Truncated or RF?

[tgator]

Opinions please. Any difference in performance between a truncated nosed boolit as for an auto loader and a RF nose? Weights comparable, cal .45 and 900 - 1000fps. My guess is that the RF will transfer energy faster and that the truncated would have a bit more penetration. Thanks for your thoughts.



Tim

[runfiverun]

i like flat points.

[RobS]

A truncated may be better if your throats are short. You are talking about a Truncated with a flat point??? Regards to energy transfer and penetration, it depends on the meplat diameter and weight between the two boolits.

[GabbyM]

Hornady used to make a 230 grain TC-FN in 45 and a 124gr TC-FP in 9mm. Much testing was done on these two bullets. Both those bullets were the best in there calibers for making a wide long wound channel. 9mm bullet was #3556 and 45 bullet was #4518. H&G made the 9mm profile as there #309 mold. It has a slightly wider meplat and 2 more grain weight than the Saeco #377 TCFP.

The USAF designed the 9mm-124-TCFP along with the 45 caliber TCFP bullets but they were never adopted. Not sure if Hornady even makes them anymore as I don’t look at J bullets much. The Lee 230 grain TCFP is a bit of a dud as it cast a 240 grain bullet. Suppose you could mill about .030” off the top of the blocks.

Advantage of the TC design over the RNFP is the shock wave created clears the bullet sides from friction which increases penetration in flesh. The 9mm bullet was shown in ballistic clay to blow twice the hole diameter and for a deeper length than a standard 45 acp 230 grain RN ball round it was looking to replace in the M9 pistol. Military didn’t adopt it because it would not meet NATO barrier penetration test.

[Piedmont]

tgator, I would be more concerned about feeding. In .45 and 9mm there has been a swing from truncated hollow points to ogival hollow points because they feed more reliably in more guns. You could vary the meplat for penetration depth.

[Bob Krack]

If the meplat were the same size, I think it's a "Ham or Spam" question.

Not much difference either way with the girls I run with.

Bob

[missionary5155]

Greetings
Energy transfer is what we are looking for and the largest diameter flat nose is going to do that. Even if it is just .005 wider on that flat it would be a difference.
If they are both the same diameter then it would make an interesting experiment the two shot equally and cast of the same mix but I would think the RF would win in the expansion game. My personal preference is to cast soft to garentee expansion. I am not real concerned about leading if it is a one shot type hunt. If there is alot of shooting then I wll work for a clean barrel for how many shoots I might need between swabbing like in shooting rats at the dump.
Mike in ILL.

[tgator]

I guess the TC design is only made to get a flat on a round for autos that will feed. I should have been more specific asking is there any difference in penetration/expansion if both types have same alloy, weight and area on flat? Straight sides versus curved. Thanks all for your imput.


Tim

[paul h]

I'd wager you could take a dozen animals with each type of bullet and not see a discernable difference between the designs, given identicle meplat dias and impact velocity.

Generally truncated cone bullets have had smaller dia meplats than the rf style autos, I think that is what has colored alot of comments regarding truncated cone designs.

In theory with the rf having more bullet mass in the nose, you'll have less bullet in the case and hence more powder capicity. Again, I don't think you'd ever be able to detect an advantage from this very slight difference.

Personally I prefer the rf design as I think it is aerodynamically superior to a truncated cone. I don't believe for the same nose length and meplat dia you'll find a gun that will reliably feed a truncated cone and not feed and rf. If you have feeding problems with one, expect problems with the the other. It's more an issue of trying to get a very large dia meplat bull to feed in a gun that is happier with ball ammo than straight vs curved sides transitioning from meplat to full dia.

[BoolitSchuuter]

.... The Lee 230 grain TCFP is a bit of a dud as it cast a 240 grain bullet. Suppose you could mill about .030” off the top of the blocks....


I have that mould. With a 96/2/2 alloy they come out 228 - 229 grains and .452 diameter. Casting pot at 725F.

[45 2.1]

Neither........................
A good HP (correctly dimensioned and cast out of suitable alloy) will transfer energy, more of and a lot faster, into the vitals of the animal without the necessity of shooting bone or having to follow it after it ran off.