Home Forums Hunting & Shooting Hunting Rifles 6.5x55 twist rate

I had been thinking about building a 257 Bob on a rifle I had until my friends boy found out that I was tearing apart a good rifle to do the build and decided he wanted to buy his first rifle from me and now I have nothing to build on. So now I am thinking of a new 270 or 6.5x55. The rifle will be a CZ 550 American Kevlar stock. I notice that the Swede has either a 1:9 or 1:8.66 twist depending what and where you look. If it does indeed have the 1:8.66 twist will this be sufficient to stabilize a 140 grain cup and core bullet if I did desire to shoot a bullet that heavy? Right now I will be trying 125 Partitions, 129 Hornady Interlocks,120 and 140 Speer hot cor's and maybe 100 TTSX's if my buddy will loan me a few. This will be a treestand rifle for deer with most shots being under 100 yards and most of those probably under 50. I am sure I will find satisfaction with something in the 120-130 grain range but don't want to regret dropping $800 on a rifle that is going to be very limited.

You'll be fine. I prefer a 1-8 but a 1-9" will do fine with CC's and a 1.866 mo better.

Built a Swede using 1:8 twist it's very accurate with 140gr bullets. Same for my Tikka with 1:8 - loves the 140gr.

If you contact CZ they'll tell you that the twist is 1:866. Interestingly enough, it's the same on the 7x57 they used to offer.

Anybody know if the CZ's have a long throat or if it is shorter allowing short bullets to be seated close to the rifling and still fit in the mag?

May also be interested in using the Hornady Interlock 140's. I am going to really have to start looking for "modern" loads for this cartridge. I noticed that Nosler seems to have more modern loads in their manual. Anybody know of any other good load data?

Same thing here. My Tikka is 1:8 and loves 140 grain bullets. It shoots them so well I've never tried another bullet.

Had Smith screw a Shilen 9 twist #2 contour barrel I bought from Midway USA to a DWM Mauser action, shoots the 140 gr Partitions to 2780 fps with RL-22 into near half inch groups.

As 'The Flave' says, I'm lovin' it.

Gunner

The only time a 6.5x55 with a 1-9 (or 1-8.66) twist might not stabilize 140's is with VERY long bullets such as the Berger VLD or Hornady V-Max, and even then a 1-9 will usually do OK at higher elevations above in "normal" temperatures. Any typical soft-nose spitzer such as a Hornady Interlock, Nosler Partition or Speer Hot-Cor will stabilize fine in a 1-9.

Just what I was hoping to hear MD. I may not need to shoot a 140 at deer but with my short woods ranges I may like the extra punch and ability to drive deep without over expanding at close range.

The website claimed 1:220mm twist (1:8.66") in 2005 when I purchased mine. Admittedly, I've never bothered to measure it.


+1

140g Remington CoreLokt, 140g Hornady Interlock, 140g Speer HotCor, 140g Sierra GameKing... obviously, some have shot better than others, but never an issue with stabilization.


The mag length is 3.150" and there has been a only a few bullets where I haven't been able to touch the lands and still fit at mag length (usually with room to spare).


Most all load data you find will be limited to 46,000 CUP (~51,000 PSI). You will find some data that is listed at 55,000 PSI (essentially the C.I.P. pressure standard). I know Ramshot does, or used to, list at 55,000 PSI. Speer shows a "military" 6.5x55 section and a "modern" 6.5x55 section. However, both Ramshot and Speer have reduced their loads in more recent publications...

My CZ shot all 140s fine although I never tried the bergers. It even worked great with 155 Lapua's but they are semi-points. The only bullet I tired that didn't stabilize was the 160 Woodliegh protected point but that was dumb on my part for even trying.