My quest for speed and accuracy with powder-coated cast bullets
- Thread starter Ian
- Start date
Dude, his wife is gonna kill you
Ian
Notorious member
Not rebuilt but I had to rework a couple of things like the left leadscrew bearing, the leadscrew gear lever detents, and made an off-side spider for tje headstock. Still need to make a carriage lock, in fact that is quickly becoming a dire necessity.
I might make a nose-forming die for .30-caliber, its really handy to be able to final-size the nose and body at the same time while ironing out any mould seams or powder-coat warts and putting a little taper in the right places.
I might make a nose-forming die for .30-caliber, its really handy to be able to final-size the nose and body at the same time while ironing out any mould seams or powder-coat warts and putting a little taper in the right places.
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Ian
Notorious member
I went back and re-read what we talked about on the first page regarding what the 5.56 was doing and what to try, and thought some more about everything I've done so far and how it went, and not a lot of it really worked like we're used to. This PC thing is a different game entirely.
First I toughened up the alloy and played with sizing. Then tried going up and down with different powder burn rates at the same velocities, tried jacketed bullets at the same velocities, bumped the bullet shape, tried different seating depths, sanded the coating off the bases, weight sorted, and chased vibration nodes around with bedding and velocity.
Most of the time the rifle would group pretty much the same no matter what. Excepting the Dacron, I averaged about 1.75", 10-shot groups across more than 40 targets with the MX3 bullet. I don't think any of them were under an inch or much over two inches at 100 yards. Usually I see clear likes and dislikes with a rifle and one bullet after that much shooting and changing so many things, but the only thing that really stood out was pushing the velocity up even more with the harder bullets. Maybe I've been having a stability problem the whole time and didn't realize it? That doesn't explain why the rifle doesn't like the MP NATO bullet or Lee 55 when I coated them since they are lighter by a few grains.
It's kinda weird to try something new and find out the old way of finding clues to improvement doesn't necessarily apply. Well, that's what this thread is all about, finding out what makes this coating thing tick.
First I toughened up the alloy and played with sizing. Then tried going up and down with different powder burn rates at the same velocities, tried jacketed bullets at the same velocities, bumped the bullet shape, tried different seating depths, sanded the coating off the bases, weight sorted, and chased vibration nodes around with bedding and velocity.
Most of the time the rifle would group pretty much the same no matter what. Excepting the Dacron, I averaged about 1.75", 10-shot groups across more than 40 targets with the MX3 bullet. I don't think any of them were under an inch or much over two inches at 100 yards. Usually I see clear likes and dislikes with a rifle and one bullet after that much shooting and changing so many things, but the only thing that really stood out was pushing the velocity up even more with the harder bullets. Maybe I've been having a stability problem the whole time and didn't realize it? That doesn't explain why the rifle doesn't like the MP NATO bullet or Lee 55 when I coated them since they are lighter by a few grains.
It's kinda weird to try something new and find out the old way of finding clues to improvement doesn't necessarily apply. Well, that's what this thread is all about, finding out what makes this coating thing tick.
RBHarter
West Central AR
I had a rifle I shot a lot . I saved a pile of targets from it trying to log every change .
Loads , rifle tweeks , scope tweeks , the whole ball . One rainy day when I really wasn't in the mood for anything I got out the back lighted glass and made a + in the center of a white sheet and commenced to placing each target over it centering the groups on the + . With 50+ targets down representing over 500 rounds down range from the summer what I discovered was that 2" was as good as that rifle was ever going to get . Oh sure I had a couple loads that really shined , 5 touching but .3 of a gr of 4350 would take it from that to 1.5 and .5 would open it up to 1.5 between holes . Could be that like mine you have a very consistent 2" rifle .
Loads , rifle tweeks , scope tweeks , the whole ball . One rainy day when I really wasn't in the mood for anything I got out the back lighted glass and made a + in the center of a white sheet and commenced to placing each target over it centering the groups on the + . With 50+ targets down representing over 500 rounds down range from the summer what I discovered was that 2" was as good as that rifle was ever going to get . Oh sure I had a couple loads that really shined , 5 touching but .3 of a gr of 4350 would take it from that to 1.5 and .5 would open it up to 1.5 between holes . Could be that like mine you have a very consistent 2" rifle .
fiver
Well-Known Member
it is staying pretty consistent.
but the little tweaks and tunes have changed not just the group size but the group shape.
the shape of the group is important.
there is a huge difference between having a hole 1/2-3/4" away from where you were pointing, and having holes 3/4" apart.
looking at the MP and LEE the diameter changes to them was the most significant disruption.
that little area right in front of the front drive band on the LEE is what makes that bullet work or fail in the 5.56 throat.
and yes .001 matters.
anyway IMO the major difference is the engraving bump in the pressure rise.
the PC is taking that away, and we have to learn to work with it.
I would bet you could re-size [cast for a smaller diameter] some of these to 224 and see another change maybe good.
I run several of my rifles at barely over groove diameter and some right at groove diameter.... just sayin.
but the little tweaks and tunes have changed not just the group size but the group shape.
the shape of the group is important.
there is a huge difference between having a hole 1/2-3/4" away from where you were pointing, and having holes 3/4" apart.
looking at the MP and LEE the diameter changes to them was the most significant disruption.
that little area right in front of the front drive band on the LEE is what makes that bullet work or fail in the 5.56 throat.
and yes .001 matters.
anyway IMO the major difference is the engraving bump in the pressure rise.
the PC is taking that away, and we have to learn to work with it.
I would bet you could re-size [cast for a smaller diameter] some of these to 224 and see another change maybe good.
I run several of my rifles at barely over groove diameter and some right at groove diameter.... just sayin.
Ian
Notorious member
That's the way I see it, too. That slippery, tough coating also helps dynamic fit/alignment and toughens the drive side of the land engraves so we can push things a lot more. The bullet slips into the safety of the bore before pressure gets high enough to start doing bad things to the back end of the bullet.
There is a balance point between that easy engraving/low-damage launch and not having enough resistance to make the powder work properly. That's why I started jamming the bullet for those last few groups, trying to bump the pressure a little bit.
Sizing to groove diameter has worked for me too sometimes, but with this rifle, anything under .2255" causes trailing edge washout and leading in the corner of the grooves. Maybe it would work better now that I have the nose-shaping die and can jam the bullet for a glove fit.
Using the nose die I made to bump a taper on the front band of the Lee might be an option too.
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Ian
Notorious member
Yep, had several of thise in the past. Thing is, the multitude of ten-shot groups with only 4-5 separate holes tells me this one wants to shoot better than that.
Ian
Notorious member
Two more groups today, rifle still dirty from yesterday. 50 shots down the pipe since it's seen a cleaning rod. The test was crusty vs. sanded-clean gas checks. I also pushed the bullets a little deeper to get somewhere around .015" of jump.
It was 85 degrees out, rifle and ammo started out from 68.
First shot went way low, kind of surprised at that one. I got disgusted and change my hold to a chickenwing-style with both hands on the grip, both elbows on the table, pulling back into my shoulder, face hard down on the comb. Chaned aim point and shot the last five with cruddy checks into 1.25".
Then I dialed in some more windage, changed target, let the rifle cool for ten minutes, and shot the last ten with sanded check bases. These are things that make grown men cry, eh? 6 of 10, including the first shot into 5/8", dead nuts on the expected center of the group. The high shot might possibly have been my fault, but I felt really confident in the far right and bottom two "flyers". One that I felt might have gone high landed in the center group.
It's silly to draw conclusions from two groups especially with a hold change halfway through the first group, but it appears that sanding the checks may have helped a little. One thing's for sure, still have that tight group and flyer thing going on, and a 1.75" dependable average.
One other tidbit, if I give the bullet .015" jump, the necks get very sooty on the outside. If I jam them, the necks are completely clean.
It was 85 degrees out, rifle and ammo started out from 68.
First shot went way low, kind of surprised at that one. I got disgusted and change my hold to a chickenwing-style with both hands on the grip, both elbows on the table, pulling back into my shoulder, face hard down on the comb. Chaned aim point and shot the last five with cruddy checks into 1.25".
Then I dialed in some more windage, changed target, let the rifle cool for ten minutes, and shot the last ten with sanded check bases. These are things that make grown men cry, eh? 6 of 10, including the first shot into 5/8", dead nuts on the expected center of the group. The high shot might possibly have been my fault, but I felt really confident in the far right and bottom two "flyers". One that I felt might have gone high landed in the center group.
It's silly to draw conclusions from two groups especially with a hold change halfway through the first group, but it appears that sanding the checks may have helped a little. One thing's for sure, still have that tight group and flyer thing going on, and a 1.75" dependable average.
One other tidbit, if I give the bullet .015" jump, the necks get very sooty on the outside. If I jam them, the necks are completely clean.
RicinYakima
High Steppes of Eastern Washington
Question, is a slightly faster powder possible? I through all the PC baked on gas check bullets away as they would stay on a 16" target backer.
fiver
Well-Known Member
dammit.
that's frustrating me and I'm not the one working the process.
one thing more you could try.
sanded bases, leave the jump [it definitely worked on that last group] and tightening the neck tension up another thou.
I want to say upsizing the bullet might help too [yeah the opposite of the last post] not just with avoiding the jam fit but to help with more neck tension.
there is a direction here because things are getting better, it's just which problem to address.
soot could indicate velocity variations from lower pressure [maybe the cause of the flyers]
and there is more than one way to try and fix it.
the flyers are kind of horizontal and out [you being a lefty would throw them that direction from the front of the rifle bouncing off you and the rest,,, had this problem with the 308 the other day]
just raising the cushion height on your bench seat a little could help this too.
combine a few small things [shrug] and they become inconsistencies that will have you chasing your tail.
it's almost time to address the alloy.
I know I know the coating... but., heck melt down some of those XCB bullets I sent you,
or PM me for a few more lbs of that alloy.
that's frustrating me and I'm not the one working the process.
one thing more you could try.
sanded bases, leave the jump [it definitely worked on that last group] and tightening the neck tension up another thou.
I want to say upsizing the bullet might help too [yeah the opposite of the last post] not just with avoiding the jam fit but to help with more neck tension.
there is a direction here because things are getting better, it's just which problem to address.
soot could indicate velocity variations from lower pressure [maybe the cause of the flyers]
and there is more than one way to try and fix it.
the flyers are kind of horizontal and out [you being a lefty would throw them that direction from the front of the rifle bouncing off you and the rest,,, had this problem with the 308 the other day]
just raising the cushion height on your bench seat a little could help this too.
combine a few small things [shrug] and they become inconsistencies that will have you chasing your tail.
it's almost time to address the alloy.
I know I know the coating... but., heck melt down some of those XCB bullets I sent you,
or PM me for a few more lbs of that alloy.
Ian
Notorious member
You got some good ideas there, Fiver. I went to the ball powder just to change directions...didn't want to go faster because of the pressure/velocity trade-off, and "slow" powders still are appropriate for the system. Plus, I have an idea of what to do to manipulate the H345 burn rate. Playing with jam, nose/throat shape and engagement a little......and did someone mention neck tension? Primers are also something to work with, so far all I've been using is my old stock of WSRs. Aaaaannd then there's crimp, haven't used any at all for any of this.
Knocking the rear band and gas check from .2275 down to .2265, the neck tension seemed too loose. Consistent, but loose. I did that before with 3031 and had the same shape to the groups, but now with the nose sized down, the gas check is only just a little over halfway down in the neck. I'm using an RCBS fl sizing die with the neck honed out. Its just enough tension for jax, but my RCBS cast bullet expander is .225" and too big for this. Now that I have some drill rod a new one is on the dockett, probably will make it .2235".
I have superhard, cerified lino, and pure, along with some 4/2/.25 modified ww alloy from the lead'n'brass group buy, so no need to melt your bullets. I'm just not ready to change the alloy quite yet because I'm nog through playing with the launch.
Knocking the rear band and gas check from .2275 down to .2265, the neck tension seemed too loose. Consistent, but loose. I did that before with 3031 and had the same shape to the groups, but now with the nose sized down, the gas check is only just a little over halfway down in the neck. I'm using an RCBS fl sizing die with the neck honed out. Its just enough tension for jax, but my RCBS cast bullet expander is .225" and too big for this. Now that I have some drill rod a new one is on the dockett, probably will make it .2235".
I have superhard, cerified lino, and pure, along with some 4/2/.25 modified ww alloy from the lead'n'brass group buy, so no need to melt your bullets. I'm just not ready to change the alloy quite yet because I'm nog through playing with the launch.
fiver
Well-Known Member
I was just thinking ahead with the alloy suggestion.
if you had them now they would be ready for the queue.
I should have sent you some of my smp copy's with the 223 sides and a 224 drive band [accuracy band they call it]
once you figure out how to seat those and keep them in the necks properly while still feeding in an AR, stuff like this gets real easy.
you can set your tension all you want with those, seating the bullet screws it all up so you have to fix it in the loading/anneal management process.
too much/too little and you change the bullet, too little/too much and they all get shot back in the case when feeding from the magazine.
get it right and groups shrink and stay together like magic.
if you had them now they would be ready for the queue.
I should have sent you some of my smp copy's with the 223 sides and a 224 drive band [accuracy band they call it]
once you figure out how to seat those and keep them in the necks properly while still feeding in an AR, stuff like this gets real easy.
you can set your tension all you want with those, seating the bullet screws it all up so you have to fix it in the loading/anneal management process.
too much/too little and you change the bullet, too little/too much and they all get shot back in the case when feeding from the magazine.
get it right and groups shrink and stay together like magic.
Just tap the base on some paper towel to remove powder. I went through this test with 300BO and PB. Just fowled the gas more, cut the base. Didn't really see any difference. I remove PC from the base with towel on GC loads for 308W. Basically have to be a better shot to see a difference. Itty bitty bullets don't work with my fat fingers.
F
freebullet
Guest
Try a .020jump & a very minor crimp.
Ian
Notorious member
I'm down to trying to make 2" groups into 3/4" groups, or rather getting the flyers to get into the core group. With my chest-high, rickety wood bench raised up on stilts and standing to shoot, I doubt I can do better than 3/4" for ten consistently even if the rifle can. The crosshairs are at least 3/4 MOA wide on 11 power, have to focus on crosshair intersection and center that in the big circle on the target in my peripheral vision to get groups.
I bought a Hyskore machine rest to see if that helps the groups any.
My challenge here is to figure out what's causing the flyers. Shooter error? Is it bullet imperfections? Launch irregularities (getting crooked in throat, erratic timing, slight variances in neck tension)? Is it a problem farther up the bore, or even at muzzle exit? Are the bullet bases getting slightly crushed and crooked so they don't leave the crown the same way?
I'm thinking of backing down the load and trying some buffer with the H335, leaving all else the same as last go, since the bullet base isn't protruding into the powder space. The other thing to do is start experimenting with lube in the grooves again. I got some really good core groups early on, before fixing the bedding and bullet fit problems. I still had lube problems, but at least I know how to correct those.
I bought a Hyskore machine rest to see if that helps the groups any.
My challenge here is to figure out what's causing the flyers. Shooter error? Is it bullet imperfections? Launch irregularities (getting crooked in throat, erratic timing, slight variances in neck tension)? Is it a problem farther up the bore, or even at muzzle exit? Are the bullet bases getting slightly crushed and crooked so they don't leave the crown the same way?
I'm thinking of backing down the load and trying some buffer with the H335, leaving all else the same as last go, since the bullet base isn't protruding into the powder space. The other thing to do is start experimenting with lube in the grooves again. I got some really good core groups early on, before fixing the bedding and bullet fit problems. I still had lube problems, but at least I know how to correct those.
How do you verify your GC are on straight or no damage occurred when installing? I line mine up with straight edge on a flat plate and look at the noses. Rotate them 90 and look again. HiTek coated some yesterday and see coating scraped off hard alloy when sizing, just on one side. Bases aren't square! Plinking ammo. I ran soft alloy first, no problem. IMHO (I don't have any top punched) the base needs to be run first through larger sizer, then nose first to desired size. I've about given up on HiTek for HV rifle, PC is so much easier with consistent results.