New barrel is on the way

[jtoews80]

Well, I have built a custom once before and was sorely disappointed with the results.

So, I went back to the drawing board and tried again. Ordered a 30" Pac Nor Super Match SS barrel with a 1-12" twist prefit for the 6.5mm RUM.

My objective is to be able to hunt coyotes at 800-1200yds with 142 SMK's or 140 Accubonds.

It's a Rem Sendero contour and polish finish, dies are from redding and the donor is a 700 SPS 300 rum. Still toying with buying a B&C A2 stock for it to get that great aluminum bedding rail, but that requires more funds for the vault and it ain't there right now. I am hoping to have it finished by the end of August, but it will be later if I have to wait for the barrel or order a stock. The barrel is at a depot and waiting importation.

JT.

 

[YoteSmoker]

I'm thinking a 1:9 twist would serve you better for the 140+ grain bullets. Either way it ought to scream!

 

[yeayow]

the bullets may be going real fast but i don't think 1-12" will stabilize 140gr. 6.5 mm

 

[Powerstroke]

JT,
SWEEEEEET ! :wink: I've always wanted to do one of them, but still looking at the 6.5x47 first.

Is there something different with the excessive over-bore etc that I'm overlooking? I'd have to go with the above as well and say at very minimum a 1 in 9 with a 1 in 8.5 or 8 even better for the 140/142 weight range ??

 

[onesonek]

I love my Pac-Nor's, but I too suggest going with an 8" twist. My Choice would be the 8" polygonal.

Dave

 

[Antelope_Sniper]

That sounds like alot of fun. I'll be interested to hear what kind of loads you work up for it!

 

[ACLakey]

I would opt for a faster twist as well. Here is a good guide to start with.

http://shilen.com/calibersAndTwists.html

 

[jtoews80]

I have a 1-8.5" poly 6.5mm barrel chambered in 264 win with a turn neck. It is a medium palma weight 31" and is a tackdriver. It's limited to 3050FPS, I can't seem to keep the pressure down on it. It has 100 rounds thro it and is limited to the velocities that my 26" winchester 70 would reach. With WC 860 and 868 I'm still unable to keep primers looking healthy or for that matter the bolt opening easily which tells me we are into serious pressure a ways.

I calculated the twist off of bullet RPM of a 6.5-284 with velocity @ 2950FPS in a 9 twist it is going 236,000RPM, same calculation leaves a 142 @ 3500FPS @ 210,000RPM. It might be a touch slow, but I have a supply of 130 grn Accubonds too, so if the 140's fail I'm pretty sure the 130's won't. They ought to go pretty good, considering I used to push them to 3300FPS in a 264 win :twisted: If I can get those to 3300, a RUM case should go 400FPS more.

JT.

 

[30-338]

I get on LR Hunting and Kirby Allen build the
6.5mm Allen Magnum it's off the 338 RUM case with 142gr bullets they claim 3550fps with 30" barrels and it's a Lilja 3 groove barrel and 3450fps with 27" barrel.

Lilja has the spec on those barrels.

I had a 8.5 twist in my 6.5x284 with 28" Hart barrel .290 neck so had to turn neck and I could run that over 3000fps using H-4831 with 142gr bullets. I'd pulled the barrel off appr 400rds and it was showing wear.

Hard to say on these twist anymore when you get to those longer barrels makes me wonder what a gain twist barrel do. Well good luck with your project.

 

[jtoews80]

I'll let you guys know when it is finally put togather, still going to be awhile. However, the waiting will soon be broken up by hunting insted of working most of the time.

JT.

 

[DrMike]

the waiting will soon be broken up by hunting insted of working most of the time.

Always a good thing! :lol: