I slugged my barrel now what

[bigarm]

I slugged the barrel of my Marlin 30-30 today. I will be the first to say this was not a professional job, but I am pretty sure it is about .309. I looked and Lee makes sizing dies in .309 and .311, but not .310. I will be powder coating the bullets and will be using the Lyman 311440 mold thanks to Bill*B. So should I size at .311, .309 or have a die made at .310? There is a person on here that lives in Missoula and makes Lee type sizing dies, so that is no big problem.

[VHoward]

I would buy the .311 die and go for it. I usually go for .002" over the slugged size.

[John Boy]

Lee makes sizing dies in .309 and .311, but not .310.Order the 311 because of the 20 some Lee Lube/Sizers I have ... they all are 0.001 under the size you order

[el34]

How did you do it?

[bigarm]

How did you do it?

I got some sinkers and they were still a little too big (don't ask how I know) and squeezed one down in the vise and then pounded it through the barrel with a steel rod covered with painters tape. I did it once and then pushed the same one through again. It isn't pretty, but I think it gave me what I needed. Probably shouldn't have done it as the voices in my head said to go with .309 as the bore size anyway.

[farmerjim]

Get the 309 and lap it out yourself. Easy to do and only takes a few minutes. If the 310 does not work you can make it 311 or 312.

http://castboolits.gunloads.com/showthread.php?134533-Honing-lapping-Lee-Sizing-die

[el34]

Probably shouldn't have done it as the voices in my head said to go with .309 as the bore size anyway.

What else are those voices telling you? :smile:

[georgerkahn]

I just found out my mid-priced digital verniers indicate almost one thousandth of an inch bigger than my (also mid-priced) Proto micrometer. A machinist friend checked both out for me with a Pratt & Whitney 0.500" check block, and proved the micrometer to be dead on. I'd been relying on the digital calipers for about a decade :( ...

I've added this to the thread, as -- hey -- before *I* make any more purchases or use (sizing) dies -- I'm gonna' not even wait until the redness/embarrassment fades, and ascertain the measurement I get is correct. I'm hoping your micrometer/calipers are right on, but felt obligated in the best interest of things to perhaps bring my experience to your attention... just in case (I hope not) your device is a tad off, as mine is. As a btw, machinist checked mine out gratis.
BEST!
georgerkahn

[GhostHawk]

My experience is saying that Lee push through sizers are trending to throw a touch small from the factory.

My .311 was .3105 until I honed it out. My .314 is showing a majority at .313 with a few at .3135.

So you have 2 choices, get the .311 and hope it throws a half small. (Ideal IMO) But it is taking a small risk.
Or buy the smaller one and keep honing it out, and test firing bullets until you get accuracy. (More work, but probably the most sure fire answer)

Your call.

How confident are you in that .309 slug? Rifling marks clear and easy to see? Fully developed groves?
Got someone you can show or send the slug you made to have them measure it?

Balls in your court, worst case scenario you end up buying a new 20$ sizer because you got in a hurry and tried to rush it or didn't test for size often enough and went too far.

20$ for the cost of Higher education in the school of hard knocks seems pretty reasonable to me.

[5Shot]

I can lap it out for you Mike if you don't want to do it yourself...takes about 5 minutes.

BTW - if you go big and the throat is tight you could have a tough time getting the action closed. I have a bolt rifle with a tight throat and wouldn't be able to close the bolt if the bullets were anything over 0.358.