detroitcharlie
10-04-2015, 06:13 PM
I got the LEE TL309-230-5R mold to shoot a big honking piece of lead for subsonic loads in my 300 Blackout. There seems to be a lot of controversy concerning this round. Being the contrarian that I am, I figured let's prove it is indeed a reliable boolit.
Other users of this boolit have reported mixed results. It seems that the main issue is 'tumbling' and poor accuracy. Remedies for this are crimping on a .310 or .311 GC to cutting off the boat tail, leaving behind a plain base shank for a GC to go on. I've heard various reports that the biggest issue is the spin (or lack thereof) contributing to tumbling and poor accuracy. Admittedly, the bullet design is kinda weird for a cast boolit, given the boat tail design. Before giving in to modifying the boolit I thought I'd just give it a try myself, so, here's what I did.
Gear:
300 BLK 16" pistol gas length (not cut down, full 16") 1:8 twist from KAK. http://www.kakindustry.com/ar-15-parts/upper-parts/barrels/contract-300-16-inch-pistol-melonite-barrel
Standard low profile .750 gas block (non-adjustable).
Spikes Tactical Carrier group (nothing fancy.) http://www.spikestactical.com/bolt-spikes-mp-tested-bolt-assembly-556-p-326.html
Boolit:
LEE TL309-230-5R http://leeprecision.com/mold-dc-tl309-230-5r.html
.309 Diameter
230 Grain
Tumble Lube
5 Ogive Radius
I cast the boolit with 50% double fluxed range lead and 50% Super Hard Alloy Ingot (30%-Antimony, 70%-Lead) from Rotometals. http://www.rotometals.com/product-p/superhardalloy.htm . I'm sure there was probably about 4-5% tin in the range lead as well, but I did not add any. I poured my lead at 750 degrees. I prepped the mold with a little drop-out beforehand. I let the boolits air cool. They are too big to water quench. Dropping them in a bucket of water will cause most of them to distort, bend, crack or snap. If you are shooting these as subs, there really is no need to water quench in my opinion. After air cooling, I tumbled the boolits in walnut medium for about and hour just to clean them up and smooth them out. I then applied TWO (important) coats of Ben's Liquid Lube (BLL). I waited about 3 hours in between coats. My reasoning for doing two coats is because the boolits were designed to be tumble lubed and considering the boolit design tends to not leave much for the rifling to affect spin, I felt a double coat wouldn't hurt and could provide more friction in my 1:8 twist to stabilize the round at 1080 FPS (target velocity). Here is how they turned out:
150446
I used some Lake City (any mil-brass will do) 5.56 brass to cut down my 300 BLK cases, using the LEE 300 BLK die set (http://leeprecision.com/3-di-300aac-blkout.html). I used CCI's #400 small rifle primers (http://www.cci-ammunition.com/products/primers/primer_chart.htm). Using IMR 4227 powder, I selected the only available load data they had on their website. Their load data recommended 10.2 grains (for 230 GR. BER TACT.) (NOTE: I am not recommending this load data, this is the load data "I used" based on what the IMR/Hodgdon website provided, only use after referencing IMR's load data.)
150447
I decided I would not size these boolits, just use them as cast. I seated the boolits with an over-all length of 2.25". Lee recommends Case with bullet seated OAL is 2.240" (http://leeprecision.com/cgi-data/instruct/90307.pdf) I chose this number based on the ribs in my MAGPUL PMAG 30. The shape and size of the round can cause feed problems in a lot of magazines. I chose only to load 10 at a time.
I was using a $50 red-dot with zero magnification since I don't have a dedicated optic for my 300 blackout upper. But it was good enough for some basic testing. Here's what I got.
25 Yards 150448 50 Yards 150449
I didn't have a chronograph to verify my velocity, but if the load data is correct, It definitely 'felt' well within subsonic velocities. As you can see, I shot 5 rounds in each test. At 25 yards, they grouped nicely. At 50 yards, still not bad at all. I had nothing to compensate for boolit drop so just kinda guessed with the crappy reticle I had. All rounds fed and cycled perfectly with no feed errors or jams. If you look closely at the targets, there is no evidence of tumbling at 25 or 50 yards. I did not test at 100 yards.
So, there you have it. The boolit does what it is supposed to do, fly straight and true. I dunno if my pistol length gas system and 1:8 twist barrel is the reason for better performance, but I will say that I believe the double dose of BLL closed the gap when it comes to creating enough initial friction to get the rifling to do it's job. All-in-all, I would say go ahead and spend the $20 for this mold. I plan on shooting it with a suppressor with a 10 1/2 inch barrel (same specs, 1:8 twist pistol length gas system) in the coming months, I'll report on those results when I do. Good luck and happy shooting =]
Other users of this boolit have reported mixed results. It seems that the main issue is 'tumbling' and poor accuracy. Remedies for this are crimping on a .310 or .311 GC to cutting off the boat tail, leaving behind a plain base shank for a GC to go on. I've heard various reports that the biggest issue is the spin (or lack thereof) contributing to tumbling and poor accuracy. Admittedly, the bullet design is kinda weird for a cast boolit, given the boat tail design. Before giving in to modifying the boolit I thought I'd just give it a try myself, so, here's what I did.
Gear:
300 BLK 16" pistol gas length (not cut down, full 16") 1:8 twist from KAK. http://www.kakindustry.com/ar-15-parts/upper-parts/barrels/contract-300-16-inch-pistol-melonite-barrel
Standard low profile .750 gas block (non-adjustable).
Spikes Tactical Carrier group (nothing fancy.) http://www.spikestactical.com/bolt-spikes-mp-tested-bolt-assembly-556-p-326.html
Boolit:
LEE TL309-230-5R http://leeprecision.com/mold-dc-tl309-230-5r.html
.309 Diameter
230 Grain
Tumble Lube
5 Ogive Radius
I cast the boolit with 50% double fluxed range lead and 50% Super Hard Alloy Ingot (30%-Antimony, 70%-Lead) from Rotometals. http://www.rotometals.com/product-p/superhardalloy.htm . I'm sure there was probably about 4-5% tin in the range lead as well, but I did not add any. I poured my lead at 750 degrees. I prepped the mold with a little drop-out beforehand. I let the boolits air cool. They are too big to water quench. Dropping them in a bucket of water will cause most of them to distort, bend, crack or snap. If you are shooting these as subs, there really is no need to water quench in my opinion. After air cooling, I tumbled the boolits in walnut medium for about and hour just to clean them up and smooth them out. I then applied TWO (important) coats of Ben's Liquid Lube (BLL). I waited about 3 hours in between coats. My reasoning for doing two coats is because the boolits were designed to be tumble lubed and considering the boolit design tends to not leave much for the rifling to affect spin, I felt a double coat wouldn't hurt and could provide more friction in my 1:8 twist to stabilize the round at 1080 FPS (target velocity). Here is how they turned out:
150446
I used some Lake City (any mil-brass will do) 5.56 brass to cut down my 300 BLK cases, using the LEE 300 BLK die set (http://leeprecision.com/3-di-300aac-blkout.html). I used CCI's #400 small rifle primers (http://www.cci-ammunition.com/products/primers/primer_chart.htm). Using IMR 4227 powder, I selected the only available load data they had on their website. Their load data recommended 10.2 grains (for 230 GR. BER TACT.) (NOTE: I am not recommending this load data, this is the load data "I used" based on what the IMR/Hodgdon website provided, only use after referencing IMR's load data.)
150447
I decided I would not size these boolits, just use them as cast. I seated the boolits with an over-all length of 2.25". Lee recommends Case with bullet seated OAL is 2.240" (http://leeprecision.com/cgi-data/instruct/90307.pdf) I chose this number based on the ribs in my MAGPUL PMAG 30. The shape and size of the round can cause feed problems in a lot of magazines. I chose only to load 10 at a time.
I was using a $50 red-dot with zero magnification since I don't have a dedicated optic for my 300 blackout upper. But it was good enough for some basic testing. Here's what I got.
25 Yards 150448 50 Yards 150449
I didn't have a chronograph to verify my velocity, but if the load data is correct, It definitely 'felt' well within subsonic velocities. As you can see, I shot 5 rounds in each test. At 25 yards, they grouped nicely. At 50 yards, still not bad at all. I had nothing to compensate for boolit drop so just kinda guessed with the crappy reticle I had. All rounds fed and cycled perfectly with no feed errors or jams. If you look closely at the targets, there is no evidence of tumbling at 25 or 50 yards. I did not test at 100 yards.
So, there you have it. The boolit does what it is supposed to do, fly straight and true. I dunno if my pistol length gas system and 1:8 twist barrel is the reason for better performance, but I will say that I believe the double dose of BLL closed the gap when it comes to creating enough initial friction to get the rifling to do it's job. All-in-all, I would say go ahead and spend the $20 for this mold. I plan on shooting it with a suppressor with a 10 1/2 inch barrel (same specs, 1:8 twist pistol length gas system) in the coming months, I'll report on those results when I do. Good luck and happy shooting =]