I know the 6.5x55 earns its keep with the 140 grained, high SD bullets.

However, I read that most 6.5x55 rifles have a twist rate that inhibits them from shooting smaller bullets at high velocities.

I only ask bc I was hoping my 6.5 could occasionally be used with smaller bullets at speeds of around 3,000 fps (that way I have no need for a small long distance rife).

Does the twist rate in the cz rifles inhibit this, or compromise accuracy?

you can shoot 100 grain hollowpoints and 85 to 90 grain varmint bullets out of a swede. varget is the powder that works best for me in that situation.

-Matt

I have a CZ that I am getting 3,000+ with the 120 ballistic tip using either 4350 or RL22. Accuracy is definitely sub MOA. Used that load on Antelope with good success.

The twist rate in that rifle has nothing to do with inaccuracy of light bullets. That is another internet wive's tale, much like the one of needing a faster powder for a shorter barrel given guns in a like chambering.

I've enjoyed terrific -- make that surgical -- accuracy with the stubby 85 grain Sierra HP in a number of 1:8 Swedes and even in a 1:7.5.

Load 'em up and enjoy them...

Loading some 100's right now.

Setting up a load that matches impact point of my 160's.

So I'll have 2 loads at the same 100yd aim point.

Though the little carbine is capable of much longer ranges, I've adopted it as my short yardage stalker.

Having some lightweights in my pocket for the crows and other varmints is a habit .

My steyr Prohunter in 6.5x55 shoots the 85gr very nicely with the Hybrid 100 powder. Haven't chronied the load but the data suggests it to be well over 3000fps at max load. FS

Twist rate does indeed have an adverse affect on the accuracy of some light weight bullets and is not an "internet myth". Specifically referencing your question on the 6.5 Swede. The Sierra 85 and 100 gr HPs shoot well at higher velocity. I shoot the 100 HP at 3200 fps out of my Swede with excellent sub moa accuracy and devastating results on varmints.

However the thinner jacketed Hornady 100 gr SP is another story. At 2950 - 3000 fps the RPM begins to spin the bullet apart and accuracy goes south quickly. At 3100+ fps some bullets come apart 40-50 yards in front of the muzzle. I've not used the 90 gr VMax or TNT so perhaps others can comment.

The adverse affects of high RPM holds true with SX and Blitz type bullets in faster twist .22 CFs.

Larry Gibson

Larry Gibson wrote:
"Twist rate does indeed have an adverse affect on the accuracy of some light weight bullets and is not an "internet myth". Specifically referencing your question on the 6.5 Swede. The Sierra 85 and 100 gr HPs shoot well at higher velocity. I shoot the 100 HP at 3200 fps out of my Swede with excellent sub moa accuracy and devastating results on varmints.

However the thinner jacketed Hornady 100 gr SP is another story. At 2950 - 3000 fps the RPM begins to spin the bullet apart and accuracy goes south quickly."
-----

Larry-

May I suggest you actually section a Hornady 100 grain SP. You are completely off base here. The Sierra 85 and 100 grain HPs are indeed varmint bullets. The Hornady 100 grainer is NOT. It is a medium game bullet and serves that purpose quite well, I might add.

I have used it at 3400+ fps in a 1:8 barrel 6.5-06 and never, ever had a problem.

We are not talking .22 CFs and the Blitz and SX here. We are specifically speaking of 6.5mm projectiles.

As I have said before and will say again: Within reason, you can't overstabilize a projectile. But you can certainly UNDERstabilize one.

Back to that 100 grain Hornady:

Larry, there are a number of guys on the board here who use it in the 3300 fps range for deer and antelope. They have no issues with it, either.

If Seafire is around, maybe he'll chime in.

Larry,

I run the 100 grain Hornady SPs at 3350 to 3450 out of a couple of 6.5 mm's with one in 8 twists and even a one in 7.5 twist...

I have NEVER had a 100 grain bullet come apart at those speeds...and that is probably having shot 5000 plus of them at that speed...

In fact I have never had any 6.5 bullets come apart out of any of my rifles...regardless of bullet weight or MV...

85 and 90 grainers, can be accelerated at 3500 fps out of several of my rifles.. and still no problems...

if you have experienced something different, then I'd have to say that had to be a fluke...

if you have seen it regularly.. well then I don't know what to say... but in a lot of experience under my belt, I haven't seen it...

and not calling you a liar my friend...or trying to start an argument..I just haven't seen it...

quote:

Originally posted by Bobby Tomek:
The twist rate in that rifle has nothing to do with inaccuracy of light bullets. That is another internet wive's tale, much like the one of needing a faster powder for a shorter barrel given guns in a like chambering.

I've enjoyed terrific -- make that surgical -- accuracy with the stubby 85 grain Sierra HP in a number of 1:8 Swedes and even in a 1:7.5.

Load 'em up and enjoy them...

Funny you mentioned internet myths. I figured the myth was go with the fastest twist available, because it will shoot the light bullets and heavy too just as accurately.

I'm glad to have your report Bobby from your personal experience, because I would also like to shoot some lighter bullets sometimes in my CZ as well.

In my limited experience with twist rates and bullet weights, I noticed that my 280 with 9" twist shoots 154-160gr bullets far more accurately than lighter bullets. I also noticed that my other 280 with a 10" twist shoots bullets 140 gr and lighter much better than the 154-160 gr bullets. My tests were not extensive because I noticed what worked well in each rifle, and that's what I feed them.

Same thing with a couple of 338 WMs, the one with 12" twist shoots 200-225 gr bullets most accurately, and will shoot 250 gr well too, but the rifle with 10" twist drops off in accuracy very noticably with the lighter bullets, so again I just feed them what shoots best.

I've experienced the same thing with 30-06 in 10" and another in 12", and also with two 308s, different twists. I have come to expect those results, so perhaps I'm predisposed. I dunno, but those results were confirmed on targets at the range, predisposed or not.

Those limited personal experiences pretty much convinced me twist rate matters. I don't believe it's one size fits all. But there's always another persons experience.

Also in limited experience, about 15 years ago I got the bright idea of testing the fast vs. slow powder in a short barreled 35 Whelen that I still have. I loaded up a bunch of cartridges using a variety of powder shown as acceptable by the manual, then went out to a shooting range way out of town on a dark night. I lived in eastern Colorado at the time, and the place was way out, so as to not disturb anyone. Anyway I already knew the relative burn rate of all the powders, so I put on my hearing protection and held the rifle so I could see the fire ball. Shore nuff - the slower powder created the most fire ball, and the least was W748 and AA2460. Next I tried all the loads over the cronograph, and shore nuff again - the slower powder with the biggest fire ball, produced the least velocity and greatest variation, and all loads were a little below max per book. Of course it could all be chalked up to me being succeptable to interned myth, and being predisposed, I could have imagined the size of the fire ball, but I haven't yet been able to rationalize that damn cronograph.

KB

Yep, eyeballing those fireballs to determine if a powder is fully-burned a sure-fire exact science...

So, then, how do you explain that H4350 and a 120 grain Ballistic Tip produces some of the highest velocities from a 14" 6.5mm JDJ barrel? How does that explain that N160 consistently gives some of the highest velocities in AI-type wildcats based on the 30-30 case?

Coincidence? Or perhaps the bullets are riding the wave of that giant fireball...

In a Rem VLS .260, the powder giving me the best accuracy AND the highest velocity was H4350. 46 grains gave me 2975 fps from the 26" barrel. And do you know what load gave me the highest velocity and best accuracy from a 6.5x.308 built on an XP action with a 14" Shilen barrel? Yep, good ol' H4350. That same load -- with only the seating depth varied -- clocked 2,693 fps.

Also, I've never said twist rate is irrelevant; that would be ludicrous.

But far too many folks fail to realize that velocity is part of the equation -- and even some renown gun makers aren't as well versed on the subject as they should be. I've seen numerous instances when a minimum twist was recommended and used, something that later hampered shooting with longer bullets or standard bullets at lower velocities.

I also recall ordering a barrel blank directly from the maker, and the salesperson/tech tried his best to get me to take a 1:14 for the 6mm-.223 I was building -- that AFTER I told him the bullet weights I intended on shooting (primarily 80s with perhaps a few 85s but NOTHING lighter than 80 grains).

Told him I had a 1:14 I picked up in a trade and that is was borderline with the bullets I intended on shooting -- and that 3 other 1:10s I had did EXCEPTIONALLY WELL with those bullets.

To make a long story short, I went with the 1:10 and was pleased as punch when it grouped the 80 grain Sierra SSPs into teenie, tiny groups.

I've also had a couple of 1:8 .223 Rem barrels in Contender format, and they digested everything with aplomb, from the stubby 40 grainers up through the streamlined 75 grain A-Max.

No, there is no magical one-twist-does-all, but logical choices do exist.

Yea, I like the exact science thing, but I like fire balls better.

On that same 280 with the 9" twist, it shoots 175 gr bullets OK at 100 yards, but opens up a lot at 200. So much that I know it's not just me. I figured that the bullets just need a faster twist for the long shots, so I quit using 175ge bullets in that rifle. It shoots 160gr darn well at 200 yards. I don't have it here now, but I may fetch it soon, and try it again at the 300 range available to me now.

We can debate the twist rate thing, but I would rather not. I just write the experiences I've had. But of course I hope to have many more opportunities to test light and heavy bullets in various rifles and various twist rates. Hopefully I'll learn a little more along the way, and remain open minded about it too. Now ya'll have me curious about the 6.5x55 fast twist/light bullet thing. Gotta try it for myself.

I agree with you about velocity being part of the equation. Recently I ordered a 6.5 barrel from PacNor. The cartridge I plan on using through it, 6.5 Grendel, I think will be about like your 6.5 Bullberry in velocity. I had a tendency to argue with the fellows at PacNor (imagine that) when they recommended 8" twist. But they were patient with me as always, and I listented to their reasoning that the faster twist is better for the velocity I expected. I just figured they knew more than I do about it, and I could always step up to heavier bullets if that's what it takes to get the barrel shooting right.

Incidentally, I think the CZ in 7x57 has a twist rate faster than 9" - or 8.something. I'm gonna try some of those 175gr bullets in my CZ at 300 yards and see if they are accurate and stable.

KB

KB-

Also, sometimes it's more of a function of bullet design and quality in regards to the accuracy. To boot, some guns are finicky and may not shoot a particular bullet well no matter what the twist may be.

For instance, in a Van Horn full bull Encore barrel in 6.5x55 with a 1:9 twist, I started out by using some loads I had on hand to get a feel for the barrel's preference and began my testing at 200 yards. Even from a new, unbroken-in barrel, the first group with the Hornady 140 grain SSTs was not acceptable.

I could have passed it off as being a matter of twist as a 1:9 is on the fringe for 140 grain BTs.

But I didn't, and it turned out that barrel LOVED the 140 grain A-Max and the 140 grain GameKing (my go-to bullet for most 6.5x55 hunting). In fact, after all was said and done, the 140 grain GameKing ahead of 47 grains Re-22 would consistently produce 3-shot, 300 yard groups of 1.5" with conventional hunting loads.

Even with varied powders, seating depths, etc., that barrel was not fond of the SST, be it in 140 or 129 grain weights. Yet with everything else it would afford eye-popping accuracy.

As to bullet quality, certain Remington bulk bullets come to mind. You may get stellar accuracy with them at 100 yards, but as the range increases, the flaws of the bullet begin having a magnified impact on accuracy and make themselves known.

In a customized M98 in 6.5x55, the Rem 120s would give me groups virtually the same as -- and sometimes better than -- the 120 grain Ballistic Tip and 120 grain Sierra spitzer at 100 yards.

But as the range increased, the Rem groups would open up disproportionately while the others maintained their high degree of accuracy.

Yes, the Rems still gave me acceptable hunting-grade accuracy, but they could not maintain the precision the others exhibited -- and were far from the precision I demand of my own guns/loads. With that being said, however, I must point out that I am indeed very picky when it comes to accuracy.

Well, maybe Hornady has changed the 100 gr bullet since I test fired them some years back or I ran into a bad lot. I went through 2 boxes (smae lot) in 3 different 7.5" twist Swedes (one M96 and 2 M36s). I suspect that Hornady has beefed up the 100 gr SP. If you'll notice in their 4th Edition Manual they refer to it as a varmint and medium game bullet. However, in the 3rd Hornady edition and earlier they refer to the 100 gr bullet as an "exlosive" in the rather sedate 6.5x54 MS. I also see they show 3600 with the 9" twist barrels with the magnums. That makes sense to me as when they failed to give results in the Swede with it's 7.5" twis I shot the rest of them up at 3500 fps out of my 9" twist 6.5-280. One might not that the RPM out of a 7 1/2" twist at 3000 fps is the same as out of a 9" twist at 3600 fps.

Say what you will but I did in fact have several Hornady 100 gr SPs come apart down range at a velocity of 3150 fps or so (I was chronographing at the time) when shot out of the 7.5" twist 6.5 Swede. That velocity out of the Swede is cranking around 303,000 RPM. The .264 Winchester with a 9" twist pushing the same bullet at 3600 fps is only cranking 288,000 RPM. See the difference?

Perhaps it was a "fluke " or a bad lot of bullets (doubt Hornady would admit to that). However the facts remain the same. Now I too have fired thousands of 85 and 100 gr Sierras at 3500-3600 fps without a single problem in both 7.5 and 9" twist barrels. The fact is the Hornadys came apart at the higher RPM of the 7.5" twist barrels but not in the lower RPM but higher velocity of the 9" barrels.

One other thing to consider is the adverse affect that the obturation of the .264 bullet in the Swedes .266 groove depth might have on a particular bullet. That you can shoot that same bullet faster in a 8" twist with .264 groove barrel might mean the extra obturation might have something to do with it. It apparently doesn't adversely affect the 85 and 100 gr Sierra HPs but then they are different bullets than the Hornady 100 SP.

I suppose I expected this type of response. It is the same when the discussion of SX and Blitz type .224 bullets blowing up due to high RPM at higher velocities out of faster twist rifles. Some say it won't happen simply because it hasn't happend to them, yet. Guess that's what makes it a "myth".


Larry Gibson

Slightly off-topic but....

I had a modern 6.5x55 with a 1.9 twist and it would not stabalise the long Barnes X in 140 grains. They were hitting the target sideways.

When I fitted a barrel with a 1:7.5 twist the problem was solved.