Prime Brass

[ReaperDriver]

I got a decent deal on Prime head stamped .260 Rem brass from powder valley to complement my Lapua .260 stash. The intent was to use them for "training" in a new Gas gun build that I hope to start shooting soon once the Upper from JP arrives. Anyway, out of curiosity - I loaded up about 50 rounds of the Virgin brass using the same load I shoot in my AI AT .260 bolt gun. I'm shooting 42.8 of 4451 with a Berger 140 Hybrid and am getting about 2910 fps using a Lab radar. That load in Lapua brass is 1/3 MOA and is a hammer out to 1300 yds. I loaded up some of the Prime brass with the same load, keeping everything the same except the brass. Lab radar velocities are pretty much identical and accuracy was good - both at 100yds for groups as well at at long range on steel. Very good in fact. As good as the Lapua.

However, after 1 load, about 25% or more of the primer pockets were smoked. I had several blown / pierced primers at the first session with the virgin brass. When I went to reload the ones that didn't blow a primer, several of the new primers literally fell out in the loading tray.

The only thing that seems different from the virgin Prime vs virgin Lapua was the headspace. The virgin Prime was a good 6-8 thousandths less headspace than the virgin Lapua. How do I get around this issue without blowing out all my new Prime brass? Just load it light to fireform it?

 

[918v]

Did you compare the case weight to your Lapua brass? Maybe Prime is heavier thicker brass with less capacity?

 

[XLR308]

I would have personally stopped when it started blowing and piercing primers.
If the headspace on the new brass concerns you just run a moderate pressure load with a light jam.

 

[ma smith]

Is the Prime headstamp brass Lapua or a different OEM?

 

[TxWelder35]

2910 with a 140 is smoking fast out of a 260.

like so smoking fast you are going to blow primers and ruin primer pockets in very short order.

im running 2860 FPS out of a 26” barrel bolt gun and that still fast.

you need to back way down.

For why it’s hotter, it probably has smaller interior dimensions, which means more pressure than the same load in a larger capacity case

 

[TxWelder35]

Is the Prime headstamp brass Lapua or a different OEM?

Original prime headstamp brass was made by RUAG

 

[PrecisionRifleGuy]

If you get different brass you absolutely need to rework your load to make sure it is safe. This is part of basic reloading safety.

Please get a reloading manual and read it.

 

[Baron23]

Original prime headstamp brass was made by RUAG

But is this legacy Prime brass or the new Peterson brass that Jim is using now?

Anybody know if the new brass is still stamped Prime or does it show Peterson?

I have a few cases on back order with Prime and decided to wait for him to ship them with 130 gr SMK in the summer....so, just curious how the new stuff is stamped.

 

[Average guy]

I believe the new American made prime has a Peterson head stamp

 

[ReaperDriver]

But is this legacy Prime brass or the new Peterson brass that Jim is using now?

Anybody know if the new brass is still stamped Prime or does it show Peterson?

I have a few cases on back order with Prime and decided to wait for him to ship them with 130 gr SMK in the summer....so, just curious how the new stuff is stamped.

They appear to be an independent company out of Las Vegas. https://www.primeammo.com/about-prime-ammo

Not sure if they contract with other brass manufacturers or not.

 

[ReaperDriver]

Did you compare the case weight to your Lapua brass? Maybe Prime is heavier thicker brass with less capacity?

Yep, the Prime brass weighted LESS than the Lapua, so therefore should be more case capacity and theoretically less pressure. The Virgin Prime stuff weighed about 164.5 gr and the virgin Lapua was 173.5. That weight was the average of 10 cases each.

That's why I didn't do the traditional load workup, as it should have needed a higher charge to get to the same place as my Lapua. I fully expected to see lower velocities than my Lapua.

 

[Baron23]

They appear to be an independent company out of Las Vegas. https://www.primeammo.com/about-prime-ammo

Not sure if they contract with other brass manufacturers or not.


View attachment 7535653

Hi friend - yes, I am familiar with Prime and no....they do NOT manf anything.

They do have a contract manf building cartridges to their spec including the brass.

Just wondering if anybody knew if the new Prime ammo (their relationship with Ruag is....well, on the rocks would be an understatement) also carried the Prime head stamp. If not, then its a way to tell old (Ruag) from new manf.

 

[camocorvette]

You should weigh brass and check case capacity. If its heavier and thicker. Your case capacity is decreased. Same charge of powder is gonna be higher pressure...

 

[ReaperDriver]

2910 with a 140 is smoking fast out of a 260.

like so smoking fast you are going to blow primers and ruin primer pockets in very short order.

im running 2860 FPS out of a 26” barrel bolt gun and that still fast.

you need to back way down.

For why it’s hotter, it probably has smaller interior dimensions, which means more pressure than the same load in a larger capacity case

I would have thought so too. But I'm not getting any excessive pressure signs or swipe out of the Lapua and the brass has lasted 10-12 loadings with the same load. It's definitely a very "warm" load but no flattened primers or swipe that you would expect from overpressure. I'm also shooting a 26" bbl in an AI platform.

Interestingly, the speed has increased over time with the same exact load combo of brass/powder charge and Bullets. The same load started off around 2860 fps and just recently I've been chronoing it above 2900. And I haven't changed anything. Still excellent accuracy as well. And the weird thing is it's gotten faster as the winter temps here have gotten colder. I would have expected the opposite. I've shot this in the summer when it's been above 100F and now when it's around 50-60F, the speed has actually increased.

 

[ReaperDriver]

You should weigh brass and check case capacity. If its heavier and thicker. Your case capacity is decreased. Same charge of powder is gonna be higher pressure...

Nope. See post #11 above. The Prime brass is about 9 grains lighter than the Lapua, so should have been just the opposite.

 

[XLR308]

Yep, the Prime brass weighted LESS than the Lapua, so therefore should be more case capacity and theoretically less pressure. The Virgin Prime stuff weighed about 164.5 gr and the virgin Lapua was 173.5. That weight was the average of 10 cases each.

That's why I didn't do the traditional load workup, as it should have needed a higher charge to get to the same place as my Lapua. I fully expected to see lower velocities than my Lapua.

They may be very similar in weight but more importantly internal volume.
The major difference most likely is the Lapua brass has a stronger case head and is less susceptical to yeilding at equal pressure.
I have heard others say Norma brass is softer and doesnt last as long and doesnt handle pressure as well but it is high quality brass.

 

[TxWelder35]

Nope. See post #11 above. The Prime brass is about 9 grains lighter than the Lapua, so should have been just the opposite.

Weight of the brass itself doesn’t matter. Put the case on your scale, zero it out. Then fill it with alcohol or water so you are getting the weight of the water itself, then do the same with the Lapua brass. I’ve also used really fine ball powder and vibrated it as it went in to make sure it was all settled.

 

[spife7980]

Weight of the brass itself doesn’t matter. Put the case on your scale, zero it out. Then fill it with alcohol or water so you are getting the weight of the water itself, then do the same with the Lapua brass. I’ve also used really fine ball powder and vibrated it as it went in to make sure it was all settled.

This. Weight difference of brass itself is mostly in the rim and case head so the internal volumes could still vary wildly between the two.

Easy way is to do fired cases and leave the primer installed to plug it, hopefully it doesn’t leak on you then.

 

[ReaperDriver]

If the headspace on the new brass concerns you just run a moderate pressure load with a light jam.

I agree. I just went back and remeasured the headspace difference between the two virgin bass headstamps and the Prime is right at about .005 shorter than the lapua when measuring off the index of the shoulder. For comparison, a fired case in this chamber is about .004 greater than the virgin lapua and about .009 to .010 greater than the virgin Prime. So .010 is a big headspace difference and likely accounts for the blown primers with a hot-ish load. I'm going to run a very light load and jam them slightly so it keeps some pressure on the bolt face when chambered. I'll probably have to single feed them as I'm already loading to max mag length (2.958) in an AI mag.

 

[ReaperDriver]

Weight of the brass itself doesn’t matter. Put the case on your scale, zero it out. Then fill it with alcohol or water so you are getting the weight of the water itself, then do the same with the Lapua brass. I’ve also used really fine ball powder and vibrated it as it went in to make sure it was all settled.

Ok, I'll try that as well. Thanks.

 

[918v]

Yep, the Prime brass weighted LESS than the Lapua, so therefore should be more case capacity and theoretically less pressure. The Virgin Prime stuff weighed about 164.5 gr and the virgin Lapua was 173.5. That weight was the average of 10 cases each.

That's why I didn't do the traditional load workup, as it should have needed a higher charge to get to the same place as my Lapua. I fully expected to see lower velocities than my Lapua.

Maybe it’s neck thickness? Do you have enough clearance in the chamber?

 

[ReaperDriver]

Maybe it’s neck thickness? Do you have enough clearance in the chamber?

Not sure how neck thickness would cause pressure. I could see it they were way thick.

But the Prime necks are thinner than Lapua. I use a .292 neck bushing for the Lapua and I have to go down to a .288 or .289 bushing to get the same neck tension with the Prime. If I use the .292 bushing with the prime, the bullet literally falls through the neck.

 

[TheOfficeT-Rex]

Interestingly, the speed has increased over time with the same exact load combo of brass/powder charge and Bullets. The same load started off around 2860 fps and just recently I've been chronoing it above 2900. And I haven't changed anything. Still excellent accuracy as well. And the weird thing is it's gotten faster as the winter temps here have gotten colder. I would have expected the opposite. I've shot this in the summer when it's been above 100F and now when it's around 50-60F, the speed has actually increased.

This sounds like carbon ring - how's your cleaning regime, and have your bore scoped lately? At a minimum, one more variable to rule out.

 

[Cascade Hemi]

Maybe it's just the 75KPSI chamber pressure wrecking your brass? Hodgdon's max charge weight is 39.0gr, perhaps the Prime brass isn't made well enough to handle the significant over pressure load you're putting in it?

 

[918v]

Not sure how neck thickness would cause pressure. I could see it they were way thick.

But the Prime necks are thinner than Lapua. I use a .292 neck bushing for the Lapua and I have to go down to a .288 or .289 bushing to get the same neck tension with the Prime. If I use the .292 bushing with the prime, the bullet literally falls through the neck.

I read people talking about .295” loaded neck diameter of their rounds and I know that causes pressure issues. I think it was with Alpha brass. Whenever you approach that kind of clearance you have to rethink the load.

 

[Nodakplowboy]

I agree. I just went back and remeasured the headspace difference between the two virgin bass headstamps and the Prime is right at about .005 shorter than the lapua when measuring off the index of the shoulder. For comparison, a fired case in this chamber is about .004 greater than the virgin lapua and about .009 to .010 greater than the virgin Prime. So .010 is a big headspace difference and likely accounts for the blown primers with a hot-ish load. I'm going to run a very light load and jam them slightly so it keeps some pressure on the bolt face when chambered. I'll probably have to single feed them as I'm already loading to max mag length (2.958) in an AI mag.

This is one method of blowing out brass to a 40 deg shoulder that has worked well for me in the past, may work for you.

A) Use a moderately hot load. Not max, but enough to generate reasonable pressure.
B) Seat bullet with .020-.025 jam.
C) Just prior to firing, very lightly lube the case with a fine oil. Lightly like molecules thick. This light lube helps the brass move in the chamber giving better expansion. That's the theory, in my experience it works
D) When fireforming use a chamber mop every few rounds to wipe out the chamber.

Be safe.

 

[spife7980]

A light load won’t fully form cases.


I sure wouldn’t oil my brass if bolt thrust means anything to you.

 

[XLR308]

A light load won’t fully form cases.


I sure wouldn’t oil my brass if bolt thrust means anything to you.

Very true, thats why i mentioned using a moderate pressure load.
By moderate i mean upper 2/3 of max load range.
I have recently had issues fire forming neck turned 6.5CM brass to chamber dimensions with less than optimal pressures with Varget and AR-COMP and 123CC bullets.
Above starting loads even with Varget have left dirty cases, undefined shoulders and erratic velocities obviously.

 

[ReaperDriver]

This sounds like carbon ring - how's your cleaning regime, and have your bore scoped lately? At a minimum, one more variable to rule out.

I'm not familiar with the carbon ring issue. I'll go read up...... As for cleaning, I probably clean about every 75-100 rounds with Boretech Eliminator to get any copper fouling out. Right, wrong or indifferent - I'm not a "clean after every range trip" person. Probably every other or every third outing with it depending on how many rounds in a session I shoot.

 

[ReaperDriver]

Maybe it's just the 75KPSI chamber pressure wrecking your brass? Hodgdon's max charge weight is 39.0gr, perhaps the Prime brass isn't made well enough to handle the significant over pressure load you're putting in it?

I'm not sure I buy that my load is "significantly" over pressure. I run two loads that are identical except for the powder and they are both practically identical MV and on the OCW node. The sister load to the one I posted above (42.8 IMR 4451) is 42.3 of H4350. If you look at the .260 Rem Reloading Depot thread, you'll see that 42 to 42.5 H4350 is pretty much a consistent "pet load" for many SH members. Both loads seem to run flawlessly in my Lapua brass and while definitely on the "warm" end of the spectrum, I'm not seeing the usual pressure signs of overpressure.

 

[Cascade Hemi]

I'm not sure I buy that my load is "significantly" over pressure. I run two loads that are identical except for the powder and they are both practically identical MV and on the OCW node. The sister load to the one I posted above (42.8 IMR 4451) is 42.3 of H4350. If you look at the .260 Rem Reloading Depot thread, you'll see that 42 to 42.5 H4350 is pretty much a consistent "pet load" for many SH members. Both loads seem to run flawlessly in my Lapua brass and while definitely on the "warm" end of the spectrum, I'm not seeing the usual pressure signs of overpressure.

42.3gr of H4350 is 14KPSI lower pressure than 42.8gr IMR4451. Hodgdon lists the max load as 39.0gr of IMR4451 with Hornady brass and your brass has even less volume. The pressure data I posted is probably lower than what you have going on too.

 

[ReaperDriver]

42.3gr of H4350 is 14KPSI lower pressure than 42.8gr IMR4451. Hodgdon lists the max load as 39.0gr of IMR4451 with Hornady brass and your brass has even less volume. The pressure data I posted is probably lower than what you have going on too.

That's from quickload, correct? I had assumed that given identical MV's w/ the same brass and bullet, the two loads would be roughly equal pressure. Hmmm.

 

[TxWelder35]

That's from quickload, correct? I had assumed that given identical MV's w/ the same brass and bullet, the two loads would be roughly equal pressure. Hmmm.

Different powders=different burn rates=different pressure curves

a safe MV with h4350 ≠ safe MV with Varget

 

[ReaperDriver]

Different powders=different burn rates=different pressure curves

a safe MV with h4350 ≠ safe MV with Varget

Yep, I understand that for powders that are far apart like Varget. But since H4350 and 4451 are supposedly next to each other on the burn rate chart, my assumption was they would produce roughly the same pressure curves. It sounds like I need to update my very OLD version of QL.

 

[Cascade Hemi]

That's from quickload, correct? I had assumed that given identical MV's w/ the same brass and bullet, the two loads would be roughly equal pressure. Hmmm.

They are not equivalent. Hodgdon makes no such claims and all provided data specifically states otherwise. Reloading data from anonymous users on the internet is highly suspect at best.

 

[Snuby642]

One thing about Lapua brass is the metric flash hole I have heard as I don't use it.

It's about .005-.007 thousands smaller than the American stuff.
Don't make me dig out my notes.

If you were on the ragged edge of pressure, would that roughly 10% larger flash hole be enough to blow those primers?

I have not tested that it's speculation as if I started to use Lapua brass first thing I would do is standardize the flash hole to my equipment.

It's a question, not a known thing.

 

[TxWelder35]

They are not equivalent. Hodgdon makes no such claims and all provided data specifically states otherwise. Reloading data from anonymous users on the internet is highly suspect at best.

This. A safe load in my old barre I could run past 43gn of 4350 with no pressure signs with a 140. New barrel and I’m a full grain less before I start getting swipes on the brass.

some of these 43+gn loads would not be safe in some guns. Everyone’s barrel is different and has different amount of wear on it.

compare published load data to suspect at best data from the internet and make an informed choice for your gun.

 

[ReaperDriver]

Guys, I think we’re all getting hung up on the 4451 load itself and whether it’s over pressure or not. That’s not what’s at issue. I’ve been shooting that load in Lapua brass with no issues for several years now and no undue pressure signs or brass that prematurely wore out. The question is why did that same seemingly safe load blow out fresh virgin brass on the 1st go.

Yes the Prime stuff *could* be significantly less volume thereby increasing pressure. But given it weighs so much less than Lapua, I find that hard to believe. I still need to go weigh the two with water to check true case capacity but I’d be surprised if it was that much different.

So far the carbon ring theory seems to be the most plausible. Especially since both the H4350 and 4451 loads has sped up in just the recent months. I’m going to attack that issue first.

 

[ReaperDriver]

Ok so I finally got around to measuring the case capacity with water of the two virgin cases. The Prime is actually 0.4 grains (water weight) more capacity than the Lapua brass. So in theory that should equal slight less pressure, all other things being equal. Right?

 

[TxWelder35]

Ok so I finally got around to measuring the case capacity with water of the two virgin cases. The Prime is actually 0.4 grains (water weight) more capacity than the Lapua brass. So in theory that should equal slight less pressure, all other things being equal. Right?

Yes