View Full Version : PP velocity gain?
09-21-2008, 01:40 PM
Hi, I'm not a blackpowder cartridge shooter, and what I've found on paper patching bullets seems geared towards that audience, and has done little to answer the one possibility that makes me interested in paper patching.
Can I use paper patching to drive cast lead bullets to copper jacketed bullet velocities in a modern 30 caliber smokeless rifle, ie 2800 fps?
09-21-2008, 02:21 PM
I have read, and been told, that almost that velocity is quite possible with paper jacketing. That is with accuracy also. I am working on my rifle accomplishing almost that. I hope for 2200fps.
So far, I have been able to hit the berm at 100yds. I have just begun however. If I can get 3" at 100yds, I will have died and gone to heaven!
My barrel, is a loose .303 British. Almost unfired, but loose. Lead sized to .311 gives me 20ft groups, no leading however. Paper patched to .3125 got me 3ft groups. I am going to try .3135 soon.
By the by. For my smokeless loads, both .30cal, and .303, I use the 185gn Lee 303C mold. I size for the .30cal, .308 and wrap and size to .311. Does real well. For the .303, I size to .308 wrap to .3135, and can do .314. I am trying .3135 with 20 loaded rounds to Lee Load Data for starting load. No gas check with paper. I can get .314 using different paper. On the remainder of the .3125 rounds, I smeared 400grit lapping compound into the exposed paper.
I figuire tight enough to polish ok, light enough to not polish really heavily. I will fire 20 of those, then 20 of the tighter patches. I do plan on bore scrubbing before firing plain patches. I have chatter all the way down the barrel.
09-21-2008, 04:37 PM
The Lyman Cast Bullet Handbook says "yes". It has a section on paper patching and possible velocities.
I can't speak from experience as I haven't pushed PP boolits that fast - yet. If you do you will likely need a reasonably hard alloy or at least a design that is well supported so it doesn't slump.
If you search this forum you will likely find posts and information on PP and high velocity.
09-21-2008, 05:10 PM
Since I seem to be using a mold for lube, and I size most of the lube grooves off, I have been considering some zn for stiffness.
I did cast some of this batch with zn in it, and they came out ok. A little light, but ok. The sizing die cleans off the rounded corners.
Now, adding zn will add another dimension to sizing. I am looking at .3135 at final wrap. With zn, I possibly might be able to go thinner.
I have considered going .312 with jacketeds. The standard .311 is a little sloppy. My fired cases, they fall in and the neck die cannot size it down.
To stiffen with what I have on hand, I cannot expect if zn is added, that the sizing can remain water quenched wheel weight size.
But that is down the road. I am now finding the size that works.
I am betting .3135 will equal milsurp. The steel in the jacket is what makes the cuprometallic loads work in a sloppy bore. Standard .311 is not tight enough in straight cupro jacketing.
At least what I have been finding out from research.
And, according to the Lyman Casters Handbook, paper jacketed projectiles can be pushed. I am trying to find the correct fit. I am not pushing hard though. I suspect that although it can be done, it might not be done in my rifle. The bore is not match grade, indeed. It has chatter marks.
Almost did it. 165 gr PP in 308 Win at 2700 fps - 6" @ 200 yds. That boolit at 2400 fps goes into 4" @ 200 yds on a good day.
09-22-2008, 01:13 AM
...............Bobby Ironsights, one of the other benefits of paper patching is that you can take a dead soft lead slug and drive it to velocities well over what a naked GG slug would stand. While you won't make 2800 fps (I don't think) with a pure lead PP'd slug, for hunting you don't have to.
By your handle, if you're a hunter I doubt you're one who thinks a deer shot at less then 600 is pitifull, and the hunter was not trying. Remember that from the 1300's until the late 1880's, ALL shots taken in target, plinking, hunting, self defense and warfare were done with pure lead or a lead alloy slug, naked or PP'd. Cartridges were also ALL fueled by black powder so velocities were not much over 1600 fps (except for patched RB's).
09-22-2008, 05:13 AM
In my test 2200 is about all I can get with pure lead. Add enough Linotype to get to 12.5/13.0 BHN and 2600 is reachable. Alloy to 14.5/15.0 and 2900 to 3000 works fine. Straight LT and I haven't found the limit yet, not even in my 300 RUM.
Like you Bobby, I am working on this issue also. I have successfully patched and tested rounds in my .30 cals., .243, and .38-55. All of these with what would normally be thought of as cast boolit loads, 2000 fps or less. This week I'm gonna try pumping the .243 up to full jacketed velocity, working up very slowly of course. We'll see what happens. One thing is for sure, paper patching is fun and interesting to experiment with.
09-27-2008, 07:30 PM
I shoot .458 Win Mag and rarely shoot jacketed. I have found that using standard PP techniques I could push bullets up to 1800 FPS with accuracy of 2.5" at 100 yds. Most shooters and rifles would be pleased to get that. Hotter loads groups got larger fast with increased velocity. Then I changed some of the dimensions that were for BP shooters to those more suited to smokeless. I have been able to shoot 1" groups at 100 yards with a velocity increase to 2100 FPS. Of course that is with a custom match simi-heavy barrel, fiberglass stock, tuned trigger, shot in a rifle rest on a solid bench. I could and have shoot faster/ hotter but then the recoil factor kicks my a*s and the muzzle blast passes into painful, even with muffs. When the muzzle blast slaps your face so hard your eyeballs quit seeing for a second its time to back down. I shoot to hit with max accuracy with the most "smash" to the target I can get but do that with the most comfortable load I can. Velocity is not everything, in fact velocity is nothing if you miss.
Besides, everyone on the range complained about my hotter loads because the blast (under the tin roof) was so disturbing they could not shoot.
09-27-2008, 07:50 PM
A follow up.
I had loaded paper patched .303 British loads, with paper patches sized .3125, swabbed with 400 grit. This I loaded with 32gns of 4895. The starting load for 180gn jacketed bullets.
19rds went down the barrel, the 20th had a shoulder crumple I missed, common with the brass I am using.
ALL the chatter marks in the barrel went away! My first round was in the black at 100yds with the scope zeroed to milsurp ammo!
The next 20, were paper jacketed to .3135. Three wraps of Meade Tracing Paper, rather than the two I had been using to get .3125.
Same point of aim!
My barrel however is unbedded. Before the 20 were fired, my point of aim became unpredictable.
I had loaded up 50 jacketed at .311 as called for. Blech on those groups. I am going to go up to .312 with jacketed.
I do not know if that answered your original question. I am however using starting load data for jacketed. I do not have a chrono, so I am just guessing.
I am not sure speed matters that much over accuracy however. I do know, that with just gas checks, I got 10 MOB. Ten minutes of berm, maybe.
Besides, some of the big time competitors stop and take a look see at what I am loading. Some even ask.
09-28-2008, 04:27 AM
docone31: If my memory is correct you stated in another post that your wife was a jeweller. If that is correct try treating a couple dozen paper patched bullets with jeweller's rouge the way you used the 400 grit abrasive.
I have had better sucess with paper patched bullets fitted to the throat than to the boar, especially with the military chambered rifles.
09-28-2008, 05:36 AM
Paul Matthews says 2000 fps for pure lead and 3000 fps for alloy bullets is doable. My experience does not support that fully with pure lead due to stripping issues but that may reflect on my technique or bore specs., not his knowledge. 1800 fps, sure, I've seen that over a Chrony and accuracy was quite good.
Just an opinion borne of my purpose for doing the patch thing. I hunt with my loads. Large bore pure lead bullets do not need a lot of velocity to kill cleanly. Double caliber expansion is the norm with transonic velocity impact. I think small bore PP pure lead at fast twist rates is a conflicted regime from the point of dynamic loads and lead's mechanical properties. If I was planning on rock and roll with high velocity loads....I'd save the work and use jacketed bullets. I do not have much faith in work-a-day alloys at high velocity in the terminal performance realm.
OTOH, if it's what you pursue, I think 3000 fps is doable with patched bullets of suitable alloy. Hard alloys will not obturate easily and finished size on the bullet will be critical to accuracy.
09-28-2008, 07:50 AM
Rhead, I have found that out to be true. My Smelly is an example. I went nuts trying to fit to bore with limited success. I was happy the casting exited the bore without damage.
As I have learned more, I definately agree, at least with milsurp rifles.
My wife and myself are both jewelers. For polishing, we use green rouge.
I used the lapping compound to really finely cut. Sounds like it is contrary, I just used a light dusting.
The barrel was a throw away so it did not matter. I can get those barrels any time.
Well, bore inspection after 19rds, and 20 with dry paper, absolutely amazing! Using using a rouge, or tripoli, I would use 20 to 30 to get the same results.
However it could have gone the other way. Too much grit resulting in too much pressure, stripping the rifleing, just messing up the bore all together makinng a barrel change neccessary.
I have cerium oxide for final polishing gemstones on my faceter. I had considered using this to mirror polish the bore, or Linde A, a coarser final polish. After looking at the bore I am not sure I need do anything more than than fire paper patches.
It worked for me. I went real lightly, and it worked. No measureable bore changes, just no more chatter marks.
09-28-2008, 06:39 PM
I have shot PP in the Mosin and Enfield with good results. The Mosin shot 2.5-3.5 in. at 100 yds with a 185 gr. Lee boolit , the vel. was almost 2400 fps. The Enfield did about 2.5 at 2200 fps, it has a scope so that helped my groups. I think the alloy was about 1/3 lino and 2/3 ww.
I haven't been doing paper patching very long but I did a lot of reading and fell into a good combination early on. This is not the 2800 fps you are talking about but it is getting close to full power loads in these rifles.
I do not know how these loads would perform on game, I don't hunt much anymore so I will probably never find out.I have read that cast boolits at the higher vel. will come apart or at least be inconsistant after hitting game. If anyone here has any experience with that maybe they will fill us in.
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