barrel twists in .243 help.

[^varmints^]

Hi just wondering the barrel twists best to stablise lightweight varmint bullets in 243, like 58gr or so, would a .22-250 be as accurate as a 243 with the same bullet head, say 55 grains, i have heard of BC not sure if its relevant to varmint shooting? My intentions are long range varmint, apparently 5.5mm gets blown about more so than 6mm, im not sure , i may look at a factory sako or tikka, could varmint and shoot deer with 243 instead of another 22cf and a dedicated deer rifle. Just pondering

 

best regards

[happyhunter]

If you want a .243 for long range varminting use heavier bullets, 87-115grn if the rifle twist will stabilise them. With the lighter bullets no matter what cal they move a lot in the wind. Tikka/sako come with a 1:10 twist so will struggle to stabilise bullets over 95grn. On playing with a sako m591 varmint myself at the minute for this very reason, will be using 87grn v-max and once the barrel is done will get a fresh one on to stabilise even heavier bullets. The sako performs well with the 58grn v-max also.

[kent]

The .243 is a very fine long range varminter. In my experience there isn't much in it between a 22-250 and .243 with 55 grn bullets. The .243 really scores in times and locations exposed to higher winds were you basically sacrifice around an inch of drop at 300 for 1 1/2" of wind by stepping up bullet weights ( its easy enough to dial in the new zero ). For this reason I have never really thought of the 22-250 as a good UK choice were we are limited by licencing as its limited in its versatility ( a std .243 win will do everything from long range vermin to red deer). Most don't realise this but its a very capable long range paper puncher in a fast twist / long barrel, shoots great with top end 6mm bullets but the short life sort of knocks it on the head for many of us who cannot fit their own replacement barrels at the drop of a hat, case stretching also being a consideration. As for will it be as accurate? Well that's down to the individual gun, the load etc. but my current 1-10 shoots everything from 55 - 100 grn to such an extent that I cannot blame the gun. Generally I now like fast 55's when the wind isn't hard 70-87's bullets the rest of the time on long range and 95-100 grn for Deer. Using one gun a lot sure gives you an edge and you soon develop a gut feel for the dope without having to refer to data all the time

[gbal]

Hi just wondering the barrel twists best to stablise lightweight varmint bullets in 243, like 58gr or so, would a .22-250 be as accurate as a 243 with the same bullet head, say 55 grains, i have heard of BC not sure if its relevant to varmint shooting? My intentions are long range varmint, apparently 5.5mm gets blown about more so than 6mm, im not sure , i may look at a factory sako or tikka, could varmint and shoot deer with 243 instead of another 22cf and a dedicated deer rifle. Just pondering

 

best regards

If you buy a factory rifle,you will finnd that barrel twists are quite limited,but will stabilise 58 through around 95 grain-maybe 100-it can depend on the individual rifle as you approach all limits (including velocity etc-barrels just vary a bit within manufacturing specs). Generally the mid/heavier work out best-wid is more of an issue than drop-since you do not know the wind,but distance is easily determined-eg a laser.Wind varies-all you can ge is muzzle wind speed/direction.Not much in any of the varmint calibres to 250,but by 400 the 6mm have real advantages.Have a good look at balistic charts-BC does come into it,and is related to bullet weight/length-generally,heavier is better,but bullet shape (ogive) comes into it-but it's (BC) not a huge factor compared to misjudging the wind!Nor is +/_ 150 fps of velocity-within or between cartridges-and barel length isn't always equal-shorter is slower.(?25 fps/inch?).

22/250 is no less accurate than 243 ,and is a very fine 300 yard varmint cartridge.22 or 6 ppc will tend to be a little more accurate.Varies again betwen nominally the 'same' rifle-some are just a tad better. 6mm min for deer.It is perfectly possible to do all you mention with one rifle,but it means compromises.A heavy (barrel) will be better for varmints where you need maximum accuracy at distance (1/2 moa will just miss a crow at 400 yards often-the actual hitting circle is always more than just what the moa is-2 inches here--without even factoring in your errors of wind),You will want a good hi mag scope too-say 25x. For deer-if you are carrying it-ligter is better,and you don't need quite such accuracy,as distance will be 200yards or less,and less scope mag is better. (hence a variable scope).You need to make sure your ammunition is deer legal too-do not use frangible varmint bullets for deer-so you may have two different loadins-eg varmint and deer,which will typically not shoot to the same point of impact-though can be scope adjusted,I suppose.One bullet-say an 87 grain -may well avoid all this ,and be excellent for both (there was a time when there were no 58g 243 bullets).Most all factory rifles are capable of sufficient accuracy for purpose out of the box,Sakos seldom disappoint,and Tikkas are popular too. If you do decide on a second deer rifle,there are plenty used examples around at reasonable prices,and typically not that much used-though as ever,try it first-people's honest-if erratic-idea of accuracy can vary.Note finally,the varmint rifle (though not fox) needs repeatability-good grouping-the deer rifle needs first shot accuracy-you won't be firing 5 shots at the same deer,but the first must go close to where you need it.

 

george