Others will probably have advice, but at this point I would start playing with patch length and boolit seating depth.
Very nice shooting. Maybe 303guy or someone more knowledgeable can comment on the vertical stringing that I seem to be seeing.
Others will probably have advice, but at this point I would start playing with patch length and boolit seating depth.
Very nice shooting. Maybe 303guy or someone more knowledgeable can comment on the vertical stringing that I seem to be seeing.
Precision in the wrong place is only a placebo.
I think the vertical stringing was my fault. It was 80 today and I should have let it cool between shots.
"Some times it's just better to smile an walk away."
-161
"Think ya used enough dynamite there, Butch?"
-Butch Cassidy & the Sun-dance Kid
Perhaps, but why would barrel heating cause vertical stringing? Does a H&R single shot have that tendency?I think the vertical stringing was my fault. It was 80 today and I should have let it cool between shots.
Rest In Peace My Son (01/06/1986 - 14/01/2014)
''Assume everything that moves is a human before identifying as otherwise''
I never had any vertical stringing with PP no matter how hot the barrel except when I used the wrong powder. Try some really slow-for-caliber double-base powder, pick a load that will get really close to filling the case. Don't be scared if it pushes the mid-2K fps point as long as you work up to it. Basically, use copper-jacketed STARTING load data for your equivalent boolit weight with the slowest ball powder you can find data for. That will give you a place to start. Work up some if you have room, then you can reduce the powder 10% and start fooling with compacting fillers. But try the ball powder thing first, remember you're shooting an unchecked boolit very much past it's normal accuracy limits, and the key to preserving accuracy even with PP is to get that boolit fully into the rifling, particularly the base band into the rifling without damaging it. Faster powders tend to tear up the boolit before it can get snugged into the barrel all the way, and slow, progressive ball powders tend to not only build pressure more slowly, but I think actually act as their own filler, pushing the boolit into the barrel fully before it's all lit well.
You have to protect that delicate base band or plain base on your boolit, and it's a rough trip out of the case, through the throat, and getting engraved, so during this period of transition we must be very gentle to the boolit. After the boolit gets going up the barrel, it can take an amazing amount of pressure without any further damage. We just have to be sure and hit the afterburner when it's going nice and straight and is fully supported in the barrel. This is also why seating to engrave the patch, and patching to fit the throat is so important: The boolit must get a straight start, and it needs to seal the bore from the get-go when chambered so gas doesn't leak around it in the throat before it gets fully engraved.
Gear
What powder would be good to start with?? I have H414, and I know it's not a ball powder but I have a bunch of H4831. Would either of these work.
Thanks 161
Last edited by 161; 05-04-2012 at 06:30 AM.
"Some times it's just better to smile an walk away."
-161
"Think ya used enough dynamite there, Butch?"
-Butch Cassidy & the Sun-dance Kid
I had bad luck with Hodgdon powered and PP. I ended up finding several good loads for my 35 caliber rifles with IMR4227, 3031, and 4831. I settled on IMR4831 because it filled the case and I seemed to get a little more accuracy out of it. I dont know if Gear is scientifically right, about the powder acting like a filler behind the boolit, but it sounds reasonable and its easy to think of that way for me, and besides my experience seems to back up his post 100%.
None of us actually know what happens inside that barrel when you pull the trigger, and PP complicates things. Sure you can slap a pressure gauge on the barrel and see what kind of a curve you've got, but when it comes to understanding what just happened in a millisecond to a few shreds of paper inside the barrel, we are all just looking at some streaks and powder burns and some holes in a piece of distant paper, and trying to "read tea leaves". I dont say this to be a downer, I'm just saying that every rifle is a rule unto itself, especially when dealing with PP loads. Where you are at is where it realy will be in your best interest to try lots of different powders to find out what works. This is where the heavy duty experimentation comes in.
I would also try green-bar printer paper and notebook paper. Also, make a tool that will allow you to trim your patches to the exact same length.
You might also try cream of wheat filler, or dacron or card stock to see if that helps protect the base.
Don't get overwhelmed, be stubborn and try one thing at a time until you get that level of accuracy that makes you smile every time.
Precision in the wrong place is only a placebo.
I always try to select a slow enough powder that I can get 100% load density. Get my best accuracy that way. I save my pistol powders for my pistol. My best so far in a 30-30 is a Lee 309170 over H380 for just over 2100fps and 1.7" @ 100yds. Best in my .308s so far is AA2700 and the 311414. Right at an inch and 2665fps. woops, make that a 311446
Last edited by pdawg_shooter; 05-04-2012 at 01:07 PM.
45 AUTO! Because having to shoot someone twice is just silly!
You sure? Or was that a typo? I've always thought it was a ball powder.I have H414, and I know it's not a ball powder ...
Rest In Peace My Son (01/06/1986 - 14/01/2014)
''Assume everything that moves is a human before identifying as otherwise''
First, I'd try the H414 and a tuft of Dacron to take up the little amount of space you have left between the boolit and powder, just to locate the powder. The .308 has a pretty sharp shoulder and a large ratio between bore size and case body at the front, so you have to be careful when using compacting fillers here, get a load going first and then do some volume measuring and we'll see about PSB next.
Gear
Well 45 gr. H414 gives me 2407 fps 5 shot average and 2 inch groups at 50 yards with graph paper sized .310. That's where I was 2 weeks ago at 1800 fps. we'er gainin.
"Some times it's just better to smile an walk away."
-161
"Think ya used enough dynamite there, Butch?"
-Butch Cassidy & the Sun-dance Kid
Now you're in the ballpark where you can get the most out of your PP loads; accuracy at copper-clad velocities is the whole point, at least for me.
Can you describe how far that 45 grain charge comes up in the cases you're using? If you tap the case a couple of times with a pencil to settle the powder, where is it in relation to the shoulder/body junction of the case on the inside? Also, does your boolit base poke down below the neck inside the case?
Gear
The powder comes up a little above the start of the shoulder. Maybe less than a 1/4 of the way. I load the boolit long so the base is even with the bottom of the neck. The boolit and patch start into the rifling.
Thanks
161
"Some times it's just better to smile an walk away."
-161
"Think ya used enough dynamite there, Butch?"
-Butch Cassidy & the Sun-dance Kid
That sounds absolutely perfect for compacting filler in that cartridge. You still have some room to grow with that powder charge, so I'd say back off one grain to 44.0 grains of H414, settle the powder, and fill up to within 1/8" of the case mouth with BPI Original granulated shot buffer so the boolit compresses the filler and powder slightly when you seat it. You want just enough pressure to keep the filler and powder from mixing too much. If you don't have any of the buffer, Midway and others carry it, or you might also try Cream o' Wheat installed the same way, but COW can have it's own problems, so be careful. COW can weld to the shoulder under pressure and leave a hard buildup inside the case that's difficult to remove. If you decide to do this, understand that this procedure with any sort of compacting filler raises pressure considerably, and will generally take a starting load of powder up near the max pressure, so NEVER add filler to a midrange or higher load without dropping back a few grains and working the load up again.
As you exchange powder for filler, the pressure is on a see-saw because more filler = more pressure as the compacting mass bridges the shoulder and extrudes a hard, packed plug of material though the neck after the boolit, but as you exchange filler for powder, of course the fuel load goes up so that raises pressure. This is why it's tricky to get the right powder for the right case with the right shoulder angle and the right level of powder and the right amount of compression to the filler when loading. This is not inherently unsafe, but you need to have a good understanding of how this works before jumping into it. The rewards of improved accuracy with PPCB and compacting fillers are well worth the effort to experiment with it, though. In cartridge cases similar in proportion to the .308 Winchester, you may experience as much as a 10% pressure increase by using slighly compressed, compacting filler with powder charges coming up to the shoulder/body junction of the case, this is a broad estimate based on chronograph observations I've made with a few different bottleneck calibers.
None of this PPCB and filler stuff has been tested with strain gauges by anyone as far as I know, but if I ever invest in a personal ballistics lab I'm going to dope this out so we can make more educated estimates of starting points. Once you shoot that first fillered load, you learn a lot about your particular components, and it's easy to tweak from there, but I always get the "heebeegeebees" every time I touch off a fillered load in a cartridge I haven't tried before.
Gear
geargnasher says it all.
You could similarly use Dacron as a filler. I haven't done field tests but it does seem to protect the boolit base some and doesn't raise the pressure much. I've tried more than the recommended 1/2 gr, actually doubling it. It may not produce the results of shot buffer but then again it's easier to find some lying around in the home. I've tested wheat germ and that seems to behave well in the case. It is quite compressible and needs to be settled to get enough in. One day I'll get some shot buffer and try it for myself.
Last edited by 303Guy; 05-06-2012 at 04:26 AM.
Rest In Peace My Son (01/06/1986 - 14/01/2014)
''Assume everything that moves is a human before identifying as otherwise''
I tried the Dacron yesterday it didn't go so well. Midway is out of the BPI original. Looks like I'll try COW today. I read back in the posts and found where goodsteel mentioned card stock. I took some gasket paper I have and a 5/16 punch. That makes a card that fits nice in the neck. With a 1/2 gr. of dacron and a card then the boolit? As long as I don't seat deep enough to push the card out of the neck?? Or am I making a pipe bomb??
"Some times it's just better to smile an walk away."
-161
"Think ya used enough dynamite there, Butch?"
-Butch Cassidy & the Sun-dance Kid
Nope, it sounds good. powder, dacron, card gasket, PP boolit. Sounds like a good combo. Be sure to keep the card in the neck though. Also, you might try doing several cards, sometimes the simplest things make a huge difference.
Precision in the wrong place is only a placebo.
"Some times it's just better to smile an walk away."
-161
"Think ya used enough dynamite there, Butch?"
-Butch Cassidy & the Sun-dance Kid
I've tested card wads too and they too protect the boolit base. Dacron is great to hold it up because it is springy (in case it gets pushed down past the neck). I've also tried patching over the card but it was too large and made seating difficult unless I sized the patched boolit. Again, I only 'test tube' tested these.
Rest In Peace My Son (01/06/1986 - 14/01/2014)
''Assume everything that moves is a human before identifying as otherwise''
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |