petep
.30 Stingray
Central Alabama
Posts: 453
|
Post by petep on Nov 17, 2015 8:06:15 GMT -5
It may not work on this particular bullet but why not try a taper crimp?
|
|
|
Post by jjsharpshooter on Nov 17, 2015 13:12:39 GMT -5
Tried today with a very light crimp, still happened, will try with regular lubed bullets.
|
|
jefats
.30 Stingray
Posts: 309
|
Post by jefats on Nov 17, 2015 15:57:02 GMT -5
Been seeing threads on this Powder Coating thing and would like to learn more. Can anyone point to any articles showing what it entails? I don't cast but I would like to be educated. Thanks
|
|
ProGun
.30 Stingray
Posts: 246
|
Post by ProGun on Nov 17, 2015 16:34:43 GMT -5
Jim- there's quite a bit written on the PC subject here on this forum. Just search "Powder Coating" or look through Hoover's activity. He's the authority on all things PC 'round these parts.
|
|
Odin
.327 Meteor
Posts: 971
|
Post by Odin on Nov 17, 2015 19:09:40 GMT -5
Tried today with a very light crimp, still happened, will try with regular lubed bullets. Shot 50 non-PC bullets today (lightly crimped) and got the same thing. And a nice bit of barrel leading too! I didn't find a ring in every chamber, but then again there's the possibility that some of them got pulled down the barrel, hence the leading. Bullets were the same MP-477-640-PB cast from range scrap plus 1 percent tin. I don't have a hardness tester, but pencil testing came up with BHN 10, give or take. Might even be in the high nines, that's pretty soft. I've got some left from the last casting session and will try using the second crimp groove, but I'll prolly water drop this alloy from now on. A little increase in hardness sure isn't going to hurt any. -Rod
|
|
|
Post by cas on Nov 17, 2015 20:59:25 GMT -5
Kinda reminds me of a paper patch ring. Often when you shoot a paper patched bullet in a standard chamber, the bullet swells up, fills the gap between the case mouth and the throat and you're left with a little paper ring that looks just like that. I wonder if it's not the same thing, just cumulative.
|
|
|
Post by Markbo on Nov 18, 2015 10:10:02 GMT -5
Been seeing threads on this Powder Coating thing and would like to learn more. Can anyone point to any articles showing what it entails? I don't cast but I would like to be educated. Thanks Cast boolits has an entire sub forum just for alternative coatings. HUGE amount of information there as well.
|
|
dmize
.401 Bobcat
Posts: 2,825
|
Post by dmize on Nov 18, 2015 10:20:59 GMT -5
Tried today with a very light crimp, still happened, will try with regular lubed bullets. Shot 50 non-PC bullets today (lightly crimped) and got the same thing. And a nice bit of barrel leading too! I didn't find a ring in every chamber, but then again there's the possibility that some of them got pulled down the barrel, hence the leading. Bullets were the same MP-477-640-PB cast from range scrap plus 1 percent tin. I don't have a hardness tester, but pencil testing came up with BHN 10, give or take. Might even be in the high nines, that's pretty soft. I've got some left from the last casting session and will try using the second crimp groove, but I'll prolly water drop this alloy from now on. A little increase in hardness sure isn't going to hurt any. -Rod I believe its the arsenic in wheel weights that allows water dropping to harden the bullets.
|
|
|
Post by bradshaw on Nov 18, 2015 11:01:44 GMT -5
jjsharpshooter.... your good photo helps. Clear, sharp ring of lead. Deep seating is an excellent way to achieve holdback for ignition (reduced air space) at same velocity for 1.5 to 2-grains less powder----varies of course with bullet, bore, and case.
* When deep seating to crimp above front band, allow .030-.060" gap between case mouth and front band. This prevents roll crimp distorting or cutting into bullet.
* When deep seating a round nose, LFN, or WFN, which has not front band, I seat deep enough to crimp on OGIVE----without biting into bullet. Normally, I do not chamfer revolver brass, although it must be done with some some cases which have a wire edge or roughness from factory cannelure. Almost never trim revolver brass. Always keep revolver brass separate by make and lot----it lives and dies with its family.
* Check LEADE of each chamber for an abrupt step, ridge, or roughness. A lead bullet may pass through a tight CHAMBER EXIT (THROAT) without shaving----providing the transition from chamber to throat is smooth.
* Check to be sure case mouth opens behind CHAMBER LEADE.
* If you have an inertia bullet puller, use it to check for bullet abrasion.
* If bullet doesn't pass through chamber exit with finger pressure, pound it through with dowel & hammer. Check for abrasion to bullet.
Thanks to Tank, I am learning a bit about powder coat cast bullets, am impressed, and will post more results soon. For now, LEADE smoothness of your chambers, and crimp behavior remain prime suspects in biting a ring of lead from your bullets. David Bradshaw
|
|
|
Post by jjsharpshooter on Nov 18, 2015 11:45:01 GMT -5
Just tried these again using the same alloy, 70/30 ww-pure but lubed conventionally, no powder coating. Seated 5 in upper crimp groove and 5 in lower crimp groove using a moderate crimp. In lower groove shot 5 into 1 5/8" @ 25 yds off sandbags, no lead in bbl and cylinder clean of lead rings. Shot the 5 in upper crimp grove, 1 1/4" for 4, 5th shot made it 2 1/4" @ 25 yds, also no lead in bbl or cylinder. Only difference between the pc and lubed bullets was the coating and the oven heating to 400 degrees for 10 minutes, maybe the crimp cut into the pc and cut/weakened it or the heating softened the bullets too much. I had seated a pc bullet and pulled it with an inertia puller and it showed no scuffing or damage. Gonna use lubed bullets for now, may experiment with the pc again sometime. Thanks for all the advise and comments. John.
|
|
|
Post by 2 Dogs on Nov 18, 2015 15:07:38 GMT -5
I think it was either Sixshot or Hoover who said you could re quench them right out of the oven. Perhaps that will re harden them enough?
Anyways, I figured it might be the hardness...
|
|
|
Post by boolitdesigner on Nov 18, 2015 17:56:57 GMT -5
I think it was either Sixshot or Hoover who said you could re quench them right out of the oven. Perhaps that will re harden them enough? Anyways, I figured it might be the hardness... Hardness obtained by quenching depends on these things...... 1) the alloy used, 2) time for the dendrite matrix to grow, 3) quench temperature. The less the amount of antimony %, the longer it takes to stabilize in hardness. The amount of arsenic and tin in the alloy effects the process also and not all alloys act the same.
|
|
|
Post by hoover on Nov 18, 2015 18:42:10 GMT -5
I'm more suspect of the PC itself, pertaining to the leading. What PC was used? If Harbor Freight, they recommend a 20 minute bake at 400 degrees per directions on bottle. I'm wondering if half the bake time didn't allow the PC to melt/bond/molecularize, or whatever it does to properly cure, giving it its toughness. Just a thought....
|
|
|
Post by jjsharpshooter on Nov 18, 2015 22:57:12 GMT -5
It was harbor freight red and you are correct for the 20 minute bake, I missed that, I read 10 minutes on the forums and never looked on the bottle. You know guys dont need instructions, but I will try these again with a proper bake time, thanks.
|
|
jsh
.327 Meteor
Posts: 884
|
Post by jsh on Nov 19, 2015 7:20:34 GMT -5
I used the HF red and my rings looked just like the OP's. 20 minutes in the oven. My thoughts were 180 degrees from David's. Bullet jump sheared the driving band? I thought of this as there was no extraction or loading issues in any of the cylinders? Thus seating the bullet out for that front driving band to support the front of the case/bullet to align straighter and truer. Rather than having it shave like a 38 will some times do in a 357. ?? I need to do some measuring and looking. Jeff
|
|