can i go a bit bigger?

sniperman

hi all and seasons greeting,just wondering can i go a bit bigger on 223 ammo, have a rem 700 1 in 12 twist,was told im limited to 55 grain,and any heavier would keyhole,would like to try maybe 60+grain for long range targets,?thanks all....ps anyplace sell 60 grain 223 ammo?

yubabill1

I can't remember offhand, but I think 60gr is marginal for 1:12 - you may be able to use them, depending on the projectile length.

I think Hornady make a 60gr ballistic tip in 223.

The heavier bullet only shows an advantage at extreme range, you may actually get better results out to 300m with lighter bullets.

It's been shown that flat shooting in cals like 223 depends more on velocity than bullet weight out to around that range.

Heavier bullets help in the wind and retain velocity a little better at extreme range, but a lot of guys here will tell you that the 40gr ballistic tips are very flat shooting and devastating.

I like the heavier bullets, but as I rarely shoot over 150yds, they have no practical advantage for me, except that my favourite 64gr Federals hit like a train at that distance - I know the ballistic tips are devastating; I used nothing else for a year or two - but I just like to flip them over with sheer power. Absolutely pointless, of course.

Cass

I doubt they'll stabilise.

I have a 1:9 and a 1:12 and neither do well with 75gr. I've tried a couple that i can find and none of them group well enough to keep using. Also 75gr are the equivalent of say 215gr in 308 or 105gr in 243. So not just heavy, but at the upper end of heavy.

I've found 40 to 55 gr work best in 1:12 and 62 to 69 gr work best in the 1:9.

Kat1170

Sorry for going O/T but how does one figure out the twist rate of a barrel ???

Cass

There are two ways i use:

1. Check the manufacturers website. They'll usually have the info there.
2. The cleaning rod method.

The cleaning rod method is actually fairly accurate. Here is what you do:

• Get a cleaning rod.
• Put on a mop or other cleaning head. Something that engages the lands/grooves.
• Draw a line with a marker along the top of the rod for about 16 inches.
• Mark 16, 1 inch markers along this line. Crossways so you have a "ladder" effect.
• Place the rod into the bore of the rifle and push it about 3-4 inches down the bore while keeping the 16" line pointed as straight upwards as possible (to 12 O'Clock).
• Now slowly push the rod down the rifle until the rod does a full revolution and the line returns to an upward facing position.
• Make a note of the number of inches the rid has gone down the barrel. If its 8, 9, 12 then your rifle is an 1:8, 1:9, 1:12.
• All of this is measured from the back of the reciever. Where the bolt would "touch" when closed. Just make sure one of the inch markers is dead level with it when starting.
• Do this 2- 4 times to be sure.
• If the rod starts on inch marker 3 and ends on inch marker 15 then it's 1:12. IOW it doesn't have to start at the first one.