Rebated Boat Tail bullet question

[Alucard]

Hey guys,

I have tried some of the Rebated Boat Tail design bullets and was wondering, do they really make much of a difference in accuracy at long range? Or are the conventional boat tail designs fine for long range shooting?

I have only shot them as far as 300 yards, not a far enough test.

Also, what would be the ideal 300 RUM long range bullet weight and design be? Opinions of course /ubbthreads/images/graemlins/laugh.gif

Thanks for the info!

 

[abinok]

[ QUOTE ]
I have tried some of the Rebated Boat Tail design bullets and was wondering, do they really make much of a difference in accuracy at long range? Or are the conventional boat tail designs fine for long range shooting?

[/ QUOTE ]

Its my understanding that the rebated boattail is easier to form precisely than a conventional boattail, which theoreatically makes it more accurate, provided everything else is done properly. Almost evey LR record I am aware of is held by either conventional boattail bullets, or (in a few cases) flat base bullets. The conventional boattail bullets obviously shoot very will.

[ QUOTE ]
Also, what would be the ideal 300 RUM long range bullet weight and design be?

[/ QUOTE ]
I think that the "perfect bullet" would have the same criteria regaurdless of the case it is shot from...
1. High BC for weight.
2. Adaquate bearing surface for stabalization, but little enough to reduce friction for increased velocity compared to bullets of the same weight.
3. Absolute consistancy in bearing surface length
4. Absolute consistancy in base to ogive length
5. Absoulte consistancy in meplat area, and shape
6. Absoulte consistancy in jacket thickness, and concentricacy.
7. Absoulte consistancy in weight
8. Superior stability at conventional twist rates, so it is compatable with most production twist barrels.
9. Ability to maintain stability while transiting the transonic zone.
10. Devistating terminal performance on game

Of course if I was dreaming... it would steer its way into the target as well... but lets not go too far /ubbthreads/images/graemlins/grin.gif Oh and of course they would cost $5.00 per 100. /ubbthreads/images/graemlins/grin.gif

When I was picking a bullet for LR use in the RUM I primarily looked at the 200SMK, the 210Berger, the 210JLK, and the 220SMK. The RUM I was working with prefered the JLK over all others, but my 300WM likes the 220SMK.
Some of the lighter bullets will shoot flatter at close range, but getting much past the 400yd mark with any rifle whether it be a 308, or a 308/416, my nod goes to the heavies. The more powder that that case holds the heavier they get. To me the 300RUM is a case that is designed for 200-250gr bullets.
Im waiting on my 225gr Wildcats to arrive. Im hoping they will meet a good number of the above list. If they do they will be a great match for the RUM, and like sized cases.

Hopefull Kirby will be by shortly to chime in on the rebated vs. conventional boattail stuff. He has probably used more rebated boat tails (at least in terms of wildcat bullets) than anybody else on here.

 

[Alucard]

Thanks for the info abinok.

I was thinking of trying the Wildcat 200gr ULD RBHP, or the 200 gr SMK. I have shot a few different 168 gr match bullets and they shoot great. I am thinking of trying the heavier bullets for the longer shots plus the 200 gr will be flatter shooting then the 220 gr bullets. Thanks for the info!

 

[Fiftydriver]

Alucard,

The Rebated Boattail combines the best features of the flat base bullet design with the best features of the Boattail design.

As mentioned you get a more consistant and precise base with the rebated boattail just as you do with the flat base bullet. As far as pure accuracy goes, the flat base bullets are kings because they can be produced nearly perfectly consistant from bullet to bullet at least at the base.

For shooting under 400 yards there really is no need for any Boat tail bullet. And now with some of the ULD nose profiled flat based bullets such as those from Wildcat Bullets, there really is not anything out there the Flat base bullets can't do out to 1000 to 1500 yards.

Richard is waiting on some jackets to build me some 160 gr FBHP Bonded Core bullets which will have a B.C. higher then any conventional hunting bullet on the market and probably higher then most VLD bullets as well. In fact it should be nearly the same as the 300 gr Sierra Mk in B.C.

Remember that nose profile has as much if not more to do with high B.C. then what is on the end of the bullet.

So the Rebated Boattail offers some of the same advantages a flat base offers in terms of consistancy in the base of the bullet.

Along with that they also offer the advantage of the boattail at extreme range so it really is a hybrid between the two bullet designs.

There is also another advantage and that is that when case prepping there is no need for anything but a conventional case mouth deburring tool whereas to get the most out of VLD bullets the case mouth should be chamfered with a steeper angle to ease the steep angles boattail into the case without damaging it.

I personally feel that the reason you do not see more RBBT bullets winning competitions is that most comp shooters will seldom use anything that is not already being used by the top shooters.

As such it is very difficult to get a new product introduced into the world of comp shooting because unless the new product blows the doors off everything it will not be accepted as a viable option to the mainstream crowd.

With the modern bullets today and the rifles that we are building today, it is often difficult to prove one bullet is consistantly superior to another bullet, at least with top end match bullets.

For this reason, you really need to sample the best of what is out there and see what your rifle prefers and go with that bullet. I feel the Wildcat Bullets rank at least as full equals to the very best well established match bullets out there.

But hey, how can you go wrong when everyone and there dog is shooting the SMK bullets. They are good bullets but I feel most shoot them simply because they are on the componant lists of the top shooters around the country and why is that. Well first off because they are certainly good bullets, no question but also because thats the bullet that everyone has been using for decades.

I too started with the Sierra bullets and was totally impressed with their performance but then I tried some Wildcat bullets and proved to myself that my rifles on average held tighter groups and had less drop and wind drift with these bullets so I use them nearly exclusively now.

Do the same for yourself, test different brands and listen to your rifle. The best thing is that rifles are not biased by public opinion.

Now before everyone shooting Sierra bullets jumps all over my case for this, please realize that I fully realize Sierra bullets are top quality bullets and that if I built a new heavy rifle tomorrow it may well shoot the Sierra better then any other bullet.

Point is try more then one brand and see what happens!

In my personal rifles though, the Wildcats are winning nearly all the accuracy testing awards!!

As far as the 300 RUM goes, I think 200 to 220 gr bullets are about perfect for this case capacity as they reach solid 3000 to 3200 fps velocities with comfortable pressures and these bullets just work great at these velocities.

The 165 and 180s are also good but I feel the slightly heavier bullets are a better ballance for this case size.

The heavier 240 to 250 gr pills are in my opinion better suited for the 30-378 class case capacities.

Good Shooting!!

Kirby Allen(50)

 

[Alucard]

Wow, thanks for the great explination Fiftydriver. That answers alot of questions that I was having. I have tried a few of Richards bullets in 22 cal and 30 cal. I have been very impressed with the accuracy and quality in both calibers. I will have to email him and get some of the 200 gr ULD RBHPs. Thanks again for all the great info!

 

[Len Backus]

Kirby

there is no need for anything but a conventional case mouth deburring tool whereas to get the most out of VLD bullets the case mouth should be chamfered with a steeper angle to ease the steep angles boattail into the case without damaging it.

Now I am curious! I turn necks and I have been shooting Cauterucio VLD bullets without any special angled case-mouth prep. Just a normal chamfering process. I have never pulled an already seated bullet to look for seating damge. Have you actually ever seen such damage yourself?

 

[Fiftydriver]

Len,

I have not used the Cauterucio bullets so I can not comment on them but I have seen deformation on thin jacketed VLD bullets such as the Bergers with the J-4 jackets if neck tension is to high.

There is actually a slight swaging effect that occurs at the bsae of the bullet.

To be honest, the only real reason I know this is because quite awhile back when Moly was really the in thing to be using. I did some testing on case mouth chamfer angles to see which was best for using Moly coated VLD bullets.

Depending on the coating process used, the conventional chamfer angles marked up the bullets much more then the steeper angled VLD chamfering tools.

THis led me to measure bullet bases and I often found that using a conventional angle would reduce bullet base diameter by as much as 0.0003". Now some of this may have been from actual material being removed but in many cases it appeared to be more from the swaging effect of the steep anlge.

THis is another benefit of thin necked cases as they have much less neck tension when used correctly and bullet deformation is dramatically less.

Now I will also say that if your cases are sized properly to offer the correct 0.001 to 0.002" of press fit over the bullet, and your cases are chamfered smootly with no remaining burrs at all, I have not seen a problem with the heavier jacketed match bullets such as the Sierra MK and the heavy jacketed Wildcat bullets.

The steeper anlge certainly works much better when loading thin jacketed VLD bullets, espeically in cases used for big game hunting where slightly more neck tension may be desired.

I will also say that I have not proven that this actually detracts from the accuracy potential of the bullet as when it is punched in the rear by hot gases it will expand to fill any void that may have been imposed on the bullet during seating.

I have actually measured this and seen a difference in bullet base diameter with the thin jacketed bullets. Again I have not used the Cauterucio bullets so I can not say with those.

Good Shooting!!

Kirby Allen(50)

 

[3sixbits]

I would give this fellow a call and ask that question as he is best qualfied to answer your question. These swage die makers are smart folks. /ubbthreads/images/graemlins/wink.gif web page RCE Co. - Commerci

 

[moosehunter]

I have shot a few of Richards Wildcats in .30cal. Mostly 230gr. in a 300 win mag at 1000yd. I found them extremely consistant in weight and bearing surface, near to the point of it being a waste of time to check them. The other thing I found was that my brass immediatly developed donuts from one time firing and required inside reaming, no big deal problem solved. Richards bullets took my group averages of 12" to 14" down to 9' to 11", (ya, no hell I know). However I dont feel the BC is anywhere near what his tool maker told him they should be. I found that at comparable velocities the 230gr. Wildcat dropped approx. 5 feet more at 1049yds than the Sierra 240gr. Playing with the numbers on the Sierra infinity program I would put the BC on the 230gr. ULD at about .510. Now if Im out in left field and doing something wrong here please point it out because Id love to keep using Richards bullets.

 

[Fiftydriver]

Moosehunter,

I am not sure why your load is droppign that much compared to the 240 gr Sierra. Was this from actual impact heigth measurements taken in the field?

I would be curious to see your midrange tajectory figures comparing both bullets. I would suspect that the Wildcats are landing much lower at midrange resulting in your lower 1000 yard impacts.

That said, Even if they are producing this kind of B.C. value, why in the hell would you not use them if they are cutting 25% off your group averages? In my way of thinking it would be obsurd to use a bullet simply because of a slightly higher B.C. especially when they did not shoot as well as the Wildcat Bullets. I do not understand what more you need in the bullet.

I think we get way to caught up in B.C. and forget to look at the actual groups we are getting on paper and pick the best bullet that way. Personally I would give up .2 in B.C. for 25% smaller groups, bullet drop is easy to figure!!

GOod Shooting!!

Kirby Allen(50)

 

[Brent]

Kirby,

It's true, a bullet with BC's just several points lower than another will often be overlooked when in fact it's not much lower at all and downrange it would be very hard to notice on a given day which of the bullets was used. Take a look at the 200 gr Nosler Accubond. Good bullet, relatively high BC (.585), and compare it to the 210 JLK (.665). One has a distinct advantage in the wind, retained energy and offers a larger window with regaurd to range estimation error, all of which lead us to look for high BC bullets. Still, the 200gr Accubond is a good choice as well.

Giving up .2 in BC is a little too steep for me, .1 or so maybe, but it better shoot way better than the higher BC bullet did or have something else to offer cause it's going to get hammered in the wind way down range. Comparing groups on a decent day is ok with high and low BC bullets, but it's when condition get more adverse that the high BC bullet is way more forgiving.

Sierra's 240 and 300gr MK's are hard to beat. Thankfully there are more and more high BC bullets that are real close to them now days, and like you say, offering even better accuracy in many rifles.

 

[Brent]

Moosehunter,

If both bullets were good and zeroed at 100 yards, I'd say the 240 SMK has a substantially higher BC. If the Wildcat bullet printed 7-8" lower at 100 yards vs. the 240 SMK then it might be higher in BC. Hard to tell not knowing the MV of each and how well each were zeroed at 100 yards.

 

[Fiftydriver]

Brent Moffitt,

Yes I agree, wind is a major consideration. Perhaps I was goign a bit over board with my .2 drop in B.C. comment. I would agree it would be closer to .1 that I would give up if accuracy was better.

Good reply!!

Kirby Allen(50)

 

[Jon A]

Moosehunter, what exact style of bullet was that? I don't see a 230 listed in the price list Kirby just posted, so you had them made special?

So what ogive, base & tip did the bullets you shot have?

Thanks.