need help 310 CADET

[bladeracer]

While searching I also found there's a decent amount of info on this forum, like here - https://enoughgun.com/forum/viewtopic.php?f=12&t=10334

[SHV]

What diameter is the heel of your .323" bullet?-----------bottom part .314 driving band is .323
Did you push it deeper into the case than just the heel?---------not too deep just stopped at heal line or leave a little gap
What is the diameter of the case neck with the bullet seated?----------.335
Have you slugged the bore?------not yet but I put .311 projectiles to the barrel it can be pushed totally inside with out too much effort, also I insert the 310(316) factory ammo projectile into the barrel it get in easily the rifling only scratches the wax off

thanks

It certainly sounds like the bore is around the .323" area then. Will the bullet (not the cartridge) drop all the way into the throat until it touches the rifling?
The specs call for the loaded case neck to be .327". With age, the chamber could certainly be larger than spec, but .335" is getting extreme I think.
This CIP spec also calls for the reamer to be .328" max at the case mouth and .325" in the throat. And the case length should not be over 1.130" - if it's longer it might get crimped in the throat (but you already said the empty brass chambers fine).
https://bobp.cip-bobp.org/uploads/tdcc/tab-ii/tabiical-en-page78.pdf

You said the new cases and the old factory ammo both chamber fine, what is the diameter around the neck of those cases?
You said the cast of the throat is .335", do you mean the case neck area of the chamber rather than the throat? Did you cast the whole chamber? If the chamber measures .335" it would certainly make it difficult to force a .335" case neck into it. I can only surmise that the case is being enlarged too far when seating the bullet. Which could be due to the neck wall thickness being too thick, or the heel of the bullet being too wide (it seems fine at .314"), or you need to crimp the bullet, or perhaps it's shaving lead off the bullet when seating and piling up in the case neck due to the heel. Is the bullet going in nicely without much force? Are you flaring the case mouth and crimping it back afterwards?

I would take a cast of the chamber and use those measurements to determine what I size the case neck to (probably .002" under the chamber dimension), and what size bullet (.001" or .002" under throat diameter) and heel (case neck diameter minus the neck wall thickness) I want to use. You can make a neck sizing die similar to a bullet sizing die by boring an under-size hole through a 7/8"-14tpi bolt then hone it out to the size you need (start under-size and test load and shoot before honing it out further). You can do the same with the bullet, and the heel - you would basically be doing the same as nose-sizing the bullet to fit the bore but at the other end of the bullet. To size the bullet (driving band) you push the whole bullet through a die. To size just the nose (so it fits neatly into the rifling) or the heel (to fit into the case), you push the bullet partially into a die then push it back out. You can also make a simple crimp die out of a bolt if you have to, but the bullet will also be sized down about .001" smaller diameter than the case neck by this sort of crimp die.

fire formed case neck size is .33, very close to the spec you mentioned .328
I tried few times to seat the bullet, the case neck always around .335 so it couldn't chamber

if there is a kind of bullet sizing die can only change the heel (not the driving band part) diameter smaller or if I can find a crimp die for 310 cadet will be fine, where can I find those kind of thing?

cast chamber is not an option for me, for now...

I do cut a case from 1.08 to .98, after seating the bullet the case neck still around .335 but because the case is shorter now I can chamber it with a little push, I am thinking if can not find crimp die or bullet sizing die (just reduce the heel diameter) maybe cut the case is an option?

[bladeracer]

fire formed case neck size is .33, very close to the spec you mentioned .328
I tried few times to seat the bullet, the case neck always around .335 so it couldn't chamber

if there is a kind of bullet sizing die can only change the heel (not the driving band part) diameter smaller or if I can find a crimp die for 310 cadet will be fine, where can I find those kind of thing?

cast chamber is not an option for me, for now...

I do cut a case from 1.08 to .98, after seating the bullet the case neck still around .335 but because the case is shorter now I can chamber it with a little push, I am thinking if can not find crimp die or bullet sizing die (just reduce the heel diameter) maybe cut the case is an option?

Okay, so it appears the issue is that the case neck is too fat after seating the bullet. I would think almost any .30-cal crimp die would bring the case mouth down below .335", but I don't think most of the common (cheap, readily available) dies would bring it down to .325" or less.

Yes, nose-sizing dies are available but I think most are custom ordered, I can't recall seeing any offered as standard stock anywhere, but they're not difficult to make. Anybody with a lathe can make them for you. You might have to make a "top punch" to suit the shape of the nose of your bullet if you're using a hard alloy and need to size them down a lot. If just want to see if that might fix the issue, put a bullet in a drill chuck and use a file to take a few thousandths off the heel, load it up and see if it works. Use the file's safe edge against the shoulder so you don't also push the heel further up the bullet.

Chamber casting is very easy, surprisingly easy. The casting alloy melts at around 60C, hot enough to burn you if you immerse yourself but far short of the boiling point of water. Push a patch or foam earplug into the chamber maybe a half-inch further than the length of a loaded cartridge - you want to get an impression of the start of the rifling but there's no need to form a mechanical bond between the alloy and the rifling grooves. Hold the barrel with the chamber upwards and simply pour the molten metal into the chamber until it's almost to the top - that's it. It'll set in a few seconds and it will contract so it should push out fairly easily with a rod from the muzzle - use a wooden dowel or length of aluminium or brass rod ($2.50 from Bunnings https://www.bunnings.com.au/metal-mate-6-3mm-x-1m-aluminium-solid-rod_p1130541 ). Within a couple minutes, as it returns to room temperature it will expand back to give you a perfect impression of your chamber. You can keep it in your die box to refer to in the future. I use a John West tuna can, bent to form a spout and a gas torch, no special tools. Some rifles don't have clear access to the chamber so you might have to fabricate a funnel. If for some reason you can't get the cast out just heat the chamber and melt it and pour it back out (I have one rifle with a badly pitted chamber that was a real bear to get a cast out of). Northern Smelters do casting alloy. They also do bullet alloys if you want that as well. https://www.northernsmelters.com.au/pewter-casting-alloys

I don't think cutting the case that short is going to work great, though it may work sufficiently to allow you to get shooting. I would try to fix the primary issue of why the case is being expanded so far when seating the bullet. File the heel of a bullet down and see if it works. You might find it easier to turn the case necks of your brass down a few thousandths rather than modify all your bullets. Alternatively, a 5/16" (.3125") drill bit should ream the case mouths out to about .313" so that may be an option. An 8mm drill bit is nominally .315", but unless you use a lathe it's likely you'll drill slightly over-size - if you have plenty of brass you could try this also.

[No1Mk3]

G'day SHV,
Your projectile and cartridge dimensions are correct, the HRBC 128g projectiles I use are 0.323" bullet with 0.3135" Heel, when loaded into 1.075" long cases the dimeters are 0.354 Base and 0.332" Neck. This cartridge loads into all 7 of my Cadets, but only shoots well in 2, but OK in another 2, and poorly in 3. The original Australian Military FMJ cartridge uses a 0.315" straight projectile and the cartridge is almost identical to mine, 0.352" Base and 0.332" Neck with 1.08" case Length. I really feel you need to do a chamber cast to ensure it is not short chambered or some other issue, the use of a W.W. Greener rear sight on a BSA actioned rifle could mean a custom chamber also (PS: The sight is correctly mounted, hinged at the rear). You have tried the Super cartridges in the rifle haven't you? Cheers.

[SHV]

update

I use 8mm drill to enlarge the inside and still can not chamber, have to trim/polish outside of the case neck to chamber (still very tight fit)

I trim new case short from 1.182 to 0.98 after bullet seated, the case neck is 0.338, it can chamber easily, I will try it again to make sure it really work

[bladeracer]

update

I use 8mm drill to enlarge the inside and still can not chamber, have to trim/polish outside of the case neck to chamber (still very tight fit)

I trim new case short from 1.182 to 0.98 after bullet seated, the case neck is 0.338, it can chamber easily, I will try it again to make sure it really work

What die are you using to size the case neck down? Sounds like it's not pulling it down small enough.

[bladeracer]

The heel of your bullet is .314" in diameter.
The outer diameter of the fire-formed case is .330".
You bore the inner diameter of the neck out with an 8mm drill bit, so it's at least .315".
You put in the bullet, which is at least one-thou smaller in diameter than the case mouth, and suddenly the case neck becomes at least .005" larger up to .008" larger...for no reason?
There must be something you are doing during the seating process that is causing this.
As the bullet is clearly not an interference fit (being at least .001" smaller than the case mouth), does it fall out of the case?

What are you using to neck-size the case?
What is the outer diameter of the sized case neck?
Are you flaring the case mouth for the bullet (even though you don't need to as your bullet is smaller)?
Are you crimping the case mouth?
If so, what are you crimping it with?

[bladeracer]

Can you post some nice clear photos of the cartridge and bullet you're trying to load?

[SHV]

case length 1.18

5D19054B-4EC5-43C9-A44C-F9D45B93B67A.jpeg (422.06 KiB) Viewed 3164 times

[SHV]

2D0AFAFB-CB07-4A4B-BECB-C49E5CD35657.jpeg (291.47 KiB) Viewed 3164 times

Put into the chamber stops here

[SHV]

Case length 1.00 nearly get into the chamber if push hard enough can go in and close the chamber

DB5CB89E-586C-4708-8582-5C858703ED1F.jpeg (200 KiB) Viewed 3163 times

[SHV]

8C9356AC-8198-42E7-B5A5-8C1CD818B5C8.jpeg (595.28 KiB) Viewed 3162 times

Once the case length is 0.98 or less
chamber nicely, this is the comparison 0.98 case and full length case

[dnedative]

Doesnt seem right at all, might be time for a chamber cast

[No1_49er]

That picture describing the case length 1.00 shows the problem.
How can a heal seat bullet expand the formed case that much. My experience is that the case will be a straight "taper" from the rim, right through to the projectile shoulder.
Your photo shows a clear expansion where the "heal seated" bullet is inserted into the case.
In my experience, that aint right.

[bladeracer]

I think the issue must be your measurement of the heel, it can't be .314" OD if it expands the case which is at least .315" ID (if an 8mm drill bit bored it out). The bullet must be larger than that. If the bullet is .314" it should pop in and out of the .315" case with virtually no contact, it should not need to be forced in to expand the case neck.

[SHV]

I think the issue must be your measurement of the heel, it can't be .314" OD if it expands the case which is at least .315" ID (if an 8mm drill bit bored it out). The bullet must be larger than that. If the bullet is .314" it should pop in and out of the .315" case with virtually no contact, it should not need to be forced in to expand the case neck.

sorry for the confusion I didn't drill the new case, I use expander die to open it up a little then drill otherwise seems will get through the wall easily especially using handhold tools , I don't have drill press

I made 3x 0.98 case two chamber nicely, one need a little push and close the chamber a little hard, I check them and find out that one during the bullet seating the bullet isn't 100% straight. is hard to put the bullet straight due to the shape of the tail, if it's boat tail shape will be much easier

it shoots well though, 20m 3 shot looks like really promising

[bladeracer]

I think the issue must be your measurement of the heel, it can't be .314" OD if it expands the case which is at least .315" ID (if an 8mm drill bit bored it out). The bullet must be larger than that. If the bullet is .314" it should pop in and out of the .315" case with virtually no contact, it should not need to be forced in to expand the case neck.

sorry for the confusion I didn't drill the new case, I use expander die to open it up a little then drill otherwise seems will get through the wall easily especially using handhold tools , I don't have drill press

I made 3x 0.98 case two chamber nicely, one need a little push and close the chamber a little hard, I check them and find out that one during the bullet seating the bullet isn't 100% straight. is hard to put the bullet straight due to the shape of the tail, if it's boat tail shape will be much easier

it shoots well though, 20m 3 shot looks like really promising

You don't need a drill press as you would only be taking perhaps one or two thousandths out of the mouth, a hand drill would be fine.
But there is still some reason why the case neck is being expanded so much when pushing the bullet into it.
An expander or case mouth flaring die would certainly cause your issue, and should be unnecessary if the bullet is already smaller than the case mouth. You only need to expand or flare the case if the bullet is larger than the case mouth. After expanding the mouth you need to crimp it back to size or it will certainly be too large to fit the chamber.

[bigpete]

Try running a loaded case through your sizing die with the depriming rod removed with plenty of lube....

[boingk]

I reckon your projectile is enlarging the case to the point it wont chamber, or perhaps the projectile is engaging the rifling?

I've got a bunch of .314" 78gn projectiles I use for my Cadet, using brass I've made from resized Starline 32-20. They hold palm-sized groups using the low profile open sights at 50m and I suspect they would work better at .316" but hey, they work. I use 1cc Trailboss, otherwise a fast pistol powder would be perfect.

Happy to send you a few if you're keen, or ask for samples from BlackWidow as they do them regularly.

- boingk

[SHV]

Try running a loaded case through your sizing die with the depriming rod removed with plenty of lube....

yes I did exactly the same, it works on 0.98 case length ones

if I can find tapper crimp die I believe I can use the full length case

[SHV]

I reckon your projectile is enlarging the case to the point it wont chamber, or perhaps the projectile is engaging the rifling?

I've got a bunch of .314" 78gn projectiles I use for my Cadet, using brass I've made from resized Starline 32-20. They hold palm-sized groups using the low profile open sights at 50m and I suspect they would work better at .316" but hey, they work. I use 1cc Trailboss, otherwise a fast pistol powder would be perfect.

Happy to send you a few if you're keen, or ask for samples from BlackWidow as they do them regularly.

- boingk

Thanks a lot
I think the barrel takes the 323 pills is just fine, the only thing is make it chamber, cut case and use sizing die(pin removed) works

554AF02D-D6CE-46C1-816E-D8CE49C984B1.jpeg (417.63 KiB) Viewed 3088 times

[bigpete]

Try running a loaded case through your sizing die with the depriming rod removed with plenty of lube....

yes I did exactly the same, it works on 0.98 case length ones

if I can find tapper crimp die I believe I can use the full length case

And did they load into your gun after?

[SHV]

Try running a loaded case through your sizing die with the depriming rod removed with plenty of lube....

yes I did exactly the same, it works on 0.98 case length ones

if I can find tapper crimp die I believe I can use the full length case

And did they load into your gun after?

yes it chambers nicely!

[bigpete]

Excellent. Simple fix huh. Now,do they shoot ok ?

[SHV]

Excellent. Simple fix huh. Now,do they shoot ok ?

it shots ok, looks quite accurate although I don't have right powder just use 2207 to try, it leaves few pieces powder in the barrel unburn but colour change to yellow

[SHV]

IMG_9782.JPG (634.08 KiB) Viewed 2997 times

[bigpete]

Excellent. Simple fix huh. Now,do they shoot ok ?

it shots ok, looks quite accurate although I don't have right powder just use 2207 to try, it leaves few pieces powder in the barrel unburn but colour change to yellow

Excellent! I'm very happy to hear that.

[SHV]

IMG_9954a.JPG (703.52 KiB) Viewed 2974 times

[SHV]

IMG_0007.JPG (716.96 KiB) Viewed 2972 times

[SHV]

what's this logo?

IMG_0007a.JPG (686.75 KiB) Viewed 2972 times