Is this normal when sizing a Smith bullet?

[Maillemaker]

Well, my closest range was shut down due to C-19. I forgot my portable holes and it was an hour and fifteen minutes out to the unmanned range on the mountain and it was already 3pm, so no shooting today.

Steve

[Kevin Tinny]

Ok, Steve on .512" OD in a .510" groove depth bore.

I have done two-step sizing as a fit testing experiment to learn what dim is correct, but sizing over .002" is not the best approach, and it adds work steps.

Ultimately the correct OD CASTING has to be achieved so minimal sizing is needed.

R/Kevin

[Harry Gaul]

I am a fan of a small bullet. If the grooves are 510, I would shoot a 508. Scientifically, the law of physics demand that two things can NOT occupy the same space at the same time; bullet and fouling are competing for the same groove space. If they try, it is called an accident. There is guy on Facebook by the name of Robert Bradley. He makes a very nice sizer and pusher for an loading press (7/8 X 14) for reasonable amount of money shipped. I purchased two sizers from him. Be sure to mention that the lead in portion of the sizer should be larger than the finished diameter.

Back to physics. I am trying to shoot a second model , 50 cal , Maynard. People are telling me to shoot a 515. I tried that, and after three shots the fouling is so bad that the bullet actually hesitates in the barrel and then spits out at some unknown velocity and place. I switched to a 510 bullet and I can shoot maybe 20 to 25 rounds before cleaning. I am not a good shot but win a medal from time to time. If my eyes and nerves were better, who knows what kind of shooter I would be. Maybe not good, but it would certainly more fun.

True Blue and Diamond hard,
Harry
3rd US
03626v

[Michael Bodner]

But the North East Trading Co. die just isn't very good, in my opinion. It has a very harsh chamfer that provides the change in diameter from the entry bore to the sizing bore. So it is much more unforgiving to an over-sized bullet.


Steve,

A few years back, a whole batch of North East Trading Co sizing dies were made terribly... Basically, they lacked any taper and were simple two diameters. Made by a sub-contractor and John replaced them if you brought them to him... However, if you bought this second hand, you may be out of luck.

For future reference, Tom Crone makes OUTSTANDING dies. Mirror polished... I highly recommend his work...

-Boots

[Michael Bodner]

Steve,

I shoot an identical bullet in my Smith (my mold is Rapine). The mold is stamped .515 but it really tosses out 0.520. I size down to 0.517 (again, an poorly made 0.515 sizer)?

If I slug the barrel, the bullet gets pretty swaged down. The grease grove is greatly reduced. HOWEVER, the dang gun shoots like the bullets are laser guided... BTW: I'm casting with hard lead, about 7-8 BHN

So....

Although I won't dissuade you from exploring the 'best' diameter to cast/size based on the land and groove dimensions, I highly encourage you to simple cast some, size them slightly to get uniform dimensions (see other post about bad North-East sizer) and see how they group... YES, I know that everyone says 'Just try', but in this case, I'm encouraging you based on very similar dimensions for my Smith (Lands and grooves are way down near .505 range). BTW: I'm loading 31 grains 3f, plastic cases, and some grits on top of the powder to get the bullet over-all length longer (so bullet touches the rifling). When I close the breech, the bullet is pushed back and compresses the powder... I lube BEFORE sizing with MCM lube.

Of course, if you give up, I'll give you $300 for that crappy gun!! LOL

-Boots

[Maillemaker]

A few years back, a whole batch of North East Trading Co sizing dies were made terribly... Basically, they lacked any taper and were simple two diameters. Made by a sub-contractor and John replaced them if you brought them to him... However, if you bought this second hand, you may be out of luck.

Here is a picture of the bore of the NETO sizing die. Basically it looks like it has a simple 45 degree chamfer between the inlet and sizing bore.





Full-sized pictures here: https://imgur.com/a/NqmrG9E

I bought it from Lodgewood, new. The box, however, says North East Trading Company.

Although I won't dissuade you from exploring the 'best' diameter to cast/size based on the land and groove dimensions, I highly encourage you to simple cast some, size them slightly to get uniform dimensions (see other post about bad North-East sizer) and see how they group... YES, I know that everyone says 'Just try', but in this case, I'm encouraging you based on very similar dimensions for my Smith (Lands and grooves are way down near .505 range). BTW: I'm loading 31 grains 3f, plastic cases, and some grits on top of the powder to get the bullet over-all length longer (so bullet touches the rifling). When I close the breech, the bullet is pushed back and compresses the powder... I lube BEFORE sizing with MCM lube.

Of course, if you give up, I'll give you $300 for that crappy gun!! LOL

Well, that's re-assuring, thanks! I believe when my .515 and .512 dies come in I will start with .515 and see how they do.

Steve

[bobanderson]

GUYS, GUYS, GUYS! Take a breath.

A civil war carbine is 50 caliber. The reason we use .515" bullets, or larger, is because the 50 caliber is the diameter of the bore across the lands, the tops of the rifling. The .515 is because each rifling groove is cut to a depth of five to eight thousandths. You cannot usually measure a slug pushed through the rifling because, with an odd number of grooves, your measuring tool is reading from the top of one land to the bottom of one groove. The reason we have an odd number of grooves is because you need to support the rifling cutter on the opposite side as you cut your grooves.
A thought occurs to me if you want to accurately measure your bore. Start with a set of minus plug gauges measuring .498, .499, .500, .501 and .502. Use these to find the land diameter of your bore. (I just tried to insert a piece of 1/2 cold roll steel into my Maynard 50 barrel. It was too tight, but it's possible plain steel bars are not exactly to size. Another possibility is to try a 1/2" drill bit.)
Anyways, then push a slug through as before and measure with a dial caliper. You should get somewhere between .505 and .510. Subtract the land diameter of your bore, say .500 from this second measurement, say .507 (or even .5075) and then multiply that by 2 to get your actual groove diameter. For instance, .5075 minus .500 equals .0075 times two equals .015 which gives you a bullet size of .500 plus .015 equalling .515. Because most cast bullets shoot better a bit oversized, size your bullets to .517.

Boy will I be glad when we can get back to shooting again!

[Maillemaker]

I modeled up the bullet cross section in Solid Edge:



It is possible to get a good measurement across the groove in the bullet, and the groove depth in the bullet, and then use this with the diameter measurement - in spite of the odd number of lands and grooves - to determine the actual OD and ID.

Based on these dimensions, it appears that the groove diameter is .51, and the bore diameter is .50.

I believe I will start with .515 and see what happens.

Steve

[Maillemaker]

I put a 1/2" drill bit shank (measures .496" in diameter) in my bore and it just fits. I suspect my bore is .500.

Steve

[ms3635v]

Steve,

I have been using sizing dies made by Tom Crone (301-473-5699). They are high quality sizers that have a true, gentle lead in. I buy the dies he makes that thread into my RCBS Rockchucker press (7/8x14). I size my Moose Smith/Maynard mould from .520" to .518" with no damage to the bullet. This is the bullet I use in both my original Smith and my Second model Maynard.