Powder Coating 300 BLK BTHP Boolits

[Phantom30]

What is your objective for the 30 cal AR round? Target accuracy, lethality,...as per above the lee TL309-230-5R is limited in how you load it PC. Further there have been reports that the raw alloy round is a tumbler because of the part that makes contact with the rifling is so far behind the CG and contact area is small. A .002 thick PC fixes some of that because it brings the band in front of the crimp pocket into contact.

[Wreck-n-Crew]

Not totally related but how much longer does it take to cast hallow points over regular bullets?



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[ryokox3]

What is your objective for the 30 cal AR round? Target accuracy, lethality,...as per above the lee TL309-230-5R is limited in how you load it PC. Further there have been reports that the raw alloy round is a tumbler because of the part that makes contact with the rifling is so far behind the CG and contact area is small. A .002 thick PC fixes some of that because it brings the band in front of the crimp pocket into contact.

I did a load test today with that boolit, though I reamed out the gas check shanks. Both hi-tek coated and PC. No sign of tumblers through my 16" blackout AR. Used lil gun, h110 and reloader 7. Overall reloader 7 worked the best function wise.

I know you said raw alloy, and not coated, but I wanted to share my results with that boolit. Maybe reaming it out gave enough extra contact area with the coating to stabilize it.

[Phantom30]

wreck-n-crew less than a second difference to cast on average. Open mold tap, close mold maybe slight slower

Ryokox3 The chart had both raw and PC on it with two thickness of PC for comparison. Actually the .002 thick PC works best

[Hickok]

Those boolits look flat-out wicked!

[Wreck-n-Crew]

wreck-n-crew less than a second difference to cast on average. Open mold tap, close mold maybe slight slower

Ryokox3 The chart had both raw and PC on it with two thickness of PC for comparison. Actually the .002 thick PC works best

Thanks....that's what i thought.

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[Phantom30]

OK people have been commenting about the metplat being too wide to feed properly in an AR and that the limit should be 0.18" with a COAL in the 2.1 neighborhood. So I looked at the accurate design and the 31-215F has a 4R ogive instead of a 5R which brings gets better rifling clearance, and has adequate separation for even thick PC. It also reduces the sizing efforts when you start with a 0.307 OD boolit. Casting the HP cavity maybe to large for the tip but you can always just shift the design to increase the tip thickness. When you use the spike mount for PC, you get PC to the tip but not on it, so you could still end up to fat again.

[Phantom30]

The design above has a potential for feed jams in some weapons so with the help of mto7464, some testing was conducted and it indicated that the metplat or tip should have a max diameter of 0.18" with an averge3 COAL of 2.117". So in order to PC the boolit the casting would need a 0.16" tip diameter. Therefore, the design was modified to achieve this result.

The issue of sizing is reduced with the main boolit body reduced to .307". I think we have converged on a design that is robust for general applications. I anybody has any further advise please sound off. Or we are going to move to production and accuracy testing.

[popper]

Might consider putting a couple thin shallow bands in the drive area. Would collect some PB and allow tumble lubers some space for BLL. I run the 31-142C (~3R nose) to 2100 with H110, haven't tried faster. Did several versions - you can go a little larger than 0.18 but a 2R nose gets in the way (feed problems). Your BB will get wiped out with soft alloy when sized, unless you have a nose punch. The chamber on this barrel is pretty tight but the other will take 311 sized. Point being, if ordered 312 and sized 311 (or smaller) how does the nose/drive area get effected, i.e. the 'seat' area goes away? I use the 31-165C in 308, thinking of removing the GC for 170gr but maybe shortening your design would work better?

[Phantom30]

We are still adjusting it, more later, trying to incorporate a lot of suggestions include popper's ideas and making it compatible with HiTek Coatings

[Phantom30]

Update. The HiTek guys want a more usable round so the rider band should be at 308 instead of 307 so that they can coat and still size properly.

Tried Elvis Ammo's PC technique, wasted 6 pounds of pistol boolits still haven't gotten it to work. Moving on to HiTek Zombie green R good.

Guy at work said that opening the feed ramps solves a lot of boolit jamming issues with fat boolits. Going to ask him to post his DIY jig design. mto7464 has confirmed that by testing

[popper]

Pmags don't feed fat noses well but Lancers do. Making the feed ramps almost square helps a lot.

[mto7464]

Pmags don't feed fat noses well but Lancers do. Making the feed ramps almost square helps a lot.

My new barrel from Ballistic Advantage has wider ramps then my barrel from PSA. It feeds the flat nosed boolits great where my PSA barrel would only feed up to .16 metplat. FYI all my mags are pmags.

[Phantom30]

Attachment 170369OK here are the results of all the suggestions. The lower one is for those without feed ramp issues and the upper if you have problems there. The drive band diameter is set to 307 so you can PC or multi coat HiTek to get it up to but not beyond .3085, popper has advised that is the limit for BLK without risking a chamber pressure spike with an over stuffed barrel throat. So sizing to 308 is desired after PC. The lube bands were added for two reasons, first to give the tumblers a place with the design and two to ease the sizing, the long uninterrupted drive band is a real .... to size, it will lead your dies before PC and or jam in either case it is not what you want. Therefore, the lube bands make sizing easier and makes a place for the lead to flow. The drive bands can range from .310 to 307 or even 306, you can also deepen the grooves to about .29 as designed. I set them at .300 and 307 to make the design be as universal an application as I could come up with. The boat tail might also support the use of GC prior to PC. The only reliable method for PC on large long boolits, that I have found, is to ESPC and the HP makes that work well because you can use the HP as a mount fixture with spike boards. You also get a real good boolit base coat where you need it in supersonic loads. Of course all this is good science fiction until you spend the $250 for a mold, validate powder loads and muzzle velocities and then do the accuracy testing. All will be well when you show the nice tight grouping on target paper, QED. Well not so fast, Erik Called and said long boolit design doesn't leave enough metal in mold to insert hollow point so reworked again current picture as of 17 Jun 5pm CDT. Erik also said that he does support group buy pricing whatever that means.
PS just got a message from a collaborator, he coated and fired some of the 31-240A boolits and recorded a single hole grouping at 50 yards.

[Phantom30]

Well the last one worked well in the barrel but the support in the case neck needed help so this is the Mohican design attempt for lee lube, PC and HiTek application in a 30 Cal. The barrel specifics are 300 BLK assuming typical M4 feed ramps. There are custom features shown in the design. The red outlines are for the drive band max limit of .311 for those who need it. The cyan notch example is for the lubers. The standard blue is for PC and HiTek. The HP is optional, I prefer it for ESPC and impact performance.

[Dutchninja]

4 shot group with the 240 hp. Boolit was bb tumbled sized twice. Powder was 5744. Range 50 yds. One little flier was likely me.

[Phantom30]

Well here is the final version for those without feed ramp issues. Its now available from Accurate Molds as design 31-215G. The provider has tooling limitations, the meplate is limited to .180" flat, which is OK for the larger HP modification which takes place at Hollowpointmolds.com The boat tail is also limited to a length of 0.06", which makes the base drag a little higher and slightly reduces the BC. The 0.3XX drive band is to allow anything between .306 and .311 as your option depending on weapon chamber, alloy, and lubrication choice. AK tumblers with Lee Lube might want .311, while HiTek 300 BLK users might want .308, and ESPC folks might go for the .306 given the propensity to generate a heavier coating. As it turns out this design is not so far off the original Lee design which started this thread, only a long educational process in between. Thanks for all the comments and contributions. The previous 3R small tip design can not be produced by Accurate Molds so it is up to those with M4 feed ramp issues to find a producer if you need the narrow tip.

[Phantom30]

Please comment on the above 31-215G design, if there are no issues I am going to buy it tomorrow. Plan to get 306 and ESPC for 300 BLK

[popper]

Moto - found the pmag lip to be too long by a tad, caused a 3 point jam for long OAL. Noses up and hits the top of the chamber. Ground the lips back a bit so the base can pop out before the jam occurs.

[Phantom30]

Well finally got boolits loaded for the Accurate HP converted 31-215G mold, and I am getting this nose indentation from the seating die. The die uses a Lee 'custom bullet seating plug'; fit for the 31-215E which has a 5R nose the G has a 4R nose. Just too much force or what? I am sure this is going to effect the ballistics but.... Its not the HP crushing in because the indentation is below the bottom of the HP. Although the 6% SN alloy makes for a smooth boolit and good ESPC.