Best cartridge for silhouette

[kevinbear]

I shot cowboy silhouette before it was an nra sanctioned event , I used a 30-30 with cast bullets loaded with 8 grains of unique topped with super grex, velocity was 1100 with a 150grain bullet, that load took cpt just fine. I switched to a 170 cast for the rams with 18 grains of 4759, I do not remember the exact velocity of that load but it was less than 1800 from my marlin 336A. These were cast with Lyman molds and gas checked, on occasion I had trouble knocking down pigs but other than that never lost an animal in spite of these being very low energy and velocity loads. A friend of mine and I shot matches for several years with that gun and loads.


I got to looking back at some old notes and I used a load of 31.0 grains of 4064 and a 170 Lyman flat point on rams, this was still nothing on par with what we use on 500m rams
yet knock them down like gangbusters. So what is the explanation? I didn't sprinkle any magic dust on those wheelweights before they melted, one can only assume that the flat point and rather direct angle of approach transfered every possible foot pound of energy to the target.
To bad we don't know some pointy headed engineer that could write a five paragraph dissertation on the subject...wait we....

[Jason]

Are you sure the angle of impact from that big point bullet at 200 meters was so much less than the angle of impact from the sleek, high-BC bullets we use at 500 meters?

[kevinbear]

Pretty simple really, with a chicken zero at 50 yards top of the back or slightly higher will drill a ram at 200 yards with a 30-30, try that with a 260 or 7-08 at 200m and 500m, it's not even close.

[Jason]

Didn't the other thread establish that the angle of impact even with the slower, heavier 7mm bullets on the rams at 500 meters was so shallow that it made no appreciable difference? The way you are talking, it sounds like they're coming in at a 40+ degree angle and just glancing off the rams.

[kevinbear]

Two real life experiences lead me to believe this to be true, seeing bullets impacting targets then skipping into the dirt below. Second, somewhat intact bullets found at the ram line that have the appearance of being glanced off a steel target. Most ram settings are somewhere between 11.5 to 13 on a leupold scope unless your useing big bullets in a dog cartridge like 7br which you have to crank up a full revolution + 1 or 2. That's about 4 to 5 minutes higher which at rams is a couple of feet, doesn't sound like much but when you visualize it remember bullets are not straight cylinders, they have a long hollow angled point that at some point becomes much more susceptible to glancing off. I've never bought into the bad bullet theory when people tell me stories about how their 308 with 190's failed on a ram, usually they have it loaded down to something in the low 2000's like 22 or 23 and the scope a full rev + up. The bullet glanced off, it's that simple.

[Jason]

I haven't ever seen any data here or anywhere else to support that. A bullet impacting at 1 degree downward angle isn't going to "skip off" a flat target facing the shooter, perfect tube wadcutter bullets or the sleek .500+ BC bullets that most use for rams, freshly painted or not. If it doesn't happen with BPCR bullets with much higher arching trajectories, it surely isn't going to happen with highpower bullets going much faster and striking the targets much more directly. If you find a bullet that stays intact when shot at any of the velocities that we've discussed for highpower silhouette use in this thread, please find out what bullet that is! It's the "holy grail" tough bullet that we've all been looking for.

[kevinbear]

I don't believe anything I say at this point is going to convince you Jason or Dan of my beliefs on lost targets, furthermore it occured to me this morning at 430am while I was waiting for the sun to come up { I was collecting data on the vulnerabilty of the Merriams turkey to #5 shot} that the 162 amax's I shoot in my 7mm ihmsa topples rams with boring predictability and I don't really care if anyone else's gun and load won't.

[Jim Beckley]

This will be my last post on this subject (PROMISE), far as data collected, examined and finally tested, this is what I have learned. I did 8 years in a Field Artillery unit, which is just shooting on a much larger scale. Data was collected at the Yuma Proving grounds and Aberdeen, Maryland using the latest greatest equipment and the best engineers that the tax payers could get (yeah right it was a government job so the leader of the project was probably promoted from his last job, simply because he was incompenent, so was booted to the next level, so he would't screw anything up, the stamped employee, sex, creed, color, and of course the suck ass or two, and the ones that knew nothing about the subject but were grabbed from the hey you roster), no matter what method was used to gather the firing data from charts and darts to the latest at the time an HP-71 hand held computer, there was always two sets of data. The should hit and the did hit. My advise to anyone out there that lives and dies with their computer data, always go with the did hit!

[Snake]

FYI to DanDe---my 7 mm PPC 40 degree was designed in 1986 with JGS making the reamer to specs...and I'm sure i wasn't the first one. We also reformed brass 7.62x39 cases since they were cheaper and used large rifle primers (the cups are a little thicker) Oft-times I think slower may be better but a steep approach angle is just a bad thing period unless your projectile is proportionately weightier (hence 400+ gr 45/70 lead at a muzzle of 1200 fps works virtually 100%). I suspect that a lighter jacketed bullet requires more speed commensurate with the weight loss (which also improves the approach angle). At some point light can just be too light no matter how hard the impact. Remember velocity is shed geometrically..the faster it goes the faster it slows geometrically...gravity you know. We also noticed that the rams need to be turned to keep them from bowing/distorting with use...otherwise the center hit is deflected down and out instead of back and down So the question begs...what's best for Rams?...Depends on the range and what works well there...otherwise we're stuck with "mostly" and "overall" and "very good". It is after-all an outdoor game...and there ain't no free lunch.
And by the way i thought only Mcalice would be cutting open perfectly good bullets to see what's inside!

[Bob Mc Alice]

I like to cut metal, it's what I do best.

[Snake]

OH Bob Mc..!! I could really really make a smart ass comeback ...but i won't as i am trying to turn over a new leaf

[Innocent]

A lawyer turning over a new leaf?

Innocent

[DanDeMan]

Ladies and Gentlemen,

Since several posters have said the 7mmBR is marginal on rams, I thought I'd copy part of a 7mm TPP (tight-necked 7BR) range report from back in September of 05.
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Remington 71/2 primers and VVO N150 powder were tested along with heavier charges of the VarGet and H4198 Extreme. These last two powders were tested during the first testing session. For moly-coated bullets in the 168 to 180 grain range in the 7mmBR, VarGet has shown to be the powder that delivers high MV’s and great accuracy. However, with naked bullets, N150 is looking mighty good. If you think the 7mmBR does not have the stuff to whack rams, the N150 produced MV’s above 2,500 fps (launching the 175 SMK) with no pressure problems. As a matter of fact, the heaviest charge tested, 35.0 grains of N150 produced an average MV of 2,521 fps. Probably the case will accommodate 36.0 grains of powder, but I don’t know if pressure problems will make loads heavier than 35.0 grains of N150 unsafe in my rifle. From extensive experience it has been shown that a bullet like the 175 Sierra MK only needs to be launched to 2,300 fps to be more effective on rams than the hottest 260 Remington out there, and I do mean that in spades.
========================================

Here's a picture of the 7mm TPP. The round on the left has a 177-gr Cauterucio and the one on the right a 139 SST. The 7mm TPP launched those Big Bad Boys to just under 2,500 fps. A load like that will knock rams silly with just 35.0 grains of N150. Ram-line momentum = 1.45 ft-lbs per sec.

[lone ringer]

Dan, where you using the Lapua 6mm BR brass or the 7mm BR Rem brass?
The reason I am asking is to warn people thinking that they will be able to duplicate your loads on run of the mill 7mm BR chambered rifles with Remington Brass. Also were you using a Remington action and was your bolt bushed?
Thank you

[DanDeMan]

Dan, where you using the Lapua 6mm BR brass or the 7mm BR Rem brass?
The reason I am asking is to warn people thinking that they will be able to duplicate your loads on run of the mill 7mm BR chambered rifles with Remington Brass. Also were you using a Remington action and was your bolt bushed?
Thank you

Tony,

Good point. Yes, Lapua 6BR brass was used. And, no Jared Perry's RemShortAction's firing-pin hole was not bushed. It was his rifle, built by MetalHead (Marvelous Marvin Pearson), that I used for the reported testing. Jared's rifle had a standard 0.080" firing-pin. Years ago I purchased Imas' 7TCU silhouette rifle that a lot of guys laughed at before the matches; not so much after the matches. Anyway, I had the barrel (9-twist Douglas) setback and rechambered with a tight-necked reamer in 7mmBR. That little bugger would launch the 168-gr, JLK VLD's to 2,450 fps with zero pressure problems, super accuracy and 100% ram performance.

Like that epic line in the movie Cool Hand Luke, "What we have here is a failure to communicate." I've heard over the course of many years that the 7BR is too weak for HP Pistol Silhouette and doubly so for HP Rifle Silhouette. Now, those naysayers that actually tried a 7BR and suffered poor ram-knockdown results should have said is, "I couldn't get it to work for me." That's way different than saying it will not work. And, as I've learned over 32 years of silhouette shooting, many trash-talking the 7BR are simply repeating received wisdom.