"Half-jacket" PP boolits?

[mosinman]

Was reading about Col. Harrison's early smokeless PP experiments in Mar. '72 American Rifleman. One of the things he tried with conventional two-diameter bullets was a PP that extended only slightly past the front driving band where it was folded over to anchor it there. The front bore-riding section was left bare like a regular cast bullet. Everything else was treated like a normal PP config. with patch lightly lubed and ogive contacting the rifling if possible.

He didn't discuss the results he got with this particular method, compared to full-length patching, and was wondering if any of you boolistas might have tried it? TIA :smile:,

mosinman

[pdawg_shooter]

I have tried it, with so so results. I prefer to keep ALL the lead off the bore. Why go half way when all the way works so well?

[Nobade]

It has been a failure for me. Leaded the bore and shot terrible.

[303Guy]

I have 'test tube' tried it. It worked in that the boolit chambered and did not shear the rifling (two-groove). My patch formed a 'seating cup'. I patched the boolit, seated it then cut of the exposed patch. I then dip lubed the exposed nose section. I got zero leading. BUT - I also filled the case with wheat bran which seems to scrub the bore clean anyway. The nose section of the boolit was destroyed in the catch medium, being a fairly fast boolit.

Ummm.... I have fired un-patched, nose dipped boolits through this rifle before without leading but accuracy was inconistant due to rifling shear. The boolits were a poor fit.

[rhead]

If his results were anything like mine I can make a good guess why he did not want to discuss it. I can throw rocks with better accuracy. Try it the time proven way first and then you will have some data to compare it to.

[barrabruce]

I tried a limited few half patch.
Lee 170 fl pt 30 cal style bullet.

Wet patched to just above driving bands.
Lubed and sized to 1 thou over groove.
The nose section is bore size in this mould for my rifle.
painted lee alox on nose after seating and let dried upside down.
Loaded to around 17-1800 ft/s with air cooled WW. slow powder.

Shot pretty good for the 5 or shots I tried. @1 1/2-2 MOA.
Gave me normal seating depth for projectile instead of having to seat real deep.

Didn't lead as far as I could tell.

Keeping all variables consistent seemed do-able but harder than full length patching.

Old cartridge photos seem to show similar type wraps thou.

But I think the orgave starts on the bullets a long ways back from the nose portion.


Maybe worth another try some time.

Barra

[Zeek]

The short (~0.04" wide) "DD-Band" of some NEI CBoos seems to work rather well when the bands are patched. The DD-Band right behind the nose engraves and centers the nose, which need not touch the lands otherwise.

I see no reason why a normal bore-riding nose (given a good fit) should not work well up to around 2100 or 2200 fps, which is rather the top-end for two-diameter GC/groove CBoos for giving at least hunting accuracy. Above that speed, a bare nose might give problems.

The beauty of most older military rifles' throating (other than the 30-06) is that they have a long taper to the leade cone, so you can put a patched Loverin or a patched-on-nose-and-bands 2-diameter PPCBoo in there and let it stick out far enough to get some initial close-fit-in-the-cone alignment and, therefore, guidance.

You just flat CANNOT do that with "modern" throatings (short cylinder terminating in a fast three-degree inclangle leade cone). Either you shoot only short PPatched Lovern PPCBoos or you shoot a two-diameter boolit patched only on the bands. A too-large-diameter nose (on a two-diameter PPCBoo) just flat will NOT enter the rifling during chambering.
Zeek

[mosinman]

Thanks to everyone for your comments :-) !

barrabruce, was particularly encouraged by your experiences with HJPP, just goes to show what is possible with them.

Gotta agree with Zeek that there should be no reason why HJPP can't be done, assuming bore fit, alloy hardness, and velocity are all in sync.
Primarily interested in PPing some 140-170 gr. boolits for .357 Mag rifle loads. One of the designs might require proper bore dims, but most are sharp-shouldered SWCs which should have no lead in contact with the bore. With some of the more recent powders/data it's possible to push 170-180 gr. J-word boolits close to 2000 fps, right on the heels of .30-30 performance :shock:, might be fun to see what some lightweight PP boolits can do :D

[303Guy]

.... With some of the more recent powders/data it's possible to push 170-180 gr. J-word boolits close to 2000 fps, right on the heels of .30-30 performance :shock:, might be fun to see what some lightweight PP boolits can do :DYou gotta try it! You got me all fired up interested to find out how it goes!:Fire:
Would these 'modern powders and loads' happen to include Lil'Gun? I made my 22 hornet perform like magic with the stuff!

Keep us posted! :drinks:

[mosinman]

303Guy, yes! One writer used 19.0 gr. Lil'Gun and a 158 gr. JBoo and was getting over 2000 fps. Unsure of barrel length but most likely was 18.5 in.

Same article (from 2004) recommended Lil'Gun and Vihtavuori N110 as the top new powders, also mentioned the old standards H-110, W296, and 2400 as still very good. Just my two cents, but I'd include Accurate No. 9 and 4227 as well :smile: .

There's probably much more up-to-date data online that I haven't checked yet. Need to go to handloads.com, powder mfg. websites, etc.

Food for thought....one reloading handbook lists 2300-2400 fps with H-110 and a 110 gr. JBoo from a handgun barrel. The longer carbine barrel can bump that up 400 fps. or more. I keep thinking of that Lee 358-105-SWC, PPed and using this data in my Rossi ss w/23 in. bll.....not that I'd ever actually try it, of course...[smilie=1: .

[barrabruce]

Got a few more 1/2 PP to try next time I'm out.
left and middle are 170 lee fp.
Full patched and half patched note paper.
You can see how far I have to seat these with my std modern 30-30 chamber.
The nose "just rubs" on the bore of the 170's and to the right is a 150 gn cig wrapped with std nose about 1 thou or so under bore
I painted a dab of LL Alox on the noses for good luck and let dry standing on there nose in a pistol round styrenge case found at the range.

If my loading book is right then the 170's will be about 2150 fps
the 150's (a few loads) 2150-2350 fps.

The 150's showed promise at 100 yrds last time. 2" groups.

I have actually weighed the powder charges this time.

I will post my results of the next excursion here good or bad and how long it took to get the lead out or not.

Hell I might even clean my brass sometime soon...maybe.

Bruce:D

[303Guy]

Hell I might even clean my brass sometime soon...maybe.Nah, don't do that. You'll make me feel lazy and alone!:mrgreen: Besides, it's 'bad luck' to clean your brass. (I made that up![smilie=1:)

I'll be awaiting your test results.

[barrabruce]

Well I had mixed results with 1/2 PP today.
Had to do some lead mining after using 150 grn fn.
The nose is smaller than the bore. Still seated out to where the patch touches the start of the throat thou.
The 170 fn which are just bore in the nose seemed to fare better with the alox coating than the dry.

My PP mould ones which are dead soft din't fare to good with out the alox either as good as the coated ones on the exposed nose.

These were all "just" a lick coating.

I seemed to accumulate a lot to debri in the bore and after the 5 shot groups I cleaned.
It was hard to push a toilet paper patch though to the end without it stripping off.
With a bit of ed's red on the patch it seemed to pass though and clean up well if I didn't have little lead gobules or skiddies in there.

Best groups of the series. About as good as anything else I have tried. and a lot better than some.
Still have a long way before neck of bowling pin can be achieved.

100 yrd groups. I'm going to try a harder aloy water quench or something :neutral:

[barrabruce]

Attempt #369 with this PP lark.

Well since I had some sort of a result from the 17 lee fp I thought id try something else as well.
I cast a few wc ww mostly cores and sizing was a lot tougher.
I may have decreased the hardness through sizing but the nose riding section will still be hard.
If the all exposed nose works ( I'll try then last for the lead mining) they may be the go in this rainy environment.
Plus I could see them working in a lever action with out paper to tear.
Don't know how on would cope with crimping or not. Maybe you would have to use a filler.

To mix it up a bit I'm using 28.5 gns 2206h as before but 5 loaded dry 1/2 patched 5 with alox when sizing.
5 cut to the crimp groove aloxed and dry.
I'll report on my findings.
24017

I will see if there is a difference of the throat not being filled one way or the other.
AS loaded these are 10 thou off the lands/lead contact before cutting them down...so should be good for hunting and not debulleting.

I'm on me way .....do some lead mining to--day ahaa ahaa

By the reloading manual they should be @ 2000 fps or more. Huhh I'll settle for what I get.

Barra[smilie=1:

[CJR]

I reviewed the NRA work on PPCB and half PP jackets. E.H. Harrison et.al. found that if the final sizing diameter was close to or greater than the entrance diameter of the chamber forcing cone, the PP was getting cut by the forcing cone before the PPCB got to the rifling. For a 308Win, a final size of 0.309"D or 0.310"D was not good. The NRA stated they improved their grouping by going to a final size of 0.308"D. This apparently allowed the PPCB to enter the forcing cone, without stripping/damage, and engage the rifling properly. I've got some sizing dies on order to try this and see if it makes a difference.

Best regards,

CJR

[Zeek]

CJR: that is a valuable observation. We've been working on this stuff so long that some of the basics have just floated away from us.
Thanks, Zeek

[barrabruce]

Well today I fired off my loads.
Ergghh not good.
The jump from to the lands/throat contact area didn't help any with acuracy.
But the PP ones just to the start of the crimp groove and exposed nose didn't lead any worse than the 1/2 PP ones.
The barrel was noticeable less hot after a 5 shot string with the deeper seated bullets.


I have come to the conclusion that I would have to load more powder to get the same velocity / pressure.
Maybe that could tighten up the groups some.
I did get more flowby of powder on the neck with these loads.

I doubt if the pitting and roughened bore in front of the chamber will be any good in this rifle.
Cleaning was easier with the jump but accuracy was poor.

I will try some normal 1/2 PP with the harder lead (WQ WW)seated to just rest on the throat/lands.

I may have bubba'd everything up.
I different throating and free-bore would me nice but unless I fit a barrel with a custom reamer I doubt if I will get much better than 1 1/2" at 100 yrds with my set-up.

I couldn't see any cloud of paper or strips flying.

I tried some wrapped to .308 with receipt dockets and they seemed to go as bad or good as the others.

I will see if I can find another the same thickness to try.

All in all a step backwards and a few frontwards for me.

Such is life!!!!

I'd do everything "inside the square " if I knew'd what that actually was.
Barra

[barrabruce]

A bit of an update on 1/2 patches for me.

After I have lapped ...fire-lapped ..honed ground and buggered around with my shooting stick a bit more..this is my latest endevours.

I have switched to 2208 (4895).

The lead mix a few strips of printers lino in with polly 50/50 ww lead. cast well and maybe a bit harder than acc ww. Not much!!!

powder 2208 (4895)

150 fp lee sized to bit over bore. Very hard thumb pressure in muzzle end of gun. leaves rifleing grooves.
30 grns
patched doubled over cig paper 2x to where the cig paper will fold over and cover the base of the bullet.
About 1/3 way up the nose.

170 fp lee sized same but nose it a bees dick smaller and just bears on the bore when thumb pressure.
Wrapped as above but the patch ends up about 1/4 way up the nose.

Here's what I think is the "nugget" of info.

I let one drop from my lee alox bottle onto some grease proof paper I use to lay my tumbled lube stuff on to dry.
I then smear that over say a 2" area.
With a bit of rag etc under the paper for a bit of give I gently roll the patched offering over that.

I can usually get around 3-4 or maybe 5 bullets done that way.

Make sure the nose has a smear on it all the way around.

Fingers will get sticky!!!

After the bloke who was gunna turn up with his cone-er-o grapghy didn't make it I had a session with the 300 mtre gong.
I took enough time out to fire a few small groups at 100yrds.

5x 150's into a 1 1/2 vert x 1"hoz
2x 3shot group 170's small enough to clip a 1" target dot.

All shot after a rub with a bit of ed's red in quick succession.

This is looking very promising to me.

After about 20 rounds . something like 4 x 5shot strings (to let the barrell cool some) I couldn't hit the 300 mtre gong.

All thou they were flung to the right 3" at 100 a few shots grouped pretty well.
After a quick rub with the cleaning rod she would shoot straight again.

so I'm getting a bit of lead maybe..or paper build up.
But.....Not bad.
Well I'm chuffed and am continuing along with it.
I seem to be getting heaps better groups out of this 30-30 since I can seat the nose on the lands and not just in the throat of my gun.

Ohhhh. I got a xmas present from 2 different people.
Both gave me a few sheets of that obscure onionskin to try.
[smilie=w:[smilie=w:

[nanuk]

Primarily interested in PPing some 140-170 gr. boolits for .357 Mag rifle loads. One of the designs might require proper bore dims, but most are sharp-shouldered SWCs which should have no lead in contact with the bore. With some of the more recent powders/data it's possible to push 170-180 gr. J-word boolits close to 2000 fps, right on the heels of .30-30 performance :shock:, might be fun to see what some lightweight PP boolits can do :D



I have a 357 IMI Timberwolf pump that I am interested in trying CB/PPCB in.

I look forward to more info

[nanuk]

Both gave me a few sheets of that obscure onionskin to try.
[smilie=w:[smilie=w:



barrabruce: I usually end up with a pile of that stuff after dicing up my onions for a big pot of chili. if you need some more, I could put some in a envelop for you.

but you'll have to wait till I eat all my chili!