primer questions

[bluetick]

I have selected two recipes that I would like to try. The first is for a 123gr HPBT projectile. It uses H322 and a small rifle primer. The second is more of a hunting bullet; 130 gr HPBT but I noticed it calls for a small rifle magnum primer. I'm curious as to why. Also, since I've never used any size magnum primer, will both the small rifle primer and the small rifle magnum primer fit a standard 6.5 Hornady grendel case? That is, are they interchangeable or does the magnum primer require a case with a deeper pocket? If there is such a thing.

[bluetick]

A little reading shed some light on this subject. The magnum primer is for recipes that call for a little more oomph to get a consistent ignition. Such as a larger grain projectile. So it's off to the LGS for some small rifle magnum primers. I hope they aren't a pain with Hornady cases; It's been my experience that Hornady cases are finicky in this regard. I once had to toss a batch of once-fired Hornady cases for 270.

[LR1955]

I have selected two recipes that I would like to try. The first is for a 123gr HPBT projectile. It uses H322 and a small rifle primer. The second is more of a hunting bullet; 130 gr HPBT but I noticed it calls for a small rifle magnum primer. I'm curious as to why. Also, since I've never used any size magnum primer, will both the small rifle primer and the small rifle magnum primer fit a standard 6.5 Hornady grendel case? That is, are they interchangeable or does the magnum primer require a case with a deeper pocket? If there is such a thing.

BT:

Both are the same size. Alexander used CCI 450 Magnum primers for all of his load testing when developing the Grendel and that is the primer he has advised. The magnum primers have thicker cups so there is less of a chance for a slam fire when shooting a AR-15. Many of us go with the CCI 450 with all Grendel loads.

For the Grendel I recommend CCI 450's.

There are a number of threads on primers for the Grendel so you may want to run a search on the forum

LR55

[KZero]

Small rifle primers are not different diameters in relation to magnum and non-magnum; they will all fit the same. Different brands may fit more or less tightly, depending on their material or tolerances. But there is no fit difference between magnum and not.

Welcome to the forum!

[grayfox]

CCI 41's are pretty close in performance to the 450 (I use the 450's like LR55 says)... this just in case your LGS doesn't have the 450's in stock.
Or another option is the federal AR-205's, these all work fine in an AR. Don't use the regular small rifle primers, go AR or magnums.

[1Shot]

First off please do not take this a a bashing of you. I am stating this for YOUR safety. If someone has to ask what the difference between a small rifle and small rifle mag primer is and their usage they should get a good reloading manual and read it so as to understand the difference and to really know how to safely hand load. Others have basically described the difference and usage but I still urge you to get a good manual and read it so you don't blow your face off. Also H332 is a pretty fast burning powder for heavy 123 and 130 gr bullets so you will run into too much pressure quickly and your velocity will be lower than powders with a slower burn rate. H322 is more suited to 100 gr and lighter bullets. You did not state which make of 130 HP bullet you have but most that heavy are designed for rounds that provide a little more impact velocity at distance than the Grendel can provide to get good expansion. I would suggest that if you are stuck with H322 that you explore 100 gr Nosler BT or Partition bullets for deer/hog size game. Good luck finding small rifle mag primers or any primers at all much less bullets and powder. I have seen some powders still available in my area but they want twice the price or more as just a few months ago.

[bluetick]

I’m not running these through an AR; they’re for a bolt action. So thickness isn’t a concern. Width and depth are, and I believe the magnums exceed regulars by about .04 in that regard.

[bluetick]

The H322 for a 123r Hpbt recipe is straight out of Hogdon’s load data. If you don’t trust that datum, barring Gel-Mann Amnesia, why would you trust anything Hogdon publishes?

[Lemonaid]

For bolt action rifles a difference to factor into your testing is that the magnum primers will withstand more pressure before failure. Practically speaking that means at the upper load levels you won't get pierced primers as soon as their non magnum brothers. Example cci 450 and cci 400.
This also means that when over pressure for the semi-auto rifles you won't seen primer evidence as soon, possibly until well over max.

[Trashy]

+1 for what 1shot said.

One should not ask for help unless one knows what it’s asking and certainly one should not reject the help offered without due consideration. Simply put the difference between 450’s and 400’s is the cup thickness.

[bluetick]

+1 for what 1shot said.

One should not ask for help unless one knows what it’s asking and certainly one should not reject the help offered without due consideration. Simply put the difference between 450’s and 400’s is the cup thickness.

I know it's not a big difference, but there is a difference in dimensions between magnum and standard. And all I'm saying is that given the finickyness of Hornady cases (based on my experience) there may be a little reluctance on the part of said primers to allow themselves to be seated properly. Also, I'm aware that Alexander Arms recommends magnum primers for all reloads for Grendel, but they are largely concerned with AR platform usage and I'm going to be using this in a bolt action rifle with a 22" barrel. Thirdly, I'm quite sure that Hodgdon wouldn't publish risky data and a given recipe should not be dismissed as such.
And lastly, I am quite familiar with magnum primers although my knowledge is strictly apriori since I've never actually used them. That's just the way I load and have done so for quite a few years.

[LR1955]

I know it's not a big difference, but there is a difference in dimensions between magnum and standard. And all I'm saying is that given the finickyness of Hornady cases (based on my experience) there may be a little reluctance on the part of said primers to allow themselves to be seated properly. Also, I'm aware that Alexander Arms recommends magnum primers for all reloads for Grendel, but they are largely concerned with AR platform usage and I'm going to be using this in a bolt action rifle with a 22" barrel. Thirdly, I'm quite sure that Hodgdon wouldn't publish risky data and a given recipe should not be dismissed as such.
And lastly, I am quite familiar with magnum primers although my knowledge is strictly apriori since I've never actually used them. That's just the way I load and have done so for quite a few years.

BT:

You will not have any problems seating any small rifle primer into any Grendel brass. Standard or Magnum. Just note that some brands of primers may seat more tightly than others. And that has nothing to do with performance.

You may find out if you look at some other performance shooting web sites that many shooters use CCI-450's in their bolt rifles because the primers are very consistent and can take the types of pressures that guys tend to get out of a bolt rifle.

Personally, I use them exclusively for my Grendels and bolt rifles.

LR55

[bluetick]

Thanks, LR. Now if only I could find some Hornady 129gr SST bullets.