Minimum safe COL

[Tyrone Slothrop]

I've been reloading for a lot of years but I'm new to the 6.5G.

I bought a couple of Amend 2 poly mags to round out my build. Turns out cartridges loaded to the spec 2.26" can not be properly loaded into the magazine. If I seat them to 2.21" they function fine. Maybe it is an overabundance of caution, but I wanted to check with you experts before I ramp the pressure up on an already high-pressure cartridge. Am I approaching any kind of borderline here?

Loads are 120gr PPU HPBT, Starline brass, 29gr CFE 223 and 29.5gr CFE 223, Winchester WSR primers.

(Edited to reflect correct powder name)

[JASmith]

SAAMI Specs for the Grendel read in part:

MIN: 2.135 inches

MAX: 2.260 inches

First takeaway, your 2.21" falls within the specification and should be fine as long as the chamber is also compliant with the SAAMO spec..

Second takeaway, you may have a basis for returning them as defective, especially if you also have trouble loading factory ammunition into the magazines.

[Zeneffect]

Get different mags. You are doing yourself a disservice going any shorter than 2.26 if you are a hand loader.

[Klem]

Tyrone,

You can hand-load to any COAL you like, as long as (1) the pressure is at or below SAAMI, (2) the bullet does not jam into the lands when fed into battery, (3) you are prepared to hand load the longer one's individually into the breech, and (4) you have enough bullet shank in contact to keep it from moving, especially if it's being auto cycled.

Having to load shorter increases jump-to-lands, which in an AR is already longer than precision bolt guns. But, it is an auto loader so par for the course. Plus it won't have too much influence on precision in that type of rifle. Unless you are shooting very competitive competition, and those guys hand feed their overly long 223 rounds into the breech anyway - even with spec mags.

If you don't plan on returning the mags then you can still use them - just load shorter to fit and watch those concerns. To be fair, the mags should at least be SAAMI 2.26" and unless the factory ammo you buy is 2.21" or shorter then you are stuck with hand-loading. Some stainless mags can take 2.28" because the walls are thinner.

Never used that powder so someone else might be able to help with pressures.

[grayfox]

Do you mean "CFE 223" as the powder??

[lazyengineer]

Step 1 : romantic walk along river with a loved one.

Step 2 : Throw Amend 2 mags into river

Step 3 : go buy Elander's

[FBOldCrow]

Step 1 : romantic walk along river with a loved one.

Step 2 : Throw Amend 2 mags into river

Step 3 : go buy Elander's

I missed the poly in his original post. I have 5 Elander's and 3 from someone else but they're all metal mags. FWIW.

[Happy2Shoot]

I've been reloading for a lot of years but I'm new to the 6.5G.

I bought a couple of Amend 2 poly mags to round out my build. Turns out cartridges loaded to the spec 2.26" can not be properly loaded into the magazine. If I seat them to 2.21" they function fine. Maybe it is an overabundance of caution, but I wanted to check with you experts before I ramp the pressure up on an already high-pressure cartridge. Am I approaching any kind of borderline here?

Loads are 120gr PPU HPBT, Starline brass, 29gr CE 556 and 29.5gr CE 556, Winchester WSR primers.

Unless you are recording pressure vs time, you are only guessing about safety.

That said, start with a reloading book from the bullet manufacturer you are using.

If you only make one or two small changes at most, you should be fine.

If you make many changes, even small changes, you will be in unknown territory. (Example: If you change the brand of the cartridge case, brand of primer, seating depth, and brand of bullet (still the same weight), you could easily be off by 10kPSI.

[Zeneffect]

With most things grendel, factory load development isn't nearly as extensive as other calibers. You will eventually find yourself in the unknown, but hopefully you will have built the experience and habits to keep you safe on those ventures.

[FBOldCrow]

Unless you are recording pressure vs time, you are only guessing about safety.

That said, start with a reloading book from the bullet manufacturer you are using.

If you only make one or two small changes at most, you should be fine.

If you make many changes, even small changes, you will be in unknown territory. (Example: If you change the brand of the cartridge case, brand of primer, seating depth, and brand of bullet (still the same weight), you could easily be off by 10kPSI.

OK, so with the old time EXPERIENCED reloaders here, can someone please explain how switching brand of primer can do to the PSI and actual changes if they are all supposedly are to be to SAMMI specs? I have Federal and CCI mainly but have been using my few Remington primers up. And lots of people were saying during the shortage to substitute magnum for regular with no issues which i DID NOT. Or am i just ignorant? (Yes I know how the other parts of the cartridge can.)
Thanks & much appreciation for the answers.
Humbly,
Frank

[Tyrone Slothrop]

Do you mean "CFE 223" as the powder??

I do indeed. Brain fart.

[Tyrone Slothrop]

Never used that powder so someone else might be able to help with pressures.

As others have noticed, I meant to say CFE 223, not CFE 556. Unconscious metric conversion.

[Happy2Shoot]

OK, so with the old time EXPERIENCED reloaders here, can someone please explain how switching brand of primer can do to the PSI and actual changes if they are all supposedly are to be to SAMMI specs? I have Federal and CCI mainly but have been using my few Remington primers up. And lots of people were saying during the shortage to substitute magnum for regular with no issues which i DID NOT. Or am i just ignorant? (Yes I know how the other parts of the cartridge can.)
Thanks & much appreciation for the answers.
Humbly,
Frank

I keep a part of a page from a reloading magazine where they posted pressure measured from different primers. I have it taped to the inside of my self built primer magazine box. I tried to post the picture but this website needs the picture to be exceptionally small so I'll just give the fun parts here. 45 colt +P 310gr Keith cast Enforcer 21.0gr WLP 22,490 psi, and CCI#350 35,950 psi. Wow, that is a delta of 13,460 psi right there!

[Happy2Shoot]

different article, more data.

https://www.rifleshootermag.com/editorial/critical-factors-affecting-rifle-chamber-pressure/83492

[lazyengineer]

OK, so with the old time EXPERIENCED reloaders here, can someone please explain how switching brand of primer can do to the PSI and actual changes if they are all supposedly are to be to SAMMI specs? I have Federal and CCI mainly but have been using my few Remington primers up. And lots of people were saying during the shortage to substitute magnum for regular with no issues which i DID NOT. Or am i just ignorant? (Yes I know how the other parts of the cartridge can.)
Thanks & much appreciation for the answers.
Humbly,
Frank

In my own experience, very very little. I won't say all primers "are the same", because I do see different primer behavior itself. For example, S&B LR primers in a 6.5 Creedmoor with a skinny "high pressure" firing pin, will punch out a blunt the diameter of the firing pin, almost every shot. Where other primers do not. CCI400's will fail to light off a high-void charge of H335 in an ultra-weak load of 5.56, whereas otherprimers will work, CCI41's will light a small rifle primed 6.5 Creedmoor casing of 4064 at a very light charge and high void, where all other SRP in that load will fire .02-0.2 second delay hangfire in same. I have recorded a measurable amount of FPS better speed in using Blue Dot in 9mm when using magnum primers (but note, blue-dot is really too slow of a powder for 115 gr 9mm, so harder to light by a weaker primer). I tried SR primers in 9mm once, and coincidentally etched the crap out of the breach face on the slide with lots of gas-leaking around the primer diameter. I suspect the pistol pressure wasn't enough to swell the primer to seal right, so it leaked. They otherwise fired and ran fine though. I wouldn't use a SP primer in a SR, since I would expect those to punch or leak pretty easy - more than worry over ignition behavior if a standard load with little void space.

So yes, primer power level can play a roll in difficult to light powders. But when it comes to a more normal load with more typical powders, I've not really experienced one lick of difference when switching primers and for the most part just use them interchangeable, so long as same type. I don't retest a thing or worry about it at all any more. It's the gunpowder that makes it go.