Post by: hookr88 on February 05, 2010, 11:32:13 AM
Post by: JackOfAllTrades on February 05, 2010, 12:00:07 PM
-Steve
Post by: hookr88 on February 05, 2010, 12:37:09 PM
Post by: shaneman153D on February 05, 2010, 12:56:52 PM
That said, for single shots or bolt guns I seat my bullets to be ~.002" from the lands of barrel/chamber I'm loading cartridges for
-Steve
Sorry to hijack, but how do you measure this? Would you do the same for an auto? If not, why?
Post by: Intruder on February 05, 2010, 01:01:52 PM
Be very careful having significant variance from the published COLs.... seating and feeding problems can arise as well as pressure variances. Starting out, probably best to stay at or near specified COLs.
Post by: carpsniperg2 on February 05, 2010, 01:41:56 PM
Post by: hookr88 on February 05, 2010, 04:54:46 PM
Post by: Red Dawg on February 05, 2010, 06:13:46 PM
Post by: hookr88 on February 05, 2010, 07:16:52 PM
Post by: shaneman153D on February 05, 2010, 09:59:19 PM
The best way to find your true col is insert a bullet in some brass that has been shot but not re-sized. Color desired bullet with a sharpie. Put the round in your chamber and lock the bolt. When you eject you will most likely just get the brass so use a cleaning rod and lightly tap the bullet out of the chamber. Insert bullet into brass until you are all the way to your mark. Then you measure with a caliper. That is the length all the way to lands of the rifle. I like to back it off a bit from the lands but some like to be right on it. Sometimes it will fit in your magazine and sometimes it wont but that is where I start and compare to data in my reloading books. Your col will vary greatly with different bullets and it sometimes does take a lot of trial and error depending on your gun.
Thanks red dawg, I'll give it a try, but IIRC, with an AR, it won't fit the magazine so most guys load to mag length.
Post by: JackOfAllTrades on February 05, 2010, 10:52:14 PM
That said, for single shots or bolt guns I seat my bullets to be ~.002" from the lands of barrel/chamber I'm loading cartridges for
-Steve
Sorry to hijack, but how do you measure this? Would you do the same for an auto? If not, why?
A precision mic like this one will help you get that just perfect. https://shop.rcbs.com/WebConnect/MainServlet?storeId=webconnect&catalogId=webconnect&langId=en_US&action=ProductDisplay&screenlabel=index&productId=3186&route=C11J149
But Reddawgs method has been used by many reloaders for years.
Steve, thanks. I was looking at the specs from Sierra's reloading manual and getting ready to load Nosler bullets. Brian
If you're going to use Nosler bullets, use Noslers manual.
For an AR or other semi-auto, Load to max OAL listed in the book minus just a tad and load a few to function test. Once you know what functionsw well in your gun then load a bunch and blast some Yotes!
-Steve
Post by: fremont on February 06, 2010, 07:23:59 AM
Insert bullet into brass until you are all the way to your mark.Sorry to be dense, but this is where I get lost. What mark are we talking about?
Post by: Red Dawg on February 06, 2010, 07:27:35 AM
Post by: fremont on February 06, 2010, 07:36:39 AM
I have always done it this way. Take bolt out of gun. Drop desired bullet into chamber and have a friend hold it firmly against the lands with a pencil's eraser (a new pencil works best....long enough and no sharp point!). Run an appropriately sized wooden dowel down barrel and carefully mark it at the muzzle with a pencil when it contacts bullet's point. Remove pressue on bullet and tap out. Replace bolt and lock down. Run wooden dowel down again and mark at the muzzle when it contacts bolt face. The difference between those two marks is your max. COAL for that particular bullet. Then, there's the debate about how far off that max. length should you load.
This said, it's always best to confirm with reloading manuals. You also have the issue of magazine length.
Post by: Intruder on February 08, 2010, 02:43:06 PM
As many have pointed out specs don't always match guns. That's were figuring the COL (and subsequent seating depths) to achieve the best fit and potentially best accuracy for a particular gun comes into play. There are several methods for doing this, as folks have described. There are actually tools that help with this too.
This concept is similiar to why you'd fire form your brass... so it conforms to your guns chamber better. It may be out of spec when fire formed but it will often lead to more accurate loads.
Fire formed brass and COLs that are out of spec are essentially specific to a particular gun. If you full length size and stick to published COLs then the rounds would be considered usable in another firearm of the same cal.
Post by: Skinnyman on February 11, 2010, 09:55:18 AM
The new COL that you just found for your gun might not fit in your magazine, COL is too long. So load to your new COL and run a magazine full of ammo through (not firing it) to make sure it operates smooothly in your magazine. My 30-06 has a longer COL than the magazine will allow, but my 338WM it works just fine. If it is too long then keep slowly shortening the COL until it will run smoothly through the magazine.
If you use this method, you will get better tighter groups than using NAAMI published COL (at least that has been my experience). NAAMI is what all of the reloading manuals (at least the ones I know of) use to publish their measurements of cases.
Post by: C-Money on February 12, 2010, 09:16:43 AM