223- are there any disadvantages to a fast rate ?!

[Geek]

I have a Remington 700 in .223 with a 1 in 9 twist and I shoot 69gr bullets (Sierra Matchking) out to 600 yards. I use 25gr of Viht 140 (works in my gun, don't know about others) and load within COAL to fit the magazine.

[Blackstuff]

1 in 8 seems to be the sweet spot in my experience of .223. I have a 1 in 7 that patterns like a shotgun with anything lighter, sorry shorter, than 62gn bullets, whereas my first AR had 1 in 12 and didn't like the heavy stuff. I later got a 1 in 8 barrel and that was great with everything I put through it.

[billy_boy_2010]

1 in 8 seems to be the sweet spot in my experience of .223. I have a 1 in 7 that patterns like a shotgun with anything lighter, sorry shorter, than 62gn bullets, whereas my first AR had 1 in 12 and didn't like the heavy stuff. I later got a 1 in 8 barrel and that was great with everything I put through it.

Interesting thanks. I have agreed to buy a 1:9 twist gun today so I'm hoping it will shoot 55gr nicely and also allow me to shoot the heavier stuff if needs be.

I won't be doing any real target work so I'm not massively worried. But it seems a faster twist has very few disadvantages.

I have a Remington 700 in .223 with a 1 in 9 twist and I shoot 69gr bullets (Sierra Matchking) out to 600 yards. I use 25gr of Viht 140 (works in my gun, don't know about others) and load within COAL to fit the magazine.

Is that handled or factory ammo ? i went to a local gunshop and they didn't have anything heavier than 55gr.

I would hazard a guess that as the faster 1:240mm twist rate stabilised the longer bullets better it destabilised the shorter bullets slightly.

The Soviet military accuracy standard required of 7n1 sniper ammunition (148 grain bullet) allowed for no more than 1.24 MOA extreme vertical spread with 1:240 mm twist rate barrel but no more than 1.04 MOA extreme vertical spread with 1:320 mm twist rate barrels......a difference of around 19% between the two twist rates.

Length-wise a Soviet/Russian T-46-M tracer bullet is a fair bit longer than the standard steel-core LPS bullet with an average weight difference of only a few grains, around 146 grains for the tracer compared to 148 grains for the LPS.The B-32 armour-piercing incendiary bullet isn't a lot heavier at 160 grains but is a hoofing great thing length-wise, probably around a third longer than the LPS bullet.

Interesting. there there is a disadvantage to a fast twist rate- at least on occasion .

[Geek]

To answer your question, I am using handloaded ammunition.

[billy_boy_2010]

To answer your question, I am using handloaded ammunition.

Ah ok thanks. I will try and find some heavier factory ammo to try :)

[DaveB]

I have a Savage 110FP which I have had for 20+years with a 1-in-9" twist rate and it does well with everything up to and including 69 grains.

It has been known to stabilize heavier bullets but in order to do so, you have to drive them faster and that raises pressures.