Reload COL: 308 150 gr

[DustBuster]

Just Curious... I bought a bunch of PMC 147 gr 308 loads, and they measure 2.792 COL.

I’m also having someone reload me a bunch of rounds... Brass trimmed to 2.005,

Does anybody else here reload and have a favorite COL for best cycling...and also, Does anybody bother with Crimping the bullets?

Im a rookie in both building the DPMS and with reloading knowledge

Dust

[dpete]

You don't determine COL for best cycling.  You determine powder charge and COL of reloads by finding out what the rifle shoots the most accurately.  First powder charge, then COL as long as the bullet isn't jammed into the lands.  That measurement is different for every rifle.  A properly built rifle will cycle just about anything that is adequately loaded.  Get the rifle built first, then cycling factory ammo, then start thinking of making reloads for it.  In this buying panic, finding factory loads is tough and finding all the components for reloading is even tougher.

[98Z5V]

For 150gr loads for .308 Winchester, I only use that for plinking ammo, and I only load Hornady 150gr FMJ-BT projectiles.  They have a cannelure, so I seat them to the cannulure-at-the-case-mouth, and crimp them.  I crimp everything I shoot with a Lee Factory Crimp Die - no matter what caliber I shoot, no matter if it's for a bolt gun or semi-auto.

[98Z5V]

For semi-autos, I load to magazine length, or damn near it, and tailor the best load via powder charge.  For bolt guns, here's a great video detailing loaded-length:

 

 

Here's a great section,right here on this board,  for you to read:

https://forum.308ar.com/forum/34-reloading/

[DustBuster]

Ok, great info you guys... Dpete, yes I was kindof knowing the answer would be that.  Every gun and barrel will probably have the best COL for it based on the bullet and charge and playing a tad with setback some from the lands.  I just read that in the Lyman manual.  98z5v, I also have two boxes of those same plinking bullets..and with those loaded into a dummy brass at the cannelure, they are 2.710 ( .082) shorter than the pmc factory ammo I bought, with an unknown  147gr FMJ. I can experiment with those Cannulure set with 2.005 brass.

Im also having the reloader make me a few more dummies with the Hornandy bullets seated to the same COL as the new PMC, just to simulate the longer bullets as I configure my as of yet non-working gun.

They look funny and are beyond the max COL for Hornady...so I won’t ever load the live ones up that way.  I just want to see if the PMCs will load up ok on the first round. 

Thanks for info I will look at that other thread and video!

DummyDust

[98Z5V]

13 minutes ago, DustBuster said:

Ok, great info you guys... Dpete, yes I was kindof knowing the answer would be that.  Every gun and barrel will probably have the best COL for it based on the bullet and charge and playing a tad with setback some from the lands.

If you're reloading for a magazine fed semi-auto, you'll always reach max meg-length before you'll ever get to the lands in the barrel.  Fact.  Well, unless you have a cheap, shiit barrel that wasn't machined right - not a slam on you, just a fact of barrel manufacturing for these things.  If you load to max mag length, and you're in the lands on a barrel - you need a different barrel, because that one wasn't made right.

"Setback from the lands"  that you stated ties directly into the videos that I posted, and why I posted them.  Knowing where the lands are is smart, on bolt guns.  Using the lands to determine your loaded length isn't smart - because the lands erode every time you pull the trigger and send a round down the barrel.  "Off the lands" is the backwards way of doing it, and it fails you most of the time.  Erik Cortina 'splains that well, in those two vids - with excellent info to back it up. 

[DustBuster]

Roger (10-4) on shitty barrels...

I know there are case length gauges and stuff... Go NoGo gauges for head space...

So many variables.  Since I’m a cheap bugger, after blowing more than 1500 I’m sure on cheap ass gun parts(except my barrel, I think..Faxon), I might try to avoid buying a go or no go gauge.  Use the resized brass with some paper on the bolt face to check that variable..headspace.

And since you’ve told me about the magazine length most likely being well short of the Lands, I will feel better about not having the bullets blowing up or getting stuck.  Maybe just getting stuck is the major worry for that.

 If the neck was too long on brass that is what might be catastrophic.

I am gonna watch that video now... Eventually I’ll be trying to learn about other possible bullet types and sizes.  This gun could help me get a speed goat some day. That bullet would most likely be a PSP and will probably show altogether different behavior on the feed ramps... 

 

 

[Rsquared]

17 hours ago, DustBuster said:

Since I’m a cheap bugger, after blowing more than 1500 I’m sure on cheap ass gun parts(except my barrel, I think..Faxon), I might try to avoid buying a go or no go gauge.

I would hope that you're joking. After spending 1500 bucks, what's another 100 (ish)for a set of gauges that can be used on every other build of that caliber?

[Cunuckgaucho]

I personally buy the go/no go gauges, worst case you can always sell it after your done.

I'm thinking if it's possible to rent them here in Canada I can't imagine the same thing isn't available in the US. Basically you pay retail and they mail it to you, when you send it back your card is refunded minus rental cost.

[DustBuster]

I guess it would be a relatively cheap way to eliminate a jaw or eyeball flying away at a good ejection 3-4 o’clock direction 🙂. Before I spend the 50 bucks for at least one of the gauges I might try a trick I read about somewhere... glue a little rod to the dummy bullet and manipulate it through the bore, seeing how much back and forth there is with the bolt closed... maybe the 2 or 3 thousandths recommended.  Paper thicknesses on the bullet or on a go gauge... I might have the details wrong but I’d research and test much more before feeling confident.  Point taken however, 50 dollars for a gauge is 3% of 1500, not too bad for good assurance.

[98Z5V]

Good luck. 

Take pictures. 

Edited February 25, 2021 by 98Z5V

[DustBuster]

Thanks, you are right.  My English is poor on emails and threads, but a picture is worth a Thousanth, or two.  Here are 6 test Dummies I had my reloader make me up for my experimentation on feeding and maybe for go or no go practice.

[98Z5V]

I'm completely not understanding what's on your notebook. Please explain.

[shooterrex]

They headspace off the shoulder of the case not the bullet or case mouth.

[DustBuster]

This work on empty brass I sent to my reloader occurred over the last two days.

He measured the brass before resizing and after... and wrote the difference in the third column.  Since he told me trimming was wearysome and boring on his old fingers, I selected the ones closest to 2.005 and he trimmed them down for me.  He seated two bullets to the Cannulure...two near to the Hornady max COL and then I insisted he try and make me two to the same COL of the pmc Live rounds I have, which are 2.792.  He got one exact and one close.  He likes to make very detailed notes.  I’m learning a bit through this process too.  It’s surprised me that his hornady book said max COL for that bullet was 2.777, and the pmc live ammo I have is so much longer, simulated by bullet 308FC in the picture.  Different projectile even though close resemblance= different COL apparently 

[98Z5V]

42 minutes ago, DustBuster said:

This work on empty brass I sent to my reloader occurred over the last two days.

He measured the brass before resizing and after... and wrote the difference in the third column.  Since he told me trimming was wearysome and boring on his old fingers, I selected the ones closest to 2.005 and he trimmed them down for me.  He seated two bullets to the Cannulure...two near to the Hornady max COL and then I insisted he try and make me two to the same COL of the pmc Live rounds I have, which are 2.792.  He got one exact and one close.  He likes to make very detailed notes.  I’m learning a bit through this process too.  It’s surprised me that his hornady book said max COL for that bullet was 2.777, and the pmc live ammo I have is so much longer, simulated by bullet 308FC in the picture.  Different projectile even though close resemblance= different COL apparently 

Max COL is whatever the max mag length is for your magazines, in your gun, since you're shooting a semi-auto AR, and not a bolt gun.  Don't rely on the load manuals to tell you what your Max COL is - when the mag in your gun is restricting that number, and nothing else will. 

[DustBuster]

Roger on max COL limited by mag length.

I wonder if I need to need the brass necks longer to ensure good bullet seated if the cannelure is a strong 1/16th above the neck, as the dummy round labeled FC is.

That COL is close to the max for my magazine.  Even if I let the necks be longer by .01 reaching the SAAMI max of 2.015,

The Hornady cannelure would still be sticking out proud by .072”. But it would stick out more by .01” if I trim necks to 2.005.  

And thanks for that Advisory, Shooter Rex, I know about the headspace shoulder point, although I’ve never checked headspace before.  I guess I was kind of mixing together two different topics into one thread which could be Dangerous for Super Newbies.

[dpete]

2 hours ago, DustBuster said:

Roger on max COL limited by mag length.

I wonder if I need to need the brass necks longer to ensure good bullet seated if the cannelure is a strong 1/16th above the neck, as the dummy round labeled FC is.

That COL is close to the max for my magazine.  Even if I let the necks be longer by .01 reaching the SAAMI max of 2.015,

The Hornady cannelure would still be sticking out proud by .072”. But it would stick out more by .01” if I trim necks to 2.005.  

And thanks for that Advisory, Shooter Rex, I know about the headspace shoulder point, although I’ve never checked headspace before.  I guess I was kind of mixing together two different topics into one thread which could be Dangerous for Super Newbies.

A strong NO.  Trim to your 2.005 and let the cannelure come to where ever it comes to.  Your final COL will be determined by what your rifle shoots the best, not where some groove is placed by Hornady.

[DustBuster]

Okay dPete, I wont press this topic farther, I agree with you on that.  COL Concluded

 As soon as I get my dummy round I will be testing the chamber fit with my barrel, maybe renting or buying a go/no go farther along, and will start a new thread and tell you all what is happening.  The space between my Head/Skull is slowly shrinking

Edited February 26, 2021 by DustBuster
Clarification

[Albroswift]

On 2/23/2021 at 7:26 PM, 98Z5V said:

Lee Factory Crimp Die

The only way to fly. Pretty much replaced most if not all of my crimp dies with the Lee over the years. 

[392heminut]

3 hours ago, Albroswift said:

The only way to fly. Pretty much replaced most if not all of my crimp dies with the Lee over the years. 

Same here!

[Albroswift]

Non canalure bullets like the ELD and Matchking (lots of others, just naming 2 I use quite a bit)  scream "LEE FACTORY CRIMP!"

[98Z5V]

7 hours ago, Albroswift said:

Non canalure bullets like the ELD and Matchking (lots of others, just naming 2 I use quite a bit)  scream "LEE FACTORY CRIMP!"

Yes, they do.  Indeed.  Everything, no matter what it is, should be crimped with a Lee Factory Crimp Die, IMHO. 

[DustBuster]

I lucked out... my reloader Dad has all of those Factory Crimpers. He originally asked me about crimping and I didn’t know if they had to be.... but sounds like they should be.  The only thing I have done to about 125 brass is to knock out the Crimped primers of the LCity and NATO stuff.  Either I’ll be Swaugin or a chamferin with a 5/8 bit.  Lucky he had a small stockpile of primers cause remaking primers looks to be a big pain in the butt

[Albroswift]

338 Win Mag factory crimp die, extended .325 to use with the 340 Weatherby and a birdsmouth so the bullet tip clears when rotating through the progressive.