Best Accuracy-Boat Tail vs Flat Base

[Catpop]

Question: Given .223 Remington and 50-55 grain bullets, which seem to give the best accuracy, Boat Tail or flat base? I'm using 16 inch barrel with 8 or 9 twist (not sure).
Thanks, Catpop

 

[jwrowland77]

Yes. Let your rifle pick which one it likes best.

In all seriousness, what I normally do is get one box of each and test them (good thing about .223 bullets is they're not terribly expensive). The one that works the best, I bunch a lot more of. The other one, I'll either test a different powder with, or put them in a section to just plink with.

In 8 or 9 twist, I'd be looking at a bit heavier bullet. Like in the 69-75gr range.

First I'd find out a definite on what my twist is though.

 

[Catpop]

Good point. I'll check that tomorrow.
Tx catpop

 

[Clint M]

Most of the time a flat base bullet will out shoot a boat tail out to around 300 yards then the boat tail will takeover from there. That however can vary barrels can be picky about bullet type, brands and weight, I would start with a 40gr polytipped varmint bullet v-max, b-tip, blitzking, also I really like the 60gr polly tip varmint bullets as well. Find your twist rate, then you can decide max bullet weight for your twist rate you can test some of the heavier bullets if that tickles your fancy.

Overall .224 bullets i like for accuracy are varmint type 40gr-60gr polymer tipped (hollow point also works well), match bullets 52gr and around 52gr hollow point all these in flat base, but you can also get many or most in boat tail...try both as previous poster has said it's the fun in shooting buy more shoot more.

 

[Otto]

Boat tails have a higher ballistic coefficient, flatter trajectory, better long range accuracy and are less sensitivity to crosswinds. Now you know why Federal uses boat tails in their Gold Medal Match ammo....

 

[GooseGestapo]

Out to 200yds or so, the flat-base are typically more accurate.
Most of the br-cartridges I've shot with Shilen and Euber bullets were at or near 1-hole accurate to 200yds.
However, a few rifles "like" the 52gr Boat-tail Hornady's or Sierra's a tad better.

Only at 300yds+ do boat-tails begin to have an advantage. And then, it's only better cross wind deflection and retained velocity/energy.
NOT accuracy/precision.

 

[Catpop]

I determined through actual test mine is a 9 1/2 - 10 1/2 twist. I did this a number of times but never could nail down a true 10. A search of the internet given my rifles (mini 14) serial number 187-03xxxverified mine should be a 10. I feel good with that.
Question: Now given a 10, what is the optimum bullet weight for my barrel twist at 100 yards. I've had good results with 50 grain flat base and when that box was gone I switched to 55 grain fmjbt thinking that might be better. But the results were no better.
I know its a trial and error thing, so I wanted the threads opinion as to what might be the best place to continue.
And yes I'm still on the mini 14 quest to make a mini shoot clover leafs at 100 yards. 55 fmjbt best group 7/16", but still not the proverbial cloverleaf.
Tx. Catpop

 

[jwrowland77]

Hmmm, I've always had great success with the 55gr Vmax in 1:12 and I believe it's a flat base.

With a 1:10, you might be able to stabilize the 69gr SMK or TMK.

Check out the jbm stability calculator and see if they will. Jbm page has bullet lengths as well. I've recently had great success with the 69gr Tipped Match King. It's a boat tail though but it's given me .5" groups down to .333" groups at 200yd.

 

[Clint M]

I would try some 60gr varmint bullets, buy several different weight varmint flat base bullets, and if you want try some boat tail bullets. I didn't see any range other than 100 yards, and your quest is clover leafs... I stand by my first post 40gr-60gr poly tipped varmint bullets, also match type hollow point, and varmint type hollow point all flat base. These types are bullets are made more for accuracy versus FMJ bullets. You can't really look at twist rate and say this will work well in this twist, you can look at twist and say this 1-10 should stabilize a 60gr v-max no problems, so I will buy a box of 40gr v-max, 50gr v-max, 60gr v-max, a box of 40gr blitzkings, 55gr blitzkinds,, 40gr b-tips, 50gr b-tips a box of 52gr smk, maybe a bok of berger 52gr match all flat base, also if you want to try boat tails pick one out. You will want an assortment of bullets, and powders and a couple of primers to try when requesting that kind of accuracy from your gun.

That seems like a lot of bullets, however if you were say shooting a cooper, a rem 700 bolt gun chances are you could pick 3 of list bullets and find a clover leaf load pretty easy, however an auto loader that is designed to function regardless can be a bit more picky...you may get lucky tho and find your goal picking 2 or of above bullets.

Clover leaf groups cost money .25"-.5" will cost you in initial investment of gun, or in work done to the gun, and possible a good barrel and work done to gun as well as bullets along with components that are up to the task of reliably shooting these groups. Good luck, and the fun is in the shooting.

 

[Potatohead]

Gosh I hate fiddling around with those flat base things (in 223). Im always dropping em, cant hold em on the case mouth, shaving the tips with the seater because they flop over, and any other little goofy thing that can happen with those little guys. That doesnt answer the question I know, but man I'll try any combo their is if it allows me to stay with boattail.

 

[jwrowland77]

Gosh I hate fiddling around with those flat base things (in 223). Im always dropping em, cant hold em on the case mouth, shaving the tips with the seater because they flop over, and any other little goofy thing that can happen with those little guys. That doesnt answer the question I know, but man I'll try any combo their is if it allows me to stay with boattail.

Do you use a VLD chamfer tool? If not, try one, makes it a bit easier.

 

[Catpop]

Potato head has a good point on value of bt----ease of handling for an old, big handed fart like me. Haha.
If I'm reading other fine posts correctly, a heavier bullet than 55 would be better in a 10 twist barrel.
Powders tried so far are imr 3031, h4198, win 748, cfe 223, imr 8208--- cfe seems to be best so far with 8208 close behind. 3031 was worst. Test cases are LC10 fully prepped. Oal max for 223. Primers cci small rifle.
Tx for all the valuable info, catpop

 

[Walkalong]

All the custom Benchrest bullets intended for 100 to 300 yards, mostly 100 & 200, are flat base.

Long range a boat tail has a wind advantage.

 

[lysanderxiii]

Gosh I hate fiddling around with those flat base things (in 223). Im always dropping em, cant hold em on the case mouth, shaving the tips with the seater because they flop over, and any other little goofy thing that can happen with those little guys. That doesnt answer the question I know, but man I'll try any combo their is if it allows me to stay with boattail.

This:

 

[jcwit]

223? Flat Base Sierra #1400 53 gr. Match King. Wilson dies with an arbor press.

 

[gamestalker]

I've had excellent results with both, I think it just depends on the gun, distance, velocity, and how fast your pushing them.

Then there's the rebated BT, an interesting bullet design, which is supposed to reduce drag even more than a standard BT. Never tried them, but I've talked to a couple of reloaders who have, and rave about them for long range.

GS

 

[Offfhand]

All the custom Benchrest bullets intended for 100 to 300 yards, mostly 100 & 200, are flat base.

ALL? Let's double check that.

 

[Walkalong]

99.99%?

I never saw anyone loading any custom Benchrest bullets that were not flat based. But you're right, never say never, or all.

 

[climbnjump]

Well, for what it's worth, here's what Berger has to say about flat base bullets (emphasis mine):

FLAT BASE BULLET DESIGN

Berger produces a full line of flat base bullets in several calibers. We consider the flat base bullet a staple of extreme precision bullet makers. These bullets are used most often by short range target and varmint shooters who are focused on the tightest possible accuracy. The ability for a bullet maker to produce very accurate flat base bullets is a significant indicator of how focused that bullet maker is on consistency. Flat base bullets are the easiest to make consistent since flat is always flat. No boat tail tooling or considerations during the manufacturing process need be made. The vast majority of flat base bullets are made with a tangent ogive which is easier to produce than the secant ogive. The tangent ogive is also easier than a secant ogive to make shoot well. A tangent ogive of the same length as a secant ogive will not perform as well in the wind however these bullets are used primarily for 300 yards or less so this is of little concern.

From: http://www.bergerbullets.com/information/line-and-designs/

 

[Catpop]

Hum..... my very limited testing supports what yawl are saying about flat vs bt. I've already begun another batch with my remaining 50 grain fb and some new 55 grain fb I just acquired. I'll let you know how it turns out.
Tx catpop

 

[Offfhand]

Regarding the comments and opinions about flat base and boat tailed bullets used in short range (100-300 yds.) benchrest competition expressed in this thread, there appears to be a disappointing lack of knowledge and understanding of current trends. Even casual inquiries of what's happening in this area of accuracy competition will disclose that boat tail bullets have become widely used, especially among the game's top shooters. With recent records having mostly been set with boat tailed bullets. Attached is the equipment list of the top shooters in the recently held Cactus Classic tournament, a major BR competition drawing over 100 shooters. Note the high percentage of BT bullets indicated, with others not so indicated probably also being BT's as well. For fuller details, google Cactus Classic and peruse the equipment lists, which also provided interesting info about the barrels, scopes, actions and related equipment. It will certainly provide a valuable up-date for what's been going on in the benchrest game. Further, regarding bullets currently used in short range benchrest, attached is a photo two of the most popular and widely used and successful custom bullets in recent times, both of which are boat tail designs. Purpose here is not to embarrass any above posters, who are no doubt sincere (99.9%?), but simply to get the facts straight and provide useful information

 

[Jim Watson]

Yes, and I have read on the internet that benchresters have gone to full length sizing, too.

 

[Walkalong]

Purpose here is not to embarrass any above posters, who are no doubt sincere (99.9%?), but simply to get the facts straight and provide useful information

Thanks, things change, and 100% sincere, if not 100% wrong.

My Barts Bullets were flat based, as were my Watsons, Gentners, etc, etc. I can't read the list, what percentage used BTs, and what percentage of the top shooters used BTs?

Some Benchrest shooters were FL sizing with bushing style sizers then as well, but, there is a big difference in how much the case is getting sized and they were/are using tight necked chambers. The dies were generally cut with reamers for chambers on the guns and barely sized the case smaller, were adjusted to barely (.001 or less) move the shoulder back, and the bushings were set up to give a final neck clearance of .001 or less all the way around. I was one that moved from neck sizing with shoulder bumping only to a custom bushing style FL sizer cut with the reamer that did my barrel.

It's very big difference from FL sizing with standard dies for a standard chamber, even using bushing style dies.

 

[GLOOB]

Flat base leaves the crown with better stability. The boat tails will leave the crown with a little more wobble, on the whole, before settling down. But after a couple hundred + yards, the boat tail's better in-flight stability and BC will make up for it.

In my opinion, this has less to do with tooling and precision of the bullet than the fact the boat tail allows high pressure gas to start pushing on the base of the bullet at mach 6 while the base is still in the bore, and one point on the base is most likely going to allow gas to escape slightly before the rest, which only further pushes that side out of whack. Whereas with a flat base, the cork unplugs more abruptly. So Berger can make their boat tails as precise as possible, and a flat base will still probably outshoot it under 200 yards. That's my bet, anyway.

 

[bush3755]

When I looked up the short range benchrest records for several groups shot for an aggregate, those at 100 yards seemed to have all individual groups under about 1/4 inch. I think virtually all were shot with flat based bullets.

I've read that when Sierra Bullets introduced their .308" diameter 168-gr. BTHP match bullet, good lots of them shot several 10-shot groups well under 1/4 inch in their 100-yard indoor test range during production tests. Some were near 1/10th inch. Sierra's 180, 190 and 200 grain HPBT match bullets at .308" diameter did the same thing.

That to me means, if the bullets are spun with rifling twists best to stabilize them for the speed they leave at, they will shoot virtually into the same hole at short range.

Sierra's earlier reloading manuals mentioned their tests show their boattail bullets stabilize in flight by the time they reach 100 yards.

I've also read that Sierra changed their 30 caliber match bullets from FMJBT to HPBT ones (starting with the 168), the dimensional uniformity at the heel was better than the FMJBT ones. And they shot more accurate than the hollow base ones so they changed their 180 and 200 grain match bullets to HPBT types and added the 190-gr. at the same time.