Is it practical to size a .312 down to .309

[Bear foot bowhunter]

Hi guys about to order my first mold from what iv read i need 0.001 larger than actual barrel die so im planing on grabing a lee 309 sizing kit but the only 189ish mold availible from mysuplyer is a 185gr 0.312 is this too big to be putting throught the 309 ? And is the 309 adiquit for a modern remington 700 308 thanks heaps

[Bear foot bowhunter]

Has any one loaded up a similar bullet over trailboss?

[Themoose]

Don't think there is a "right answer" to your question mate... First, molds often vary as to the diameter that they really cast... can depend on quality of mfg... you can read several threads talking about Lyman mold variances.. also depends on the alloy you use... rifle bores may vary... only way is to slug the barrel to see what size you actually need... some would recommend that you do a pound cast to get good fit... as far as sizing down .003", I don't think that should be a problem at all... especially if you do it or air droppped(not water quenched) bullets before they age harden... but if they are a little too tight you could always lightly lube them before sizing... all of this is why I say I don't think there is a "right answer"... it all depends on the combination of variables.

Kindest regards,

TheMoose

[Bzcraig]

Have you actually slugged your bore or are you assuming a 308 groove? .002 over groove is very doable and sizing .002 is also doable in one pass whether with lube sizer or push through. If the mold you're looking at is a Lee, they often run at or below the stated diameter so I think you'll be fine.

[Bear foot bowhunter]

No . is a rolled 00buck suficiant to slug it ?

[Yodogsandman]

Yes, it's practical to size down by .003" but, you shouldn't have to. The boolit needs to be sized to fit your chambers throat, .001"-.002" over bore groove diameter. You find the measurements by doing a pound slug of your chamber (see below). The quick and dirty way is to measure the inside diameter from a case neck, from a case that's been fired in your rifle. Your size will probably be more like .310"-.311".

http://castboolits.gunloads.com/show...o-a-pound-cast

[lotech]

Try it; may work and may not. I've been sizing a .314" ww alloy rifle bullet to .311" for years and accuracy has been great, though I was surprised at initial results. I expected less.

[Loudy13]

I have loaded some 308 with Trail boss and it works pretty well, you can find the "Trail boss" recipe on line it is basically filling the case to a percentage of capacity and going from there. I wont state what capacity cuz I cant remember it right now but I know I looked it up and used it for 308 and 30-06 and it worked well. Trail boss is one of my favorite powders for 45, sub 300BO, -06 and 308.

[Bear foot bowhunter]

Sluged it came out at 7.83mm or 0.30826inch when i converted it

[Wayne Smith]

Lead with tin/antimony = buckshot in most cases. You will get some springback and not a true measure with it. Get a soft lead fishing sinker to do this. It won't move after it comes out of the chamber/barrel.

Then measure with a micrometer, not a caliper. Caliper threads do not have the sensitivity as mic threads.

Finally, as long as you fill the lube grooves before you size you should have no trouble sizing that much air dropped or water dropped if you size the same day as you cast.

[skeet1]

Bear foot bowhunter
I am curious as what you are doing and with what rifle you are doing it with? Are you sure you need to size your bullet down to .309"? I am guessing that it is some kind of .308" rifle. Just to let you know that some times it is not necessary to be that precise in sizing I would like to let you know that I shoot a .311" bullet in my 300 Blackout. The reason I use a .311" bullet is that I wanted a .310" but didn't have a .310" sizer so I went to .311". This rifle shoots very well with the 312-155 Lee bullet sized at .311".

Ken

[Kraschenbirn]

I currently own two .308 Remington; I size .310 for newer one (less bore wear) and .311 for the other (that's seen, at least, 7,000 rounds down the tube). Boolits for both are gas-checked and PC'd before final sizing. For your "modern" Remmy, I believe I start with a .310, leaving myself the option of opening it up to .311 if necessary.

Bill

[Bear foot bowhunter]

Awsom the buck round i was using was soft lead most are that are soled here as far as ik . arfter the initial few taps it almost pushed through . i did yuse a micromiter . its a remington 700 sps tac that i hardly shoot caus of ammo prices and most farmers wont alow me to hunt on there properties with it . im wanting to work up sub/reduced load for plinking mainly and see where i go from there .

[Hick]

I regularly use 32 caliber pistol bullets (lead alloy and moly coated) for plinking in my 30-30. They run 0.314 as purchased and I size them down to 0.309 in one pass with my lee sizer. Keep in mind, these are lubed already when I buy them-- that helps with the sizing. So, sizing is generally not an issue.