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What is the std rate of twist for it,if there is such a thing. Need to know before I send my out to be redone.
til later
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Sako & Tikka use 1:16
CZ = 1:9.5 or 1:10
Krieger & L barrel makers say 1:12 or 1:14
1:12 is good, and I think 1:10 is better
Spot
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That's my concern! The twist rate for this thing seems to be all over the place. I'm thinking 1-10 or 1-12 also. Maybe some others will chime in. Guess I'll start me a poll on my note pad and see where I end up. Thanks,Spot!!
til later
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Some CZ's are 1:14 like mine, measured. Given a choice I would have probably said 1:10, but my 9.3X62 shoots fine. 1:16 seems a little slow to me, the Scandinavians seem to prefer rifling a little on the slow side, but I like their rifles and they seem to shoot well.
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I miss quoted.
Sako & Tikka 9.3 twist rates are 1:14
Remington uses 1:16 for the whelen but the custom makers recommend 1:12 or 1:14..
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Ken Waters in his 9.3X62 Pet Loads article (Handloader #155 Jan.-Feb. 1992) states his Husqvarna has a 1:16 twist but shot accurately. My Husqvarna 30-06's have 1:12 rifling as opposed to the 1:10 norm.
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No problem Spot! In general you weren't wrong as I have seen reload data with twist rates topping out as high as 1-16. THANKS Husqvarna! I'll put you down as 1-10 on my poll here. Weatherby did there early thirty cals. in 1-12 or 1-12.5 I believe,for some reason.
til later
Last edited by EZEARL; 03/23/08.
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As near as I can tell the original twist in the 9.3 x 62 from Germany was around 1 in 14.
I don't know what the optimum twist is. But if I was building a 9.3 I would likely go with a 1 in 12 just to make sure it stabilized some of the very modern long heavy bullets such as the 9.3 300 grain Swift A frame.
Something to also consider is. It seems like back in the early 80s I remember reading the US military conducted tests with the 5.56 in the M16 with various twist rates. And concluded the a slightly fast twist rate helped out on penetration tests. It could have been in NRA publications I read this.
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That test would kinda make sense as the bullet would be stabilized more and would maybe help keep it on a straighter track when penetrating. THANKS for the input! OK,that's a vote for 1-12. I'm bettin 1-10 or 1-12 is gonna be right and that's so close it won't matter.
til later
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Blaser does the 9.3 at 1-14 out of a 22" barrel. I don't have that barrel, but have heard it is extremely accurate. I would probably copy that.
Coop
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Jon Speed's Original Oberndorf Sporting Rifles reproduces a table of cartridge specifications from the Mauser factory c.1925 that shows the 9.3X62 twist as 360 mm (14.17" converted to English measure). A-Square used this twist in their barrel for the loads they developed to match CIP ballistics.
The .375 H&H standard twist is 12".
jim
LCDR Jim Dodd, USN (Ret.) "If you're too busy to hunt, you're too busy."
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EZEARL, I found this site. It may help. http://stevespages.com/page8e.htm
The Karma bus always has an empty seat when it comes around.- High Brass
There's battle lines being drawn Nobody's right if everybody's wrong
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The twist rate is determined by the LENGTH of the bullet and to a lesser extent the velocity...a heavier LONGER bullet needs a faster twist than a shorter bullet.
You need to determine what bullets you want to use, determine the bullet length then pick a twist that will stabilize it.
For the most part, the normal rates most rifle makers use are good ones to pick. If you are undecided about which bullet you want to use and might go with lighter bullets over heavier ones then a twist in the slower range, 16-18 range will work. If going with the heavier bullets then 10-14 range will work. I wouldn't go with a twist outside normality for anything except special target or varminting work, there are too many problems that can arise from doing things of this nature.
For the 9.3 cal at normal velocity ranges for all normal weights...250 to 320 gr...and 2100 to 2600 f/s...any twist from 14 to 19 will stabilize for normal hunting usage.
I'm building a 9.3x62 right now using a Lothar Walthar 24" #720 barrel, 1-14.2 twist. It will stabilize all the bullet weights I plan to use...mostly on the heavy side...286 to 320...but will also work with the lighter but longer 250gr Barnes TSX BT's if I decide to try them, and any weight RN or cast lead RN's I want to try.
As always...the rifle will determine what bullet it likes after you start load development as far as the highest accuracy is concerned.
For hunting accuracy...5 into <2"...any normally available for the caliber twist will do.
'Njoy
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My Husqvarna is 1:16 and stabilzes 286 gr bullets just fine.
My old pre-war Model 70 has a 1:14 Bauska barrel on it, and doesn't shoot any better than the Husqvarna.
Ted
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Blaser does the 9.3 at 1-14 out of a 22" barrel. I don't have that barrel, but have heard it is extremely accurate. I would probably copy that.
I have two Blaser 9.3x62 barrels, and both are one hole groupers with every load that I have tried.
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Dave,GREAT site,THANK YA!! I've got some 270gr Speers coming any day now. I'll use the formula and see what it says. Did a good bit of reading and rereading the past few days and it seems I was over the left field wall on this 1-10 to 1-12 twist guess. 1-14(or its metric equivelent)seems to be the norm in the factory rifles and most custom rifles. Speer #12 uses a custom Rem 700 at 1-10 but the next cartridge is the 9.3x74R in a Valmet 412S at 1-14. Maybe the 9.3's are VERY forgiving with twist rates. 1-10 to 1-16,anyone know of another caliber that runs with a twist rate variation that wide? Really APPRECIATING all the info/suggestions too!!
til later
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EZEARL, did you get the PM I sent yesterday? The reason I ask I posted something yesterday and it didn't go through. Dave
The Karma bus always has an empty seat when it comes around.- High Brass
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Ed Plummer of AHR recommended a 1-14 twist for my 9,3x62mm build. Said it would handle the 250gr. TSX on up through the 320gr. Woodleighs.
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The Karma bus always has an empty seat when it comes around.- High Brass
There's battle lines being drawn Nobody's right if everybody's wrong
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