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All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: CarsonRatSniper on October 06, 2013, 11:02:03 PM

Title: What is the MOST ACCURATE nose profile?
Post by: CarsonRatSniper on October 06, 2013, 11:02:03 PM
What is the nose profile that proves to he the most accurate in your guns?
I'm looking specifically for people shooting cast boolits out of their Airguns but Diabolo style pellets apply too.

I'd like to hear your opinion as to WHY you think that particular style shoots the best (if you have one other than 'because it just does).

I'm looking at making the most accurate boolit with the highest BC.
Right now I'm having an internal battle over Conical vs Round nose (like a rimfire bullet).

#1 = Accuracy
#2 = High Ballistic Coefficient
#3 = Penetration

What's your experience on majority of what has met these 3 criteria the most consistently?

Please base your answer on real world, off the bench results.

Thanks in advance!!!
Title: Re: What is the MOST ACCURATE nose profile?
Post by: Motorhead on October 06, 2013, 11:49:20 PM
Velocity and Range ones shooting plays a HUGE role in that question .... Sorry to say NOT so Black or White a question  :P
Title: Re: What is the MOST ACCURATE nose profile?
Post by: CarsonRatSniper on October 06, 2013, 11:53:14 PM
Agreed
Velocity window = 850-950 fps
Range = 25-75 yards
Title: Re: What is the MOST ACCURATE nose profile?
Post by: Motorhead on October 06, 2013, 11:56:21 PM
Agreed
Velocity window = 850-950 fps
Range = 25-75 yards

 As stated .... DOMES
Title: Re: What is the MOST ACCURATE nose profile?
Post by: mcc1961 on October 07, 2013, 01:11:17 AM
My mrod likes the benji domes and AA in .25 the best.My disco shoots the CPHP's  better than anything else I have tried.
Title: Re: What is the MOST ACCURATE nose profile?
Post by: Nomadic Pirate on October 07, 2013, 01:35:08 AM
is Hunting involved, or it's just a target shooting matter ?
Title: Re: What is the MOST ACCURATE nose profile?
Post by: CarsonRatSniper on October 07, 2013, 04:54:15 AM
100% hunting :)
Title: Re: What is the MOST ACCURATE nose profile?
Post by: Nomadic Pirate on October 07, 2013, 05:14:01 AM
the low speed of airguns will aloud bullets with a good Meplat to be just as accurate as dome pellets and round nose bullets,.....but, the bullet with a decent Meplat will be significantly more efficient in hunting situations.


Check out SubSonic, "Julius" .25 cal bullets,...just perfect.

I used to shoot the 158gr Snakebite out of my Career 201 and that was one incredible accurate hunting bullet

Title: Re: What is the MOST ACCURATE nose profile?
Post by: CarsonRatSniper on October 07, 2013, 07:50:57 AM
I agree with a meplat 'hitting harder' as far as shocking the target and transferring energy, but I believe if the meplat is not perfectly square it may cause some instability issues in flight. There are other variables but from an airgun bullet standpoint I'm not convinced about a truncated cone style.

I ordered some 43.2 grain Eun Jins to beta test a conical design in my TJ barrel but they are backordered.

I have 3 choices of round nose for my die:

1/2 E - one half caliber elipse which is basically cylindrical like old Sheridan pellets

3/4 E - three quarter caliber elipse which is more like a Kodiak nose profile

1 E - one caliber elipse which is essentially a 22 LR rimfire nose profile

Experience has shown the 1/2 E cylindrical design to be the most accurate in airgun barrels, but I'm shooting a PB barrel designed for 50 grain bullets in my velocity spectrum.
The 1 E tends to be nose heavy in shorter bullet designs causing instability.

I'm seriously leaning towards the 3/4 E. I believe its the best balance of weight forward design, low frontal drag for a good BC and in between a dome and conical in regards to penetration.

It looks like most everybody (myself included) is voting roundnose/domes.
Title: Re: What is the MOST ACCURATE nose profile?
Post by: rsterne on October 07, 2013, 09:56:10 AM
Pointed pellets, like the EunJin, do not have as good a Ballistics Coefficient as a true round-nosed profile.... and neither do domed pellets like the EunJin Dome or RWS SuperDome (.177 and .22 cal) or Gamo Hunter.... I suspect some of that is the sharp shoulder where the nose meets the front driving band at the head.... For maximum BC, either a true round-nosed pellet (JSB Exact, Crosman / Benjamin Domed, H&N FTT) or the round nosed / slightly tapered pellet (H&N Baracuda / Beeman Kodiak / RWS SuperDome .25 cal) are the best choice in a diablo (waisted) pellet.... For a given weight, the penetration of pointed and round-nosed designs are very similar, and are superior to domed, wadcutter, or hollowpoint designs....

A SMALL Meplat or hollow-point on a round-nosed pellet should not have a lot of effect on the BC, but it will have some.... It WILL decrease the penetration and increase the diameter of the wound channel.... moreso if the pellet is soft enough that it expands / flattens at the velocity in question....

Bob

Title: Re: What is the MOST ACCURATE nose profile?
Post by: CarsonRatSniper on October 07, 2013, 10:10:51 AM
What's your take on nose design of a single diameter straight bodied bullet? (excluding true spire points).

Any results yet on the Dutch bullets?
Title: Re: What is the MOST ACCURATE nose profile?
Post by: rsterne on October 07, 2013, 02:11:19 PM
I don't think you can make a generalized statement about the accuracy of different bullet nose shapes at close range.... Once you factor in the wind, the better the BC the more likely you are to hit what you're aiming at, however.... so the same thing applies to bullets as to pellets in that regard.... with the ultimate being boat-tailed spire-points....

I really don't think the nose profile is near as important as getting the base perfectly square so that it releases evenly all the way around the crown.... I mean why spend all that time striving for a perfect crown and then use a bullet with a crooked base, or one with a rounded edge on one side.... I would venture to guess that only about 10% of cast bullets could be considered to have a perfect base.... My understanding is that the old-time bench rest shooters used to chuck all their cast bullets in a collet in a lathe and turn all the bases perfectly square.... From the cast bullets I have seen and made, I can understand why....

I'm still hoping to get a chance to test the Dutch bullets before the snow flies....  ::)

Bob
Title: Re: What is the MOST ACCURATE nose profile?
Post by: CarsonRatSniper on October 07, 2013, 02:56:28 PM
The bases are exactly why I've decided to swage - the bases will be square and identical due to the base punch.

I've considered an elongated conical nose design to get close to a spire point but I don't believe it will be all that beneficial due to the velocities I can drive them at (sub 1000 fps).

That's why I'm polling for a nose design consensus.

:)

I'm looking forward to your Dutch tests........
Title: Re: What is the MOST ACCURATE nose profile?
Post by: rsterne on October 07, 2013, 04:06:45 PM
IIRC, aren't the subsonic "stealth" sniper rounds used by the Seal Teams, etc., a boat-tail spire-point?.... It stands to reason that you still want the best possible BC, even with a subsonic bullet....

I found the link I was looking for....  http://sadefensejournal.com/wp/?p=1318 (http://sadefensejournal.com/wp/?p=1318)

740 gr. brass .50 cal boat-tail spire-point at 970 fps (1550 FPE).... up to 1173 gr. at the same velocity (2450 FPE) for the Armour Piercing version....

Bob
Title: Re: What is the MOST ACCURATE nose profile?
Post by: CarsonRatSniper on October 07, 2013, 04:16:28 PM
Point taken (pun intended)
;)
Title: Re: What is the MOST ACCURATE nose profile?
Post by: Nomadic Pirate on October 07, 2013, 05:14:34 PM
In the real Hunting World at those ranges at that power the accuracy difference from a pointed round to a flatnose round is negigable, a dime group is as good as a Nickle group.

therefore for hunting the flatnose is significantly superior than any round/pointed bullet,.....target shooting is a different cup of tea ;)
Title: Re: What is the MOST ACCURATE nose profile?
Post by: lefteyeshot on October 07, 2013, 07:14:46 PM
For punching paper wadcutters have been the best for me, RWS, Crosman, Gamo. Peak are good in some of my guns and they're cheap. I ordered 1000 each of .177 and .22 a couple of month ago and only got a few hundred .177 left. I use the Peaks alot zeroing to get close or to chrony and check trigger pull. Has anyone used that Gamo Speed Oil. It's suppose to make for better groups. Seems to work with some of my guns in .177, .22 not so good. It cost to much. Later.
Title: Re: What is the MOST ACCURATE nose profile?
Post by: oddtodd on October 07, 2013, 07:27:23 PM
I like my cphp's in .22. THey aren't that expensive and they are accurate enough for me. In .177 I like crosman accupells. Again, they aren't that expensive and they work well in my guns. THe hollowpoints have too many fliers in .177 for my taste. I only hunt with my .22s though. The rest are target and pest only. I pest a lot different than I hunt. When I am hunting, I am in full camouflage being as quiet as I can, moving slowly, etc. When I am pesting, I am usually on somebody's back porch just shooting the breeze with a CO2 rifle or breakbarrel sitting ready. I take the shot when I am pesting, where I usually make the shot hunting, if that makes sense.
Title: Re: What is the MOST ACCURATE nose profile?
Post by: jessered on October 07, 2013, 08:30:45 PM
Give me till the weekend and I'll let you know what I think about .25 50 gr hollow points from mrholllowpoint. See what happens when a Sumatra carbine pushes em down range.
Title: Re: What is the MOST ACCURATE nose profile?
Post by: CarsonRatSniper on October 07, 2013, 09:12:09 PM
NP - True, but why sell yourself short? You never know when you may want or need to stretch the legs out on your gun to the extreme. The highest BC possible while maintaining supreme accuracy is what I'm after. If I have those 2 nothing else matters as I will simply punch a hole through the kill zone.

Lefteye - I use Napier's Power Pellet Lube. It looks exactly like Gamo's, just rebranded. Expensive - but 2 bottles have lasted me a few years. It allows me to go longer between barrel cleanings.

Oddtodd - That makes sense but either way your lining up crosshairs and pressing off a shot.

Jessered - Got a pic? Try them at long range too if you get a chance (75-100+ yards). Pay special attention to how uniform and square to the bore the bases are on each bullet before you load and shoot it, if you don't mind. Maybe see if one looks a bit squirrely if That seems to have affected POI.

Thanks for everybody's input so far!


Title: Re: What is the MOST ACCURATE nose profile?
Post by: Nomadic Pirate on October 08, 2013, 03:01:26 PM
An Other great Bullet shape for airguns is the EPP/UG,
nice round nose for good flight and the sharp front band cuts a beautifull hole, the design with the 2 narrow bands is excellent for minimal barrel contact