Starting a custom light(ish) weight .338 Norma build!!

What magazine are you using? I use the AICS CIP's and they are not designed for the Norma mag cases. The shoulder is further back so the cases can slide forward and smash the bullet tips when fired. Had to modify my mags so they wouldn't do this. Haven't done much looking but I'm not sure there is a 5 round CIP mag that would fit Normas. Mile high shooting has a 10 rounder
It's the AI mags, I may have to modify them slightly, that isn't too big of a thing. I haven't looked around for specific norma mags, we will see how big an issue it is and go from there if we need to
 
And thanks for the compliments, it is kind of bitter sweet having this rifle here now, because Ammon isn't here to enjoy it. He will be over in the sand bowl until the end of this coming July, and since we start smacking critters August 15th (doe/fawn pronghorn) and don't stop until December (otc whitetail doe/fawn up north) all the load developement will have to be done so he can use it. We're stoked to see how it ends up throwing those HBN coated 300 bergers though. Gonna be ordering some Peterson brass soon, then pick up some bullets and get to testing/barrel break in. But, not till after the first of the year. Leaving on sunday to go visit family for the holidays.

Speaking of that, Merry Christmas everyone.
 
While on Christmas vacation I managed to get a little time to do a pillar bed job, it came out pretty nice!!
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Cody, the rifle turned out great! I was curious if there were any updates from the range and how the rifle shoots? How is the load development coming along? I just got my stock and am planning to start my build here in the next month or so. Already bought all of my brass, bullets and dies for the Norma.
 
Ok, finally an update!!

Got a chance to do some load developement, started off with Ramshot Magnum, HBN coated Berger 300 grain EH's seated .015" off, CCI 250's, and peterson brass. I started at 86 grains and worked up to 94 grains in 1 grain increments, 2 rounds at each charge. I loaded 3 of the 86 grain load, as the first round in an hbn load and clean/treated barrel is generally higher pressure. All rounds were ran over my magneto speed. Though with only two shot groups it doesn't mean much, accuracy results were as follows:

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And velocities were as follows:

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On these loads, light ejector marks appeared at only 87 grains and 2650ish fps, but were very faint, needed to be held just right to even see them. Primers did not look very flattened, and as I worked up the marks barely got more noticeable, they never got to the point of smearing or even got a lityle shiny, there was never an increase in bolt lift, and velocities don't indicate being terribly high pressure, except maybe the last couple could be getting up there.

The loads I used are higher than published loads, but that is because with HBN you will be at a slightly higher powder charge (1-3 grains or so depending on cartridge) for the same pressure/velocity as a naked bullet, due to the bullet having less friction going down the bore, thus generating less pressure and needing more powder to generate the pressure.

So I'm not exactly sure what to make of the very faint ejector marks, when I size them I will measure to see if there was any primer pocket expansion.

Today I will do another load work up with three other powders, including Retumbo, H-1000 and Reloder 26 (26 may be too fast but I will find out) and loaded 7 of each in 1 grain increments working up. I have them loaded, and will go out today to shoot them and see what I end up with.

On a seperate note, recoil is very mild. I would say about like an unbraked 10-12 lb .308 or so. This T3 brake is phenominal!! Very sweet shooting rig, I would let my 13 year old niece shoot it without hesitation.
 
Applause Applause Applause ,& Congrats fantastic job !Great luck on all your up and coming hunts with your Partener ,& thks for posting this all .
 
So I got a chance to shoot the Retumbo, H1000, and Reloder 26 loads, and found some interesting data, and would like to share it and see what everyone thinks. I'm finding that reading pressure in this particular rifle is a lot harder than most other rifles I have worked with, likely because I'm not usually loading for guns built on a custom action that masks pressure signs better than a typical production rifle action. Also, I have found that this action seems to give a false positive for an ejector mark, I believe the edges around the ejector hole may be somewhat sharp, as even on a load going in the upper 2500's with ramshot magnum, there was an ejector mark, and that just shouldn't be. So I am not terribly concerned solely by the presence of the ejector circle, I will take other signs into account. I will also add, that simply when opening and closing the bolt on a loaded case, it leaves a faint shiney spot where the ejector plunger slid along the case head. Not as much as a smear from an over pressure round, but a visible shiney line.

So I put together pictures with the case heads of the 6 highest charges (left out the first/lowest round so that the case heads would fit better in a picture) labeled with charge, powder, and velocity next to the case head. Following that, I will add a picture of the group.

First off, Reloder 26:

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This started off odd, as the first round impacted 6" high and 1.25" right. I adjusted that on my scope to center the group up, and it impacted 5" low and 1" left.....strange.....so I adjusted up 5" and back right 1" and fired the group you see. The black dots are where the first two rounds would have impacted had they been fired on the same adjustment as the group. So what does everyone think of the pressure of these rounds? None had any increase in bolt lift, all could be opened and extracted with just my index finger. Remember, it seems to make the ejector circle on all rounds reguardless of pressure, I will try to lightly polish the edges when I can, that may fix it

And here we have H1000:
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Obviously, accuracy with H1000 was pretty outstanding. For a 6 grain spread to all go into a sub 1" group is jist awesome to me, and every progressing round moved downward comsistently, they did not bounce around. I think my best accuracy may come from H1000. So on these ones, what pressure signs are you seeing? Again, never had any bolt lift increase and used my index finger to open all of them.

Next, Retumbo. And I will warn you, I was very surprised.
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So this just didn't make sense to me. On my first round, I thought that I had loaded too high of a set, and would never get to the 93 grain load, based on my first round going mid 2700's. But as the loads increased, I kept looking harder and harder trying to find a certain sign of being well over pressure, but was unable to find any. There is some primer cratering, but no smear from the ejector, primers were getting flat but not more than the other loads, there is faint marks from the extractor, but again, there was on some of the other ones, pressure was increasing smoothly and consistently, no spikes or flat spots, accuracy seemed excellent, and strangest to me, bolt lift NEVER CHANGED OR INCREASED. Again, light lift and extraction with only my index finger. I stopped for a solid 15 minutes at 91 grains and spent a good amount of time inspecting the last couple cases and recalling bolt lift before I pressed on. I just don't see how it is possible for this cartridge to send a 300 at 2950 fps without being extremly over pressure and causing obvious pressure signs like heavy ejector smear, heavy bolt lift, velocity dips, or something more than what I was seeing. Anybody else have any thoughts? Obviously accuracy was pretty decent with this powder too, though not quite like the H1000 set of loads.

And since I wanted these in here too, the 6 highest Ramshot charges.
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These didn't really even show any primer cratering until the top load of 94 grains. I may play with this some more, but I like the stability of H1000 and Retumbo, though I have read RSM isn't terrible, somewhere around .7 fps per degree.

So what does everyone think of this? I am seeing what I thought was just mild pressure signs, but they didn't increase much all the way up to 2950 with Retumbo, and they should have. I want the brass to last, but if the loads from 2750 all the way up to 2900 show the same minor signs, where is safe? Thoughts?
 
I think that it all depends on what you're seeing, and your comfort level. If you think the bolt throw is smooth, and the primers aren't flat, and the cases are surviving the ride, run an accurate load in that range. Or, push it to see where real signs rear their heads. Push one load far enough to cause a clicky/sticky bolt, and observe the brass at that level. You may find the signs you're looking for and then you can back off to the next best level.
 
Have you measured case head expansion? This is what I would be looking for.

While 2950 is awesome, your knocking on the door of Lapua Ai speeds.
 
Have you measured case head expansion? This is what I would be looking for.

While 2950 is awesome, your knocking on the door of Lapua Ai speeds.
That was my thought, and this is just a simple 338 Norma in a 28" barrel. I'm hbn coating my bullets, but I haven't really seen mich if any gain in velocity from it in the past, I use it for the other benefits.
 
Have you measured case head expansion? This is what I would be looking for.
I have actually, though this is my first time doing so, and I left that data out because my method is somewhat primitive. Also, it seems like a very controversial way to check for pressure, some people say it is very accurate, others say it is useless. I just went off of what Hodgdon reloading data said to do, this is how I measured. First issue, I don't have a blade mic, just a simple set of rcbs calipers, but I did find a way to measure the web just in front of the extractor groove that yielded consistent measurements. I have to roughly estimate where the needle falls in between the thousandths, but I do believe I'm able to get within .0001" of the actual measurement. I was not able to measure each load prior to fireing, then again after firing, but upon measuring the remaining 10 unfired cases (as Hodgdon stated you want to start with virgin cases as they work harden) they were consistent, only varying about .0002", with the largest of them at .5810", and the smallest .5808", though there was only 1 of the 10 at .5808", 2 at .5809", and the remaining 7 at .5801". When I was going through this I measured every case 3 times, and every time came up with the same number.

According to hodgdon, a .223 case will stretch .0004"-.0005" at max, cases like .270, .308, 30-06 and such will be at max around .0005"-.0006", cartridges like 300 wm and 7mm rm will be at max around .0006"-.0007" stretch. It did not state what cases like the Lapua and Norma should stretch, though I think it would be safe to say, they would likely tell you .0007"-.0008". It did not say a specific pressure this would be, and that makes sense, as different cases will stretch differently (a lapua case would likely stretch less than a soft hornady case under the same pressure) however it may show what the limit is for that specific brass, which is generally what we look at with other pressure signs, such as primer pocket expansion, ejector swipes, etc. Hodgdon also stated that you must watch for other signs of pressure as well, don't rely simply on this measurement.

Anyway, here is what I ended up with.

H1000 had all .5810" up until 88 grains which was .5811", 89 was .5813", and 90 also .5813". Throwing in my variables, max charge could have been as much as .0006" stretch or as little as .0002", likely .0003" stretch. According to this, I didn't reach max.

With Retumbo, 87 was .5810", 88 was .5813", 89 was .5816", 90 was .5815", 91 was .5815", 92 was .5818", and 93 was .5819". With variable at max charge, as much as .0012" stretch or as little as .0008" stretch, likely .0009" stretch, and max would be around 91, or my 2884 fps load.

For Reloder 26, all were .5810" until 84, which was .5812", then 85 was back down to .5810", and 86 was .5811". Up to .004" stretch, as little as .0001", though I feel I didn't reach a max here if going off of this info.

Finally is Ramshot, which I had 2 of every load on this one. 86 was .5809" and .5810, then all loads were .5810" up until 92, one was .5811", the other .5810", then at 93 we had .5810" and .5813", then 94 were both nack ad .5810". So again, somewhat inconclusive, or a consistent "max" was not attained.

Now, I take this data with a healthy dose of salt. I know my measuring methods, while they did show some consistent increase as velocity rose, are primitive, and open up a large door for inconsistency, and measuring case web is not the best way in many peoples opinion to get a good idea of pressure, and this is the first time I have done it. I only did it to attempt to get some more data on this. And I am not putting much weight in it, though I do think it shows a significant increase in pressure with the upper retumbo loads, obviously more than any of the other ones, which corresponds to the velocity I was seeing. Even still, I have no idea what that pressure is.

I'll leave a link to Hodgdon's information on measuring case web. I know many people that do this say there is better/different methods, I jist went with Hodgdon because, well, they are Hodgdon, not some guy on the internet I don't know.

https://www.hodgdonreloading.com/re...-trick-monitoring-pressure-your-rifle-reloads

One more thing, sorry for the novels. I like to add a lot of detail. Appologies.
 
Cody, thanks for posting this data!! This is excellent info. What kind of velcities were you seeing with the H1000?
 
With your retumbo case head expansion @ 91 grains that would be my stopping point.

That would put you in the realm of real world Norma velocities (albeit on the high side)

However if it were me, I would not be comfortable running them above that velocity.
 
With your retumbo case head expansion @ 91 grains that would be my stopping point.

That would put you in the realm of real world Norma velocities (albeit on the high side)

However if it were me, I would not be comfortable running them above that velocity.
Seems like most people are using 89-91 grains of Retumbo, and almost everyone uses 88-89 grains H1000, generally with HBN you use a grain or so more, but also every rifle is different. I think the velocity I'm seeing is more important.

I think my next loads are going to explore some groups with H1000 in the 87-89.5 range and 88-90.5 range with Retumbo . Those are more common velocity nodes in this cartridge, and were displaying very promising accuracy, were in the mid to upper 2700's w h1000 and lower to mid 2800's with Retumbo, and should give me a saftey margin, especially considering it was 35° when I was shooting these loads.
 
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