dwight

First of all, if you have the barrel handy, you can measure the twist yourself, rather than wait for answers as to what might be the twist. If you have a cleaning rod and fresh brush, run that thru the bore until you just about get to the muzzle. Make a mark at top dead centre on the cleaning rod just where it comes out from the back of the action or rear of your bore guide. Pull the cleaning rod back towards you, making sure it doesn't slip(it needs to freely swivel in the twist) until that mark is again top dead centre. Measure along your cleaning rod from that mark to the back of the action or bore guide, wherever you made your initial. That is your twist rate.

 

Second. If a bullet is stable at 100-150yds, it's not going to lose stability in the next 100-150 yds. There's probably some other reason.

 

a 10 twist is the absolute minimum I would use for many of the 100gr projectiles in 6mm/243, and who knows how close to 10 some are using in factory pipes unless you measure it yourself..Better to use faster than 10 if going to the heavy end of the spectrum of 6mm bullets. The reason Remington and the like would use 10 twist is because they are more prone to consider 85-90 ish grain bullets as the heaviest, aren't making rifles for the UK market. I've seen enough difference in group diameters versus twist rates that anyone asking to rebarrel the 6mm for deer would get a recommendation of faster than 10 twist.

 

JR

Thats just too easy...lol

Why didnt i think of that method

Dwight

 

It could be that or that the bullet is simply running out of steam at that range if its spot on at 100yds

 

If you look at Federal ballistic charts the 243 100g bullet drops around 6" to the 250 mark

 

It`s probably best to put up some targets at various ranges to work out the drops.

 

If the bullet is unstable at longer ranges you`ll see the keywholing

Thanks mate..

We`ll give it a go

The reason i posted this question was because my friend shoot deer with his heym 243 using 100gn fed powershock.we recently did a bit 100yd target shooting and it shoots spot on to 100..

He said to me that when out deer shooting deer to 100-150 is no bother but any further out than that is more often a complete miss.

Last thurs we were both out shotting deer and we spotted one around 200-220 out and he asked my for my rifle(6.5x55) to take the shot as he has taken shots at this range before with the heym and had total misses.He took the shot and was bang on for a heart lung.

So what im thinking is that the 243 100gn is losing stability beyond the 100-150yd range...I could be wrong.It might just be him.

If a bullet is unstable at what range would it be noticable..

Dwight.

Hi there

Can anybody tell me the twist rate for a heym sr 21 .243.. Is it able to stablize a 100 gn bullet?

Thanks

Dwight