Varmint Bullets - Which have tangent and which have secant ogives?

[222Jim]

I'm trying to figure out which .224 cal. varmint bullets have tangent ogives and which have secant ogives.

Specifically, in the 40 to 60 grain range of .224 bullets from the (a) Berger Varmint, (b) Hornady V-Max, (c) Nosler VArmageddon, and (d) Sierra BlitzKIng product lines, which have tangent ogives and which have secant ogives.

I've looked at each under a magnifying glass, and have come close to convincing myself that Hornady V-Max are secant and the rest are tangent, but would love to find an external reference to confirm or refute my unscientific observation!

Why do I care? As a retired engineer with time on my hands, I'm trying to better understand some seating depth consistency and precision trends I'm seeing with my .222 Remington and .22-250 Remington.

 

[Tommie]

Hornady is secant

 

[searcher]

I used to try to determine the best seating depth, taking the seating characteristics of secant versus tangent ogives into consideration with the varmint bullets, as it was applied to target rifles shooting larger and longer bullets. I came to my own conclusion that, with the varmint bullets, there was no rhyme or reason why a particular small varmint bullet (such as those in the 40-55 grain range) liked a given seating depth as it related to the differences in the ogives. At least there wasn't the degree of a predictable pattern that I could find and use to cut corners, such as is somewhat the case with the larger bullets. I did find that the lighter and shorter the bullet, the more beneficial it was to have the bullet seated well into the case, even on a bolt gun and lead-free bullets tending to like that no matter the length or weight. That tends to hold true with the V-Max bullets too, from my own experience. For years, I often tried to seat them really long, as I did in my target rifles. Accuracy almost always suffered. Of course, most varmint rifle chambers are throated too long for the smaller varmint bullets, so jamming them is out of the question usually - and trying to get close leaves too little of the bullet supported in the case.

 

[222Jim]

I used to try to determine the best seating depth, taking the seating characteristics of secant versus tangent ogives into consideration with the varmint bullets, as it was applied to target rifles shooting larger and longer bullets. I came to my own conclusion that, with the varmint bullets, there was no rhyme or reason why a particular small varmint bullet (such as those in the 40-55 grain range) liked a given seating depth as it related to the differences in the ogives. At least there wasn't the degree of a predictable pattern that I could find and use to cut corners, such as is somewhat the case with the larger bullets. I did find that the lighter and shorter the bullet, the more beneficial it was to have the bullet seated well into the case, even on a bolt gun and lead-free bullets tending to like that no matter the length or weight. That tends to hold true with the V-Max bullets too, from my own experience. For years, I often tried to seat them really long, as I did in my target rifles. Accuracy almost always suffered. Of course, most varmint rifle chambers are throated too long for the smaller varmint bullets, so jamming them is out of the question usually - and trying to get close leaves too little of the bullet supported in the case.

Thanks for the fulsome reply.

In my .22-250 Sako Varmint Laminate, I have a similar experience to yours with respect to the fact I can't jump 40 grain bullets 5 Thou or 10 Thou or whatever "short" jump because the throat/leade is to long. So, I load to 0.120" of Jump and get amazing results with all 40 grain varmint bullets. For reference, based on 20 shot groups fired at 100 meters, I consistently achieve a Mean Radius of 0.16" with Berger Flat Based Varmint bullets, 0.20" with Hornady VMax and Sierra BlitzKing, and 0.26" with Nosler Varmageddon bullets. These 40 gr bullets shoot much better than heavier ones (1:14 twist FYI). I'm using Lapua brass, GM210M primers, and IMR-3031.

In my 1:12 twist .222 Cooper 51 I have different results. With 52 gr Berger Flat Base Varmint bullets, I get 0.17" Mean Radius groups (again, 20 shots at 100 meters) with a jump between 0.010" to jammed .010" (noting I do not shoot anything between a jump of 0.003" and a jam of 0.003" to avoid accidentally jamming a bullet I think is jumping). Once I increase the jump beyond 0.10", i.e., 0.020" and above out to 0.100", the groups immediately open up to a Mean Radius of 0.27". I'm using Nosler brass, GM205M primers, and IMR-4198.

The .222, unlike the .22-250, is somewhat bullet sensitive. Nosler 53 gr Varmageddon are almost as good as Berger's (0.21" Mean Radius), followed by Sierra (0.28") and Hornady (0.35").

Of course, I have tried a variety of powders in each rifle, as well as different primers, but am at a point now where I've bought 8 pounds of IMR-4198 for the .222, and 8 pounds of IMR-3031 for the .22-250. Now I'm slowly depleting my bullet and primer inventories on gophers (Richardson's Ground Squirrels up here in Alberta) and Coyotes until I only have Berger bullets and Federal GM210M and GM205M left.

But I won't get bored.....I bought a .308 Bergara HMR Pro and am starting to do load development on it.

 

[searcher]

Those 52 Bergers are sweet little bullets.

 

[Coyotefurharvester]

Secant shaped bullets have a long flat ogive with a short bearing surface. Tangent bullets have a short curved ogive and a longer bearing surface. A line touches the curve of the ogive of a Secant bullet in 2 places.

 

[Infrequent Shooter]

Thanks for the fulsome reply.

In my .22-250 Sako Varmint Laminate, I have a similar experience to yours with respect to the fact I can't jump 40 grain bullets 5 Thou or 10 Thou or whatever "short" jump because the throat/leade is to long. So, I load to 0.120" of Jump and get amazing results with all 40 grain varmint bullets. For reference, based on 20 shot groups fired at 100 meters, I consistently achieve a Mean Radius of 0.16" with Berger Flat Based Varmint bullets, 0.20" with Hornady VMax and Sierra BlitzKing, and 0.26" with Nosler Varmageddon bullets. These 40 gr bullets shoot much better than heavier ones (1:14 twist FYI). I'm using Lapua brass, GM210M primers, and IMR-3031.

In my 1:12 twist .222 Cooper 51 I have different results. With 52 gr Berger Flat Base Varmint bullets, I get 0.17" Mean Radius groups (again, 20 shots at 100 meters) with a jump between 0.010" to jammed .010" (noting I do not shoot anything between a jump of 0.003" and a jam of 0.003" to avoid accidentally jamming a bullet I think is jumping). Once I increase the jump beyond 0.10", i.e., 0.020" and above out to 0.100", the groups immediately open up to a Mean Radius of 0.27". I'm using Nosler brass, GM205M primers, and IMR-4198.

The .222, unlike the .22-250, is somewhat bullet sensitive. Nosler 53 gr Varmageddon are almost as good as Berger's (0.21" Mean Radius), followed by Sierra (0.28") and Hornady (0.35").

Of course, I have tried a variety of powders in each rifle, as well as different primers, but am at a point now where I've bought 8 pounds of IMR-4198 for the .222, and 8 pounds of IMR-3031 for the .22-250. Now I'm slowly depleting my bullet and primer inventories on gophers (Richardson's Ground Squirrels up here in Alberta) and Coyotes until I only have Berger bullets and Federal GM210M and GM205M left.

But I won't get bored.....I bought a .308 Bergara HMR Pro and am starting to do load development on it.

is your sako laminate a 75? will it shoot a 50gr flat base very well? I think some of the early 224 50 gr bullets were made w 14 twist in mind?

 

[222Jim]

is your sako laminate a 75? will it shoot a 50gr flat base very well? I think some of the early 224 50 gr bullets were made w 14 twist in mind?

It's a Model 85 with a 1:14 twist. It shoots 50 - 55 gr bullets very well, noting that my best groups (20 shots @ 100 meters) using 52 gr Berger Flat Based Varmint bullets over H380 or Varget were 0.17 - 0.20" mean radius groups.

I should note that I recently had it rebarreled after ~8,000 rounds. Why? My groups started to open up. I had the guys who did it (K.S. Arms in Edmonton, Alberta) keep the original 1:14 twist, but didn't have the barrel fluted like the original. I also had it shortened by 1-5/8". Why? I didn't need the velocity and complete powder combustion was still achieved before the bullet left the muzzle. I'd say it's marginally better now, but haven't shot as many 50 - 55 gr bullets in it simply because I have a large inventory of 40 gr bullets (that also shoot marginally better), and they are all I need on our local gophers (Richardson's Ground Squirrels) and the occasional coyote.

Oh, I should add, with respect to being able to shoot "heavier" 50 - 55 gr bullets "with precision" in a 1:14 twist, I'm 1,000 meters above sea level ( ~3,280 feet). So, the air is somewhat thinner (air pressure here ~13 psi vs. 14.7 at sea level). This adds a margin of stability to firing heavier bullets in slower twist rifles.

 

[Idaho-Lefty]

Those 52 Bergers are sweet little bullets.

Yup,.. ^^^ This,.. Along WITH,.. Hornady's 50 Gr. V-Maxes and 52 gr. ELD-M's !
My 3, most Accurate and,.. Favorite,.. .22-250 Rem., Bullets !
And IF, the Velocity IS kept "reasonable", I can SEE, the Sage Rat, "Splodies", in my 8 pound, Braked, varmint Rifle !
My Search for, .22 cal., Varmint Bullets,. IS,. over !

 

[searcher]

Yup,.. ^^^ This,.. Along WITH,.. Hornady's 50 Gr. V-Maxes and 52 gr. ELD-M's !
My 3, most Accurate and,.. Favorite,.. .22-250 Rem., Bullets !
And IF, the Velocity IS kept "reasonable", I can SEE, the Sage Rat, "Splodies", in my 8 pound, Braked, varmint Rifle !
My Search for, .22 cal., Varmint Bullets,. IS,. over !

Yeah - those 50 V-Maxes are my "go to" rat bullet. Used to be able to get 500-paks of the "Z-Max" packaging for about $50.00. Still very reasonable. Crazy accurate little bullets.