Is this not normal for casting?

[Wolfdog91]

So is loading to Custom CBTO's / COAL's not common for cast reloading or something? I'll get a pm on the FB or something and someone will ask about my load data and when tell them I don't use book COAL/ CBTO's ( really prefer cbto) 9/10 times they act like I'm crazy or something. I learned to reload from more the precision side of things , loading the best ammo you can for one rifle and it's individual characteristics ,instead of the just racking out blasting ammo so doing it like that has always just made sense to me so I do it with cast to but seems to be a strange concept. Why is that ?

[DDriller]

I only use the COL as a maximum length number. A lot of my cast will not chamber to that length.

[JimB..]

Don’t recognize the term CBTO, but that aside I think it’s because we scare the heck out of them to keep them from losing fingers. Our intentions are good, but it becomes a rigid rule to only use published data. I think the NRA reloading class even says to use the same brand primer as in the book.

Of course for most pistol and nearly all 5.56 loading the COAL is dictated more by the magazine than the chamber, so book COAL will help ensure that things feed which is more important to most shooters than the last min of accuracy. Heck most shoot a decent shotgun pattern with a rifle at 50 yards, rested, with a 4x optic.

Just my thoughts on the subject.

[Wolfdog91]

Don’t recognize the term CBTO, but that aside I think it’s because we scare the heck out of them to keep them from losing fingers. Our intentions are good, but it becomes a rigid rule to only use published data. I think the NRA reloading class even says to use the same brand primer as in the book.

Of course for most pistol and nearly all 5.56 loading the COAL is dictated more by the magazine than the chamber, so book COAL will help ensure that things feed which is more important to most shooters than the last min of accuracy. Heck most shoot a decent shotgun pattern with a rifle at 50 yards, rested, with a 4x optic.

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[nicholst55]

CBTO = Cartridge Base To Ogive.

[SoonerEd]

With j words I use CBTO as COAL is not repeatable giving the variation in bullet tips even for premium bullets like bergers. In bolt hunting rifles I often exceed max COAL as long as they feed from the magazine. In my prairie dog guns i feed them one at a time and the cartridge often exceeds magazine length. In autos I load to at or below max COAL then test for feeding. My records and dies are set off the ogive as that is more accurate/repeatable when trying to replicate die set up at a latter date.

For casting I'm still a nube. So, I'll refer to others what they do.

I use one of the stoney point / hornady comparator gauges like you pictured.

[405grain]

Wolfdog 91: It seems to me that it would be preferable to match your ammo to your particular gun rather than mass producing standardized specification ammunition. But there are considerations: What if your FB buddies are shooting a gas operated semi-automatic, and are more concerned about reliability than accuracy? What if they're loading for more than one gun in that caliber? They may have different priorities than you do. Besides that, the load that works best in your gun might not be as good in their gun. Just load the way that works for you, and if they have a different way that's working for them, then everyone wins.

[Dave Dill]

I’ve honestly never used either for my cast bullets because I’ve just roll crimped to the appropriate crimp groove (there is only one exception which is my Lyman 358156 which has two crimp grooves). But with my PRS bolt gun, I’ve found myself chasing lands as I’ve gotten better at reloading than chasing COAL or CBTO. HOWEVER, I’ve used both as general references and still do if that helps with copper coated rifle bullets.

With cast bullets and especially with revolvers, I’ve fired several different calibers through the same revolver and even still with the right loads and bullets, have never found accuracy to be variable,
I.e, 148 grain full-wadcutters shooting the same groups from 7-25 yards out of a 357 GP100 that equally fires 170 grain SWP HP’s behind max load of H110.

[stubshaft]

I'll crimp it in the groove (if any), set it to the maximum length for the magazine (AR's), seat it out just off of the lands, then adjust for best accuracy. The loading manuals are fine and dandy, but the chambers are NOT identical!

[JimB..]

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Thanks, and I’m indeed familiar with the application, and use it for my rifle loads other than 5.56 to run in an AR, just didn’t know the term.

[G W Wade]

I found the Sinclair Bullet Comparator years ago, It's basically a large hex nut, with each of the 6 flats drilled for a different caliber. GW

[PopcornSutton]

My starting point for seating depth, is done through the barrel. I take a wood dowel, close the bolt, and run the dowel to the bolt face and mark the dowel. Then remove bolt and drop a bullet into the chamber, be sure it goes into the freebore, hold in place and put the dowel back in, and mark. But that's a starting point, tuning a load comes from powder charge and seating depth changes.

[Jack Stanley]

I found the Sinclair Bullet Comparator years ago, It's basically a large hex nut, with each of the 6 flats drilled for a different caliber. GW
I use one like that mostly while working out a new load . Very handy .

Jack

[MostlyLeverGuns]

Magazine length usually drives my COAL, though some bullet seating needs to be set by the bullet ogive, the 311407 in a 30-30 is an example. Many Marlin's have very short throats and some 'fat' nosed bullets need to be seated deeper than 'book' COAL. Single shots need only seating that shoots well or makes you happy. Whatever the length, the bullet should not jam into the lands so that it does not extract when the unfired cartridge is extracted, dumping powder and leaving a bullet stuck in bore/chamber. I have encountered some rifles that feed a cartridge from the magazine and not successfully eject an UNFIRED cartridge because the ejection port is too short, both Savage 99's and Marlin's MAY have this occur, probably others. Load for the individual rifle, 'book' COAL or COL will USUALLY work but may not be the best choice.

[popper]

I don't use any length measurement, seat to what fits and works. As seating depth changes pressure, work up the load for a proper seated bullet. Any published load is just a hint to me. Too many variables. I don't have any molds with crimp grooves.

[Soundguy]

I look at coal as a magazine or clearance issue.

I generally seat to a good crimp location, assuming all else fits and is ok.

[mdi]

I have used base to ogive specs, but only for one rifle. My Ruger 308 is more accurate than I am and I did a lot of "tweeks" to get every 1/64" reduction in groups. I used the Hornady gauges/tools to determine bullet to rifling and played with that for a few months (best groups turned out to be Hornady 155 A-max over IMR 4895 using book OAL. 7/8" @ 100). OAL for my handguns is determined by the plunk test and crimp groove location...

Loading cast for my rifles I just used mold mfg. or Lyman manuals recommendations for plain old OAL (base to nose). I got some fairly accurate loads from my Ruger 308, M1 Garand, and 7.62x54 MN...

[lar45]

I like the Hornady tool that uses a cartridge case and bullet to get the distance to the lands. I then measure the coal and adjust +- to get the distance off the lands for jacketed, or into the lands for cast.
My high velocity cast rifle loads for the 30-06 xcb get best accuracy at .05" off the lands with the 30xcb bullet.

[PrestoColumbus]

The arguments for CBTO over COAL are convincing to me as a new reloader. But I have noticed when loading on the edges I have to stick with the COAL in the manual.

For example, 300 blackout: (for my rifle anyway)
110gr hornady vmax are too short to load .02" off the lands, they'll just fall out of the case if i tried to load it long enough.
220gr berry's spirepoints are easy enough to load .02" off the lands, but they won't fit in the magazine (although they chamber just fine if i load the round by hand)

So I want to prefer CBTO if I can, but with these particular boolits I just gave up on CBTO and used COAL from the load manual.

Anyway, I appreciate this thread. I'm still learning and haven't blown my face off yet.

[44Blam]

For each new gun I take my intended boolit and set it in a case (seated/crimped) to the max col of the round in the magazine and close the action until it hits. Then you know if it goes, you are good. If not, you have a pretty good idea of how far to seat it back. I then pull the boolit, resize/bell/seat/crimp closer - until I get it about 0.005-0.01 from the lands or at the COL of my magazine. Then with an AR, you might have to tweak it so it cycles, etc...

Anyway, after I get the right chambering, I save that "dummy" round for future reference.

[44Blam]

I don't use any length measurement, seat to what fits and works. As seating depth changes pressure, work up the load for a proper seated bullet. Any published load is just a hint to me. Too many variables. I don't have any molds with crimp grooves.

^^ this ^^
Quickloads is good for getting general hints on boolits with no official load data in various guns (various COL). I tend to use that and then see if the "predicted" velocities match the actual velocities and adjust from there.

[fredj338]

Most misunderstood aspect of reloading imo is COAL. It is 100% bullet & gun/barrel specific. Even your CBTO isnt going to work for all guns, magazine length comes into play too. Why data in any reloading manual is a guide, not a bible.

[Willie T]

So is loading to Custom CBTO's / COAL's not common for cast reloading or something? I'll get a pm on the FB or something and someone will ask about my load data and when tell them I don't use book COAL/ CBTO's ( really prefer cbto) 9/10 times they act like I'm crazy or something. I learned to reload from more the precision side of things , loading the best ammo you can for one rifle and it's individual characteristics ,instead of the just racking out blasting ammo so doing it like that has always just made sense to me so I do it with cast to but seems to be a strange concept. Why is that ?

Base to ogive is commonly used hand loading precision rifle ammunition. Overall length is often a more useful measurement for loading handgun ammunition. More boolits are cast for handgun ammunition than precision rifle. As a whole I find loaders who cast their own boolits to be among the most well rounded handloaders.

[charlie b]

I use both, kinda. .308Win bolt gun.

For cast I use a version of CBTO, but, I measure it with OAL. Why you many ask? My cast bullets are seated with a regular stem, which touches the bullet at the nose, not the ogive. I set them such that the nose portion is an interference fit in the bore and the first drive band engages the rifling. I can feel that as each round is chambered. So, why do I measure the OAL? To make sure the seating stem is still in the right position. I could measure to the first drive band instead, but, I find just minor differences in consistency between the drive band and nose measurements. Since I can frequently get MOA groups I am satisfied that this method is working.

Basically, if you seat with a stem that works on the nose, then measuring CBTO can be an exercise in frustration. You'd have to 'tweak' each bullet seat depth to get the CBTO the same.

Jacketed I use CBTO only. It works well since I use a Redding competition seating die that seats based on the ogive, not further up on the nose. I determine the proper seating depth by shooting a "ladder" to get the most accurate setting. And, yes, Berger bullets are not consistent lengths, at least not within a few thousandths. Hornady ELD-M's are more consistent in length than the Bergers. The 155 ELD-M's and 155 Bergers are both good for around 1/2MOA at 200yd and about MOA at 1000yd if I do my part (I suck at wind doping).

[justindad]

I pay attention to COAL length because I calculate the effect on case fill of the powder. Most of my boolits are absent from any load book, and boolit weight is neither a perfect nor complete indicator of what charge to use.

[Taterhead]

Fred makes a great point. I will also add this point. When it comes to pressure in handguns, it is the depth of the bullet base in the case that is important because that affects the volume under the bullet. Where the bullet tip is located is only relevant to magazine length.

Therefore unless loading an identical bullet, loading to book or copying factory COL specs is going to give a different depth of bullet base and therefore varying volumes under the bullet.

Each bullet and gun is a different story. Figure out what fits then workup loads.

[HumptyDumpty]

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In light of that explanation, it seems that I have been using CBTO quite a bit. It always seemed to me that, if the round chambers and safely performs to my satisfaction, it really doesn't need to exactly match whatever reference material I am using.

[M-Tecs]

So is loading to Custom CBTO's / COAL's not common for cast reloading or something? I'll get a pm on the FB or something and someone will ask about my load data and when tell them I don't use book COAL/ CBTO's ( really prefer cbto) 9/10 times they act like I'm crazy or something. I learned to reload from more the precision side of things , loading the best ammo you can for one rifle and it's individual characteristics ,instead of the just racking out blasting ammo so doing it like that has always just made sense to me so I do it with cast to but seems to be a strange concept. Why is that ?

Reloaders come in all experience and knowledge levels. Application generally drives requirements. Things like cowboy action have very low accuracy requirement and most any ammo will do as long as it's safe. Long Range benchrest or F-Class requires the very best methods. Blaster ammo methods will not work for long range high level accuracy. On the other hand those techniques will not benefit the cowboy action shooters.

[Bigslug]

My father and I have conversations along this line.

We both went pretty far down the accuracy rabbit hole back when we were into Highpower Rifle competition, and did a whole lot of fiddling around with seating depth for best consistency on paper and over the chronograph.

But more times than once, it's bit us on the butt - usually with failures to chamber or failures to fit/feed from the magazine after developing performance single loading. Dad gets pretty fussy on his accuracy matters from time to time, but I've come to always start the conversation with "DOES THE DAMN GUN WORK???"

My Ruger Gunsite Scout .308 pretty much cured me of worrying about setting bullets some special distance off the lands. When I set the California Required non-lead bullet's (Barnes 130gr TTSX)ogives at Dad's preferred .005" off the lands, they simply don't fit in the magazine. Seated considerably farther back to where they do, it's still a half-MOA rifle. . .AND IT WORKS.

Ran into the chambering problems chasing throat offset with the .30-06 and the 311299 - - seated them to Lyman's book COAL and they went away.

Soooo. . .I'm pretty much at a point of making the gun function first with a cartridge shape the gun likes, then work the accuracy within those confines.