Leading around case neck

[mto7464]

Tried my first loads in my k-31. groves are .307 bore .296. Sized bullets at .309. While shooting I noticed lead on the outside of the neck of the cases. Then one came out with a thin slice of lead hanging from the mouth. Are the boolits getting shaved as they enter the bore?

[klausg]

mto-
It sounds like you're not expanding your case neck enough, (or not at all). You need to get a Lyman 'M' die or Lee Universal expanding die. Your bullets are being shaved as they enter the case neck.

-Klaus

[mto7464]

This is happening after I have fired the shells not as I load the boolit. The lead is all over the outside of the necks like it is displaced there on firing and then the pressure flattens it out on the case neck.

[stubert]

Sounds like the cases are not expanding and sealing the chamber, try a heavier crimp, or your loads are not generating enough pressure to expand the cases.

[HORNET]

mto,
How sharp is the transition angle at the end of the case neck and what's the max diameter of the ball seat angle? I strongly suspect (without a bit of definitive documentation) that a lot of damage is likely to occur as the boolit gets squeezed down by a sharp angle at this location :( . Probably the reason things improve as the barrel wears or gets firelapped :roll: . A sharp transition does most of the work so gets worn faster [smilie=1: . Let me get my nomex skivvies on before responses begin [smilie=1: :( .

[mto7464]

On top of all this the barrel leaded badly. I didn't get to check that until I just got home. As far as what you asked Hornet, I have no idea.

Stubert, even if the crimp wasn't tight or pressure high enough why the lead?

[joeb33050]

What you have here is too much or the wrong powder, you're trying to make the bullet go too fast.
I have had the same thing happen.
With high fast pressure there will be lead on the outside of the case neck, and sometimes you'll see a ring of lead fall out of the chamber. The ring is ~.025" thick, and I "think" is from the bullet swelling up and then the ring is sliced off at it enters the throat.
Sometimes the lead on the outside of the case neck can be peeled off with a fingernail.
Go slower and the problem will go away.
joe brennan

[1Shirt]

MTO7464, after reading the responses, and never having experianced what you discribe, would be interested in the data for your load.
1Shirt!:coffeecom

[jh45gun]

Try 20 grains of 2400 Thats the load I came up with for my K31 and it is excellent using a cast bullet sized at .309 for my K31. I am using the 311407 bullet but I would guess any 170/180 grain cast bullet would work well.

[mto7464]

My loads were:
13 grains Herco under a Lee 180 RN (WW with some extra tin added, water dropped) sized .309 with GC and LLA.

13 grains Herco Lyman 170 FN GC sized and lubed .308.

Does this load sound like it could cause a problem?

[Maven]

mto7464, I think JoeB is correct, but I have some questions for you. Why did you size the Lee 180gr. RN to .309", but the Lyman 170gr. FN (#31141?) to .308": Do you have 2 differenct K-31's? Also, why did you add extra tin to the Lee and not the Lyman? With tin, less is more, i.e., use no more than 2% to improve casting, more is wasteful and costly. A slower powder and less speed, as Joe suggested, may greatly improve things: 18.5 -21.5gr. WC 820; 22gr. AA 5744; 22-23gr. H/IMR 4198; 26-28gr. IMR 3031; 48gr. WC 860 + mag. primer. Btw, I have 2 K-31's (fired one on Tuesday with WC 820 aand the Lee CB) and use the same CB's as you (no water dropping or other hardening), but have never got either one to lead in the bbl. or cartridge necks.

[1Shirt]

MTO Just for comparisons sake, I looked up lyman cast recommendations for cast for 30-40 K, and 308, as I have been told and have found that recommendation someplace between the two work well in a K-31. They do not list Herco. I have had little experiance with Herco except in shotgun a few years back. I do wonder if you are possibly seating your blts out a bit to far and then jamming the blt into the lands which is easy to do with a K-31 in my experiance. Might suggest you try some spire point types like 311413 which is what I have had good luck with in my K-31. Also might want to try the old 13 gr. of red dot that seems to work with just about every thing in cases from 300 Sav up to 06 and those in between. That also shoots well in mine with the 413 in mine, sized .310. Good luck!
1Shirt!:coffee:

[versifier]

Lee 180's work fine in my K31 seated to an OAL of 2.576". I have good luck with IMR 3031 and WC860. Boolits are cast of ACWW, dip lubed in diluted LLA, and sized to .310. Bore is .298, groove .309. 50yd 5shot groups run between 1-2".

[stubert]

If the cases do not expand enough to seal the chamber, lead and powder can be blown back over the case mouths giving a lead smear or very dirty cases.

[mto7464]

mto7464, I think JoeB is correct, but I have some questions for you. Why did you size the Lee 180gr. RN to .309", but the Lyman 170gr. FN (#31141?) to .308": Do you have 2 differenct K-31's? Also, why did you add extra tin to the Lee and not the Lyman? With tin, less is more, i.e., use no more than 2% to improve casting, more is wasteful and costly. A slower powder and less speed, as Joe suggested, may greatly improve things: 18.5 -21.5gr. WC 820; 22gr. AA 5744; 22-23gr. H/IMR 4198; 26-28gr. IMR 3031; 48gr. WC 860 + mag. primer. Btw, I have 2 K-31's (fired one on Tuesday with WC 820 aand the Lee CB) and use the same CB's as you (no water dropping or other hardening), but have never got either one to lead in the bbl. or cartridge necks.

The 170 Lymans are from a friend of mine. I didn't cast them. The Lee RN are from my castings.

[mto7464]

MTO Just for comparisons sake, I looked up lyman cast recommendations for cast for 30-40 K, and 308, as I have been told and have found that recommendation someplace between the two work well in a K-31. They do not list Herco. I have had little experiance with Herco except in shotgun a few years back. I do wonder if you are possibly seating your blts out a bit to far and then jamming the blt into the lands which is easy to do with a K-31 in my experiance. Might suggest you try some spire point types like 311413 which is what I have had good luck with in my K-31. Also might want to try the old 13 gr. of red dot that seems to work with just about every thing in cases from 300 Sav up to 06 and those in between. That also shoots well in mine with the 413 in mine, sized .310. Good luck!
1Shirt!:coffee:

In my Lyman cast handbook it has several loads using Herco in the 308. That is where I got my data. Also the boolits are not jamming into the rifling. I will try a different load