View Full Version : nosler cc w-canalure. c.o.a.l 2.230?
jedipatriot
08-04-13, 09:30
just got some nosler custom competition 77 grain hpbt with canalure from Midwayusa. when I seat the bullet to the top of the cannalure like I'm supposed to, the cartridge overall length is 2.230. my brass is trimed to 1.750". my question is, is 2.230c.o.a.l to short for an ar15? I thought heavy match bullets are always seated to magazine length. the Sierra manual list the 77gr smk at 2.260". I want to make these loads as hot as I can. with the bullet set so far back in the case will I get premature pressure signs? and most importantly will the accuracy suck?
This is the first I've seen of the Nosler 77s /w cann. Mine are w/o the can, so no direct knowledge here. But FWIW, both the Nosler and Sierra 77s are not finiky about COL. I load either anywhere between 2.250 to 2.260 and I've fairly sure I run some closer to 2.240 at times. I've never noticed any differences due to smallish changes in COL.
While I used to put a very light taper crimp on the Sierras, I quit soon after I switched to the Noslers. The rifles I shoot them in all have M4 feed ramps and they feed smoothly with no set-back (verified by loading dummy rounds and hard chambering ~3 times).
Personally, I would get them to about 2.240" and head to the range. Pressure with rifle bullets is much more dependent on getting them too close or into the lands than COL and case capacity.
I want to make these loads as hot as I can.Why? with the bullet set so far back in the case will I get premature pressure signs?No
and most importantly will the accuracy suck?
Shoot some and see, but I doubt it will suck.
Even thought the bullet being farther into the case will decrease capacity the bullet will have a longer jump to the lands, which should help keep pressure down.
jedipatriot
08-05-13, 17:09
thanks for the help guys. I just wanted a stash of ammo for shit hits the fan and hunting. Tac powder seems to be accurate with Max loads or close to max loads. my Daniel Defense has a lightweight barrel and accuracy does not seem to be all that great anyway. I'm a little disappointed but it's still a really nice rifle.
In your search for accuracy you went straight to max loads?
jedipatriot
08-06-13, 11:41
In your search for accuracy you went straight to max loads?
NO. I never start out with max loads. I worked up some loads with 69 gr smk and tact powder for my stag carbine and the accuracy was good with max loads and thanks to the tubbs carrier weight sys. No pressure problems with the way over gased stag. Just loaded up some test loads with the 77s I started "middle of the road" since I'm looking for a combat / hunting load. Ill keep my eyes peeled for ejector marks or the brite ring around the body. Is there any thing else I should be looking for???
Start somewhere safer, but you will likely find that max loads of TAC (24.0 per Sierra) will work very well with 77 gr SMKs. These (for me) were about 100 fps slower, but more accurate than BH red box Mk262.
I actually run them about 0.2 grains over this with the Noslers, and on a warm day I get around 2,750 fps with the chronograph. Accuracy fits my needs, but there may be better powders if small groups is the primary goal.
The BH Mk 262 load runs ~2,800 fps in my 18" SS Noveske barrel and shows excessive pressure, in my view - extractor marks moving metal off the edge of the rem. Hits on steel at 700 Meters were clearly inferior to my reloads, as well.
FWIW, my DD 14.5" pencil barrel shoots the 77s grain bullets very satisfactorily - somewhere around 2 MOA @ 100M for most with a Micro Aimpoint as the optic).
Trim your brass longer. I moved mine out to 1.756". Leaving a little more is supposed to improve accuracy. (probably too hard to measure though)
Trim your brass longer. I moved mine out to 1.756". Leaving a little more is supposed to improve accuracy. (probably too hard to measure though)
I wonder why that is? I've never heard of that before, so I'm gonna have to try it.
I wonder why that is? I've never heard of that before, so I'm gonna have to try it.
According to our bolt gunsmith... cartridges with more neck contact with the bullet are better. Not sure if it helps hold the bullet straighter or if it give the cases a better chance for neck tension consistency. ??
It's probably a bit of both Mark. Bullet jump issues, that Steve and I discussed for a bit a while back, come to mind. The more perfect the bullet enters the bore the better, and a short jump and longer neck should both help. At least it makes sense to me.
Time for a shoot, darr. Maybe Iraqgunz will come out and pose for pics and sign autographs if we beg him. :cool:
According to our bolt gunsmith... cartridges with more neck contact with the bullet are better. Not sure if it helps hold the bullet straighter or if it give the cases a better chance for neck tension consistency. ??
It definitely makes sense, but I bet it's pretty damn hard to measure with so many minute variables. I'm sure all of the benchrest guys know all about this. Where are they at?
Leaveammoforme
04-11-14, 03:08
Trim your brass longer. I moved mine out to 1.756". Leaving a little more is supposed to improve accuracy. (probably too hard to measure though)
I trim my super long once fired brass (cough, cough, LC) to 758. This cuts down on first trim time & I use that brass for non canalure bullets. I always thought of it as extra insurance against set back. But if there are actual benefits, I'll take it as a bonus.
thanks for the help guys. I just wanted a stash of ammo for shit hits the fan and hunting. Tac powder seems to be accurate with Max loads or close to max loads. my Daniel Defense has a lightweight barrel and accuracy does not seem to be all that great anyway. I'm a little disappointed but it's still a really nice rifle.
what kind of accuracy?2-3moa?
what range are you shooting?
hot does not equal accurate
try a different ammo/bullet weight maybe 75grain
my build shoots 77grn smk's better than 75's,my wife's DD shoots 75 grns better thsn 77 grn smk's
have you checked actual barrel twist rate
It definitely makes sense, but I bet it's pretty damn hard to measure with so many minute variables. I'm sure all of the benchrest guys know all about this. Where are they at?
That's where our guy's roots are. He knows a lot, but sometimes his beliefs are nuts too. His world is short range (compared to what we like to shoot).... so he's locked into light bullets for most applications.
The idea of shooting a 77 gr SMK is not even in his realm of comprehension.
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