The Wonderful World of High Velocity PPCB

[CJR]

I have been having a blast running all kinds of tests this summer to achieve consistent Hi-Vel PPCB. I started out getting some decent groups at a 100 yds and then they went down the tubes. Then I was consistently getting "minute-of-berm-angle". I went through all kinds of lubes (dry teflon, moly, etc.) and finally went to an old NRA tip; dacron on top of powder, 2-3 grains of lithium grease on the dacron, and a lithium greased PPCB. That got me down to about 6" at a 100 yds. I tried all kinds of paper and bullet sizes with no particular improvement. What I did detect was severe powder fouling that seemed to open groups. It seemed like the PP wasn't making it to the muzzle. In the beginning, when I'd look at the muzzle from the side you could initially see the leading. After the change to lithium, the muzzle leading was gone, but I could still feel the powder residue buildup. That led me to brush after each shot..

For my .308. I first tried 45 grs. of H4895 under an LBT 150gr. PPCB and 41 gr.. H4895 under a Lyman 175 gr. 311291 . With 45 gr. H4895, I couldn't get much lithium grease under the bullet, so now I use 41 gr. H4895.

I'm still in search of the "Holy Grail" of match accuracy with hi-vel PPCB. I have not been able to replicate the NRA's success with hi-vel PPCB. Eventually, after making every mistake possible, I should get there. Hope springs eternal!

Best regards,

CJR

[barrabruce]

CJR Good on yu"

I haven't the NRA's trails etc to read through and decipher to see if I can make any sense in it.
I heard of this document maybe I should see if I can get a copy from the US and also the paper patch book as well.
I think I'm missing some thing.

I could still feel the "residue build up" This sounds familiar to me.
Does it occur in the same area of the barrell or more of a global issue?

Not that I can help you out but it may confirm a theory I'm getting into.

Barra

[docone31]

CJR, it sounds like you are a little undersized.
For my .30cals, I size to .308, wrap with two wraps of notebook paper, then size to .309. I use the Lee 180gn .30cal casting.
You are 1gn under my loads but I do not think that is an issue.
You could be cleaning out the bore with your wraps.
When you are wrapping, what size do you end up with?
I have found, waxes, grease, or lubes on the patches other than to weather proof, causes its own issues.
To second size, I use Auto Wax, lightly, then size it off. Makes a shiny patch with no residue.

[CJR]

Barrabruce,

The powder residue buildup is in the forward third of the barrel, near the muzzle. Everytime I clean the barrel at home, it is spotless for the next test session.

Docone31,

What I do is size my bullets to 0.03015"D, wrap twice and dry, then size to 0.308"D. It appears that the powder residue build-up causes the barrel friction to vary as I shoot and the bullet placement on target shows that. The other funny thing I noticed was when the PP dried it was nice and tight. After spraying it with dry teflon or greasing with lithium-it loosened up. Next I'm going to try a tip Veral Smith mentioned to me. I'll let you know if that works.

Best regards,

CJR

[303Guy]

CJR

Here's what it sounds like to me; The patch is not survivng the trip down the barrel (as you have suggested). That does not mean there will be any detectable leading. I've had this happening. Have you been able to recover any patch fragments? I have the advantage of possessing a 'test tube'. The bore should come out cleaner and cleaner untill you will look down it just cause it looks soooo clean and shiney!

What paper are you using at the moment?

You could be a candidate fore fire-lapping. Or simply try reducing the loads until the patch does survive. Then you also try dry wheat bran as a case filler. That should keep the bore condition constant. It also allows for lower load densities with slower powders. (Not too low though). I'm probably pushing the limits by going as low as 30gr 4350 at around 60% load density. I wouldn't dare try that without the wheat bran filler! That stuff has been known to ka-boom with reduced loads.

Oh, wheat bran doesn't seem to raise the pressure all that much.

[CJR]

303Guy,

I have found no paper fragments. However, I sometimes will see a puff of white smoke at the shot. That should be good. At my last session, I used 100% rag drafting paper @ 0.0025" thickness. Before that I used 100% rag Vellum paper close to 0.003" thick.

The patch is not lasting during the trip to the muzzle. As I mentioned before, after the PP dries the patch is nice and tight. I use Docone31's cigarette roller tip. After lubing the PPCB, loading and letting them set for a day or so, the PP is loose. Most likely the loosened patch may be getting cut in the seating operation which then cause the PP to come off early in its trip to the muzzle. The good thing is I'm getting no leading at hi-vels. When I look up the barrel from the receiver end, the barrel looks nice and shiny as far as I can see clearly. However, looking from the side at the muzzle bore you can see the powder residue build-up and then feel it with the brush. I think I'm seeing/feeling the powder residue build-up simply because the PP is coming off the CB before exit and therefore the PP can't clean the last third of the barrel.

In my view, I need to do two (2) things; try some tricks to keep the PP tight after lubing, and play as the NRA did, with some different lubes to give me consistent friction between the PPCB/barrel during its trip. There is also another possibility which the NRA found with their .300Win Mag 3000+ fps tests, i.e. more lubricant. Hope springs eternal!

Best regards,

CJR

[runfiverun]

two things that could help your accuracy.
back down the load of 4895.
try a slower powder for a gentler push down the bbl.
something like 46-7 grs of rl-19 to start.

[303Guy]

I'm with runfiverun. I would try those two approaches he suggests.

you can see the powder residue build-up and then feel it with the brush

Mmm... I'm thinking that's not powder residue, but lead vapour deposits. Well, not really vapour but liquified mist. It'll be a dull grey colour and in my case, it even formed a muzzle star. Powder deposits on it's own should not be feel-able and should settle in the full length of the bore with a little more nearer the chamber. I hasten to add that I'm open to correction! I've only seen this lead mist deposit a few times. When cleaning it out there is a grey gritty stuff that comes out on the jcleaning patch. It doesn't look like lead but it doesn't look like ordinary powder fouling either. The use of a lube would likely keep the deposits in a powdery form. Anyway, if I'm wrong I would like to be corrected!

Getting back to runfiverun's suggestion, I did some work on developing a load that would get the patch through the bore without failing but with sufficient fragmentation at the muzzle. That involved using a slower powder and a light enough load. Too light a load and the patch did not fragment satisfactorily - well, not to my liking anyway. I took that load to the field and it worked. I did that twice, one for each of two guns. It might work for you too.

Oh yes, switching to a slower powder required pushing up the pressure and velocity to get it fragment properly, meaning I got higher velocity with slower powder for adequate patch fragmentation.

Hopes that helps.

[CJR]

Runfiverun & 303Guy,

Thanks for your comments. I appreciate them! Reducing my powder charge is my last option to try. Once I solve this 308Win hi-vel PPCB accuracy problem, I will work with my son's 300H&H to get 3000+fps accurate hi-vel PPCB.

I'm pretty convinced my barrel deposit is powder residue resulting from PP failure somewhere in the bore. On cleaning my patches continue to be black with no lead streaking evident. What's encouraging to me is that in my 4-6" pattern @100 yds. I had bullet group clusters where 2 or 3 holes were almost touching.

Best regards,

CJR

[runfiverun]

what i am thinking here is my normal jaxketed load is in the 42 gr range.
any ways what i am thinking is that the 4895 is not holding pressure long enough you are letting the pressure drop and the bullet is relxing on you letting the paper start to get tugged at and torn.

the grey puff was the clue.

it's the same thing that happens when i over run my lube with plain cast.
or when i exceed my alloys strength and strip the lands. [tear the patch]
you are oh so close but are missing one thing.
i am thinking either , alloy strength is off a couple of points or your paper just isn't strong/thick enough.
or the above scenario with the pressure curve.

[303Guy]

Once again I'm with runfiverun.

patches continue to be black with no lead streaking evident.

It does indeed sound like only powder fouling. Just for info, the type of lead deposits I was refering to (molten lead mist) does not form lead streaks - just a dirty grey paste and it is mixed with other deposits. But it's not black and in bright sunlight one can see little silvery spots.

Perhaps a slower powder that maintains its pressure curve longer would help with no reduction in velocity? On the grease you're using, lithium grease will blow out almost completely. There are stickier greases and lubes out there. Just a thought. (A problem with those is that they release the oils in them to capillary action and will eventuall 'wet' the powder. I bind my sticky lube with parafin wax. But that makes it want to stick to the boolit base if the powder charge is light to moderate.

[Crash_Corrigan]

I run 311284 Lyman cast boolits thru a .308 sizer and then wrap with computer paper wet in a cigarette roller. Overnight drying and then a dab of JPW and run thru a SAECO .309 sizer and then load over 30 gr of 4064 or 32 gr of 4985.

This gives me low recoil, speeds of 1750 FPS, good function and a nice pile of empties three feet in front of me and pretty good accuracy out to 300 yds. This works ok in my M-1 Garand circa 1954 with a very decent bore.

Next will be to use some PSB fillers and to play with that. It is the journey that is the fun not the end result.

I would love to be able to get jacketed velocity with PP and fillers but I doubt that it can be done in an M-1. Now I have a pretty good 8 x 57 Mauser which presently seems to have an undersized chamber which may require some reaming...reports to follow.

[windrider919]

Very busy with my CNC Mill and learning all the Mastercam design n control software BUT I had a chance to check what is going on here and thought I'd throw in my 0.02 cents worth.

My take - Don't go to a slower powder because PPCB have less bore friction and do not develop full pressure with slow rifle powders. Use one of the medium powders usually get you back up to speed.

I had a problem with PP smooth sided slugs shooting smokeless powder, poor accuracy as the patch seemed to be 'hanging' in the chamber momentarily while the slug moved forward some. Same dirty barrel in last 1/3 to 1/4 but no visible leading.
Are you using a smooth sided / grove less PPCB? One solution that worked was to roll the bullets under a coarse wood file to raise small burs to catch and hold the patch at the instant of firing.

As per lubricants - the old time shooters and the modern BP shooters swear AT using lube, saying you get no accuracy. HOWEVER, in working up accurate loads for my 'match' 458 WinMag I found that a petroleum based lube gave bad accuracy but a lube such as Rooster lube (which is water based and dries to a hard wax similar to floor wax) tightened them. Used diluted 4:1 with my patch water it gives tight, field grade moisture proof patches which group beautifully. Another lube which gives excellent results is Sailkote (expensive!) used by sailors to reduce friction on lines and chaff points where sails rub. I apply it lightly to the patched bullet (patch loosens some then tightens up). I also use Sailkote on my pellets for my PCP air rifles as it gives better accuracy there too.

I have used a wax lube (65% beeswax, 10% JPW, 20% LLA, 3% lanolin, 2% wheel bearing grease which is my homemade regular cast bullet pistol n rifle lube) wad between a polyethylene wad and the bullet base but got no accuracy. Dropped the wax and just use the PE wad and groups tightened up.

FYI Note: I DO NOT size my PP as the reason I wanted to try in the first place was to simplify my shooting. I cast a .454 bullet, wrap twice to .463 (which is .001 under chamber throat) and shoot in the .458 barrel. [Disclaimer - I get no excessive pressure in MY rifle, you assume your own liability with your own reloads.] My usual group with this (assuming I do my part!) shooting from a rifle rest, is less than 1", trip after trip to the range.

[Zeek]

. . . The other funny thing I noticed was when the PP dried it was nice and tight. After spraying it with dry teflon or greasing with lithium-it loosened up. . . .

THAT is a BTDT for me and is deadly against accuracy. It happened to me in spite of my following the NRA's instructions to the letter. It caused me to drop PPCBoos as an option for nearly 20 years. I got back into them after having developed my ability to see what caused my ballistic problems . . . . via LOTS of failed experiments and the occasional insight when one worked.

In MY case, what caused the loosening-up, during final sizing of the patched Boo, was the use of WAAAAY too much lube, such that the paper's pore space, which you want to keep for AIR was, instead, filled up with incompressible liquid (grease). The result is that, when you size the PPCBoo down, the force all goes to sizing down the CBoo core's diameter and then, when that Boo comes out of the sizer, it has a loose patch-to-core fit.

Suggestion: once the patch is dry, use only a VERY LIGHT coating of paste wax. I mean, by that, that there is so little on your finger/thumb combo that you can barely tell that you have the lube on your hand. Let the PPatch soak that up (as you roll it between thumb and forefinger), and then add NO MORE LUBE.

This leaves most of your patch's internal air in-place to serve as a resilient component that will "inflate" the patch (like a pneumatic tire) to fill in all the spaces, such as along the trailing (non-driving) face of each land. You NEED that air-help while the PPCBoo is traveling down the barrel, so be sure to act so as to assure that the air is not displaced.

Regards, Zeek

[docone31]

Could it be, that is why my way works?

[CJR]

Zeek,

You may have a point with the lube/pores theory. I will try it soon.

Yesterday I had a good time at the range sending many hi-vel PPCB downrange. Unfortunately, I didn't even get patterns. It seemed like I was shooting undersized CBs and they were everywhere but in a group. These .308CB, right after casting, were sized to 0.3015" D. diameter, wrapped twice with 100% rag Vellum, spray lubed with lithium/teflon spray and sized to 0.308"D (NRA recommendation). After getting home, I took the patch off a couple PPCB and miked the CB. They measured about 0.299"D- not good. So it seems I was final sizing them down too much and most likely this was the cause of the wild shooting. I've got another batch final sized to 0.3095"D with some lightly lubed with the NRA formula and some lightly lubed with LBT Blue. We'll see how these fly next week. The loads shot at the 100 yd. range were 41 gr. H4895 and 43 gr. WW748 behind an LBT 150 CB and the Lyman 311291.

Hope springs eternal!

Best regards,

CJR

[windrider919]

Would you please try some without the lube. I usually find the NRA articles to be the Bible of shooting information, but occasionally there are theorys or practices that just don't work. I am 56 years old and have been reading American rifleman since I learned to read at age 5 (looked at the pictures before that). Helping my father reload since then too. Shooting, re-loading, load development for over 170 firearms I have owned (buy, mod and customize, develop a best load n sell to buy the next) in my life has taught me SOME lessons. And one is: Sometimes, the NRA/AR contributors are.... 'Gasp'....wrong.

SO:

After LOTS of testing in my life......STAY AWAY from Teflon in barrels and on projectiles if you want good to excellent accuracy. Yup - great friction co-efficient but it just never, in my or others I have known try it - gives any accuracy!

Note; After a lifetime of shooting pretty much everything, firearm type and cartridge, I settled on 458 Win Mag as my 'keeper' All Around Rifle.

[docone31]

I have tried to tell these guys,
No lube!
Oh well. Their patches come loose, they get fouling, miserable accuracy, on and on.
I use just enough Auto Wax to make my patch go through my sizeing die. It wipes most off during sizeing.
I have tried. Perhaps one day they will discover it out, and then it will be ok.
And yeah.
The .458 is perhaps one of the most versitile load going. From plinker, to howitzer. It does it all.
Not a bad cartridge to wrap either.

[303Guy]

I've proved to myseld that too much lube on a paper patch is a no-no. I test fired cig paper patched boolits into medium and I found that the lube actually 'glues' the paper to the core. This glued on patch remained in place deep into wet wool medium. Those same loads shot OK at close range but very poorly indeed at long range. Some loads also shot poorly at close range.

I lube my patched boolits by rolling them on a case lube pad loaded with STP. The STP quickly dissappears into the fibres but allows for easy sizing and neck seating. They also shot well in the field, being responsible for my first PPCBoo turkey. There would be nowhere near enough lube to waterproof these PPCBoos. I would suspect that water emulsion waxes would apply a surface coating that would be way more effective in the water proofing and lubing depts.

[CJR]

What to do? what to do? Sigh! The NRA and Matthews( "The Paper Jacket" book) all talk about how critical lube is to the PPCB. Likewise, I don't doubt that some here have had excellent success with a dry PPCB. Likewise, I tried JPW and it didn't work for me with the loads I assembled. That doesn't mean JPW doesn't work. It means to me that something was grossly wrong with my assembled loads. Hopefully, after making every mistake possible I'll find what works for me. Right now "I'm separating the chaff from the wheat" by actually shooting what I assemble. In my mind, it's not who's right or wrong with some technique, but what technique works for me. As everyone knows, a perfectly accurate jacket load in one rifle can be a disaster in another rifle. In my view, this hi-vel PPCB adventure is no different. Be assured, I do welcome and appreciate all the constructive criticism. My hide's pretty thick.

Best regards,

CJR