1:8" twist in a .308 Win. short barreled rifle - will it work?
- Thread starter Jayjay1
- Start date
Actually it is LE agency. This agency that has a history of controversy with some of their snipers.
He wasnt exaggerating the issues and I ran into accuracy and other issues testing a 1-8 gas gun for a govt tender.
Read some of his other post and its not hard to figure out for who.
The organization that uses CSR's is that public info who that is? Im curious and what is your opinion of the CSR?
Lots of solutions to rifle problems....twist is not always the answer.
For this problem....
The solution looks to be, Stop Reloading, buy Sig 175 ammo....
Yesterday, same...
Really? Quit? No sir! Yesterday the solution was, less velocity....I think 52.2 is Victory.
Its all in the details....
Find a speed that works with your twist and run it.
For this problem....
The solution looks to be, Stop Reloading, buy Sig 175 ammo....
Yesterday, same...
Really? Quit? No sir! Yesterday the solution was, less velocity....I think 52.2 is Victory.
Its all in the details....
Find a speed that works with your twist and run it.
Thats some really good first hand information and you answered the other question regarding the ax chassis vs the RACs chassis on the CSR.
Did you notice any spin drift worth writing home about with these 1-8 barreled rifles?
I appreciate you sharing your experience.
Did you notice any spin drift worth writing home about with these 1-8 barreled rifles?
I appreciate you sharing your experience.
Im not sure if that qualifies as solid experience....I mean a HAHO jump may raise an eyebrow but ever won the monthly 5x5 in the .22 Forum?
My factory DTA has a 16” 1:8 twist barrel.
I mostly shoot factory fgmm 175 and 175 TMK 175 handloads at 2450/2475 FPS. Never had an issue up to 1000 yards which is pretty much the max effective range for a 16” 308 as far as I’m concerned. Accuracy has always been in the 1/2” range at 100. Sometimes a little better, sometimes a little worse.
I also have 155 amax loads that do 3/4 moa and I’ve also tried with SMK135 for a coyote load and you could see already the accuracy was degrading - was a 1.5 moa group and I never bothered to chase load development since I switched to a dedicated lightweight 204 ruger for the coyote problem.
1:8 308 win does shoot subsonic like a dream. I get tighter SD/ES than my 300 BLK bartlein barreled bolt gun. I usually do trailboss and Lapua 200 fmjbt, 208 amax and 240 SMK for target and LeHigh 194 or Hornady 190 subX for very light game < 100 yards.
The 190 subX is extremely accurate at 1050fps but not as effective as LeHigh on game. The LeHigh 194ME is a bit more picky on seating depth but generally accurate up to 150 yards. The older LeHigh CF 174 was absolutely crazy on game but very hard to tune an accurate load.
They key to successful long range 308 subsonic is to have a long heavy bullet that's not a VLD so it's not picky on seating depth, then you need a powder that will be fast but also fill the case as much as possible, IMR Trailboss can give you a 80-95% case fill on most heavy 30 pills. And finally consistent neck tension. Add all 3s and you can get extremely accurate, single digit ES/SD, "long range" subsonic.
I mostly shoot factory fgmm 175 and 175 TMK 175 handloads at 2450/2475 FPS. Never had an issue up to 1000 yards which is pretty much the max effective range for a 16” 308 as far as I’m concerned. Accuracy has always been in the 1/2” range at 100. Sometimes a little better, sometimes a little worse.
I also have 155 amax loads that do 3/4 moa and I’ve also tried with SMK135 for a coyote load and you could see already the accuracy was degrading - was a 1.5 moa group and I never bothered to chase load development since I switched to a dedicated lightweight 204 ruger for the coyote problem.
1:8 308 win does shoot subsonic like a dream. I get tighter SD/ES than my 300 BLK bartlein barreled bolt gun. I usually do trailboss and Lapua 200 fmjbt, 208 amax and 240 SMK for target and LeHigh 194 or Hornady 190 subX for very light game < 100 yards.
The 190 subX is extremely accurate at 1050fps but not as effective as LeHigh on game. The LeHigh 194ME is a bit more picky on seating depth but generally accurate up to 150 yards. The older LeHigh CF 174 was absolutely crazy on game but very hard to tune an accurate load.
They key to successful long range 308 subsonic is to have a long heavy bullet that's not a VLD so it's not picky on seating depth, then you need a powder that will be fast but also fill the case as much as possible, IMR Trailboss can give you a 80-95% case fill on most heavy 30 pills. And finally consistent neck tension. Add all 3s and you can get extremely accurate, single digit ES/SD, "long range" subsonic.
Well, they're spread throughout all 50 states and US territories...
I’m lost now. They’re spread out? I thought someone was looking at 400+ rifles with the 8 twist. Maybe it was that 7 twist post.
I can think of so many three letter agencies that have more than one location that they operate out of. Go watch an action movie for some idea. FBI, atf, dea, irs etc
Actually I never thought about the subsonic theme.
So, by using a .308 Win with a 1:8 twist and a 18" long barrel, I actually could download the cartridge to subsonic and have kind of like a 300 BC round?
That makes it even more interesting, more options.
Anyway, I will take the shorter barrel with 1:8.
Thanks and cheers guys,
Jayjay1 out.
So, by using a .308 Win with a 1:8 twist and a 18" long barrel, I actually could download the cartridge to subsonic and have kind of like a 300 BC round?
That makes it even more interesting, more options.
Anyway, I will take the shorter barrel with 1:8.
Thanks and cheers guys,
Jayjay1 out.
Know someone who rechambered a Remington 1:7 twist 16.5” 300 blackout to 308. Shot amazing groups with 175SMKs. Cheers
Don't forget the Capitol Police now.........
Shoot very very well
and there are some theories that faster twist increases lethality
so it’s the ones that run around murdering unarmed women and children either standing in a doorway or fleeing a building they lit on fire.
It’s not the 90s anymore. Example people coming to support the bundys. That shit won’t play and when they dress up and play army they aren’t 1000s of miles and a ocean or 2 from home
Hi,
This thread is the perfect example of knowing or not knowing whom is replying, lol
Keep up the good fight guys, lol
@reubenski
@JustSendit
@phlegethon
@Skunk
Was there a recent YouTube or gun rag article on fast twist or something??
3 of the same threads in a single week...somebody must have "influenced" via social media or something.
Sincerely,
Theis
This thread is the perfect example of knowing or not knowing whom is replying, lol
Keep up the good fight guys, lol
@reubenski
@JustSendit
@phlegethon
@Skunk
Was there a recent YouTube or gun rag article on fast twist or something??
3 of the same threads in a single week...somebody must have "influenced" via social media or something.
Sincerely,
Theis
Hmmm, interesting observation. I don't keep up with YouTube or gun rags, but if Kate Upton comes out as a proponent for 8twist bbls I could probably be persuaded!
Hi,
Kate Upton?? You are showing your age, lol..
What's next....pics of every single USMC sniper rifle model ever used, topped off with original optics??
Sincerely,
Theis
Kate Upton?? You are showing your age, lol..
What's next....pics of every single USMC sniper rifle model ever used, topped off with original optics??
Sincerely,
Theis
Ditto that. Used to shoot FTR with a 1/12 using a Lapua 155g. With a 30" barrel had to scream them at 3050 MV to be effective at LR scores. Most everybody now shoots a 200g Berger with a 1/10 or 1/11 now in FTR.
Dude why the hate?
You just insulted my entire riflery existence.
I have a sad now.
Im trying though....I finally bought a 9mm pistol and haven't had any cravings for cock.
It's possible a Hoplite is in my future but I'd have to go TacOps, AI, than Hoplite in that order to ease into it.
Expecting she will be featured on MILF Monday in the Motivating Picture thread any day now.......lotion ready.
You guys have successfully broken my major rules, I think I am gonna go NO POLITICS 100% again as if you can; t keep politics out of the information section it all needs to go
Politics has no business in the information sections so those members breaking it will be permanently banned I am waking up from my slumber, cranky at what I am seeing is an understatement,
you were told to contain your politics to specific sections, clearly I was ignored
Politics has no business in the information sections so those members breaking it will be permanently banned I am waking up from my slumber, cranky at what I am seeing is an understatement,
you were told to contain your politics to specific sections, clearly I was ignored
Anyway, this is a timely thread for me as I was looking at picking up a shorty .308W barrel for playing with subs. Been experimenting with them lately and all I have is a 10-twist.
I have some 208-Amax and 220-round nose boolitz. Some 13.5 or so grains of Trail Boss is what it took to get them to abouts 1,050-fps. Seem stable (no keyholing) at 100-yds.
Been shooting some 175 and 220 Nexus rounds I bought and can hit steel at 300-yds with them, which is fun.
Patriot Valley Arms has several tight twist .308W barrels I can put on my TL3 which is what got me interested in the first place.
I have some 208-Amax and 220-round nose boolitz. Some 13.5 or so grains of Trail Boss is what it took to get them to abouts 1,050-fps. Seem stable (no keyholing) at 100-yds.
Been shooting some 175 and 220 Nexus rounds I bought and can hit steel at 300-yds with them, which is fun.
Patriot Valley Arms has several tight twist .308W barrels I can put on my TL3 which is what got me interested in the first place.
Does that bottom one come apart real quick all Jason Bourne like ?
Excessively high twist will degrade accuracy by increasing rotation, so if the bullets aren’t perfectly concentric there will be more asymmetrical forces acting on them (this is why benchresters use the longest twist that will still stabilize their bullets). And at longer distances, overspinning can prevent the bullet from turning to follow the downward arc of the flight path, which will lead to a decrease in effective BC. Everything in engineering is a compromise.
No, any .308" diameter bullet could use them. They stabilize heavy (long) bullets and they stabilize relative heavy (long) bullets at slow speed, i.e. subsonic.
Nothing is without cost. That’s all I’m saying.No, any .308" diameter bullet could use them. They stabilize heavy (long) bullets and they stabilize relative heavy (long) bullets at slow speed, i.e. subsonic.
I'd like to see the physics/math behind that..I may be misinterpreting your statement
Correct, but you will have cost either way. Use a loose twist and you will get better accuracy at close range from an all-out accuracy platform. Use that same loose twist at long range and you will sacrifice accuracy, if not stability as a whole. This is why long range rigs all have tight twists.
And while true about loose twists, bullets today are built much better than when I was a kid in the '70's. We used to be happy with concentricity down to .002". Now we have quality bullets with tolerances in the .0004". Those are affected a lot less by tighter twists.
Two factors, gyroscopic precession and CG. May or may not cause his phenomenon. With the right CG on the bullet, it won't be as much of an issue. But, the gyroscopic precession makes it want to hold the same attitude. I won't MAKE it hold the same attitude, just that the force of it wants to keep it at that angle.
Comparitively little though. Think about a shot that takes 60 moa holdover...that's one degree. The bullet isn't going to be hugely affected by that. Low density altitude will affect it more.
Well, there isn’t “loose” or “tight.” There are specific numbers involved here. Most people are using a twist that provides adequate stability for the bullets they are using and no more. This is true in short range benchrest and long range as well. Some people in this thread have decided that it must be fine to have a stability factor of 2.5-3 or more. There will be a cost to that and there is a reason why that is not a common practice.
Actually the terms "loose" and "tight" are standard jargon in the firearms world referring to the rates of twist of a rifle barrel. The OP is asking about getting a 1-8" twist. Because it's rotation is shorter than normal (1-10" or 1-12") it's called a "tight" twist. Michael Stinnett, who just set the world record @ 100 yds. a couple years ago used a 1-17" twist with short bullets. That's called a "loose" twist. But, since you want to play semantics instead of saying something useful, I'll spell it out for you.
A 1-8" twist in a .308" diameter cartridge, i.e. .300 BLK .30 Grendel, .300 Savage, .308 Win, etc. etc. can spin a bullet sufficiently to stabilize it at sub-sonic speeds. Why is that important? Because a bullet moving faster than the speed of sound (or any air around it) will cause a sonic "crack". Thus mostly nullifying the reason for suppressing a rifle. Even though "big" .30's use suppressors, it's more for the shooter and those around him. Big brakes and big guns without them are loud. Didn't know if you knew that, so I thought I'd clue you in. With today's tolerances in bullets you have a lot more stability at long range with a tighter twist. So why not get it and shoot heavier bullets?
Now moving to the idea of nudging the OP into a "loose" twist, remember that's more distance in the barrel of a single rotation. Just remember that your "specific number" isn't going to do shit-all for accuracy, UNLESS YOU BUILD AN ALL-OUT ACCURACY PLATFORM around it. The above mention all-out accuracy platform used to set the new 100 yd. benchrest record of .0077" in. is an example of the "tight"/"loose" twist bullshit gone out of hand. That twist was used specifically to shave off thousandths of an inch. Not many people can really do that. In long range, that isn't our goal usually. In LR BR, it is.
A normal long range rifle isn't even going to be able to compete at close range bench, because they use different bullets. And, the truism comes into effect here that those bullets, to stabilize, need that tight twist and it will cause a small variance. Not a huge one as some suggest. And good long range rigs are built to be accuracy platforms. Too often people apply your statement to a tupperware stocked Wal-Mart Rem 700's. Which is pointless. Because they aren't accuracy platforms.
I was going to post exactly this, although with a smaller sample size. I have one (16" 1:8 twist), have shot quite a few. Makes no sense in .308 with conventional usage, assuming usage of 150 to 200 grain bullets. Causes issues with certain bullet types, specifically bonded/hunting rounds which can just be way overspun exacerbating issues with inconsistent jacket sizes. It also introduces a TON of spin drift, if you are shooting at any distance exceeding about 400 yards. You can plan for it, and calculate it, but it gets irritating to remember that you need to add about 1/10 mil of spin drift per 100 yards because the bullet is arcing so aggressively in flight, due to being overspun relative to the bullet weight. 1:10 twist 308 is just going to be an all around better choice unless you really want to be shooting 220 + grain bullets, at which point you're not in traditional 308 territory only.
There was a brief period of thought whereby overspinning 308 would allow you to punch through the transonic threshhold with more accuracy and consistency. This of course ignored the obvious fact that a .308 load at the transonic threshhold is, effectively, +/- 10% of a FMJ 9mm load at the muzzle, and no serious person is planning on finishing a fight with that. So serious units have moved on to better calibers (instead of worrying about how tight you can get 168 grain Sierra to shoot at 700 or 800 yards) while some of us with slower budget processes are left with theory-crafted garbage, pushed down the line by managers with an inconsistent grasp of internal and external ballistics. Or something like that.
Hi,
Ok so I have more time to reply, lol..
I think these type of conversations always has each side running to their respective corners of "extreme" and we loose our focus and ourselves from the entire functional middle ground.
Secondly, these conversations very rarely discussed with specific projectiles in mind and we begin to just assume someone is talking about a projectile extreme that we "do not agree" with, etc etc.
Both of the above personal biasness keeps us from having in-depth conversations sometimes.
For example:
When I see a "will this fast twist work, etc etc" I automatically default to my personal knowledge base aka biasness of "YES it will absolutely work" because I assume the question was asked with the intention of utilizing specific built monolithic bullets and could not care less on projectile weights pertaining to said twist rate question.
When in reality sometimes the person asking the question not only has no intention of uses monolithic bullets but has no idea as to why someone would even ask such inquiry of "what projectile do you intend to use".
So with all that transparency laid out.....lol
IF you are using monolithic projectiles (regardless of their weight)....spin till your heart is content.
1. You cannot spin them into "ghost" bullets.
2. The FASTER we can get the projectile stable to the muzzle the better IMO (Source...Hyperstabilization Theory of Jim Boatright).
3. Having shot monolithics in the ELR segment of the industry since the original Cheytac testing days there is just a reason to NOT spin them faster. Zero negative affects have been proven from the Yuma radar data.
IF you are using jacketed bullets (bullet weight absolutely plays a part)...then you can only spin as fast as the jacket will allow you to.
But you also have to realize the sectional density and center of gravity can change in those jacketed bullets due to excessive twist rates since (depending on brand/batch) the lead in the bullet can actually be moved, repositioned and compacted during crazy spinning.
Sincerely,
Theis
Ok so I have more time to reply, lol..
I think these type of conversations always has each side running to their respective corners of "extreme" and we loose our focus and ourselves from the entire functional middle ground.
Secondly, these conversations very rarely discussed with specific projectiles in mind and we begin to just assume someone is talking about a projectile extreme that we "do not agree" with, etc etc.
Both of the above personal biasness keeps us from having in-depth conversations sometimes.
For example:
When I see a "will this fast twist work, etc etc" I automatically default to my personal knowledge base aka biasness of "YES it will absolutely work" because I assume the question was asked with the intention of utilizing specific built monolithic bullets and could not care less on projectile weights pertaining to said twist rate question.
When in reality sometimes the person asking the question not only has no intention of uses monolithic bullets but has no idea as to why someone would even ask such inquiry of "what projectile do you intend to use".
So with all that transparency laid out.....lol
IF you are using monolithic projectiles (regardless of their weight)....spin till your heart is content.
1. You cannot spin them into "ghost" bullets.
2. The FASTER we can get the projectile stable to the muzzle the better IMO (Source...Hyperstabilization Theory of Jim Boatright).
3. Having shot monolithics in the ELR segment of the industry since the original Cheytac testing days there is just a reason to NOT spin them faster. Zero negative affects have been proven from the Yuma radar data.
IF you are using jacketed bullets (bullet weight absolutely plays a part)...then you can only spin as fast as the jacket will allow you to.
But you also have to realize the sectional density and center of gravity can change in those jacketed bullets due to excessive twist rates since (depending on brand/batch) the lead in the bullet can actually be moved, repositioned and compacted during crazy spinning.
Sincerely,
Theis
Over spinning does not always work ...
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