31-145C Plain base experiment

[popper]

I found I just couldn't cast PB rifle boolits good enough so I decided to try a different approach.

[DR Owl Creek]

No offense or anything, but I don't understand the attraction to powder coating.

Here's a link to a thread on another forum, where the OP was using a conventionally lubed bullet. That's a 10 shot group at 100 yards BTW. Once someone can show powder coating producing groups like that, then I'll start to get interested.
See: http://www.castbulletassoc.org/forum/view_topic.php?id=10935&forum_id=78

Dave

[Blanco]

Don't you hate it when your trying to prove out the ideas in your head and you know the idea is sound, but everyone wants to poop on your parade.
You keep on experimenting Popper I'm cheering for you

[mdi]

Sure would like to see some pics of the base you designed...

[PAT303]

No offense or anything, but I don't understand the attraction to powder coating.

Here's a link to a thread on another forum, where the OP was using a conventionally lubed bullet. That's a 10 shot group at 100 yards BTW. Once someone can show powder coating producing groups like that, then I'll start to get interested.
See: http://www.castbulletassoc.org/forum/view_topic.php?id=10935&forum_id=78

Dave
So Dave when you starting shooting cast I guess you got 1'' inch from the get go hey?,if you didn't what was the point in you going on with it?.Everything starts somewhere. Pat

[PAT303]

Don't you hate it when your trying to prove out the ideas in your head and you know the idea is sound, but everyone wants to poop on your parade.
You keep on experimenting Popper I'm cheering for you
Amen to that. Pat

[303Guy]

I have no problem with anyone expressing their feelings or thoughts. That said, I'm all for popper testing his ideas. Go for it! I've got this thing about plain based boolits. I just don't want to have to use gas checks, as great as they are. So I'm scratching my head on this problem.

[mdi]

What's "Popper" testing? Seeing how many soda cans you can Pop?

[DR Owl Creek]

So Dave when you starting shooting cast I guess you got 1'' inch from the get go hey?,if you didn't what was the point in you going on with it?.Everything starts somewhere. Pat

Pat,

I never claimed to be getting 1" groups, particularly from the "get go". The example I gave from the CBA Forum was from a member there whom I really respect. The <1" group he posted about in that thread was for 10 shots at 100 yards, using an Israeli military surplus Mauser rifle, and a similar charge weight of 4227 powder to what the OP in this thread was using.

The difference that I commented about is that one used a casting and loading technique that has worked successfully for well over 100 years - the other used something "new and different". One produced a group of under 1 MOA - the other produced a group (if the grid squares on the 50 yard target were actually 1") that looked more like 6 to 8 MOA group.

I'm all for experimenting and trying new things. I know which of the two examples I want to try to duplicate. That's what I'm still working on too. I think you guys are barking up the wrong tree though. IMO

Dave

[Blanco]

I need to see peeectures of the Boolits.
And the Carterderidges.

[mdi]

Wif out pictures, the bullet doesn't exist...[smilie=l:

[runfiverun]

i'll see what they will do in my 1-7.
i'll have to go slow with the ideas because of the limited amount of boolits on hand, but I have a little something I want to try.
I'm gonna stay at the 50 yd mark unless Tim can find the time to make me the barrel weight I spoke to him about a while back.
just tripping the trigger moves this little rifle around enough to open the groups.

[runfiverun]

after looking some data over I think I may not get to 1800 with that 4100 powder.
[too bad too, I really wanted to use it here]
I may have to go to H-110 or AA-1680 to get there.

[OuchHot!]

If I 'get it', you are looking toward a relatively low investment (time=money) projectile to keep a semiA Black Out fed that will deform on impact and be tough enough to hold together. Sounds like you are pretty much there. Do you ever see any signs of polymer build up in the gas system?.....do you use an operating rod system or direct impingement. Looks cool to me....I sure wouldn't want to paper patch a thousand boolits!

[35 shooter]

Hope you get over all that soon and get back to shooting. If i could get a plain base boolit to 1800 fps. with accuracy in my rifle i'd dance a jig! Mine does great at 1300 to 1400 fps...not so much after that. Like you i'm working on it though...think my alloy may be too hard.
Get well and show me how lol!

BTW...agreed on the getting old thing. It ain't for sissies that's for sure.

[303Guy]

Wishing you a speedy recovery, Popper. :Fire:

Take care,
303Guy

[OuchHot!]

Best wishes, Popper. You made great strides with your loads. Take it easy and do thought experiments as you body heals. You'll be back soon on turbo.

[tomme boy]

So the chamber has a parallel free bore? And you want a tapered? Is the chamber chrome lined? If it is a chrome lined chamber, good luck.

[tomme boy]

But what is the free bore cut at?

[tomme boy]

Sounds like the reamer you need is one that will cut a tapered free bore. Thats why I was asking. It should have a 0.310" entrance down to a 0.308"groove. Is this what you were asking about for a reamer?

[pls1911]

I just picked up this thread to find a number of interest points regarding PC and heat treat.
My backgrounds:
Been casting for 35+ years
I just started PC, and have not yet shot a round.
I have always HT'd (450 for 1 hour, 25-28 BHN in my alloy) and gas checked rifle bullets and have NEVER experienced a spec of leading in 30-30 or 45/70, or any of my pistol calibers.
My inquiries will focus on 30-30 and PC., my primary concern remains great accuracy without a trace of leading the standard 30-30 velocities, that is,2000-2100 fps.
I would like to think I could drive softer alloys (12-15 bhn) shot gas checked, PC'd standard bullet lubed and sizing
to 1900 fps... without issue.

Your text mentions HT,-size,-PC, re-heat treat... What temps do you use, and if you truely re HT (at 450) does your PC "over cook"?
Have you tested your HT boolits to determine how much annealing occurs to the HT Hardness when PC is cured at 400* for 10 minutes?
And , if the PC'd bullets are water dropped from curing, is the annealing process negated somewhat?

Obviously, I'll save a lot of time if you've already done this research.
I've not found specific answers in my net searches.
I'll have a few weeks downtime with hip surgery in late January, so maybe I can help fill in any data voids.
I'll also shoot some over a chrono into a sand or crumb rubber recovery chute. .
Thanks.

[runfiverun]

the 30-30 doesn't need any fancy foot work to shoot to jacketed velocity's.
you just need a strong boolit and a jacketed load under it to do that.
the rcbs 30-150 fngc actually exceeds jacketed bullet velocity's in my 30-30's.
I reeeeaally put the effort in sizing to 310, water dropping from the mold, and lube sizing in the star. [yawn]
if you want @ 1900 fps, then put 35 grs of 4831 under the boolit in a 20" barrel.
if you want more fps speed the powder up.

[runfiverun]

popper:
the launch is how you control the rpm thingy.
you have to give the boolit a chance to get started, then accelerated, then exit the bore without damaging the base or skidding.

your b.o. poses a different problem.
case capacity and pressure without a gas check to keep the base square and strong is gonna
make things more difficult.
the 16" barrel doesn't help either.

[tomme boy]

Ok, Chrony today, lets say 1943avg. Still no lockback with 16.7 of 4227. Not moa but no evidence of failure either. High one was first shot I know I pulled. 17.5 next. Bore is clean & shiny.
124164

What gas system are you running?

[tomme boy]

I thought these were supposed to be pistol length gas systems? If I had a good load that does not cycle. I would start by taking some weight out of the buffer.

[DonH]

[QUOTE=popper;2839440]I found I just couldn't cast PB rifle boolits good enough so I decided to try a different approach.

Over the last 13-14 years I have cast thousands of plainbase rifle bullets; all lead/tin alloys and all for match shooting. I don, find it hard at all to cast such bullets with bases as near perfect as the mold. That said, molds vary in the temp they like, casting rate, etc. You just have to find the sweet spot and do it the same way for every cast. Like women, you just have to find out what they like.

[tomme boy]

Try to find RL10X. That is almost exactly like the 1680. I like it in 223 with a mild load. It is very peaky in the 223 though. And it seems to be stock a lot more often than the 1680.

[tomme boy]

Popper, two things. What bolt carrier are you using? And have you thought about sing some filler to protect the base of the bullet?

[tomme boy]

So it is a Semi auto carrier? Just trying to figure out why it is not cycling. You should have enough gas volume to operate the bolt.

I'm interested in this as I want to do one of these next year. And if someone else does all the work for me, all I have to do is go shoot.

[tomme boy]

Check to make sure your hammer springs in right. If it is upside down the pins will walk right out on you.

[popper]

Long time testing but pretty much completed the project. Shooting 300BO 1:10 18" carbine gas AR. Alloy is Isocore with 0.5 to 1% Cu added. Powder coated 145gr FP, smooth sided, just a small 'collector' groove, with all but 0.02" of the GC shank removed. Objective was to get a lightweight AR for cheap plinking/hunting pigs and deer out to 100 yds with a cast boolit ($0.13/rnd at current prices). Easy to see bad bases and cull them out. Found placing a folded tea-towel over the Caldwell front stand solved the recoil problem, reduced friction. Still need to work on my shooting skills but I think 50 is OK, I still wiggle a little @ 100. Not seeing anything I would call non-linear dispersion @ 100, don't have a place to shoot further. Oh, loading between 1700 & 1800 fps. I'll loaad some aiming at 2k fps, not really sure it is necessary. I've thought about the 7.62x40WT but really can't see any advantage to it now, maybe 100 fps more. Anyway, experiment works good IMHO.
http://i1078.photobucket.com/albums/w491/popper29/TgtGfx29_zpsyirqgioi.jpg
http://i1078.photobucket.com/albums/w491/popper29/TgtGfx28_zpszk0dgkzf.jpg

[popper]

Chronyd the 16.7gr H110 load today, 2112 with es= 47. I don't trickle powder, formed brass & CCI SRP. Not bad for 145gr with no GC. I'm a happy camper.