6.5-284 question

[Jonl]

I just put a 6.5 - 284 mcgowen barrel on a savage and my Berger book says coal is 3.2283 and my hornady book says max col is 2.80 . One is so long they won't chamber and the other is ridiculously short. My measurements to lands is 2.986 with 140 Berger140 vld. are these misprints or am I missing something.

 

[spclark]

This is a new barrel you bought? This kind of question makes me cringe a little.

The 6.5x284 Norma cartridge diagram elsewhere on this website shows a case OAL of 2.1701" so that can't be the short number you mentioned, while with an unidentified bullet the cartridge OAL is 3.283", within reason depending on chamber throat, seating depth and bullet choice.

If you haven't already you may want to go to:

http://www.6mmbr.com/SixFive284.html

- to read an informative (though a little dated now) essay on this cartridge. Included are load data from a number of shooters who do well shooting it.

I'd call McGowan & see what reamer / chamber specs they use. Factory load manuals are usually pretty conservative while also known to have an occasional error that escapes correction before publication. You can also cross-reference between multiple manuals to get a more complete picture.

 

[jonbearman]

The book numbers at least in most manuals are base to the tip of the bullet for box magazine clearance.Also your new barrel may be short throated but wont be for long as this is a barrel burner and it will soon move the lands out of touch with your original calculations.

 

[jonbearman]

Go to the mcgowenoutletstore,com and you can access the print right on the barrel selector column.

 

[wiuprof]

The Hornady manual's test firearm was a TC/Encore Custom barrel. In their description, they note that it had a very short throat.
"Our own test rifle had a very short throat. A shorter barrel with this shorter throat produced lower test velocities."

 

[HFV]

Have friend w/6.5-284. He shot it just yesterday,,, 3 ea. 3shot groups @100yds. .040" off lands,,, .080" off, and .120" off. Largest group was .416",,, .040" off,, smallest group .270" ,,, .120" off. He has been shooting .6's .5's and .4's on and near the lands... Remington action,,, old w/slick bolt knob,, Kreiger, 1-9 twist,, in Rem Varmint Taper,,, 25" long... He luvs it,,, and says OOOOOH to be Damned"""

 

[wapiti25]

The 2.800" is the length for a short action Rem magazine. This length would only apply if you had a short Rem action and wanted to feed out of the magazine. Load the rounds to fit your rifle barrel unless you need to feed out of your magazine which may force you to seat shorter than the barrel chamber. Short chambers/tight barrels is why you start low and work your powder charge up for each rifle and barrel. When you change components (brass, bullets, primers, and powder lots) you should back off and work up or sooner or later it will "bite" you.

 

[C. Collins]

Are you measuring the chamber to the ogive or the tip of the bullet?