Fire lapping my 303

[DIRT Farmer]

I am finaly catching up some with the farming and am having PB withdrawal so I grabed the ole Savage 2 grouve Enfield and a sheet of 800 grit . I burned a 4in x4in piece, rolled ten PP in the ash and shoved them in over a light charge of IMR 4227. Well next time it will be lighter. I fired 5 cleaned the barrel, decided to fire the other 5. The groves had cleaned up some with the first 5 some shine , about 50% of the bottom of the grouve with 10.
The load I tried this morning was 26.5 IMR 4350 with the case filled with wheat bran under a Lyman311284 sized to .309 wrapped with two wraps of lined notebook paper. I know but I am trying to get it to shoot to the sights. Before fire lapping I was getting a 4 to 6 inch group at 50 yds, round holes, fine confetti centered around the POA. This morning the group was around 1 inch at 25 yds, with some unburned powder kernals in the case. the group was 4inches low and 1 inch to the right. The lands were bright from previous PP loads now the grouves are better.
Any ideas other than uping the loads, and wondering why the shift in POI.
303 guy I like the wheat bran, it dosent seem to show the pressure spikes I have observed with COW or corn meal. And the weveal that have snuk in get a ride.

[303Guy]

Oooh! I wouldn't use that little 4350 with wheat bran - reduced loads of 4350 have been known to detonate. I've had smoldering kernals caught on a catch cloth! Perhaps not less than 75% case volume of 4350 with wheat bran. With grits I use 30gr under a 208gr boolit. Powder burn is good in a short barrel.

Anyway, the important thing is that there is an improvement after fire-lapping! The bottom of the grooves don't really do anything so maybe it's time for finer grit for the final polishing? Or just a heap more paper patched boolits!

I haven't been able to claim any success with my two-groove and paper patching but I haven't given up yet!

[DIRT Farmer]

I took the 303 out this evening, loaded 2 rounds each 32grns 33 grns 34 grns thinking I would try full power, no signs of pressure, have gotten better groups with 00 buck. Think I will wait till morning to start scraping the lead out, after soaking in WD 40 tonight.

[docone31]

What is the final bore size, and how tight is the patch?
My patches are like jacketed. The roller I use makes them tight, almost hard. Perhaps that is why I get my results.
Your two groove most likely needs .317-.318. Those, if I remember correctly are a little large.
Not only should there be no leading, it should clean the bore.
Your loads sound about right, it is the fit in the bore.
What size are they?
My Smelly is dead on at .314, no leading at all.

[DIRT Farmer]

docone the throat is .318 the bore at the start of the rifling is .308 and the groves are .316. At the muzzle it is .306/ .314. The finished dry wraped PP is .320 dry wraped lined note paper lightly waxed. Wet patching did not seem to work as well.

Things seem to work if I load light.The wheat bran could be acting as a wad to protect things till the package gets started.

[docone31]

The dry wrapping is what is doing it.
Wrapping wet, loosens the fibers of the paper, which dry and partially interlock.
I use a cigarette roller to wrap with. I soak my patches, wrap them, twist the tails, let em dry, then size to .314. In your case, you would go .003, or .004 wider.
The patch becomes a solid jacket. The engraveing cuts the patch. Its solidity makes it engrave in the bore. Smokeless patching is not like BP patching. The patch has to enter the bore intact, engrave, and travel down the barrel.
Were it me, I would wrap and size to .319. I would then smear if needed lapping compound on the patch. If that tightens up the group, I would size larger.
When my patches dry, they shrink and the lube lands are quite visible through the wraps.
Good luck.

[303Guy]

The dry wrapping is what is doing it.I'm not so sure, doc. I have been doing dry wrapping and it has worked for me in the two guns I tried it in (field tests). I am now doing wet wrap tests (using the cig roller) so as to get a tight enough patch to hold on without a tail. That's because the load I am using is too low to separate the patch tail quickly at the muzzle. A higher charge results in patch failure and leading of the bore and no accuracy. That's because the bore is seriously rust damaged. My two-groove on the other hand while badly rust pitted throughout the bore still has enough original bore surface to approximate a good bore and it shoots j-words very well indeed. However, the roughness does not allow the use of paper patches with any serious degree of velocity. Remember that it only has two driving faces.

My particular rifle has a throat that starts at .318/.317 and tapers at ½° down to bore diameter, giving a tapered throat about as long as the protruding boolit up to it's ogive. The two narrow grooves start at the throat transition and are that diameter. The problem with sizing a boolit with the base section at groove diameter is that there is an awful lot of swaging down to bore diameter to be done and this tends to drag two extruded tails out on the trailing edge of the boolit. I am currently working on the problem and wheat bran seemed to protect the boolit base for me without raising the pressure much and seemed to give consistant ignition with slower powder and seemed to allow for slightly reduced loads of 4350.

[DIRT Farmer]

That could also be part of the problem. I was twisting the tail but have just tried folding over to almost cover the base of the core. I willhave to try a twisted tail again. The higher loads left room for very little bran. I may need to lap the barrel more, It appears fairly smooth though.

[Zeek]

Dirt Farmer:
Your 26.5, 32., 33, and 34 grain loads of IMR-4350 under a Lyman 311284 will run (w/o filler) around 10, 16, 17, and 19 Kpsi max, respectively. These all seem so very low in pressure that a PPCBoo would probably fail to obturate, seal, spin-up, and confeti-ize its PPatch (upon exiting the muzzle) unless the CBoo core were cast of pure lead.

Suggestion: try far closer to J-Boo starter loads, such as at least 43 grains of I-4350 (~36 Kpsi load). However, that charge is all SWAG*. Go by your loading manual, in any case, for a bullet of that weight, starting with the minimum J-Boo charge and working up.
Regards, Zeek

*SWAG = Scientific Wild-Ass Guess

[DIRT Farmer]

Yep Zeek I have worked offthe SWAG therioum for years. Ain't blowed up much, yet.

The confetti I normaly find is very small peices, like BB size down except for the strip of paper in the GC grouve, which will normaly be about full length and 1/8 to 3/16th wide. With the higher loads the area in the blast looks like the cloud from a load of black powder.

Today I loaded 10 rds with 9lb E slick applied wet to the cores, and wet wraped 10 cores with note paper, hope to shoot them tomorrow.

I have been thinking of backing off this gun and trying one of the more convenial bores to see if it is what I am doing or just the nature of the beast. Apperantly 303 guy has had some frustration with the simular system. Looking at the bore the edges of the groves are rounded so the barrel has a lot of wear comparable to the erosion in the throat area.

[303Guy]

Having been motivated by DIRT Farmer with his two-groove, I just applied the SWAG theorem to work out a decent load for my new PPCBoo and fired one just to make sure It wasn't going to kill me and here I am ..... !??? Anyway, it worked just as I had hoped and I shall be loading up a test batch for field trials. I can't show a picture of the fired boolit 'cause it disintegrated on impact. However, I was able to recover the patch tail and that bit I liked very much. It was cut off sharp at the boolit base edge.

Pressure was mild.
htthttp://i388.photobucket.com/albums/oo327/303Guy/3722091825_edited.jpgp://

I used 37gr of 4350 plus 4.7gr wheat bran under a 182gr casting that just wedges into the tapered throat on chambering and extracts without resistance. Beauty! The fit is just great. (47gr is like 85% case capacity and 4.6gr WB on top fills the case to the mouth - just right for light compression).

Now time and a test will tell. (I so want this rifle to shoot with PPCBoos! It's like a mongrel dog, ugly yet beautiful and heaped with character:roll:).

http://i388.photobucket.com/albums/oo327/303Guy/MVC-363F_edited.jpg
The barrel sits ¾ the length into the can.

[DIRT Farmer]

I decided to fire off the 10 rounds, they miked at .318, at 35 yds I got all of them on a foot square piece of cardboard. nice cloud of dust in front of the gun no lead in the barrel, just no pattern. If I can improve it it might start grouping. The lead from yesterday came out easy.

Zeek, I think I will try a shot of soft lead just to see if it would work. And from the other side of the forum, maybe a faster powder, those guys shoot bore sized and bump up the package to the grouve. Any of you tried this before? I may try B/P just for giggles again although it dident work last time with WW cores. I wonder if wheat bran with Crisco would make a lube cookie.

[303Guy]

I have tried 180gr Lee's with WW I think - very old castings which were by then quite soft - patched with what I believe to be 100% cotton tracing paper of the same thickness as printer paper. These were accurate enough out to 50yds but hopeless beyond that. I was using a full charge of 4350. My present PPCBoo is a pretty neat fit in the throat and case mouth - no neck sizing needed for single fire but slight sizing for magazine loading. I am about to load up and fire the second sample - that's how early days it is.

You know, if it were easy it wouldn't be any fun!:lol: I know I could easily develope an accurate load for my mint bore 1902 MkI* or even my worn but not rusted bore 1806 MkI but it's the two-groove I want in the field with me (for wet and miserable days I want my pig gun - and on good days too but it already has a reasonably accurate PPCBoo 8-)).

[DIRT Farmer]

Ok it's not the 303 but my 1917 Eddystone. just to see if I could reach the quick jump with another rifle, I loaded 5 with the starting load less 5% for the filler 311284 patched lined note paper sized to .314 Imr 4350 from the Lyman hand book. I shot them at 50 yds into damp clay soil so I could recover the cores. After digging I found 2. Both bases were small but one had been squezed down to a diamiter of less than .2, and had broken off at the back. I have to learn to load pictures to show. I have the cores on the desk, hopefuly I can get tech support ( one of the grandkids ) to show me how. The package does extend into the case past the shoulder. do I have to get the base into the case neck? I also womder if Doc's real hard cores help defete this? It would explain why some fly strighter than others. as the bases were a lot different, but both were compressed. The good one had strong rifling on it .

[303Guy]

The package does extend into the case past the shoulder. do I have to get the base into the case neck? I also womder if Doc's real hard cores help defete this?Some say a PPCBoo can be laoded like a j-word. Perhaps that is because of harder alloys like Doc uses. I don'r know. I prefer to load mine out so's the boolit base sits inside the neck (flush with the shoulder junction, actually). I have found that even with my harder/tougher alloy, when using grits as a filler, the boolit base gets cupped and grits gets imbedded and trapped there.

I would suggest that for PBCBoo developement to use unsized case necks and single load. That's assuming the unsized neck can actually hold the PPCBoo. But if it can't, the filler should be able to keep the boolit from moving deeper into the case. I use a sizer-expander that almost allows finger seating. (The expander works from the top down and puts a slight bell on the case mouth. I leave the bell - it lightly contacts the throat area of the chamber on chambering).

Now for some interesting (to me) info:- I'm getting a mint condition two-groove No4 sporter soon. (It wears a proper sporter stock and iron sights). The bore is totally mint!