• Frank's Lesson's Contest

    We want to see your skills! Post a video between now and November 1st showing what you've learned from Frank's lessons and 3 people will be selected to win a free shirt. Good luck everyone!

    Create a channel Learn more
  • Having trouble using the site?

    Contact support

243 Win Barrel length

trailrider121

Sergeant
Full Member
Minuteman
Oct 31, 2009
978
28
50
Santa Maria,California
I'm currently working on a Savage 243 win for varmint and targets. I plan to use a 26" 1:8 twist barrel and 105 amax to play with. Anyone know if theirs a big difference in barrel length? Say 26" to 22-20" barrel? I plan to shoot out to 800 yards for fun.
 
Re: 243 Win Barrel length

From 22" to 26" there's probably 80fps difference in velocity.


I use 22" barrel for my 243. Ive used a 26" with 243.
I once thought it was stupid to give up velocity in a cartridge like a 243.

I was wrong.

Its still a ballistically AWESOME cartridge at 22".


A rough estimate I use is 20fps per inch of barrel after 21".

Several tests done by others have confirmed this. I cut a 308 down to 20" from 26" and found the 20fps per inch "rule" to be true as well.


Im a huge fan of 20-22" barrels, for most practical cartridges.(impractical being like a 7RUM)




Oh and you might check out the 107 SMKs too. Every powder type and charge weight Ive tried behind the 107s has shot great in my 243. OAL doesn't seem to matter either with them in this rifle.
 
Re: 243 Win Barrel length

Theres a thread in gunsmithing about taking a 36" barrel and cutting it down inch by inch or 2 inch by 2 inch and recording velocity.

There's mention of a test done with a 300wm. From 21" to 27" only 125fps was lost in a 300WM. Ill trade 6" for 125fps any time!



Only drawback to a shorty barrel in my opinion is muzzle pressure.

Muzzle pressure can climb quite a bit from 26" to 20". But with a good crown and fast twist rate like everyone here uses, that muzzle pressure is nothin to worry about.
 
Re: 243 Win Barrel length

Thanks Keith for the great info. I heard lots of good reviews with 308's but wasn't to sure about a 243. The barrel is coming 26" long, if I dont like I'll cut it down to 22" or so. Not much fps lost for 4" less barrel. Muzzle blast will be louder for sure.
 
Re: 243 Win Barrel length

I just had a .243 Ackley built using a 26" Lilja 3 groove 8 twist. It's throated for 105 AMAX bullets. I'm sure I could have had it made shorter but 4 inches of barrel isn't going to make much difference in the weight. The gun goes about 14 pounds as is and I'm not crawling through the bush with it. It has a nice ballance to it the way it is.

It shoots in the mid threes.
243AItargetsa001.jpg
 
Re: 243 Win Barrel length

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rock Tucky</div><div class="ubbcode-body">That group isn't .272" either. </div></div>
WHY YOU SAY THAT?? LOOKS LIKE .272" GROUP TO ME.
 
Re: 243 Win Barrel length

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">There's mention of a test done with a 300wm. From 21" to 27" only 125fps was lost in a 300WM. Ill trade 6" for 125fps any time!

</div></div>

Interesting. I was under the impression that the loss/inch was significantly greater for magnums or larger powder charges.
 
Re: 243 Win Barrel length

Well I cancelled my ER shaw barrel, and pick up a almost new Shilen 243 win 26" varmint contour barrel in 1:8 twist. So I'm going to shoot it with the 26" barrel then plan on cut it down to either a 20-22" barrel to make it handier.

If only 80 fps is loss, I'd be happy. It will be a nice varmint / deer rifle.
 
Re: 243 Win Barrel length

I believe the faster twist rate is needed to compensate for the shorter barrel length. For example the 18.5" XM3 uses a 10 twist vs the 24" M40 and M24 with 11.25 twist. Not 100% on this, just an observation.
 
Re: 243 Win Barrel length

Velocity is the 243's saving grace. 40/50 FPS is a significant drop.

I went 28 inch to get the best velocity and give me room to cut and rechamber the barrel to get more use out of the barrel and increase its life span.
 
Re: 243 Win Barrel length

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 105amatt</div><div class="ubbcode-body">Is a 7.7 twist to fast for the 105 A-Max at 243 Win velocities?

Thanks,
Matt </div></div>

I am running a 25" Brux in 7.5 twist and getting 3038fps with 107SMK and 3045 for the 105amax. My rifle is chambered for the 115DTAC but it shoots less then 1/4 MOA with either of these so I will probable run the amax.
I am running around 41.5 or H4350 in lapua sparked by a FGGM primer, seated about .015 off the lands