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View Full Version : Lee C309-170-F Dropping Boolits at .309



Clinton
11-15-2014, 06:00 PM
I'm just getting into casting for rifle. I worked up some loads for 308 Win using the Lee C309-170-F mold. I had sized them to .309 and the accuracy was pretty bad but no leading. I did some searching on this forum and discovered most people are sizing 308 boolits to .311. So I melted down all I had left and cast a fresh batch. I just measured some from the new batch because I was curious how large they would drop and they're dropping at .309.

So now I'm lost. Do I go ahead and size them to .311 and just hope the gas check does the work or do I need a different mold?

dkf
11-15-2014, 06:01 PM
Different mold. Though you could give beagling a shot first.

ShooterAZ
11-15-2014, 06:01 PM
What alloy are you using, and what are you using to measure them?

Clinton
11-15-2014, 06:04 PM
I'm using straight COWW and using a Lyman micrometer. Err dial caliper, I don't guess I know the difference.

ShooterAZ
11-15-2014, 06:09 PM
Hmmm...I seem to recall that mine casts a little on the small side too. If you are not getting leading you might try a different powder or load. If you have some 2400 powder, try 16 grains and see what happens.

Clinton
11-15-2014, 06:12 PM
Only thing I have suitable is IMR4227. Shelves have been bare around here. I'm just really concerned about the diameter of the boolits before I go any further. I guess you're saying if I'm not getting leading then size should not be a problem?

Clinton
11-15-2014, 06:15 PM
I've got some SR-7625 too. I see that Lyman has load data for that.

ShooterAZ
11-15-2014, 06:17 PM
Sizing may not be your accuracy problem. If you aren't getting leading, then indications are that sizing & lube is OK. Trying to push it too fast could be a problem. What powder charge are you using? Best accuracy will most likely be in the 1600-1900 range.

Clinton
11-15-2014, 06:21 PM
I started at 21.5 gr and worked up .5 gr at a time to 23.5. Accuracy was about 4" @ 100 yards through a rifle that will shoot 1/2"-3/4" MOA all day long. I waited 1 min inbetween shots.

ShooterAZ
11-15-2014, 06:28 PM
Well it sounds to me like your rifle may not like that boolit, or powder combination. I you are really concerned about the sizing, you could try beagling with some very small strips of aluminum tape to increase the diameter a thou or 2.

Clinton
11-15-2014, 06:31 PM
Ok thanks for the help. I think I'll try a load with SR-7625 since I have some laying around. Who knows, maybe I'll get lucky.

ShooterAZ
11-15-2014, 06:35 PM
Give it a try...4" at 100 with cast is still "Minute of Deer". 2" or better at 100 is a more realistic expectation though, for me anyway.

Quiettime
11-15-2014, 06:36 PM
You can't size to .311"

If you do that you won't get any neck tension.

You can try Beagling as mentioned or try powder coating to build up the diameter. May or may not help.

Be aware this mould is a bore-rider type boolit. The nose is meant to "ride the bore" and they don't always work when this section becomes larger than bore diameter.

Clinton
11-15-2014, 06:46 PM
You can't size to .311"

If you do that you won't get any neck tension.

You can try Beagling as mentioned or try powder coating to build up the diameter. May or may not help.

Be aware this mould is a bore-rider type boolit. The nose is meant to "ride the bore" and they don't always work when this section becomes larger than bore diameter.

Ah ok good to know. By the way, quick question on seating depth with this boolit. Should I try to seat it just off of the rifling or do you want the boolit touching the rifling?

MattOrgan
11-15-2014, 06:56 PM
I prefer to have the bullet lightly engraved by the rifling as a general rule. Not so much tht it pulls the bullet from the case if you extract a loaded round. This tends to align the bullet in the bore. I am assuming your .308 is a bolt action.

williamwaco
11-15-2014, 07:06 PM
Lee molds frequently cast small.

That said, my Lee 309-170 casts .312 +/-
I size to .311. and they measure .311 after sizing.

Curious thing. Those measurements were taken with an expensive digital mike.

My $50.00 dollar dial caliper measures the same bullets as cast .310 and after sizing .309.

Many people on here size to .309 and swear it works perfect.
I have always sized .311 and I swear it works perfect.

Maybe when I get a little more experience, I will try .309.
After all, I have only been doing this since 1960.

If I were you, I would try 9 to 10 grains of Unique.
If it won't shoot that load you need to look to the rifle.

I get best results a few thousandths off the lands but the most important thing for a hunting load is that it feeds reliably.

Clinton
11-15-2014, 07:11 PM
I prefer to have the bullet lightly engraved by the rifling as a general rule. Not so much tht it pulls the bullet from the case if you extract a loaded round. This tends to align the bullet in the bore. I am assuming your .308 is a bolt action.

Yeah don't know how critical seating depth is with this boolit but I probably had it seated deeper than I should have. Yeah this is a bolt action however I'm kinda using it as a test dummy for my M1A. I planned to work up a load in the bolt gun and then see if it would also work in my M1A afterward.

Clinton
11-15-2014, 07:12 PM
Lee molds frequently cast small.

That said, my Lee 309-170 casts .312 +/-
I size to .311. and they measure .311 after sizing.

Curious thing. Those measurements were taken with an expensive digital mike.

My $50.00 dollar dial caliper measures the same bullets as cast .310 and after sizing .309.

Many people on here size to .309 and swear it works perfect.
I have always sized .311 and I swear it works perfect.

Maybe when I get a little more experience, I will try .309.
After all, I have only been doing this since 1960.

If I were you, I would try 9 to 10 grains of Unique.
If it won't shoot that load you need to look to the rifle.

I get best results a few thousandths off the lands but the most important thing for a hunting load is that it feeds reliably.

Yet another powder that is seen on the shelves with the same regularity as unicorns around here :)

JonB_in_Glencoe
11-15-2014, 07:30 PM
Does the boolit nose of the loaded ammo get engraved by the rifling when you chamber a round ?

As was already mentioned, this is a 'bore rider' design. If that nose isn't supported by the rifling, you are bound to get poor accuracy.
Jon

Clinton
11-15-2014, 07:43 PM
Ah that may be it then. No as far as I can tell I had it set about 10 thousands off of the rifling.

JonB_in_Glencoe
11-15-2014, 08:10 PM
I have a gut feel, you are not totally understanding 'bore ride".
it's not just a spot where the begining of the lands touch the bullet in a short spot like Jacketed bullets. The 'engraving' on the nose should be a long line, ...as much as 0.300"

here is a diagram that may help.

http://castboolits.gunloads.com/showthread.php?185134-Bore-rider-boolits-101-needed&p=2069344&viewfull=1#post2069344

Clinton
11-15-2014, 08:23 PM
I was actually just looking at all the info I could find on bore riders including that diagram. I believe I'm starting to get the picture however, I know the rifling will contact (scar) the boolit nose in the chamber if I seat it long enough but I dropped one nose down into the crown of the barrel and it slipped right in till the driving bands stopped it without making a mark. Now I'm not sure if that boolit will ever shoot in that rifle.

skeet1
11-15-2014, 11:47 PM
This is why I use the Lee 312-185 and size to .311. The bullet starts out large enough for the .30's but is usually to small for the .31's. It is a very good bullet for the .30-06 and some others.

Ken

Mark Daiute
11-15-2014, 11:54 PM
I'm loath to give advice but I'm a little surprised that no0one has suggested that you drop back to 16 grains of that powder and work your way up towards the 21 grain mark.

Blackwater
11-15-2014, 11:56 PM
One other thought that hasn't been mentioned yet: Are you cleaning the copper out of your bore before shooting cast? Sometimes that can create problems. Copper and lead have an affinity for each other, and it's as if the small copper deposits in the bore "catch" the bullet at various places during its trip down the bore, thus creating a variation that can't be predicted and varies with each shot. Try cleaning the bore well and running a patch with some of the lube you're using down the bore before shooting cast and see if that makes a difference.

Slow Elk 45/70
11-16-2014, 12:19 AM
If I was that intent on using that boolit in your rifle, I would do a chamber cast, check the bore diameter, and then play with different primers, powder, length of the boolit to engaging the rifleing , and on and on, if cost is no problem.[smilie=b:


The Lee .312 185 will probably cure your problem for about $20[smilie=1: , and size it to .311 to start , less if you are so inclined......As for using the same ammo/load for the M1A....you might get lucky, but if I were a betting man.....that may not happen for several reasons.:cbpour:Good Luck

Clinton
11-16-2014, 03:27 PM
If I was that intent on using that boolit in your rifle, I would do a chamber cast, check the bore diameter, and then play with different primers, powder, length of the boolit to engaging the rifleing , and on and on, if cost is no problem.[smilie=b:


The Lee .312 185 will probably cure your problem for about $20[smilie=1: , and size it to .311 to start , less if you are so inclined......As for using the same ammo/load for the M1A....you might get lucky, but if I were a betting man.....that may not happen for several reasons.:cbpour:Good Luck

Well I picked that boolit because it looked like a design that would be good for hunting. I'm about ready to give up on it though. I'm so damned confused at this point.

Is it possible for a boolit to swell .004 24hrs after casting? Last night I dropped one in the barrel crown and it slid right down to the driving bands. This morning I sized and lubed them all and tried that again and I can't even force it into the bore.

Dusty Bannister
11-16-2014, 04:41 PM
Too much pressure on the lube sizer handle will expand the nose of the bullet. Sizing bullets does not need a great deal of pressure with soft alloy bullets. Just use a couple of fingers to pull the handle to the stop, pause, then lift the handle and eject the bullet. I suppose that you have already lubesized all those on hand, but if not mic one before and after and you will see you are probably deforming the nose.

Clinton
11-16-2014, 07:19 PM
Think I'll just order the 312-185 mold. Sounds like it will be easier to work with for a noob like me. The actual mold number is C312-185-1R correct?

62chevy
11-16-2014, 08:34 PM
Think I'll just order the 312-185 mold. Sounds like it will be easier to work with for a noob like me. The actual mold number is C312-185-1R correct?

Yes it is.

Linstrum
11-16-2014, 09:17 PM
Aaarrgh!!! I am dismayed by the apparent recent lack of use of WC860, WC872, and other slow .50 BMG and 20mm Vulcan canon powders that pretty much solve accuracy issues in rifles like the .308 Win, .30-06, 7.62x54R, and similar. FIRST SLUG YOUR BORE! Then select a boolit that is 0.002" or at most 0.003" over what your bore slugs, either one that comes out of your mold that size or comes out of your sizer that size to get the 2 or 3 thousandths of an inch oversize you need. Then take your primed ready-to-load cartridge case and pour in 3 grains of IMR4895 over the flash hole, and then over that simply fill up your cartridge case to the mouth with WC860 or WC872 and press in your boolit so you have a compressed load. Having a compressed load is important to keep the IMR4895 booster from mixing in with the main charge. That is it. Cartridges loaded that way will shoot as accurately as the rifle you shoot them in. I have a 1936 hexagonal receiver Mosin-Nagant that was rebuilt in Finland in 1942 with a 3600 atmosphere high pressure Tikkakoski sniper barrel that does 1/2" at 100 yards all day long shooting Lee C312-185-1R wheel weight projectiles loaded that way. The .308 Win is almost identical to the 7.62x54R that the Mosin-Nagant is chambered in, including one turn in 10 inch rifling twist, and this loading "formula" should solve accuracy issues. Good luck!

rl 1,206

Quiettime
11-16-2014, 09:22 PM
Midway almost always shows Reloader 50 and H50BMG in stock (I just double checked). I must admit ignorance though, I've not heard anyone talk about this

Mark Daiute
11-17-2014, 11:08 AM
50 BMG powders can be had very reasonably from Jeff Bartlett/GIBRASS.com I went in a local buy and am now well stocked. The 5010 shoots well but the WC872 meters wonderfully.

Clinton
11-17-2014, 11:55 AM
Aaarrgh!!! I am dismayed by the apparent recent lack of use of WC860, WC872, and other slow .50 BMG and 20mm Vulcan canon powders that pretty much solve accuracy issues in rifles like the .308 Win, .30-06, 7.62x54R, and similar. FIRST SLUG YOUR BORE! Then select a boolit that is 0.002" or at most 0.003" over what your bore slugs, either one that comes out of your mold that size or comes out of your sizer that size to get the 2 or 3 thousandths of an inch oversize you need. Then take your primed ready-to-load cartridge case and pour in 3 grains of IMR4895 over the flash hole, and then over that simply fill up your cartridge case to the mouth with WC860 or WC872 and press in your boolit so you have a compressed load. Having a compressed load is important to keep the IMR4895 booster from mixing in with the main charge. That is it. Cartridges loaded that way will shoot as accurately as the rifle you shoot them in. I have a 1936 hexagonal receiver Mosin-Nagant that was rebuilt in Finland in 1942 with a 3600 atmosphere high pressure Tikkakoski sniper barrel that does 1/2" at 100 yards all day long shooting Lee C312-185-1R wheel weight projectiles loaded that way. The .308 Win is almost identical to the 7.62x54R that the Mosin-Nagant is chambered in, including one turn in 10 inch rifling twist, and this loading "formula" should solve accuracy issues. Good luck!

rl 1,206

Sounds kinda uncoventional. There's no danger in overcharging?

sghart3578
11-17-2014, 11:31 PM
I'll join this thread. I have just tried my second Lee C309-170-F mold tonight. It is brand new, just like the one I tried last week. They both drop bullets at .296" on the nose and .308" on the body.

It is not my alloy, I tried some of my other molds and they were fine. My C309-150-F drops bullets at .300"/.312" so I expected the 170 gr version to do the same. Silly me.

Both molds were purchased from reputable vendors. The first vendor is giving me a refund. I will contact the second vendor tomorrow about a refund also. It is beginning to look like a run of small 170 gr molds from the factory.

I would consider contacting Lee but I have not had good experience with them, even though their equipment is all I have used for many years. When I have contacted them in the past about a mold being undersized they laid the blame on me. I told them that I had 14 other Lee molds that performed flawlessly but they were having none of it.

I will bite the bullet and get a NOE or Accurate mold. It sucks because the new Lee two cavity molds are pretty nice. But .308" won't fly in my microgroove Marlin.

Linstrum
11-18-2014, 07:33 AM
Sounds kinda uncoventional. There's no danger in overcharging?

Nope. Not unconventional, either, all us "old timers" do it. Read this post from 2006:

http://castboolits.gunloads.com/showthread.php?9128-which-powder-for-308&highlight=full+case+WC860

Remember, the CAST BOOLITS website was created to try new things as well as get away from all the myths and misconceptions out there that were causing cast bullet shooters endless problems. I've been a member here before there were members in the 1990s back when the Internet was still young.

One of the key factors in accuracy is a full case of powder, which in turn creates uniformity of pressure from one shot to the next, and the best way to get that is getting the cartridge case as full as possible, and the best way of doing THAT is to simply fill it up! In the various traditional late 19th Century and early 20th Century smokeless high power military cartridges like the .30-06, which are mostly variations of Peter Paul Mauser's cartridges from the 1870s (in other words excluding modern cartridges like the magnums where you run a quite high probability of getting into trouble with full cases of 20mm canon powders), you won't run into overcharges using the Winchester WC series 20mm Vulcan cartridge ball powders such as WC870 and WC872. WC860 that is used in the .50 BMG can also be used in full case compressed load amounts except in the 6.5x55 Swedish Mauser because of its extremely high rate of twist. I use a lot of IMR5010 because I shoot .50 BMG, but because of its extra huge grain size I don't have a lot of experience with it in the .30 and .31 calibers.

One of the biggest problems beginning cast shooters have is accepting the fact that cast projectiles HAVE TO BE 0.001" to 0.003" (1 to 3 thousandths of an inch) LARGER IN DIAMETER THAN THE LARGEST MEASURED DIMENSION OF THE BORE THAT PROJECTILE IS GOING TO BE FIRED IN AND THEY HAVE TO SLUG THE BORE OF THAT GUN TO FIND THAT DIMENSION. You can't fudge on that and then wonder what went wrong! I hate to pull the old "back when I was a kid we walked 3 miles through the snow to school", but when I got a mold that poured undersize I simply lapped it out to fit my rifle. The instructions for both "Beagling" a mold and lapping molds oversize are at this site, I wrote one or two of them myself.

Let us know how you do! Good luck!

rl 1,208

Linstrum
11-18-2014, 12:02 PM
Check out these posts and threads on full cases of powder, duplex and boosted loads:

http://castboolits.gunloads.com/showthread.php?21891-Wc-860&p=1311732&viewfull=1#post1311732

The above post is from this thread:

http://castboolits.gunloads.com/showthread.php?21891-Wc-860

With cartridges like .30-06, .308 Win, .303 Brit., 7.62x54R Russian, 7mm Mag, etc., out of milsurp and commercial hunting rifles shooting cast wheel weight boolits we were getting one ragged hole groups with boosted nearly full cases or full cases of WC860 and WC872 (often re-named by the re-seller to things like PB860, H870, and W8700) using ~3 grains of medium burn rate stick powders like IMR4895 and IMR4198 as booster powders over the flash hole.

rl 1,210

Geezer in NH
11-21-2014, 06:10 PM
you could try beagling with some very small strips of aluminum tape to increase the diameter a thou or 2. What is beagling??????? I have seen this here before but no clue what it is. When referring to it please explain or give a link so us guys can learn.

wills
11-21-2014, 06:44 PM
What is beagling??????? I have seen this here before but no clue what it is. When referring to it please explain or give a link so us guys can learn.

This site has a search feature. If you use it you can find things.
http://www.castpics.net/subsite2/MoldMods/BDE.pdf (http://www.castpics.net/subsite2/MoldMods/BDE.pdf)

http://castboolits.gunloads.com/showthread.php?78746-beagling-a-mold (http://castboolits.gunloads.com/showthread.php?78746-beagling-a-mold)
http://castboolits.gunloads.com/showthread.php?172459-Beagling-tape (http://castboolits.gunloads.com/showthread.php?172459-Beagling-tape)
http://castboolits.gunloads.com/archive/index.php/t-117331.html (http://castboolits.gunloads.com/archive/index.php/t-117331.html)
http://castboolits.gunloads.com/showthread.php?91476-quot-Beagling-quot-Bullet-mold (http://castboolits.gunloads.com/showthread.php?91476-quot-Beagling-quot-Bullet-mold)
http://castboolits.gunloads.com/showthread.php?94568-how-do-you-beagle-a-mold (http://castboolits.gunloads.com/showthread.php?94568-how-do-you-beagle-a-mold)
http://castboolits.gunloads.com/archive/index.php/t-943.html (http://castboolits.gunloads.com/archive/index.php/t-943.html)



http://castboolits.gunloads.com/google.php?cx=partner-pub-6216953551359885%3A1942134700&cof=FORID%3A9&ie=ISO-8859-1&q=beagling&siteurl=castboolits.gunloads.com%2Fshowthread.php% 3F259532-Lee-C309-170-F-Dropping-Boolits-at-309%26p%3D3015930%23post3015930&ref=castboolits.gunloads.com%2Fsearch.php%3Fsearch id%3D2036425&ss=&sa.x=6&sa.y=7 (http://castboolits.gunloads.com/google.php?cx=partner-pub-6216953551359885%3A1942134700&cof=FORID%3A9&ie=ISO-8859-1&q=beagling&siteurl=castboolits.gunloads.com%2Fshowthread.php% 3F259532-Lee-C309-170-F-Dropping-Boolits-at-309%26p%3D3015930%23post3015930&ref=castboolits.gunloads.com%2Fsearch.php%3Fsearch id%3D2036425&ss=&sa.x=6&sa.y=7)

Clinton
11-21-2014, 07:31 PM
I slugged the bore the next day at .308. I also scrubbed out any copper fouling. In the end I just decided to try a different bullet so I ordered the Lee 185 mold and a .311 sizing die. For kicks I took some bullets I had cast for my AK that came out too small and sized them to .311. Loaded them with IMR4227 and SR7625. Still didn't get any accuracy out of the 4227 loads but the SR7625 loads were shooting well under an inch at 100 yards. Just gotta get some time to cast the 185s and see how they do.

Linstrum
11-22-2014, 06:17 AM
I slugged the bore the next day at .308.

Good! That is a quite necessary step most overlook.

For kicks I took some bullets I had cast for my AK that came out too small and sized them to .311. Loaded them with IMR4227 and SR7625. Still didn't get any accuracy out of the 4227 loads.

In my book, IMR4227 is not an optimum cast powder for RIFLES, you should be concentrating on slow powders like IMR4350 and slower for cartridges like the .308 Win. SR7625 can be used for low velocity rifle loads along with Red Dot. An accurate universal load for .308 Win is 13 grains Red Dot with a 150 grain cast boolit, but the velocity will be around 1500-1600 fps.


but the SR7625 loads were shooting well under an inch at 100 yards.

Well - - - there are two kinds of one inch groups at 100 yards. One is where all your shots are within one inch of the spot you were aiming at, the other is where all your shots landed within one inch of each other but are a foot from where you were aiming. Either one is a pretty good thing, but when they are a foot from where you were aiming, your work isn't quite over with for the day, it is time to get the hex wrench out and tweak your scope. But I'll tell ya what, though, most folks will give their left eye tooth to get either one! I'm glad you found one load that gives good results. Keep at it, that is the name of the game, although you have probably just about reached the limits of what your rifle will do, getting an inch at 100 yards is about as good as most modern rifles will do. Can't shoot more accurately than what your gun will do. Keep up the good work and aim at a 1/2 inch!

rl 1,215

robg
11-22-2014, 07:54 AM
are you keeping bullet base in case neck,if not you wont get good accuracy.

sthwestvictoria
11-22-2014, 09:01 AM
So now I'm lost. Do I go ahead and size them to .311 and just hope the gas check does the work or do I need a different mold?
This is exactly what I do cast in ACWW with the .309, GC on with thumb pressure, pan lube then through the Lee .311 sizer. This obviously does nothing to the bullet but does crimp on the GC. Now I do have the older style Lee molds with pins and V, not the ball and socket type so maybe these are a little larger but it works for me with the Lee 309-170-fp.

Clinton
11-22-2014, 10:50 AM
are you keeping bullet base in case neck,if not you wont get good accuracy. Yes, I think thats what most of the original problem was. The nose of my boolit wouldn't really fit well in the bore and although I was seating them long it was shoving them too far into the case neck when I chambered them. How I did not notice that I do not know.

HangFireW8
11-23-2014, 02:36 AM
Remember, the CAST BOOLITS website was created to try new things as well as get away from all the myths and misconceptions out there that were causing cast bullet shooters endless problems. I've been a member here before there were members in the 1990s back when the Internet was still young.

Keeping that in mind...



One of the biggest problems beginning cast shooters have is accepting the fact that cast projectiles HAVE TO BE 0.001" to 0.003" (1 to 3 thousandths of an inch) LARGER IN DIAMETER THAN THE LARGEST MEASURED DIMENSION OF THE BORE THAT PROJECTILE IS GOING TO BE FIRED IN AND THEY HAVE TO SLUG THE BORE OF THAT GUN TO FIND THAT DIMENSION. You can't fudge on that and then wonder what went wrong!

Back in the 1930's Phil Sharpe railed against the myth that boolits had to be oversized and were best .003" oversized. He knew better because he had star gauged bores and mike'ed boolits, and had tried them, and some loads worked, and worked well.

I have as well. I've gotten good accuracy from .309" GC boolits in .310" bores. I had to drive them a bit hard, and it did help that the lands were .300" and so was the bore riding shank of the boolit. Sharpe knew where the myth originated, the fact that early Krag's were often oversized and the owners were not aware of that fact.

So the "fact" about cast projectiles is much more complex, it's more like:

You have to avoid significant gas blow-by, and your boolits have to engage the rifling in such a way that they spin, and this is TYPICALLY done by casting them a little oversized, though there are other ways, such as bumping up, seating to the throat, managing metallurgy and the pressure curve, etc.

The "gotta be .003" mantra that has lately begun to pervade this board mystifies me. Some myths just don't die. The fact is it doesn't even have to be .001" over. The fact is I can cast/size all my boolits to bore diameter and they'll all shoot fine, because 1.) I don't have any huge oversized throats, and 2.) I can manage the measuring and culling processes to make sure there are no undersized boolits fired at all.

Please realize the reason that at least .001" over is recommended is simply to make sure you don't accidentally make some undersized. Not that undersized can't work, it's just much hard to make it work. The NRA's greatest cast boolit experimenter and writer finally settled on the best method is casting to exactly bore size (and no less) and not sizing at all, because sizing can introduce eccentricity. Most of us should try and do so well.

Now I realize that we are teaching newbies and rules of thumb are useful to achieve quick success, and experimentation can wait until we have a few successes under our belts... but let's not turn rules of thumbs into "facts", "rules", or perpetuate myths.

sghart3578
11-23-2014, 12:43 PM
To piggy back on what HangFireW8 wrote about Sharpe's findings:

I will have to dig out my copy of Sharpe's Complete Guide to Handloading to be sure but I distinctly remember reading a section about his testing of cast bullets, cast to bore diameter and not .003" larger, that performed perfectly when fitted with a gas check.

I remember, after reading that, I verified it myself in my 7X57.