Flat Base vs Boat Tail Bullets

[Charlie98]

For that rifle the max will be 300 but mostly 100 to 200 yards. I’ll load up a test batch and see how they do. If they shoot about 3 MOA then that’s likely my limit not the gun/bullet combo.

I think you will be surprised by the accuracy you'll see... but I've been wrong before.

 

[DMW1116]

I hope so. I have some 77 grain SMKs I was going to try, but I have a potential 1/2 MOA load with them in another rifle so I may save them for that and jump straight to the 55 grain soft points. Even my best shooting out of the 20” rifle isn’t close to that so the 77s might be a waste in the longer barreled rifle with iron sights.

 

[Howland937]

The article stated by Howland937 is full of ifs, possibilities and maybe's.

It does show pretty clearly the differences between the 2 immediately after firing, prior to leaving the muzzle and upon exiting. It then explains how those differences can affect accuracy. Sure it states there is no guarantee it will have any effect whatsoever in a specific rifle and we all know certain rifles like certain components better. Differences definitely make a difference though, so I wouldn't discount it as purely speculation.

 

[Varminterror]

It's been proven many times with so called brush busting bullets that once a bullet destabilizes by brush, etc. the yaw or deflection only becomes worse over time and distance.

Brush contact induced yaw isn’t the same thing as bore induced yaw. Spin stabilization does pull tips back to center, reducing yaw - we had several videos of this up here a few months ago. Contact with brush decreases spin rate as well as causing deflection and yaw, so the stabilizing force is diminished.

Spin a top on a table. It can start out wobbly, but right itself. But if you physically bump the top, into a wobble, most often it will not right itself fully again, as the spin rate is also reduced by the contact.

 

[Varminterror]

For an iron sighted rifle with relatively generic hunting bullets, worrying about flat base versus boattails is stepping over dollars to pick up dimes.

I can put together pretty small groups without much practice and without much load development, be lying if I said I was confident that I can shoot the difference between a boattail and a flat base, and I know I’m NOT lying to say if I CAN (surprisingly) shoot a repeatable and measurable difference between the two, then I KNOW it’s not enough difference to matter for anything I do.

In theory - which I do believe is supported in practice - flat base bullets have advantages in their favor, at least for short range shooting. More bearing surface (more grip on the lands), shorter overall length (easier to stabilize), less vulnerability to base disruption in the bore... but these advantages only reveal themselves as tangible improvements for exceptionally skilled shooters and under the right circumstances.

 

[CoalTrain49]

I don't know.

Hornady makes a (.224) boatail 68 gr match bullet. If BT is bad for accuracy how do they advertise this as a match bullet? It seems to be extremly popular.

 

[Armorer 101]

According to the technical department at Sierra, the actual fact of clinical testing is that the flat base bullet is stable out of the muzzle and as accurate as the BT to 200. The BT is stabilized by the vacuum created by the tapered base and require about 75-100 yards to go full stable.
If your general shooting will be within 200 yards, like in the SE or the woods of the NE for example, you might consider flat base bullets, especially with the 270-35 cals. However, if you will be shooting 100-300 yards the BT will do nicely.

 

[Varminterror]

I don't know.

Hornady makes a (.224) boatail 68 gr match bullet. If BT is bad for accuracy how do they advertise this as a match bullet? It seems to be extremly popular.

“Match” is a broad term. Lots of “matches” are fired at long ranges where the ballistic coefficient advantage of boattails outweighs the short range disadvantage. Lots of matches are fired at short ranges where there is no advantage to increased BC from a boattail, so the advantage of short range stability outweighs the null value of increased BC.

 

[Thomasss]

1 2 3 4
Here are four targets which used either Spitzer sp flat base or sp boat tail projectiles. They are all 30.06, shot at 100 meters I load for a Danish M-1 Garand, a 1970 Rem. 700, and a 2021 Ticca. Picture 1 and 2 are about right and #3 and #4 targets were taken farther out. Pic. 2 group measured 3/4" x 5/8" inches. The other targets have 1 inch squares, but kind of hard to see on #4. That's about a 1 inch group. Anyone care to distinguish which are flat base and which are boat tails. You get extra points if you can tell which gun they came from. lol

 

[BreechFace]

An important aspect of flat based bullets is that they will get up to speed faster than boat tails. Flat surface area for the combustion to push against.

Flat based bullets make a lot of sense in short ranged firearms such as AR pistols and the such because of this, and they aren't designed for long distance shots as well.

Flat based bullets tend to leave the muzzle cleaner than a boat tail as well. Many have found flat based bullets to be more accurate at short distances. I haven't spent the time to compare but I like flat based bullets for some needs more than boat tail.

 

[Thomasss]

Mr. Watson, upon further research, I cannot find the book and the quote on Nosler's development of boat-tail projectiles. During my search, I did find a reference that indicates Nosler may have been selling partitioned boat-tails to the general public as early as the late 1940s. Therefore, I decided to remove my "good authority" from the thread.

 

[Varminterror]

An important aspect of flat based bullets is that they will get up to speed faster than boat tails. Flat surface area for the combustion to push against.

That math doesn’t pencil.

We have greater surface area of the boattail which receives a fractional proportion of the force in the axial direction, such the net sum force aligned with the bore really doesn’t care about the boattail.

 

[Bfh_auto]

For that rifle the max will be 300 but mostly 100 to 200 yards. I’ll load up a test batch and see how they do. If they shoot about 3 MOA then that’s likely my limit not the gun/bullet combo.

What chambering and powder?
You will definitely be able to get better than 3 MOA if you're running peeps on an AR.
I had good results from that bullet until I ran out of them.

 

[Bfh_auto]

For an iron sighted rifle with relatively generic hunting bullets, worrying about flat base versus boattails is stepping over dollars to pick up dimes.

I can put together pretty small groups without much practice and without much load development, be lying if I said I was confident that I can shoot the difference between a boattail and a flat base, and I know I’m NOT lying to say if I CAN (surprisingly) shoot a repeatable and measurable difference between the two, then I KNOW it’s not enough difference to matter for anything I do.

In theory - which I do believe is supported in practice - flat base bullets have advantages in their favor, at least for short range shooting. More bearing surface (more grip on the lands), shorter overall length (easier to stabilize), less vulnerability to base disruption in the bore... but these advantages only reveal themselves as tangible improvements for exceptionally skilled shooters and under the right circumstances.

The not much load development is what's so attractive about the flat base for hunting inside 300 yards.
I can't tell a difference if I completely go through load work up. But I definitely find it faster with a FB.

 

[DMW1116]

What chambering and powder?
You will definitely be able to get better than 3 MOA if you're running peeps on an AR.
I had good results from that bullet until I ran out of them.

5.56 chamber in an FN barrel and PSA upper. Not sure on powder. I have to decide. I’ve been running FMJ over H335 and TAC now that I’m out of H335. I have TAC and CFE 223 available. I’ve shot about 2 MOA at 200 yards, but that was 3 shot groups instead of the 7 to 9 shot groups I tried last trip.

 

[old heeler]

Here some FB bullets that work short yardage.

https://www.accurateshooter.com/cartridge-guides/30br/