Powder Coating 300 BLK BTHP Boolits

[Phantom30]

Last post on 300 BLK powder coating design I could find was a thread active in 2014, so I thought maybe there is a discussion of newer stuff. I starter out with the Lee TL309-230-5R number 90307 mold, which has been reported to have insufficient rifling contact to be stable. So I started looking for powder coating specific mold. I found two from Accurate Molds. The 31-215E and the 31-240A. These molds where designed for powder coating. But even better you can send them off to Ohlen LLC aka erik@hollowpointmold.com and get them modified into BTHP molds. At Ohlen you can also have jig spikes made which match your HP design, which really helps in getting a solid ES coating. The spikes are mounted on a board covered with foil. However, wiring the spikes together on the back side of the board increases connectivity. These boolits come out really nice. When loaded you can get a solid performing subsonic round with 9.5gr of H-110 from a 10.5" barrel, or you can juice it up with 12.8gr to 1550 fps plus from a 16" barrel without any need for a gas check. The design data is attached. Anybody find anything better? This is my SHTF war reserve material approach to long term boolit production. Good for hunting and self defense. Cost per round not counting sunk cost of capital equipment 7.5 cents per round as long as the powder and primers last.

[ryokox3]

Ohlen LLC aka erik@hollowpointmold.com

Did not know about them, thank you for the resource.

Have you shot these or still considering buying them. If you shot them do you have an accuracy report? I'll have to google a bit to see if there are any others who posted results on these.


Edit, reread the post and see you did shoot them. Can you elaborate on 'solid performing' ? My brain works better with x inches at y yards.

-Ry

[Phantom30]

Solid performance is may be too strong at this time. I have been shooting powder load determinations at 30 yards. Looking for signs of tumbling etc. Currently, they cut paper right where I have been aiming them. Nice clean holes. Since I am looking for other effects I have not been shooting 100 yard groups. Been solving velocity for various barrel lengths and configurations looking for a subsonic load that will cycle in several gas systems. The 31-215E supersonic loads start to leave ejector impressions on the casing at about 13gr of H-110 but no evidence of primer flattening or firing pin strike melt. These run out at 1600 fps in a 16" barrel with long flash hider, that is good energy on target. To date, the 31-240A has been fired subsonic only and has difficulty cycling in the carbine gas system, works ok in the pistol gas system and 10.5" barrel with long flash hider. I was going to try the 240 with a light load in a 300 WIN MAG to see if a powder coated no gas check boolit will hold together under these conditions. The alloy is 97% PB 3% SN with harbor freight red coating. Have not recovered boolits to examine HP expansion and coating retention yet. Dug out 4 to 5 feet of berm and still could find any.

[warf73]

Phantom30,

That's a nasty looking boolit for some serious wet work in the 300blk @ subsonic speed.

[ryokox3]

To date, the 31-240A has been fired subsonic only and has difficulty cycling in the carbine gas system

I'll assume that was unsupressed?

[Phantom30]

Well it has a long flash hider that looks a lot like one but is not. If it was fully suppressed that would slightly add to the velocity in general

[Jupiter7]

Well it has a long flash hider that looks a lot like one but is not. If it was fully suppressed that would slightly add to the velocity in general

I believe he's referring to the increased back pressure induced by supressor. I've gotten 150's to cycle supressed(barely).

[Phantom30]

Yes but then I'd have a suppressor not a long flash hider

[ryokox3]

Yes I was referring to the backpressure it would give. I know you said the long flash hider but did not know if you swapped it out for a can, that's why I asked. I'm going to be working on subsonic loads in almost that exact configuration (16 inch with carbine gas) while I wait for my first can to be released from NFA-jail. I do appreciate the info you are providing as I do like that boolit and am seriously considering it.

[mto7464]

I got some of these, sans the HP, form a fellow member and had trouble with them feeding. What is your overall length?

Just saw your images. I assume that is the OAL you used?? I will PC some tonight and give it another try.

[Phantom30]

The COAL I am using is 2.11. The long flash hider is a can without guts and end cap so no added back pressure. I have been having a lot of trouble with sizing, right now the mold produces alloy at .310 (+0.002/-0.000), so I am sizing down from .314+ a real drag. I am going back to Accurate Molds and get the design's maximum diameter cut down to .306, PC adds about 0.002 thickness. So if I start with .306 alloy, I expect to have to size back down from .310 (+0.002/-0.000). I would like to size once before PC to make sure its round, acetone wash, and then size after PC again. It will take another 6 six weeks before the new mold design will be producing.

[mto7464]

I went home after reading this thread and gave it a try again. I still can't get them to feed. I have to seat the boolit too far in and they end up nosing up. See if they could release the metplat a tad as well.

[Phantom30]

OK since I have a 458 SOCOM in my inventory most of my 30rd magazines are Mil surplus metal or Israeli plastic, both rely on the chamber feeds ramps. These magazines have there characteristics a typical PMAG doesn't: 1) the sides of the magazine do not taper in toward the nose, 2) There is no nose partition guide, 3) the feed lips are short. Assuming your are loading 300 BLK with a fat nose boolit and a short COAL around 2.11, then you need these three characteristics working for you. If the feed lips are two long they will trap the round on top of the magazine and the bolt fins will disengage and slide over it. If you COAL is shorter than 2.10 you might have a problem there, although SAAMI allows <2" for 300 BLK I would not do that in an AR frame. My military loads are 2.15 and feed high speed automatic with no problem, but those are FMJ shaped bullets.

[mto7464]

I have loaded the Lee boolit, pc'ed, and shot it fine with my gen2 and gen 3 pmags. Using the above boolits I have to seat them deep after pc'ing them to get them to chamber. Even with doing them with Hi-tec and seating them longer I can't get them to function but even if I did I do not want to using hi-tek since I've gotten some leading thru the gas system before with the NOE design. The noe design has a slightly smaller metplat which makes me think that is why I have problems with these. I have not tried any "GI" mags to see if they work. I will try some tonite if I have time.

Your rifle must have a longer throat then mine. Even with hitek coating I can only get an OAL of 2.05. Any longer and it jams the boolit into the rifling making extraction difficult. I loaded some up last night with the hitec coating to try a function test but ran out of time to test them.
For pc'ing them I would want the entire boolit to drop about .004 smaller on the nose section and about .003 on the lower half. Also mine seem to be dropping just slightly smaller then your, .308-9.

[mto7464]

Got to shoot the ones I hitec coated. They will not feed. The big *** metplat kicks the nose of the shell up as it hits the feed ramps and gets jammed there. Tried both my pmags and two others with the same results. This boolit design is a no go for me.

[Phantom30]

First are you casting the Lee TL-309-230-5R mold. Second are you using a rifle with a 300 BLK SAAMI chamber? The SAAMI chamber distance to the start of the throat is 1.391 from the breech face and runs to 1.5650 at 0.309" then the jump runs from there to 1.7368 tapering to the bore at .300" So your boolit should be at or less than .300 from the 1.7368 point on. The Lee boolit design has a band from the crimp point forward of the base .483 and .305 and the a longer band at .300 which ends .551 from the tip or a run from the crimp point of .326, since the casing length nominally 1.368 then your boolit loaded at the crimp point would have the .300 band stopping at 1.694 which is within the chamber design for throat and jump. But we haven't accounted for the PC change in diameter. which is the problem.

[Phantom30]

Attachment 168512This is the seating analysis for the Lee TL309-230-5R, Why I went to custom mold

[mto7464]

I am using both the Lee and the Accurate boolit designed for powder coating. I have good success with the lee since it is so undersized and often will put two coats of PC on them. My upper is from Palmetto, 8.5"sbr.
I determine my over all length by testing fit in the chamber. I get them to where they will extract easily, not jamming into the rifling which can be a major PITA.
I seated the accurate boolit, hi tek coated, with just a little bit of the body of the boolit above the case mouth and got them to chamber well but they do not feed. Perhaps my chamber is out of spec??

[gpidaho]

I find that most of my 30cal. moulds (I have eight) are too long in the nose to chamber in my AR upper either jamming into the rifling or seating deeper in the case than I would like. The two that do cycle reliably are the Lee TL309-230-5R and the Lee C312-155-2R both sized to .309. The C312-155-2R does the best but has to be seated to 1.995 which just touches the rifling in my carbine upper. Being new to the 300 Blackout myself, it's been good to have a Handi Rifle in that chambering to shoot up the rounds that won't feed in the AR. The Handi has a much more forgiving throat. I've been looking for a 30cal. mould made for short necked cases like the 300 Savage or such but haven't seen the one I want yet. Suggestions? Thanks Gp

[mto7464]

Attachment 168512This is the seating analysis for the Lee TL309-230-5R, Why I went to custom mold

However, I still find this boolit the better "fit". Using 1 or 2 coats of PC. My OAL is 2.129 (IIRC). THey function great, they are stable in my SBR. If only I could find someone that could machine the mold to get rid of the boatail and make the entire mold up to the crimp grove the same diameter, getting rid of the tumble lube grooves.