Bullets: Boat tail vs. Flat base???

[TEXAS222]

Hello. I'm trying to educate myself some concerning bullets. The range I'll be speaking of is 100 to 400 yards and my interest is in accuracy. It seems to me at those ranges, actually max being 300 yds., that boat tail bullets are the most accurate in my .204 & in my .224 caliber rifles, flat base seem to be the most accurate. Is this just a coincidence or some fact? I've got a few questions I'd like to get some opinions on.
1. Are there advantages of one or the other at those ranges?
2. Much difference in velocity out at 400?
3. Accuracy?
4. Does ball powder vs. stick powder provide better accuracy with one or the other bullet?
5. FINALLY, and I'm guessing this will be the answer, all guns are different & it depends on just what it likes.
I know this might be a dumb post/question but I'm just being inquisitive. Thank ya'll & have a great weekend,
Jim D

[Jim White]

Hello. I'm trying to educate myself some concerning bullets. The range I'll be speaking of is 100 to 400 yards and my interest is in accuracy. It seems to me at those ranges, actually max being 300 yds., that boat tail bullets are the most accurate in my .204 & in my .224 caliber rifles, flat base seem to be the most accurate. Is this just a coincidence or some fact? I've got a few questions I'd like to get some opinions on.
1. Are there advantages of one or the other at those ranges?
2. Much difference in velocity out at 400?
3. Accuracy?
4. Does ball powder vs. stick powder provide better accuracy with one or the other bullet?
5. FINALLY, and I'm guessing this will be the answer, all guns are different & it depends on just what it likes.
I know this might be a dumb post/question but I'm just being inquisitive. Thank ya'll & have a great weekend,
Jim D

1. I've read through the years that the benefits of a B/T doesn't start to come into play until about 300 yards or so and that was for a 308.
2. The only way I know to test that theory is to find two bullets of the same dimensions and run them thru one of those on line ballistic calculators.
3. I'd say "no".
4. I'd say "no" but ball powder does typically meter better for more consistent loads but thats just one aspect of good ammo.

HTH,

[jpx2rk]

I go with #5, it depends on the gun and what it likes. Two identical guns probably will not like the same factory ammo, but, could shoot groups that are close or similar to each other with the same ammo.

Finding a factory ammo the gun likes gives you a starting point for handloading IMO as you have a bullet & velocity combo it likes, and you go from there. Factory ammo usually has some published data on it, you know the type bullet (FB vs BT, HP vs SP or BT), so try a powder that will be a safe load but give you the velocity close to the factory ammo, and go from there.

Reloading or fine tuning a load is fun to do. I trying to find a load that will work in a Ruger 223 with a bit heavier bullets in the 60gr range than the Nosler 55gr FBHP's load I have that puts a 3 shot group inside a dime right now. Why, because I've got all the components, time since I'm retired and it gives me something to do at my leisure.

[Rick in Oregon]

Just for the record, flat base bullets are usually more accurate in any given rifle than boat tail bullets. There's always exceptions of course, but just consider the fact that ALL bullets intended for BR shooting are indeed flat base. All the accuracy records that have been set are all the result of flat base bullets used in competition.

If you're shooting critters out past 300 yards, well then, boat tail bullets start to show their worth due to better BC's and less drag at longer ranges. It's not rocket science.

[MZ5]

1. Are there advantages of one or the other at those ranges?
2. Much difference in velocity out at 400?
3. Accuracy?
4. Does ball powder vs. stick powder provide better accuracy with one or the other bullet?
5. FINALLY, and I'm guessing this will be the answer, all guns are different & it depends on just what it likes.

Hello.

As RiO pointed out, flat-base bullets are normally better for precision (shooting small groups). This is because it's much harder to manufacture the boat tail itself perfectly. It is easier to manufacture the flat base straight, square, and closer to 'perfect.' This matters to precision because of the high-pressure gas pushing on the bullet's base just after it exits the barrel. Any imperfection in manufacturing of the bullet base will result in that high-pressure gas pushing the base unevenly, or in other words pushing it sideways some. This introduces dispersion (bigger group sizes). Harold Vaughn did a bunch of testing of the effect of damaged bullet bases vs tips in his book called "Rifle Accuracy Facts." His work demonstrates very clearly that small issues with a bullet's base yields large problems in precision, whereas you can really screw up the meplat (tip) and it's not _that_ big a deal.

For velocity, see jbmballistics.com

Don't count on the difference in powder shape being significant in the setting you're working with.

[TEXAS222]

Thanks guys, all the information has been things I'm searching for.
Jim D

[Darkker]

The range I'll be speaking of is 100 to 400 yards and my interest is in accuracy.
A) It seems to me that boat tail bullets are the most accurate in my .204 & in my .224 caliber rifles, flat base seem to be the most accurate. Is this just a coincidence or some fact?
1. Are there advantages of one or the other at those ranges?
2. Much difference in velocity out at 400?
3. Accuracy?
4. Does ball powder vs. stick powder provide better accuracy with one or the other bullet?
5. FINALLY, and I'm guessing this will be the answer,

A) it may be FACT that those rifles like those particular bullets and loads, or coincidence. The deal is that for most of the discussions about which bullets design is inherently more accurate. The simple fact is that if you have a good node in your rifle with a poor bullet, and a bad node with a good bullet, you wouldn't think the good bullets were actually fundamentally better. So don't lose sleep over this.
1) From a technical standpoint, of course. From a practical standpoint, that is a matter of opinion.
See pics below
2) See pics below
3) Again this is much more to do with you than anything, but see below.
4) Back to nodes and loads. One shape or method of burning rate control isn't enough to mean chit on its own.
5) Yeah, . It does kinda depend.

So again, it will depend, but here is my current atmosphere and conditions with a 204 comparison. Is there a difference? Yes.
Does it "matter"? I leave that up to you.

34gr Nochemare from Midsouth with stated .132 G1. Vs. 32gr Blitzking. Gives a similar length comparison with BT and FB; same starting velocity.

First the Nightmares, then the Blitz

[D'zaster]

Hey Guys, I am new to this forum. A lot of great information here!!

So this question about flat base vs boat tail is quite interesting and I have a related question. Last year, I started loading 204 ruger with flat base sierras and hornady 32grainers. I am using RCBS dies (two die set) and when I seat the bullets, a tiny sliver of copper is shaved off (fine like a circular piece of hair). Is this normal? Should I bell the neck of the brass after resizing? I'm thinking this must effect accuracy.

I have been reloading for years but there is always something to learn. Your advice is appreciated.

[Bill K]

Do not bell the cases as you do for bullets in handgun rounds. Chamfer the mouth of your rifle cases, with a tool, either hand or mechanical made for such, prior to seating your bullets. Chamfering should be done on them, especially after you have to trim to length. Bill K

[D'zaster]

Thanks Bill!! I should have known better......Definitely will do.

[Rick in Oregon]

D'zaster: To best chamfer the inside of your case necks for easy (non-shaving) bullet seating, get a VLD tool for this task, as it will make a much easier bullet entry into the case with the steeper angle that it will cut compared to a regular chamfer tool, which is only 45*.

Using a VLD tool will also result in the probability of better TIR* of your loads also, resulting in better accuracy.


* Machinist term for "Total Indicated Runout" (in case you are not familiar with the term).

[D'zaster]

Thanks Rick!
VLD chamfering tool is on order. I'll be loading next week.

[Fat Albert]

If you are loading compressed loads of slow powder , the flat base bullet will let you put more powder in the case. Also I see the side wall taper of the boattail contacting the inside of the case mouth so the case mouth is opened to outside bullet dia. as it contact the side wall.