instock 30 cal 1:8 twist barrel

jpgolffl

Sergeant of the Hide
Jun 21, 2017
863
293
63
Tallahassee, FL
#4
OK, thanks! look for a blank for a 26" barrel.
Not sure what caliber you are doing but I went with a 9 twist rock creek for my 300 Norma. I was dead set on 8 but after reading frank talking about his 10 twist having zero issue with the 230s and some people having issues with 8 twist I figured The slight gain on the rock creek 9 would be perfect. Just finished putting it together so I should know tomorrow!
 
Oct 29, 2017
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#5
Not sure what caliber you are doing but I went with a 9 twist rock creek for my 300 Norma. I was dead set on 8 but after reading frank talking about his 10 twist having zero issue with the 230s and some people having issues with 8 twist I figured The slight gain on the rock creek 9 would be perfect. Just finished putting it together so I should know tomorrow!
300 norma mag improved. I was looking at the 230 sierra's and they recommend 1:8.
 
Last edited:

bjay

Private
Oct 19, 2009
3,606
229
63
Aloha state HI
#7
I read a ton on it and the consensus from most who have a lot of experience with them said even a 10 twist was fine for 230 class bullets. @bjay has done a ton with 300 imp. He has built a couple I believe.
I built 6 improved version 300nm 4 diff reamers..been tweaking print here and there my last one @Dave TOOLEY helped me out..
When i ordered my other barrel trough bartlein 5R frank (lowlight) said the 8 is bit too much.i called sierra to confirm the required twist.they insist to do 8 twist coz 230smk is bit longer than 230hyb but if 230hyb can survive the 10T without issue me and frank didn't think 1/16 oal diff need 2 more twist.my 9 twist is plenty enough.other barrel is gain twist 9.25-8.5
Cant seems to see any diff.
By the way when i asked sierra what distance they're testing 230smk they said 300yards...IMO youll need longer distance to really see whats happening with the bullets
 
Oct 29, 2017
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20
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#8
300 norma mag improved.
I built 6 improved version 300nm 4 diff reamers..been tweaking print here and there my last one @Dave TOOLEY helped me out..
When i ordered my other barrel trough bartlein 5R frank (lowlight) said the 8 is bit too much.i called sierra to confirm the required twist.they insist to do 8 twist coz 230smk is bit longer than 230hyb but if 230hyb can survive the 10T without issue me and frank didn't think 1/16 oal diff need 2 more twist.my 9 twist is plenty enough.other barrel is gain twist 9.25-8.5
Cant seems to see any diff.
By the way when i asked sierra what distance they're testing 230smk they said 300yards...IMO youll need longer distance to really see whats happening with the bullets
What have you been seeing for velocities and what powders seem to work best?
 

bjay

Private
Oct 19, 2009
3,606
229
63
Aloha state HI
#9
What have you been seeing for velocities and what powders seem to work best?
Unicorn N570 will never get to hawaii (ever)
Ive heard its the best for this cartridge it gives clean burn stable and 99% fill.
Ive tried imr7977 for 210 and 215 (imo bit too fast)
H1000 with 215 85-88gr 3150 24" proof 1/10 very accurate.
230 and retumbo rl33 3100-3175 29" barrel
Rl33 gives the most fps before getting pressure signs.BUT taking my pet load to diff places diff temp..im loosing 35+55 fps from my dope average.temp sensitive and IMO its very dirty powder..SS muzzle brake started to corrode 2-3 without cleaning and its inside gun safe..
If your following Ryan pierce at FB his first 300nm he built for himself shooting .1moa is my reamer...this cartridge is VERY accurate if you build it right
 
Oct 29, 2017
170
20
18
#10
Unicorn N570 will never get to hawaii (ever)
Ive heard its the best for this cartridge it gives clean burn stable and 99% fill.
Ive tried imr7977 for 210 and 215 (imo bit too fast)
H1000 with 215 85-88gr 3150 24" proof 1/10 very accurate.
230 and retumbo rl33 3100-3175 29" barrel
Rl33 gives the most fps before getting pressure signs.BUT taking my pet load to diff places diff temp..im loosing 35+55 fps from my dope average.temp sensitive and IMO its very dirty powder..SS muzzle brake started to corrode 2-3 without cleaning and its inside gun safe..
If your following Ryan pierce at FB his first 300nm he built for himself shooting .1moa is my reamer...this cartridge is VERY accurate if you build it right
Good to know. Ryan Pierce is the one building my rifle actually.
 
Oct 29, 2017
170
20
18
#11
J
Unicorn N570 will never get to hawaii (ever)
Ive heard its the best for this cartridge it gives clean burn stable and 99% fill.
Ive tried imr7977 for 210 and 215 (imo bit too fast)
H1000 with 215 85-88gr 3150 24" proof 1/10 very accurate.
230 and retumbo rl33 3100-3175 29" barrel
Rl33 gives the most fps before getting pressure signs.BUT taking my pet load to diff places diff temp..im loosing 35+55 fps from my dope average.temp sensitive and IMO its very dirty powder..SS muzzle brake started to corrode 2-3 without cleaning and its inside gun safe..
If your following Ryan pierce at FB his first 300nm he built for himself shooting .1moa is my reamer...this cartridge is VERY accurate if you build it right
Just dropped off my stuff to Ryan today said he is going to chamber yours and mine at the same time lol
 
Oct 29, 2017
170
20
18
#14
What!!! No way Ryan's machine is set up to do zero run out chamber per day only.i hope mine goes on the machine first lol
Luckily he is about 2 hrs away from me. I will have to make a road trip with some beer, haha

We must have the same taste for actions because we both picked a defiance lol