/6/4(Pb/Sb/Sn) water dropped for 18bhn
2500+ lube with an overcoat of BLL for a velocity of 2600fps
10" steel plate at 500 yards.

That was impressive