Hi guys,
just wondering wich you prefer, Im shooting speer 52gr HPBT's in .222 rem, but Im thinking about getting some of the 53 gr sierra HP's to try and obviously these are a flat base, I dont really try to shoot anything much past 300yds anyway so the advantage of the stabalizing action of the boat tail is really a little lost on me, do you think I would be better with the sierras, I know its a little bit of a how long is a piece of string question, cos the rifle may not even like them but I do hear talk of the flat base being a better proposition under the 300yd mark.

I think you'll find that there's little difference, so it depends on which your rifle "likes" the best. Stories about boattails being "hard on barrels" are old wives tales. Likewise, the belief that flatbases are significantly less aerodynamic that boattails is based on equally poor information; under 300 yards the difference in insignificant.

Bottom line: Shoot the bullet that your gun shoots best, whether flat base or boat tail.

I have always found flat base bullets to be more consistantly accurate, but not in every case, depends on the rifle....

if you go back to the armys data on boattails you find they they do hold an advantage at 800 yards or so. until then flat base work as well. That said, I like the boattails better, if for no other reason than they sure are easy to seat.

I'd advise the man with the golden gun to go with the more accurate (in your gun)...

quote:

Originally posted by Stonecreek:
I think you'll find that there's little difference, so it depends on which your rifle "likes" the best. Stories about boattails being "hard on barrels" are old wives tales. Likewise, the belief that flatbases are significantly less aerodynamic that boattails is based on equally poor information; under 300 yards the difference in insignificant.

Bottom line: Shoot the bullet that your gun shoots best, whether flat base or boat tail.

Yes.

quote:

Originally posted by butchloc:
if you go back to the armys data on boattails you find they they do hold an advantage at 800 yards or so. until then flat base work as well. That said, I like the boattails better, if for no other reason than they sure are easy to seat.

Yes, I agree. I can see no real advantage out to 400 yards and they are easier to seat.

quote:

Originally posted by scaramanga:
Hi guys,
just wondering wich you prefer, Im shooting speer 52gr HPBT's in .222 rem, but Im thinking about getting some of the 53 gr sierra HP's to try and obviously these are a flat base, I dont really try to shoot anything much past 300yds anyway so the advantage of the stabalizing action of the boat tail is really a little lost on me, do you think I would be better with the sierras, I know its a little bit of a how long is a piece of string question, cos the rifle may not even like them but I do hear talk of the flat base being a better proposition under the 300yd mark.

I like the Sierra's better overall than the Speers. I found the BTHP MatchKings to be more consistent IN MY RIFLE, the 70g especially. Yours may not like them as well.

The other advantage to the Sierra's, IF they shoot well in your rifle, is the availability of 500 packs in most of the popular weights, which makes them less expensive.

I have found them more consistent in accuracy box to box than other brands. Even other brands that cost more.

Back before the days of monolithic bullets like the Barnes Triple Shocks and bonded Core bullets, standard jacketed boat tails DID shed their jackets easier than flat based ones. Today's technology makes that point moot, unless of course you're shooting the "perfect storm" combo of Sierra Boat Tails and MVs in excess of 2800 fps. jorge

quote:

Originally posted by jorge:
Back before the days of monolithic bullets like the Barnes Triple Shocks and bonded Core bullets, standard jacketed boat tails DID shed their jackets easier than flat based ones. Today's technology makes that point moot, unless of course you're shooting the "perfect storm" combo of Sierra Boat Tails and MVs in excess of 2800 fps. jorge

True, back in the day...

I also remember, no too long ago, the petals on Barnes X-Bullets would break off and then the rest would over penetrate, if you pushed the MV. This tendency, thankfully, has been virtually eliminated.

Also Hornady SX bullets will vaporize from over-stabilization if you go over 3600fps. Load about 5-6 and let your buddy shoot them. Then you can tell him how bad a shot he is, "What's the problem? You can't even hit the paper..."

IMO the boattail is more a gimmick than a real performance factor...and for a hunting bullet IMO it's a deficit.

quote:

Originally posted by vapodog:
IMO the boattail is more a gimmick than a real performance factor...and for a hunting bullet IMO it's a deficit.

I don't have any hard data, but wouldn't a bullet that had less bearing surface (for the same weight) take less powder with less pressure and less barrel erosion to get the same velocity? (E.G. BTSP)

Besides the easier to seat factor, I have found a BTSP or BTHP takes a little less powder (.5-1 g.) to achieve the same MV in my varmint rifle.

What makes you think a BT will necessarily have less bearing surface? Often times they will shorten the ogive, putting the bullet shoulder more forward hence requiring deeper seating. Plus, you have the BT itself then encroaching powder space. Note that the Speer manual makes a big deal about some bullets with BT (eg. 24 bores) not being loaded the same as their FB counterparts.

quote:

Originally posted by 9.3x62:
What makes you think a BT will necessarily have less bearing surface? Often times they will shorten the ogive, putting the bullet shoulder more forward hence requiring deeper seating. Plus, you have the BT itself then encroaching powder space. Note that the Speer manual makes a big deal about some bullets with BT (eg. 24 bores) not being loaded the same as their FB counterparts.

Just by holding them up side-by-side against a straight edge and looking at them you can see the bearing surface is smaller on the BT's. At least the ones I was using. Or lay them on a black ink pad, then measure the length of the black area.

If I load 60, 70 or 75g bullets with the same ogive, one FB one BT, the BT must have a shorter bearing area, otherwise it would weigh more. Plus there is no problem with the smaller bullets displacing powder in the case either even with smokin' loads. On a .243 Win case, the neck is considerably shorter than a 6mm Rem (.240 vs .351) so if you are loading a .243 this might be a problem.

Am I missing something? Help!

Why do we not see higher velocities published with BT than FBs? Moreover, why do we in fact see the opposite - Speer manual 243 and 6mm for example.

The 7mm Sierra 175 BT has about the same bearing surface as a Hornady 175. However, the bearing surface is located more forward on the former, thus it must be seated deeper, plus the long BT displaces extra powder. Now, with Nosler BTs, this is less true because their tail is quite short.

There is some physics rotational stability physics implied here I woud think. If you add a long ass end to a bullet, you would have to re-apportion the front end to maintain stability.

I've used both, but prefer flat base.
Seem to shoot better in my rifles.

quote:

Originally posted by 9.3x62:
Why do we not see higher velocities published with BT than FBs? Moreover, why do we in fact see the opposite - Speer manual 243 and 6mm for example.

The 7mm Sierra 175 BT has about the same bearing surface as a Hornady 175. However, the bearing surface is located more forward on the former, thus it must be seated deeper, plus the long BT displaces extra powder. Now, with Nosler BTs, this is less true because their tail is quite short.

There is some physics rotational stability physics implied here I woud think. If you add a long ass end to a bullet, you would have to re-apportion the front end to maintain stability.

That makes sense.

A thought to keep when thinking about bullets is: What the rifle likes and not what someone tells you they like or what you think you like. I see some companies are now selling different bullets in 5-10 bullet lots so you can try them with out buying a full 100. I don't know who all does this but would seem all the bullet manufactors should do this or maybe thet do and I am behind time. I used to think, because someone told me so, that the botail was more accurate and soon found out it depends on the rifle itself. I had a 30/06 that would shoot the same with an expensive Nosler 165 grain botail, or a 165 grain flat base. What ever Mr rifle wants

Sierra gives a BC of .506 for their .308 180 grn Gameking (boatail) and a BC of .415 for their .308 180 grn ProHunter (flat base). If they both start at 2700 fps, my ballistics program says the boat tail retains about 100 fps more velocity at 300 yds.
I'm sitting here looking at both bullets and maybe there's differences in their design other that their bases that explains why the BC of the boatail is so much higher, but it really doesn't look like it.

I think the general rule of thumb is to use flat base for 100 yard work and boat tails for longer distances. Supposedly the bullets will stabilize better. Just one mans opinion. Best wishes.

Cal - Montreal