Why Better as cast

[sutherpride59]

So I’ve been working on some subsonic loads for my 300 blackout and I have run into a number of silly things I don’t understand. One thing I learned was that after loading 5 rounds without sizing they grouped .6” at 50 yards vs the standard 1.5-2” I’ve been getting. All I did was just run these upside down to swage on the gas check without touching the driving bands, Then seated them like the rest. These are 206 grn 311299 gas checked falling at 9bhn, sized to .310 being fired out of a 16” barrel over 11.5 grains of 300blk. The barrel slugs at .3081”.

My first thought was that perhaps they were getting swaged down because the expander wasn’t expanding the mouth enough. I made a dummy round from a .310 sized boolit and pulled it, still measures .310. What gives? I ordered a .312 sized and an expander plug from NOE just so I can quit wasting time and fix both issues of undersized boolits or excessive neck tension. Also oddly with the .310 sized projectiles the velocities were not very consistent, with the as cast rounds all 5 were 6 FPS apart +-. Anyone understand an explanation for this. I will add that I sure as hell don’t anneal the necks and the brass is from converted lake city .223 brass.

[44Blam]

If your barrel slugs at .3081, .310 is plenty big enough. Maybe you are getting higher pressures with the "As Cast"?

There are a lot of things to think about - you want the pressure to burn clean, then have the boolit up almost against the lands, don't exceed the RPM for a given BHN of alloy and size. Maybe you need a little more pressure or faster or slower RPM or maybe crimp?

[Bazoo]

Sounds like sizing is swaging them out of balance slightly.

[sutherpride59]

Sounds like sizing is swaging them out of balance slightly.

I guess that could be true, maybe I should just be happy that I found what seems to work and quit over analyzing it lol.

[Dapaki]

.6" at 50 yards? Less work? I would take that without questioning the 'why', personally. Congrats on your happy accident.

[DAVIDMAGNUM]

Are the bullets being sized to .310" or are you using a .310" sizing die? With the three calibers that I cast the Lyman sizing dies ALL produce bullets 1 or 2 thousandths too small. I can only guess that they are regulated for Lyman #2 alloy that has some spring-back after running through the die. I only cast soft alloys from 20-1 to 40-1. Your bullets at a BHN of 9 are soft.
For example with 40-1 alloy my Lyman die stamped .432" produces .4305" bullets.
Just a thought. This had me scratching my head at first.

[sutherpride59]

Coo
Erect I am sizing these boolits to .310

[Four-Sixty]

As you size them, you soften the lead reducing its hardness. I wonder if you size them, then heat treat, if they would shoot better? Unless you're powder coating. What is your lube method?

[JonB_in_Glencoe]

SNIP...

All I did was just run these upside down to swage on the gas check without touching the driving bands, Then seated them like the rest. These are 206 grn 311299 gas checked falling at 9bhn

One possibility is that you bent some, or all of your boolits during GC swaging.
a long skinny boolit is prone to being bend, and a SOFT long skinny boolit, even more so.
Was this done in a lubsizer? specifically a Lyman 450?

[Larry Gibson]

Another thing to consider;

The 311299 is a long bullet with a relatively short bearing surface. If seating, crimping, sizing and lubing in the same operation, as with a lubrasizer, you may be sizing the bullets crooked. As in in, the sized bearing surface is not parallel to the axis of the bullet. Easy enough to do if the nose punch is not aligned with the axis of the sizing die.

[ascast]

I read an artical many tears ago in a Lyman or Ideal catalog. They flat said, paraphrasing from memory " sizing ruins bullets as there is no way to get them in a sizing die with the degree of precision that they MUST have to fall from a mold. You will invariable shave a bit off one side, or bend them as the top punch may not line up correctly. American shooters have convinced themselves that bullets must be sized, so we make moulds over sized and sell sizing equipment". Gas checks will always shoot better as they seat straighter and have less drag. good luck with that

[popper]

If you can chamber 312 and bore is 308, your 310 doesn't fill that huge throat. Plus, if using the crimp groove, almost nothing supporting the front drive bands. Throat in BO is ~ 1/2 the neck length.

[dverna]

Was it one group or is it repeatable? I would be ecstatic with a consistent .6" load at 50 yards.

[Conditor22]

(5 rounds without sizing they grouped .6” at 50 yards vs the standard 1.5-2” I’ve been getting.)

Rule #1 IF it works better and is safe do it.

How big are the unsized bullets? sounds like your barrel likes bigger bullets.

My shooting partner tried larger bullets in his CC 9mm and got much better groups.

Accuracy depends on so many different things boolit size in relation to hardness in relation to powder in relation to the powder charge in relation to the coating or lube you use. the temperature even comes into effect!

normally we slug or pound cast or chamber cast our barrels and go .001 to .003 over that (normally .002, less with harder lead, more with softer).

You could get a bigger sizing die to make seating the GC easier.

BUT "subsonic loads for my 300 blackout " subsonic loads don't need GC.

My 247 FN GC are tac drivers subsonic over 700X.

[onelight]

It wouldn't matter to me what size they are if they shoot good and don't lead and you get to skip sizing it all adds up to a great combination.

[country gent]

As cast may be just enough larger to 1) increase neck tension to improve ignition of the powder charge. 2) it may be giving a better seal and grip in the rifling. 3) it is probably a "truer" bullet than sized.

The more steps you perform the more to go wrong. While holding .001 on each operation isnt a problem. It is cumulative in the end results. Seating gas check sizing, lubing ( even done together) leaves for up to .003 variation. Another is your gas checks may be a little squarer done upside down and separately.

[megasupermagnum]

One possibility is that you bent some, or all of your boolits during GC swaging.
a long skinny boolit is prone to being bend, and a SOFT long skinny boolit, even more so.
Was this done in a lubsizer? specifically a Lyman 450?

This is the first thing that comes to my mind. You rarely see it mentioned, but without care, a Lyman 450 can quickly become a bullet mangling machine. Either bent bullets, or bullets sized crooked are very common.

[sutherpride59]

Well these were heat treated just for uniformities sake, then tested with a lee tester 3 days later. They may be about 9.5-10 bhn by now. For lube I only lubed one lube ring and fill it with Ed’s red.


As you size them, you soften the lead reducing its hardness. I wonder if you size them, then heat treat, if they would shoot better? Unless you're powder coating. What is your lube method?

[sutherpride59]

Star sized nose down


One possibility is that you bent some, or all of your boolits during GC swaging.
a long skinny boolit is prone to being bend, and a SOFT long skinny boolit, even more so.
Was this done in a lubsizer? specifically a Lyman 450?

[JWFilips]

Fat bullets with traditional lube shoot better as long as you can chamber them! That has always been my experience in every caliber

[JonB_in_Glencoe]

SNIP...
All I did was just run these upside down to swage on the gas check without touching the driving bands

I guess I am not understanding how your can seat/crimp/swage a GC in a Star and NOT touch the driving bands?

Does the boolit fall out of the die before the next one is inserted?
OR
Is the first boolit pushed out by the second boolit?

I only ask, because I am wondering if the boolit could be getting bent while it is pushing the previous boolit out of the Die?

[sutherpride59]

When I gas checked without sizing I pushed them in backwards just till the check got closed all the way, but keep in mind those are the ones that shot the best.

[richhodg66]

It's my general rule of thumb that the less sizing you can do, the better. Sizing a bullet is deforming it, plain and simple. Also, when you get right down to it, cast bullets, even hard ones, are still pretty elastic. The throat and chamber of your rifle will "size" it to what it wants. Bigger diameter to start with almost always works better in my experience.

[1hole]

I read an artical many tears ago in a Lyman or Ideal catalog. ... " sizing ruins bullets as there is no way to get them in a sizing die with the degree of precision that they MUST have to fall from a mold. You will invariable shave a bit off one side, ....

That "shave a bit off one side" sounds like the info was written about Lyman's original sizing dies. The die bores weren't tapered at the mouth and sized with a square shoulder that sheared off any extra metal. I know Lyman had gone to a tapered entry by '65 so that shouldn't be the problem here.

The idea of the unsized bullets forcing a bit more pressure to build up at ignition sounds good tho. I'd suggest you try a few rounds with your sized bullets but using a bit larger charge or a tad faster burning powder so the pressure builds enough to insure good ignition; that matters!

[Randy Bohannon]

A nice conversation with Paul Jones when I bought my first custom mould from him. I had asked him what die I should use for sizing his reply “ Why do you want to ruin my perfectly cast bullets from my beautifully machined mould ? Take accurate measurements , lube , load and shoot .

[sutherpride59]

I appreciate all the replies guys. Like I said I have a .311 expander coming in as well as .312 sizing die to make it faster to lube then hand lubing. When I get my equipment I’ll make 10 test rounds of each and shoot two 5 round groups of each. I will try sized to .312 (the diameter they drop at) with the current neck expander and sized to .310 with the same expander. Then the same sized boolits but with the .311 neck expander and I will report back. Mostly to make sure that these boolits work best unsized and to see if the case was simply undersizing the boolits.

[robg]

if they shoot well dont size them

[crackers]

Before you spend a nickel - while 1 1/4 moa is good, I think you need to repeat that a few times. Accidental good groups are almost as common as accidental garbage.

[Forrest r]

More often then not it's a combination of things with the most common being the expander. The size of the ball throat sets the stage for the size of the expander.

[sutherpride59]

so help me out here, i received a .312' sizer and a NOE expander. I added them into my loading mix and i have seen positive results but what still eludes me is the velocity variance in my rounds. For example. my best groups today were about 1" at 50 yards and i am more than ok with that for a subsonic cast bullet load. However 5 rounds sized to .310 expanded casings with the NOE expander resulted in velocities of 1087,1095, 1148, 1075, 1074, 1038 FPS. They were all loaded with 11.5 grains of CFE BLK(verified individually by powder scale), all seated and crimped the same(crimp might have been a little heavy). The velocities are pretty consistent except the 1148 fps. I was sitting in the sun and the rounds were hot but they were all hot, i havent shot with this powder in the winter time but is CFE BLK just temperature sensitive or is there something else i should be looking at for these random velocity spikes? The same happened with another load of 9.2 grains of H110. Every 5 shot group yields great results except for one or two rounds that open the group to 2 or 3" groups. With the H110 groups i kept getting some random low velocity rounds that were 100-200 fps slower than the rest that opened the groups.

THe boolits sit .42" inside the casing and with my sub-loads i get a touch more than half case fill with both powders. I haven't read of anyone else using filler in there sub-loads with these powders but I'm starting to think it might be necessary to make rounds accurate enough for hunting coyotes.

Do yall have any other ideas of what i can do to make my velocities more consistent in this case?

[sutherpride59]

Thoughts, try using a Dacron filler, also try annealing the casing necks,

[William Yanda]

I guess that could be true, maybe I should just be happy that I found what seems to work and quit over analyzing it lol.

My thoughts exactly. Serendipity is a good thing. Success with less effort, what's not to like?

[sutherpride59]

My thoughts exactly. Serendipity is a good thing. Success with less effort, what's not to like?

Well less sizing seemed to help for sure but still fliers due to random excessive velocity drops and gains. After some thought I decided to try a few things. For one I was using mixed brass, so I will only work with my converted lake city brass for now as I have plethora of this brass available for free. I believe one of the commercial brass casings of a different trim length may have been the real issue but who knows, it’s a factor to rule out none the less. I sorted some bullets and will only use the best most consistent weighing ones. I will also load a 5 round group of rounds with a Dacron filler and test that aspect as well. All I want is the groups I have now but consistent. I can live with 2-3” groups but I don’t like the idea of that random bullet moving only at 800fps when the rest are about 1080. I will also keep all test rounds out of the sun till the moment of loading. Just to rule out one other factor. I’m getting so close I can taste it!

[charlie b]

Are you sure the fliers are due to the change in velocity or are you just assuming that because you have one flier and one velocity that is off? I used to assume that until I plotted every bullet on a target along with it's muzzle velocity. Sometimes results were surprising.

Weight sorting bullets is an essential part of accurate cast bullets. Mainly it determines if there are any voids in the cast. Consistent weights also contribute to more consistent velocities. I also use match primers for many of my loads to get more consistent velocities.

As someone mentioned, I would also make a harder alloy, especially if this is an auto loader. Just the movement of a cartridge from magazine to chamber will 'knock' on the bullet a bit (even in a bolt gun). When too soft it will deform the bullet. If you are loading from a magazine try single loading by hand and see if there is a difference.

FWIW, when shooting my muzzle loader I want a soft bullet (~8bhn) so that the bullet base is 'upset' into the rifling. You may also be experiencing this kind of 'slump' when firing.

One other idea is to try some good jacketed bullets (match quality) and see how they do with the same loads.

[MaxJon]

.6" at 50 yards? Less work? I would take that without questioning the 'why', personally. Congrats on your happy accident.

I was thinking the same...haha

[MaxJon]

I suspect the upside down being one problem. I think you would have been better off going with a std lee push thru, nose first to seat GC. At least the bullet would have a flat base to locate from.

[sutherpride59]

Single loading is a good idea that for whatever reason eluded me.

[sutherpride59]

https://uploads.tapatalk-cdn.com/20200520/057709174e3d4346f28786de84528e64.jpg
https://uploads.tapatalk-cdn.com/20200520/70399eefdf98fa35cc5a319bb1fde0db.jpg
My 50 yard groups for a better idea of what I’m trying to explain. With the bottom two grouping being the most sever the bottom right group I got lost in the moment and forgot to record the velocities but the rest are there, the flier in every group was the round of increased velocity or decreased velocity from the Norm as I was watching the impacts with a pair of binos. So yes the off velocities are what are opening my groups. I understand a velocity may be different but result in a minuscule deviation from accuracy but with such extremes, including a 205 grain boolit, 835 fps vs 1035fps is a pretty big difference and you will notice boolit drop.

NOE means I used the NOE expander instead of the lee one.
Sent from my iPhone using Tapatalk

[megasupermagnum]

I know CFE BLK is advertised as being for subsonic rounds, but it doesn't seem like many on this site use it. Could you try a more traditional target powder like red dot, 700x, unique, etc.?

[sutherpride59]

I know CFE BLK is advertised as being for subsonic rounds, but it doesn't seem like many on this site use it. Could you try a more traditional target powder like red dot, 700x, unique, etc.?

I’ve stopped using CFE as I was getting better accuracy with H110 and plenty of gas, it’s what most use for supers but in some over gassed guns like mine it works for subs just as well. I could play around with other powders but this is being used in an AR and I want it to cycle the gun.

[megasupermagnum]

H110 is not a powder I would use for this. It does one job, it is a full power magnum handgun powder, and it does it well. Outside of that, I would move on. Something like Blue dot or 2400 work well with reduced loads, and may be slow enough to keep the port pressure up. I can't help with 300 blackout specifically, I've never mess with one.

[sutherpride59]

H110 is not a powder I would use for this. It does one job, it is a full power magnum handgun powder, and it does it well. Outside of that, I would move on. Something like Blue dot or 2400 work well with reduced loads, and may be slow enough to keep the port pressure up. I can't help with 300 blackout specifically, I've never mess with one.

Well for 300 blackout in an AR people use little gun, CFE BLK, accurate 1680, H110, H4198, and a slim few others that will produce enough gas but stay at a low enough pressure. In a bolt gun they use whatever the heck they feel like just about lol. H110 was giving me better accuracy but both were having velocity issues. I could try H4198 but I don’t remember anyone having great luck with it and my initial super sonic tests didn’t show it to be a good fit for this rifle in the accuracy or cycling department.

[charlie b]

Glad you tracked the velocity vs impact point. At these low velocities a 100fps difference (10%) can result in the differences. I noticed similar when using subsonic loads in my .308 (I am not worried about cycling a gas gun so I use Blue Dot). When shooting at higher velocities the drop difference is much less (5% or less).

Which boats were you on? Son was on the Acushnet and Boutwell back in the 90's.

[sutherpride59]

Oh cool so he was over in ba-ha-rain lol. I was on the decisive out of Pascagoula MS, the Middget out of Seattle, and the Blackpowder in Kingsbay GA (MFPU blocking vessel). I’ve made some trail boss loads but don’t want to mess with the pistol powders too much. The velocity drop might just be something I have to live with. I know playing around with it a couple of weeks ago holding the gun up then aiming down on target resulted in more consistent velocities so I think these powders due to full amount are a bit position sensitive. I’ll shoot with filler tomorrow and that would confirm it. If I have to add filler for hunting rounds I can be ok with that. Range pews just won’t have any.

[MaxJon]

Fillers are unnecessary, to me it's all about the right powder choice...

[charlie b]

Oh cool so he was over in ba-ha-rain lol. I was on the decisive out of Pascagoula MS, the Middget out of Seattle, and the Blackpowder in Kingsbay GA (MFPU blocking vessel).

No, he was on the Acushnet at that time in Eureka, CA. Got out when they sent it to Alaska.

He was warned by the Chief of Boat that if they every painted the Boutwell grey it was time to punch out :)

I agree with above about finding the right powder. Does anyone know what the original BO powder was? After all it was designed as a subsonic cartridge.

[sutherpride59]

Well that’s just it for subs everyone is using those choices that I listed, the most prevalent is 1680 but that and CFE BLK are almost identical but I just realized today that I missed a big step in referencing reloading data, the load data calls for magnum primers. As I read many folks getting erratic velocities with subs weren’t using magnum primers so I’ll try to pick up a box today after shooting if nothing I did fixed my problem.

[MT Chambers]

southern pride beat me to it, nose down on a Star and your worries are over.

[MaxJon]

Less is more.....minimal bumping/sizing/distorting, betweeen the mold and chamber the better, regardless of sizing method I believe.

[1hole]

By the time any bullet fully enters the bore it's precisely sized to fit that bore.

-----------------------------------------------
Southern Pride: Ah, Kings Bay and Camden County, GA ... and memories.

I lived in Kingsland from 1953-1956. There was no Kings Bay then; St. Marys, Kingsland and Woodbine were the "population centers" of sparsely inhabited Camden County, GA, and even combined they didn't amount to much.

Woodbine had both of the black/white consolidated high schools for the whole county. The black high school was near new, very nice brick buildings, while the white school was a ramshackled old frame and clapboard siding structure. Our's was grades 8-12 and it still only had a total of about 500 students. Then came the U.S. Navy @ Kings Bay, a wad of nuke submarines, a bigger wad of people and the population exploded.

I still pass through Kingsland on I-95/U.S. 17 once or twice a year. The old towns and schools are gone. Much of the old "woods" is now filled with modern yankees with all their lust for more goobbermint controls and higher taxes, clumps of people with odd accents mostly living in HOA rule controlled swarms.

I remember that a few of us boys had access to .22 rifles in those days. For about $.35 we could pool our nickles and dimes to buy a box or two of ammo from the Western Auto store (without raised eyebrows or questions). Everyone had a balloon tired American bike and we would pedal down some dirt side road far into the woods and shoot it.

There's nothing left that I can recognise now but Camden County, GA, was once a very good place for southern boys to grow up .... while it lasted.

[sutherpride59]

That’s pretty neat I always wondered about the history of that old town and how it used to be. I loved living in Kingsland but I’m glad I’m back in Texas, gods country.

DISCLAIMER: These are my results I don’t wish to argue about my findings or my methods. Advice is welcome.

I just wanted to make a post wrapping this whole ordeal up because I hate reading threads that never have a conclusion added and wondering what the results were. For my gun unsized ended up working just as well as the boolits sized to .312 even though my bore is indeed .3081. I believe it has more to do with needing to build good pressure in these subsonics rounds more than barrel fitment, also doesn’t help that they are 9bhn so very soft. My final load ended being .312 gaschecked NOE 311299 205 grain projectiles, .311 Noe expander to open the cases, seated with the drive bands just below the case mouth and max crimp, all over 9.1 grains of H110(w296) with CCI small rifle primers.

Things that didn’t work Or made no difference: Dacron filler opened up the groups to 3 times the size and should not be used in a gas gun as it was DIRTY AS HELL, minimum crimp lead to bigger groups and increased velocity spread(Soft lead and little case fill you need more pressure), sorting brass between factory and converted brass didn’t make a noticeable difference, magnum primers didn’t remedy velocity Inconsistency issues But shrunk the groups a tiny amount(probably more of luck than an actual gain, not enough to buy more of them), Gas check prevents leading of the suppressor completely but at these speeds didn’t make the accuracy any better, H110 vs CFE blk both performed about the same with H110 making tighter groups and I didn’t need the extra gas from CFE to cycle the gun so H110 will be the choice powder.

Still getting inconsistent velocity but I’ll play around more with that in time and it doesn’t pertain to the original post. If I find anything that really helps I’ll make a new thread and post it. Might even take the time and do a write up on it.