Handling fliers

[Zeek]

I tried a paper-patched ~12 Bh Lyman #375449 today in my Marlin Cowboy 38-55. At 50 yards, it gave decent (1.1" to 1.4") groups with compressed loads of AA-4895 an an LOA of 2.46 (about 20 thousandths off the leade contact point), using a 2X adhesive label patch with the front end of the patch tucked into the bullet's crimping groove & with the patch sized down to 0.381". Pressure was ~30 Kps. It is nice when something works well. Best of all, NO FLIERS!

Then I switched to the Australian SMLE, which has always given trouble. I used NEI's 304-200 PP (also at ~12 Bh), with a 2X 20# paper patch ending at the ~70%-of-length point and sized to 0.313". Using 40-to-52 Kpsi loads of AA-2895, and with the patched boolit jammed way into the shallow leade cone (LOA >3.0"), the best loads gave a core group at the POA from 0.9" across to 1.5" across . . . usually consisting of 4-or-5-of-the-6 shots, but the other shots went well out from that group, often as much as 4 or 5 inches away from it. Obviously, it is "trying" to work, but something is missing.

I cull any boolits more than 1 grain under the maximum boolit weight, as well as any the have obvious flaws, and I find that this really helps eliminate fliers, usually. This frequency and intensity of fliers is not something I am used to seeing.
Any ideas how I an eliminate them?
What Bh do you use for PPCBs shot in the 40-52 Kpsi range?
Thanks, Zeek

[303Guy]

What would happen if you did not size the patched boolit? The non bore riding section of my boolits are .318. They fit the throat and come out the barrel looking like they behaved themselves but I have not range tested them so .... I cannot say how the patch behaved on the front section of the boolits because that part gets totalled!

[bcp477]

The fact that you are getting tight "core groups" indicates that everything is basically right with that particular load. I wonder if your bullets are uniform enough, as regards weight. You stated that you "cull any boolits more than 1 grain under the max weight" - I wonder if this is precise enough. I have always segregated my bullets in increments of 1 / 2 grain. I found that, if I used a larger number for this, say 1 grain, then consistency from shot to shot was affected enough to be noticeable. However, 1 grain did not give me fliers 4 or 5" away from the main group - more like 1 or 2". So, that is just a rough guess on my part.

The only other possibilities that come to mind (that might cause fliers in this case) are differences in the quality and uniformity of your patching or loading....or "operator error".
But, I'm sure you've considered these possibilities already.

[303Guy]

What is the crown and last bit of bore like on the rifle?

[Zeek]

What is the crown and last bit of bore like on the rifle?

The crown is cherry and a 0.3040" gauge pin just slides in with minimal friction. I am beginning to think that I had better bed the barrel and action prior to going out again with it ~~~> then, at least that potential cause would be eliminated.
Thanks, Zeek

[docone31]

I cannot get my Smelly to hit anything under .314. I also use full tilt loads.
I feel, a tight fit, and full tilt load is the only way to get paper to work in smokeless loads.
You will have lots of fliers untill the bore gets fired clean also. Once that is done, My Smelly in .314 with full tilt load is a tack driver at 100yds. Perhaps the most pleasant rifle to shoot in my stable.
It out shoots jacketed loads, even the ones sized .312.

[Zeek]

What would happen if you did not size the patched boolit? The non bore riding section of my boolits are .318. . . . .
Well! A 0.304" boolit with a 2X 20# patch will have a 0.318" O.D. before sizing-down. The rear of the SMLE throating (long leade-cone) has an entry diameter of 0.313", according to the spec sheet. I would expect it to give me strong resistance to seating-out the boolit if I did not size it. However, If I understand your drift, you patch to 0.318", load, and fire. Is that right? If so, I'll be glad to try it, expecially after I get that barrel a bit better bedded.
Zeek

[303Guy]

If I understand your drift, you patch to 0.318", load, and fire. Yes. That's the part that stays in the neck. The rest tapers down to the bore riding section. I opted for a near parallel bore riding nose so as to be unrestricted with OACL, allowing me to seat to the base of the neck. Different weight boolits have different length bore-ride sections.

http://i388.photobucket.com/albums/oo327/303Guy/untitled.jpg The bore-ride section still has some taper.

The curious thing is that although the bore riding nose does not engrave on chambering, a fired boolit has rifling impressions right up to near the ogive! (Bore-rides after patching).

Work pressure has stopped me experimenting (too tired in the evenings) but the idea is to try different boolits weights to see what happens.

I should mention that the throat entry is smaller than the final patched boolit. It gets swaged (a little) in the leade in to the throat! (Then again in the rifling leade). Even cig paper patches survive this treatment intact and cig paper is thin and fragile. My theory is this will ensure accurate boolit alignment with the bore and of course, a good boolit to bore fit.

I have a guage I made which I use to check the the boolit enters the throat deep enough that a chambered round can be extracted without leaving the boolit behind and/or that the boolit won't get pushed back into the case on chambering. (The boolit must seano deaper than the dough-nut).

[Zeek]

What would happen if you did not size the patched boolit? The non bore riding section of my boolits are .318. . . . .
Well! A 0.304" boolit with a 2X 20# patch will have a 0.318" O.D. before sizing-down. The rear of the SMLE throating (long leade-cone) has an entry diameter of 0.313", according to the spec sheet. I would expect it to give me strong resistance to seating-out the boolit if I did not size it. However, If I understand your drift, you patch to 0.318", load, and fire. Is that right? If so, I'll be glad to try it, expecially after I get that barrel a bit better bedded.
Zeek

[windrider919]

As I said in the title = We need a Sticky on bullet fit in chambers.

Time after time I and others have pointed out that without a chamber cast you DO NOT KNOW what your chamber actually is. I have rarely found a rifles chamber to fit to the 'specs, usually it is larger. When using J-bullets there is not much you can do but adjust seating depth but with cast you can really tailor the bullet to the barrel. The chamber cast will tell you not only throat and lead diameter but also their lengths. Both can be critical for wringing the last bit of accuracy out of a barrel. I have had several rifles pass through my hands that shot 4" groups at 100 Yards with J-bullets, no matter what powder or bullet depth used. But the same rifle could shoot 1/2 inch groups with a proper fitting bullet (and powder, brass prep, etc)

Here is the core that every new PP shooter should know:

In PP I found that since the PP bullet swages down so easily and has less max pressure problems than even GC cast. Experimenting with multiple rifles, calibers and cartridges I found that bullet fit in the throat was critical for the best accuracy the rifle could deliver. The J-bullet should not be oversize of the groove diameter and the standard with cast GC was no larger than .001 over groove. But PP is a different class and I found that the bullet did NOT have to be bore size when using smokeless. In fact I found that when patched to fit the throat / lead the accuracy increased! NOTE: I did not shoot if the 'core' bullet was as large as the groove but if it was as much as .001 under (before PPing) it could be shot. I have gotten amazing 1" groups from 'shot out' barrels by doing this. Of course I need to insert the standard legal disclaimer to protect myself from the idiots and their lawyers, "Work up to this and I am not liable for your failure to apply common sense and loading safety."

An example is a Springfield 30-06 that had a throat that miked .319 and would shoot 14" groups at best with anything tried. The rifling was very worn at the chamber but still good at the muzzle. I loaded 180gr, .307 sized bullets which were PP to .316 and used cases that had been neck sized to .314 ID so as not to crush the patched bullet down. Knowing that the chamber neck size would allow this was another important datum from the chamber cast. Bullet depth was max to fit the magazine but since the rifling was worn even better accuracy might have been obtained by loading longer overall and single shoting. Using 3031 and working up I got 2100 FPS and consistent 3/4" to 1" groups.

I have done the same with my .458 Win Mag which has a throat of .464. Using a .454 bullet and PP to .463 (and sizing the case to NOT over crush the soft bullet) I do NOT have excessive pressure, have achieved velocities well above 2K (but usually shoot 1800 FPS) and my groups are 1" or less. I could not achieve this accuracy with .450 PP bullets, cast GG, cast GC or jacketed bullets.

In conclusion, shooting without knowing YOUR actual chamber size is like shooting with your eyes closed.

[303Guy]

If I understand your drift, you patch to 0.318", load, and fire. Is that right?Yes, that's what I do. windrider919 covers it well. I must say though that I did the same with smooth sided, surface lubed cast boolits. I suppose one could say they were 'lube patched'.:roll:

I suspect that only the very early Lee Enfield barrels were made to spec - the later ones were made for battle conditions.:Fire:

[montana_charlie]

Well! A 0.304" boolit with a 2X 20# patch will have a 0.318" O.D. before sizing-down.
That leaves you with a layer of paper eleven thousandths thick.
I bet your rifling is not eleven thousandths deep.
I would be looking for thinner paper.

CM

[Zeek]

I had said: "Well! A 0.304" boolit with a 2X 20# patch will have a 0.318" O.D. before sizing-down."

That leaves you with a layer of paper eleven thousandths thick.
I bet your rifling is not eleven thousandths deep.
I would be looking for thinner paper.
CM
I was WRONG! (I do that about once a week, just to keep my hand in.) Actually, a 2X 20# paper patch adds just 12 thousandths . . . pretty close to your eleven number, Charlie.
Here's the trick, though, if you compress that paper to push out the air, then it adds only six thousandths to the 0.304" PPCBoo core, giving you a compressed-diameter of just 0.310". So, the PPCBoo will have to obturate at least 0.003" more in diameter to give even a half-ass reasonable seal in the grooves.
Please pardon "Mah bayud!", Zeek

[303Guy]

Does it matter that the patch is deeper than the rifling?

I have test fired (into my 'test tube' and at low velocity) patched boolits that had a long bore-riding section - and I mean bore-riding after patching - and the recovered boolit showed rifling impressions right up to the ogive and the patch came off in shreads at the muzzle. These were quite ductile castings with no heat treatment. I should hasten to add that I have field tested exactly one such patched boolit at full power (and it hit its mark). I loaded this single round with an estimated powder charge to give moderate pressure and killed a turkey with it - the turkey was already wounded so I was allowed to take such a chance! The range was not extreme - 100yds or so.

[docone31]

If you size the .318 to .314, you might be pleasantly suprised with the results.

[montana_charlie]

I had said: "Well! A 0.304" boolit with a 2X 20# patch will have a 0.318" O.D. before sizing-down."

I was WRONG! (I do that about once a week, just to keep my hand in.)
Your desire to be wrong on a weekly basis must be infectious, because I was also wrong.
An increase from .304 to .318" is a total increase of fourteen thousandths. Dividing that in half provides the actual patch thickness, which is only seven thousandths.

If your rifling is four thousandths deep (a common depth) you are still able to 'score' the inner wrap with the land's corner...even if the paper is not cut all the way through.

If sizing after patching further reduces the paper's thickness (as you say) you are probably alright.

CM