Another great 8x 57 PP load......

[bcp477]

Finally got around to bobbing the barrel on my favorite M48 to 18".....as I have always wanted it (but was too chicken to do before). Anyway, I knew I'd have to re-work my loads....and use a faster powder than 4064. After a good bit of experimentation, I've found that about 32.5 grains of Hodgdon Benchmark, under my 170 - 175 grain flat nose paper-patched bullet, with a bit of cotton wool filler as before, works very very well. groups of 1 to 1.5", at 100 yards, through my rifle. With my eyes (and shooting skills)...and my old M48 with bobbed military take-off barrel....that is a stellar result. That Benchmark is good stuff, man.

[runfiverun]

i'm running 31.5 of i-4895 and a plain ole cast boolit.
or 51 grs of 4831sc with the same ol plain boolit with under 1" groups at 100 yds, what is the paper doing for ya?
is it helping your groups? or your velocities?
maybe, i could go with more powder? i think i could get about 2 more grains in the case.

[littlejack]

Sounds like you fella's are doing well with the 8x57 pp rounds. I patched some .314 rounds the other day. The mould is the lyman 314299. I used the .0025 tracing paper. Patched diameter was .325. Bullets were cast with ww's. I loaded these rounds in my 8mm-06 AI to top velocities for the 200 grain bullet. I have read that the pp bullets can be pushed fast. I used 4 different powders, 3031, Re7,4064 and Varget. The bullits scattered like a covy of quail. What did I do wrong? Do you fella's think I pushed them too fast. One other thing, this is a gc bullet and I did NOT use gc's. Do you guys think the gc's would have made a big difference? Need help with the paper patchin. All advice greatly appreciated.
Jack

[303Guy]

What did I do wrong?

Tracing paper could be the problem. Maybe too strong to shred?



That long sliver is a full double wrap! It made it through four or fivr layers of catch cloth. It looks like it came from the rear - can't actually say. The boolit was lubed and gas checked. (load was vvery low as the undamaged boolit reveals).

... or 51 grs of 4831sc with the same ol plain boolit with under 1" groups at 100 yds, what is the paper doing for ya?

I'm listening! Might I ask the boolit weight?

... with a bit of cotton wool filler as before, works very very well. groups of 1 to 1.5", at 100 yards, ...

I was told the world would come to an end if I used cotton wool! Well, OK, start grass fires and the like. I did get one load to actually heat the cotton wool to the point of it scourching the catch cloth. That was only once. For the rest, there is no trace of the cotton getting hot at all. Now I like cotton wool as a filler because I have this notion that it 'scrubs' the bore!

[docone31]

LittleJack, I do not know about the final sizeing, but, I would get an 8mm mold, downsize the casting, and wrap up +.001-.002.
I had bizarre groups when I first started, then bumped up .0005 and got dime size groups at 100yds. That was in my .303. I suspect the 8mm will behave in similiar fashion.

[littlejack]

Thanks for the help.
The paper come out like confetti. Seems to work ok? Maybe I should have started slow and worked up in velocity?
These things are a real PITA.
Jack

[pdawg_shooter]

What is you BHN? Lead is good to about 2200fps. After that you need a harder alloy. I have taken a 200gr 30cal to a little over 3000 using a BHN of 18. Accuracy was right at 1 inch.

[littlejack]

p shooter:
I don't know the BHN, I have not checked them. I don't have a tester. The bullets were cast with straight ww's.
Jack

[docone31]

I water drop mine. I also have just a tad of zinc in them.
They are HARD!
Fire well.

[runfiverun]

it comes out right near 180 with g/c etc..
ww's mixed to lino 19-1 water dropped.

[bcp477]

I am no expert, but I'll add as much additional info as I can....and hopefully it will help. First, my bullets are from the RCBS #32-170-FN mould, I believe (there are two different ones, with almost the same number, so I always get this confused). Anyway, they cast at .324". They are BHN 12. I am told that they are cast from the old Lyman #2 alloy, or as close as they can come to it. I buy these bullets, as I do not cast my own, but the info is reliable, I am told by the manufacturer. I re-size them to .314" and wrap two times with ordinary lined loose-leaf notebook paper (which measures about .0025" dry). As the paper stretches and then shrinks, when wet and while drying, respectively, the final patched bullet diameter is right around 0.3235". I seal the edges of my patches with a tiny bit of yellow glue, being careful to not get any on the bullet. I lube these with Lee Liquid Alox, cut to 50 % with turpentine.

As for my load, it is just as stated before.....32.5 grains of Hodgdon Benchmark, with 0.3 to 0.4 grains of cotton wool filler added. The load is definitely better WITH the filler. I have never, as of yet, been able to get "jacketed bullet velocities" from my patched bullets. Only about 2100 - 2200 fps, as a maximum - beyond that and accuracy suffers. It doesn't much matter to me though, at this point, because I consider the rifle as is to be a 150 yard deer gun..... so those velocities are just fine for me.

As to the endless controversy about fillers, and/or cotton wool in particular.... I cannot make any profound comments on this. I simply have to say: use good judgement when using them. Fillers aren't needed when really fast powders are used, such as pistol powders (in rifle cartridges) - and thus add nothing to the mix. I only use filler with medium to slow rifle powders, when the case will not be filled to more than about 65 - 70 % of capacity. Above that, I do NOT recommend filler, because it's use DOES increase pressures. As for cotton, it behaves the same as Dacron wool (in my experience), which some swear by..... except that it is biodegradable, which I do care about..... and it smells better than dacron, especially with certain powders. I have never had any problem with cotton setting anything on fire - brush, or anything else. The samples I have examined after shooting are only a bit scorched - NOT really burned. So, I think that this "issue" is really nothing, after all.

As for gas checks, with paper-patching, they are not needed - so I've never tried them.