I have a Dtech Valkyrie Shilen Match Select Upper that has a 1:6.5 twist. It appears that most of the manufacturers are settling on the 1:7 twist as the standard. I want to ultimately get a bolt gun in the the Valkyrie configuration - (old fashioned shooter who likes bolt actions for long range shooting!), but am wondering about the best twist rate for shooting a wide range of ammunition. Any reason to try and get a barrel with a 1:6.5 twist versus just staying with a 1:7?
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Ideal Valkyrie twist rate
- Thread starter prairiefire
- Start date
I would get a 6.5 twist if I just wanted to do everything I could to try to blow up bullets.
Things in red "MAY" start to cause issue with bullet integrity for lead-core copper-jacketed construction:
-Nate
Things in red "MAY" start to cause issue with bullet integrity for lead-core copper-jacketed construction:
-Nate
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I guess I should say more.
IF:
--I wanted a short barrel;
--I intend to use the rifle mostly at temperatures below freezing,, and maybe in really bad weather;
--I wanted ONLY to run the 90 grain bullets;
--I found some random steel-core bullet that was way heavier than normal AP;
--I wanted to run some random monolithic solid and "over" stabilize it for ELR trans-sonic transition...
...then maybe I'd run a 6.5" twist Valkyrie.
Other than that, 7.0 or LOOSER is the word, in my mind.
IF:
--I wanted a short barrel;
--I intend to use the rifle mostly at temperatures below freezing,, and maybe in really bad weather;
--I wanted ONLY to run the 90 grain bullets;
--I found some random steel-core bullet that was way heavier than normal AP;
--I wanted to run some random monolithic solid and "over" stabilize it for ELR trans-sonic transition...
...then maybe I'd run a 6.5" twist Valkyrie.
Other than that, 7.0 or LOOSER is the word, in my mind.
I'm not talking about 7, and since when was the gubment testing .224 Valkyries with light bullets? Or ANY bullets?
Jesus Ryan, quit talking in veiled bullshit.
Jacketed match bullets can start seeing integrity issues as low as 325,000 rpm.
You SOUND like you're talking about 5.56--an area I have quite some experience with--and equating it to Valkyrie. Not the same thing at all, but you refuse to clarify or cite.
At the speeds a longer Valkyrie is likely going to generate with hand loaded casings, that extra half inch tighter twist may make a really big goddamn difference.
My LR and Palma barrel is an 8-6.6 progressive, and it's great. I NEED that twist rate because I FILL a couple of those boxes I listed up there: short barrel + only 90s. It's also only a .223.
So no, the chart has nothing to do with cartridge specificity per se, but the way it is USED can certainly help with cartridge selection, barrels, bullets...
It's not perfect and it isn't gospel, for one because some bullets are tough and some barrels are polygonal, but it's a far sight better than 'because I think so, and the Army said it works in 5.56'.
Jacketed match bullets can start seeing integrity issues as low as 325,000 rpm.
You SOUND like you're talking about 5.56--an area I have quite some experience with--and equating it to Valkyrie. Not the same thing at all, but you refuse to clarify or cite.
At the speeds a longer Valkyrie is likely going to generate with hand loaded casings, that extra half inch tighter twist may make a really big goddamn difference.
My LR and Palma barrel is an 8-6.6 progressive, and it's great. I NEED that twist rate because I FILL a couple of those boxes I listed up there: short barrel + only 90s. It's also only a .223.
So no, the chart has nothing to do with cartridge specificity per se, but the way it is USED can certainly help with cartridge selection, barrels, bullets...
It's not perfect and it isn't gospel, for one because some bullets are tough and some barrels are polygonal, but it's a far sight better than 'because I think so, and the Army said it works in 5.56'.
I will tell you for 100% certain that Emil Praslick advised me against using the 90 Sierra at 1,000 yards. This advise was given due to the issues he had with his soldiers at the AMU getting all (or even MOST) of the bullets to the target...
In only 5.56x45. (Not Valkyrie)
Way over SAAMI*.
Through only 20" barrels.
6.5" twist cut barrels.
*Yes, this is an assumption. Civilians found, upon punching out the primers of all that giggity-free LC brass from da dumb AMU...that most of the pockets were blown on one firing. Army. SAAMI.
Sherri also tried a 6.0" twist once I believe. For those that don't think 1/2" would matter...well, most bullets wouldn't stay together so Mid scrapped it.
All of their experiences and others along with my own is what led me to say what I did about a 6.5" twist Valkyrie...a cartridge that can do at LEAST 100 fps more than my cartridge and will likely be using 2-6" longer barrels than me when everybody actually gets this new thing sorted out.
-Nate
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Just a side note, but that chart seems to match (linearly) some experiences I've had with a 9 twist 17 caliber rifle. Thin jackets and high rpms had some of the bullets becoming puffs of gray about 50 ft from the muzzle. The bullets literally spun themselves apart. These were 20gr VMaxes hitting close to 4200fps...
I don't know what the Valkyrie is capable of for speed, but I have shot 90gr vlds in a 22" 22-250 at 2800-3000fps in a 1:8 twist rock Creek and they're stable and accurate past 1200.
I would likely try 1:7 personally.
I would likely try 1:7 personally.
Really? I have a 1:8 22-250 that flings 75 ELDs at 3380 fps, but shied away from heavier due to not having 1:7.....maybe its worth giving them a whirl anyway?
Yeah It had a 1:7.7 bartlein on it that wouldn't shoot unless I downloaded to like 2850fps max (don't know why). 1-1.5 MOA at 3000-3100, so I tried a rock creek 1:8 and it's shot the lights out since. Load I settled on throws 1-hole groups @ 3005fps avg. Turned the Bartlein into an AR-15 barrel.
