Flat base vs. boat tail bullets
- Thread starter bdbrown66
- Start date
Excellent reading. I was a bit surprised that they used a hunting bullet and a match bullet for the test.
I made bullets with a buddy who is a somewhat known character in short range benchrest. His bullets are well respected, the top guys won’t turn down a few hundred that is to say. Two sizes only, a 52gr .22 and a 67gr .243. It’s a ton of tedious labor. Anyway, we talked a lot about it and the difficulties in making good bullets. It’s all about the base, flat being much easier to get consistent results. There are no boat tail bullets in short range benchrest. They shoot “ought” size groups up to 300 yards.
My unscientific experimenting has shown no gains using a boat tail over a flat base under 600 yards. Some say there is no benefit until it drops below supersonic. But, the boat tail, sleek VLD is a good marketing concept and sells a lot of bullets.
Again great reading. I bet he got a few phone calls from Berger and Hornady. [emoji1]
I made bullets with a buddy who is a somewhat known character in short range benchrest. His bullets are well respected, the top guys won’t turn down a few hundred that is to say. Two sizes only, a 52gr .22 and a 67gr .243. It’s a ton of tedious labor. Anyway, we talked a lot about it and the difficulties in making good bullets. It’s all about the base, flat being much easier to get consistent results. There are no boat tail bullets in short range benchrest. They shoot “ought” size groups up to 300 yards.
My unscientific experimenting has shown no gains using a boat tail over a flat base under 600 yards. Some say there is no benefit until it drops below supersonic. But, the boat tail, sleek VLD is a good marketing concept and sells a lot of bullets.
Again great reading. I bet he got a few phone calls from Berger and Hornady. [emoji1]
Thanks for sharing. https://www.milsurps.com/images/importe ... tail-1.jpg might be a decent follow-up.
I've had the notion - from Hatcher - that boat tail bullets came into being with machine guns. The idea was to increase the range of the bullets while also cutting down disturbances in the air for following bullets and also when they went transonic.
https://en.wikipedia.org/wiki/.30-06_Springfield seems to confirm this: "Firing tests performed around 1918 at Borden Brook Reservoir (Massachusetts), Miami, and Daytona Beach showed the actual maximum range of the M1906 cartridge to be 3,300 to 3,400 yards (3,020 to 3,110 m). Germany, which was using the S Patrone (S ball cartridge) loaded with a similar 153-grain (9.9 g) flat-based bullet in its rifles, had apparently confronted and solved the same problem by developing an aerodynamically more refined bullet for long range machine gun use. The s.S. Patrone was introduced in 1914 and used a 197.5-grain (12.80 g) s.S. – schweres Spitzgeschoß (heavy spitzer) boat-tail bullet which had a maximum range of approximately 4,700 m (5,140 yd).
For these reasons, in 1926, the ordnance corps, after extensive testing of 7.5×55mm Swiss GP11 projectiles provided by the Swiss developed the .30 M1 Ball cartridge loaded with a new improved military rifle (IMR) 1185 propellant and 174-grain (11.28 g) bullet with a 9° boat-tail and an ogive of 7 calibers nose cone that had a higher ballistic coefficient of roughly 0.494 (G1 BC), that achieved a muzzle velocity of 2,647 ft/s (807 m/s) and muzzle energy of 2,675 ft⋅lbf (3,627 J). This bullet further reduced air resistance in flight, resulting in less rapid downrange deceleration, less lateral drift caused by crosswinds, and significantly greater supersonic and maximum effective range from machine guns and rifles alike. Additionally, a gilding metal jacket was developed that all but eliminated the metal fouling that plagued the earlier M1906 cartridge. The round weighed 420 grains (27 g) and its maximum range was approximately 5,500 yd (5,030 m)."
I've had the notion - from Hatcher - that boat tail bullets came into being with machine guns. The idea was to increase the range of the bullets while also cutting down disturbances in the air for following bullets and also when they went transonic.
https://en.wikipedia.org/wiki/.30-06_Springfield seems to confirm this: "Firing tests performed around 1918 at Borden Brook Reservoir (Massachusetts), Miami, and Daytona Beach showed the actual maximum range of the M1906 cartridge to be 3,300 to 3,400 yards (3,020 to 3,110 m). Germany, which was using the S Patrone (S ball cartridge) loaded with a similar 153-grain (9.9 g) flat-based bullet in its rifles, had apparently confronted and solved the same problem by developing an aerodynamically more refined bullet for long range machine gun use. The s.S. Patrone was introduced in 1914 and used a 197.5-grain (12.80 g) s.S. – schweres Spitzgeschoß (heavy spitzer) boat-tail bullet which had a maximum range of approximately 4,700 m (5,140 yd).
For these reasons, in 1926, the ordnance corps, after extensive testing of 7.5×55mm Swiss GP11 projectiles provided by the Swiss developed the .30 M1 Ball cartridge loaded with a new improved military rifle (IMR) 1185 propellant and 174-grain (11.28 g) bullet with a 9° boat-tail and an ogive of 7 calibers nose cone that had a higher ballistic coefficient of roughly 0.494 (G1 BC), that achieved a muzzle velocity of 2,647 ft/s (807 m/s) and muzzle energy of 2,675 ft⋅lbf (3,627 J). This bullet further reduced air resistance in flight, resulting in less rapid downrange deceleration, less lateral drift caused by crosswinds, and significantly greater supersonic and maximum effective range from machine guns and rifles alike. Additionally, a gilding metal jacket was developed that all but eliminated the metal fouling that plagued the earlier M1906 cartridge. The round weighed 420 grains (27 g) and its maximum range was approximately 5,500 yd (5,030 m)."
Just saw this somewhere else & haven't had time to read it thoroughly.
https://apps.dtic.mil/dtic/tr/fulltext/u2/474352.pdf
https://apps.dtic.mil/dtic/tr/fulltext/u2/474352.pdf
I had a guy tell me at 600 yards that flat base bullets do the same accuracy wise as BT. I've gotten better accuracy with FB vs. BT. Numbers mean very little to me... it how the quarry feels after it's hit. 
If your westerners have the magnums, who needs a BT bullet?
If your westerners have the magnums, who needs a BT bullet?
jimbires
Handloader
- Aug 16, 2011
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Thanks , that was interesting reading . I've never thought about it this way . I have always been able to get decent accuracy with either style bullets . I'm not a BR shooter though , only a hunter . I did get involved with a poor shooting rifle a while ago . a friend of mine was trying to get a rifle to shoot for a relative of his . he wasn't having much luck .they were trying to get accuracy with a light per caliber bullet , in a rifle with a long free bore . he would call , or stop in , and we would talk things over . I talked him into trying a flat base bullet , in a little heaver weight . this would make the bullet bearing surface longer . long story short it worked pretty well . what I figure the problem was , is the bullet was completely out of the case neck before it was in the lands . I thought that might be causing the bullet to get weird and not get properly stabilized . after reading this , my theory could be wrong .
a long free bore or throat can be a problem. Weatherbys have a long freebore to prevent people from making to hot of loads with bullets jammed or close like standard cartridges. You can get a decent load with manual OAL's. I've achieved it both ways. Heavier bullets are the way to go long range. However..... Jack O'Connor proved otherwise !
Joec7651
Handloader
- Apr 7, 2019
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Great piece of reading. I get great accuracy from the 150gr Speer Gold Dot in my 308 Win(1/2” or better). They are bonded and I love them. I wouldn’t really call them a rebated boat tail. It’s more of a rebated flat base to me. Still extremely accurate for me.
I’ve also had consistent sub moa accuracy from Speers Hot Cor also. My longest shots would be 450 yards max but I can’t say I’ve seen any advantage to a boat tail at those ranges. I shoot them and boat tails look cooler, but I’d take my 270, 308, or 7mm RM after elk with Hot Cor’s and never have a second thought about it. Accuracy, shot placement, and knowing your rifle like it’s part of you equals a humane successful hunt.
I’ve also had consistent sub moa accuracy from Speers Hot Cor also. My longest shots would be 450 yards max but I can’t say I’ve seen any advantage to a boat tail at those ranges. I shoot them and boat tails look cooler, but I’d take my 270, 308, or 7mm RM after elk with Hot Cor’s and never have a second thought about it. Accuracy, shot placement, and knowing your rifle like it’s part of you equals a humane successful hunt.
For targets( limited amounts) with my 308 tactical, I use both Nosler CC and Sierra MK, 168 gr. boat tail bullets. I am consistently shooting dime size or smaller groups at 100 yards. It holds that consistency out 400. I do not hunt big game with this rifle or these bullets. For coyotes I prefer the 160 flat base SP. I get consistent instant kills with them. For deer, elk etc, the PT or AB, are my favorites.
Interesting indeed. Never knew any of that and still don't consider the BT inferior, but I will say most of my hunting and test bullets are FB and I've gotten very good accuracy and never considered them inferior either to the BT design. The one BT I currently use for hunting is the 165 Speer BT and that is more for the construction of the bullet than the BT design. Having a fairly heavy but soft bullet for whitetails gets you the best of both worlds. Penetration and internal damage.
In my experience some rifles just don't like BT bullets. I have had a Shilen barrel 25-06 Rem for a number of years and it just does not like ANY BT bullet. Put a flat base in it and it is a bug hole shooter waaaaaaaaay out there.
It does not really matter what bullet you use as long as you get to know your rifle and what it will do with that bullet you choose at the distance you want to make the shot.
My 25-06 with 117 Sierra Pro Hunter flat base bullet has never let me down out to about 550 yards on deer. I don't take shots over that yardage because the energy is dropping off that I THINK I need for good expansion. 95% of my shots have been inside 350 yards usually due to hunting area. BANG FLOP is usually the result and I have killed a whole lot of deer with this combo. At least a couple hundred.
It does not really matter what bullet you use as long as you get to know your rifle and what it will do with that bullet you choose at the distance you want to make the shot.
My 25-06 with 117 Sierra Pro Hunter flat base bullet has never let me down out to about 550 yards on deer. I don't take shots over that yardage because the energy is dropping off that I THINK I need for good expansion. 95% of my shots have been inside 350 yards usually due to hunting area. BANG FLOP is usually the result and I have killed a whole lot of deer with this combo. At least a couple hundred.
jimbires
Handloader
- Aug 16, 2011
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I remember reading an article years ago that stated a flat base bullet will support a larger mushroom than the same bullet with a boat tail , this should help with wound trauma . all this said , I like reloading a boat tail bullet , they set on the case so nice when raising them up in the die .
