[762Pilot]

So, I bought this Nikon M-308 scope that is set up for a .308 diameter round with a calibrated ballistic curve, marked on the elevation turret, for a ballistic coefficient between 0.453 and 0.473, at a muzzle velocity of 2680.
No problem, says I…
Only thing is, because it’s for a 22 inch barreled M1A, I want a load that is CRIMPED INTO A CANNELURE.
I don’t want to hear how that is not necessary; it’s what I want.
I hand loaded for over a decade for an M1 Garand, and I would only load crimped rounds into a cannelure. (Hornady SST 150 grain part number 30302, as I recall…I think the part number is right. The remaining rounds in their box are two floors down and I don’t feel like going down there to look at it now.)
Back in the day, I participated in handloading 168 Grain Sierra MatchKings, with no cannelure, relying on neck tension alone with the snappy action of the M1. It worked, but I would not rely on it in all conditions. I had a DCM gun and only fired in matches, not in the field.
I’m looking for that kind of a load but with positive interference between the neck and the bullet. That is to say, A cannelured bullet that is crimped in.
Yes, I know, I could hand load it…

Handloading ing sucks.

I did for years. And I had weighed every charge. I don’t believe in this bullshit of throwing by volume, even though it works most of the time. That’s just not the way to go. I’m an engineer, and powder charge energy is by mass, not my volume, strictly speaking. Yeah, I know factory loads are charged by volume, but not the way home handloaders do it; there are sampling and calibration methods that Joe Blow doesn’t have access to. And I still think it’s bullshit.
Anyone know if the load, at any cost, with that kind of a BC?
I’m looking for a standard production load; I don’t care about the money. I will probably only fire 300 rounds of this in my life.

if I never pull the handle of a goddamn RCBS press again it will be too soon…

 

[smoothy8500]

I don’t believe in this bullshit of throwing by volume,

 

[smoothy8500]

I'd like to help you out......




















Which door did you come in from?

 

[Grizzman]

Come in….tell us how your really feel.

….though I personally don’t agree with some of your self imposed rules, I’m not gonna waste my time trying to change your mind.

 

[smoothy8500]

Anyone know if the load, at any cost, with that kind of a BC?
I’m looking for a standard production load; I don’t care about the money.

Maybe try SnipersHide? They are fairly informed.....and seem to share similar sentiments, or at least the same vernacular.

 

[RAMMAC]

You're probably not going to get a lot of help, most people will take your language as being a reflection of a demanding, inflexible person that probably will argue over every detail of anything they say.

 

[WaM14gunner]

 

[Sorry Dude]

It worked, but I would not rely on it in all conditions.

What conditions are you shooting in? The various cannelure crimp loads depend on the conditions you are in. We would have to know these conditions.

I’m looking for that kind of a load but with positive interference between the neck and the bullet. That is to say, A cannelured bullet that is crimped in.

Are you using a Turbo Encabulator? The Turbo Encabulator will give you the specific load based on your varying conditions. Perhaps some of the older members here could help you with this.

 

[KurtC]

Looking for a 168 Grain crimped load

Where do plan on finding a 168 grain bullet with a crimp?

 

[762Pilot]

Seen them online. I want to say an A-Max or something. I remember it had a plastic tip and three cannelures.

 

[luigi]

Seen them online. I want to say an A-Max or something. I remember it had a plastic tip and three cannelures.

Like this?

Barnes Tipped Triple-Shock X (TTSX) Bullets 30 Cal (308 Diameter) 168

The Barnes Tipped TSX features a 100-percent copper body with rings cut into the shank. A polymer tip boosts the ballistic coefficient, improves...

www.midwayusa.com

 

[762Pilot]

Sorry, Barnes TTSX.

 

[Grizzman]

To help you find your answer, here are three options.

Most manufactured ammo uses bullets that are available to handloaders as components. The BC is always stated in the specs of the bullet.

Option 1 -
Step 1 Find a bullet with a BC that meets your requirements that has a cannelure.
Step 2 Find and purchase one box of every ammo option using this bullet driven to approximately the correct velocity.
Step 3 Shoot all varieties of this ammo through your rifle over a chronograph to determine which one has the required velocity
Step 4 If successful, go buy 1,000 lottery tickets, since you just accomplished the impossible, and luck is on your side. If not successful, see option 3 or 4.

Option 2 -
Step 1 Contact Nikon to ask them for recommended ammo that meets the requirements of their scope
Step 2 Buy and shoot all varietes of this ammo hrough your rifle over a chronograph to determine which one has the required velocity
Step 3 If successful, go buy 1,000 lottery tickets, since you just accomplished the impossible, and luck is on your side. If not successful, see option 3 or 4.

Option 3 -
Sell the optic and buy one that doesn't have a stupid BDC requirement.

Option 4 -
Shoot the ammo you prefer (at distance) and come up with your own ballistic data based on actual results.

 

[RAMMAC]

Barnes TSX and TTSX bullets do not have a cannelure, those groves are not designed for crimping. The grooves are designed to reduce fouling, reduce pressure, and increase velocity due to less surface area contacting the bore and the edges of the grooves tending to push fouling out of the barrel.

Hornady is the only manufacturer that makes anything close to what you want, it's their 165gr SST. The G1 BC is advertised as being .447 but testing done by Bryan Litz produced a G1 BC of .437.

 

[762Pilot]

Yeah, I know why the groups are there on the TTSX. I’m pretty sure they would make a good taper crimp cannelure.
I’ve seen other group configurations than a rolled cannelure; Aussie F4 surplus has (had) an asymmetrical groove as the crimp shoulder.
I have been advised that a Lee Factory Crimp Tool works well for this purpose.

 

[762Pilot]

Grooves, I mean

 

[charlie98]

Yeah, I know why the groups are there on the TTSX. I’m pretty sure they would make a good taper crimp cannelure.

It depends on what the OAL would turn out to be, crimped into the front band... it may or may not be the correct OAL for your rigid requirements.

 

[762Pilot]

Already thought of that; when I worked up the loads for the Garand I started low and chroney’d the rounds in 5-shot batches with IMR 4895 till they were 2740 about 15 feet from the muzzle.
Volume in the cartridge case would be decreased with deeper seating but that would show with velocity vs charge. No doubt IMR 4895 has the appropriate burn rate for the M1A. Port pressures and all.
I’m putting rounds through a 22 inch barrel; standard length.
It did occur to me to use the Hornady SST 165 grain with the cannelure, but I really wanted to be able to just dial the scope in and have the BC reflect the ballistic drop curve for distance.
Yeah, I know I could get a scope in mils, and then do the math and blah blah blah. I know the trig. I just thought it would be cool to have one that roughly correlated with pre-marked yardage.
I couldn’t go to Nikon for a custom turret anyway because they are no longer in the scope business. Or such is my understanding.

 

[RAMMAC]

🤣🤣

Wow.

 

[Cranky182]

1. Sell the bdc scope and then use that money for a new one without the bdc
2. Do as others have said, buy a truckload of ammo and then try to match it up to the bdc
3. Start reloading again to make sure you have your magical bullet & bdc combination
4. Buy lottery tickets after attempting #2
5. Contact the bullet manufacturer’s and see what they recommend for your required bullet/ ammo configuration.
6. All else fails, get a non bdc scope