PDA

View Full Version : My little project



SGT.G
12 December 2014, 15:13
So after having only mediocre results with standard oal hand loads I've decided to try something else.

Currently I get .3 to .4 moa with 77gn ncc bthp on top of 24.3 gn of n140. I know, most everyone will say that's a great grouping.

So I took my basic knowledge of oal and how far of a jump the projectile makes. I figured I could shorten the jump and possibly kiss the lands.

So I took one of many gi mags, cut the front, and measured for optimum oal. I'm now able to load to 2.336.

Now that I can have a longer oal my options have opened for a projectile with higher bc. Such as Berger vdl 90 gn, and hopefully work a load that will be accurate with the ability to hit 800 reliably.

http://tapatalk.imageshack.com/v2/14/12/12/2cdcee68a6a57911f9367e57a526f6b7.jpg

SINNER
12 December 2014, 22:06
You need a little jump to the lands. The single shot semi's and bolt guns with the possibility to touch the lands still run .5mm jumps. I doubt you can get long enough rounds through the magwell, but run your lengths too far and when you eject a unfired round the bullet will stick in the lands. Blowing up fire arms is never fun.

GaSwamper
13 December 2014, 17:05
Ahhh! Put a file to those edges man before somebody gets their hand sliced off! Did you cut that out with kitchen scissors? [BD] Sorry had to do it.

FortTom
16 December 2014, 20:09
SGT.G,
For what little it's worth, I've found, in bolt action hunting rifles, that the bullet just kissing the lands, almost always gave me best accuracy, of course counting the other factors such as load and primers. And I mean JUST kissing the lands. I used dykem to paint a dummy round, and set the O.A.L. out, a bit at a time until I could just barely see the land marks on the bullet. A majic marker works about as well, but I guess you probably know that.

FT

SGT.G
16 December 2014, 21:51
SGT.G,
For what little it's worth, I've found, in bolt action hunting rifles, that the bullet just kissing the lands, almost always gave me best accuracy, of course counting the other factors such as load and primers. And I mean JUST kissing the lands. I used dykem to paint a dummy round, and set the O.A.L. out, a bit at a time until I could just barely see the land marks on the bullet. A majic marker works about as well, but I guess you probably know that.

FT
Yea that's what I did with a Sharpe, took a while to get it right. I'm thinking about trying a few different lengths just off the lands as well as kissing them

SGT.G
16 December 2014, 21:52
Ahhh! Put a file to those edges man before somebody gets their hand sliced off! Did you cut that out with kitchen scissors? [BD] Sorry had to do it.
Lol kitchen scissors would have cut faster than the saw I had, was to cold to go outside to get one out of the garage.

Ordnance
16 December 2014, 22:07
You need a little jump to the lands. The single shot semi's and bolt guns with the possibility to touch the lands still run .5mm jumps. I doubt you can get long enough rounds through the magwell, but run your lengths too far and when you eject a unfired round the bullet will stick in the lands. Blowing up fire arms is never fun.

^^^ This...

I don't know where you're getting that you can't take a 77gr reliably to 800. Having a longer bullet doesn't guarantee a better BC or more stability either in a semi because you're limited by pressure allowances and a gas system that bleeds pressure as the projectile is traveling down the barrel. I've personally shot 77 SMK out to 905yd reliably in an 18" barrel. Everyone is also always trying to kiss the lands but I've had several firearms including one of my old 308 Semi's that rather than loading to 2.81 OAL it preferred 2.79 and my groups tightened up another 1/4". Also, even in some bolts you'll discover that off the shelf manufacturers like Remington have deep throats where it's near impossible to reach the lands even if you wanted to.