Will I be over stabilized?
- Thread starter slowbalt
- Start date
As I test this more, I'm not sure there is any such thing as "over stabilized." That is, as long as the bullet can hold up and make it to the target. Even in full blown BR rifles, I'm struggling to see an accuracy difference. YMMV
There is a max RPM for each bullet you might want to stay below.
55gr 6mm is probably pretty high before you have problems with over spinning.
55gr 6mm is probably pretty high before you have problems with over spinning.
6BRA
Gold $$ Contributor
Did he mention anything about off center cores and overspinning...and flyers? Ppc 101
I agree in principle but the results aren't backing that up. Maybe jackets are better. IDK anything except what the target is telling me.
There are other reasons, like torque but again, I trust the target.
NC/Br Shooter
Silver $$ Contributor
What is the device that tests a bullet's inner composition? Seems like I have read about such a test device. I may be wrong,. Seems like it was something that spinned a bullet and it could give a reading of some kind
Juenke Machine by Vern Juenke. Probably misspelled.
NC/Br Shooter
Silver $$ Contributor
I'm gonna read up on this, From what I remember, It was most interesting thing I thought I had ever heard of. At least reading about theory. It was one of those things, If Id remember to do it. Kinda jogged my memory abit.
I agree. If the bullet will stay together I don't think you would have to be worried about stabilization.
They weren't cheap and have fallen out of favor over the past several years. Not sure if he's still with us or not but pretty sure the machine is no longer in production but I have seen them for sale on here, not a really long time ago. Maybe in the last year, just guessing.
You can measure unused jacket concentricity pretty easily if you think about itA good mandrel, a stop to make sure they are measured at the same spot every time and a really good test indicator is all you need.
That said, if cheap enough, it'd be neat to have around to check already made up bullets. If nothing else, just to rule out one variable and maybe sort for big matches, etc. I have zero experience with them and not sure how they work but someone on here knows. Maybe someone will speak up. I'd think it's a good tool for anyone making bullets...fwiw.
There may be a point of diminishing returns, or break point, if you will. I started using 6mm 12 twist bbls a few years ago and after a couple of national championship yardage/grand aggs with them, I'm sold on the 12 vs the more common 13.5-14 twist barrels for 62-68gr bullets and 12 is fast enough to use 80's too. They seem to be consistently good. if not better, ime. Nothing earth shattering here, mind ya but one of the natty yardage wins was with 80's at 200. The grand agg natty was with 68's, both in a 12 twist. I'm not telling anybody what they should do but I'm not going back to the 13.5's unless something changes.
Since the 12s work so well, I'm still testing a 10 twist now. Contrary to what you read on here and other forums, that bbl shoots 68 and 80s better than any of the roughly 8-10 different bullets I've tried in more "twist appropriate' bullets from various factor and custom makers.
This leads me to believe that regardless of stability, it's just harder to make longer bullets shoot as well as shorter bullets. This does not factor in bc for longer ranges but does make me consider say mid weight bullets for longer range in smaller cases, like a BR or Grendel variant. It makes me take a closer look at bc vs velocity vs accuracy. From what I'm seeing, in "normal" conditions, I think there might be enough accuracy difference in those cases to reconsider strictly going with heavier for caliber bullets.
Just something else we have to test to know for sure. But, I'd suggest to anyone that cares, to test 90-95 class bullets, even for 1000 but certainly so at 600 and in, to see how things stack up..consistently, especially in the smaller cartridges that have their tongue hanging out to push the heavies to their full potential. I don't think one barrel is enough to proclaim a definite winner either way, so it'll take some time and effort to come to a reasonably reliable answer to this. Even then, you'll have that voice in your head and especially on the internet, that you MUST use the heavies to be competitive at longer ranges.
I know it's been done before. I also know that human nature is to work hardest on what we hope or think is best, for whatever reason. This puts the "untested" stuff at a disadvantage to the other stuff unless we really and truly put the SAME work into both. It's easy to stay with the status quo unless the difference is big enough to really jump out at you and it's not, but I think it might be enough to be very worthwhile, at least in some guns.
Just run the numbers and go test is the best thing I can add to this. Keep an open mind and just read the dang target over the internet. The target won't lie but the internet is full of well intentioned but wrong advice.
Testing is how we know stuff!
At the very least, a more stable bullet will yield a slightly better and more consistent bc vs one on the edge. That may be enough to offset the bullet imbalance that others brought up above. It might be that jackets are enough better that what used to be true in that regard, is no more.
I've been shooting 103gr projectiles for several years now in my 6BR through a 1:8 twist 28" Benchmark barrel and have had great success with that weight, even out to 1'000yds if conditions are good.
Nothing in the Berger range seemed to go as well. Had good results from Sierra 107's but the 103 grain bullet just seems to be the "ideal" weight for everything out to 600 for sure. Have nailed a 200.14 with them at 600yds. The 103's are made using Sierra jackets.
Also use them in my Tikka T3 based "Dog Gun" chambered with the same reamer so I don't have to load two different batches of ammo as I did when running 87gr Hornady Varmints.
dellet
Gold $$ Contributor
The problem with a fast twist, is velocity. The effect of barrel length isn’t often talked about, nor is drift.
Bullet integrity is very good these days, so as long as the bullet is designed for the spin rate generated, imbalance or stability due to over spin spin at any speed is really rare. The tough part is getting the information from manufacturers, sometimes it takes a couple tries.
The problem is that sometimes your best load is on the high end of the velocity range. If you’re a believer in “load density matters”, then you either run on the edge of disaster, knowing one day it will bite you in the butt. Moving up in bullet weight or shorten the barrel. There really isn’t too many ways to reduce velocity, if you don’t want to drop a powder charge.
This was another lesson learned from the 300 Blackout experiments. The 1/5 twist was developed for ultra short barrels, 5-5.5”. It was hard to gain the velocity needed to blow up bullets. 2100 fps nets 300,000+. Hard to do that in a 5” barrel, but 2300fps in a 8” is no problem with a 110 grain or less bullet. You have to choose your bullet wisely, monitor rate of fire and temps.
For perspective 2550 fps in a 1/6 is about the same 300,000, all of a sudden full auto is on the table in a 24” barrel.
When you crunch the numbers
1/9 3000fps = 240,000
1/9 3400fps = 272,000
1/9 3900 fps = 312,000
1/8 3000fps = 270,000
1/8 3400fps = 306,000
1/7 3000fps = 308,000
1/7 3400fps = 350,000
1/5 2100fps = 302,000
1/5 2350fps = 338,000
Knowing the velocity windows helps in choosing a twist rate that best brackets the velocities you plan on shooting, and a bullet that will hold up.
Bullet integrity is very good these days, so as long as the bullet is designed for the spin rate generated, imbalance or stability due to over spin spin at any speed is really rare. The tough part is getting the information from manufacturers, sometimes it takes a couple tries.
The problem is that sometimes your best load is on the high end of the velocity range. If you’re a believer in “load density matters”, then you either run on the edge of disaster, knowing one day it will bite you in the butt. Moving up in bullet weight or shorten the barrel. There really isn’t too many ways to reduce velocity, if you don’t want to drop a powder charge.
This was another lesson learned from the 300 Blackout experiments. The 1/5 twist was developed for ultra short barrels, 5-5.5”. It was hard to gain the velocity needed to blow up bullets. 2100 fps nets 300,000+. Hard to do that in a 5” barrel, but 2300fps in a 8” is no problem with a 110 grain or less bullet. You have to choose your bullet wisely, monitor rate of fire and temps.
For perspective 2550 fps in a 1/6 is about the same 300,000, all of a sudden full auto is on the table in a 24” barrel.
When you crunch the numbers
1/9 3000fps = 240,000
1/9 3400fps = 272,000
1/9 3900 fps = 312,000
1/8 3000fps = 270,000
1/8 3400fps = 306,000
1/7 3000fps = 308,000
1/7 3400fps = 350,000
1/5 2100fps = 302,000
1/5 2350fps = 338,000
Knowing the velocity windows helps in choosing a twist rate that best brackets the velocities you plan on shooting, and a bullet that will hold up.
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