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Preliminary Range Results

16 Dec 2017
@ 11:05 am (GMT)

Paul Leverman

I don't have to put in the usual disclaimer about these loads being too hot in anyone else's rifle. Mine is the only one on the planet that is chambered for this round.

These are only the preliminary results, coming from an assumed low pressure load, increased by 0.5 grains for each successive load, until pressure signs indicated it was time to stop. Primers and brass showed no signs, but the bolt started to stiffen up, so I quit (well, after one more round, just to make sure).

Cartridge Info:

Bertram Brass. Parent case 577Nitro Express x 3-1/4". Trimmed and necked down to accept .338"

Primer: CCI LR Magnum #250

Powder: IMR 7828SSC

Bullet: Hornady 285gr ELD-M

Maximum COAL: 3.225"; loaded to 3.205" for this excercise

Starting Load: 79.0gr = 2718fps

Maximum Safe Load: 83.0gr = 2835fps

All in all, a really good day at the range.

Next step to do: get a new stock. The one I am using is a POS. What I really need is an Apex. Once the new stock is put into play, the accuracy load will be developed.


18 Dec 2017
@ 04:36 am (GMT)

Paul Leverman

Re: Preliminary Range Results
Follow-up to the range report for the pressure fans: up until the max load was found, case head expansion was in the .0004" - .0006" range. Max load showed +.0007", good time to stop. No point in going further.

In reference to the new stock, it may be a while before I get it done, so in the mean time, I will probably play with other powders, eg., RL-25, RL-33 (if I can find some), Retumbo. I was thinking about the Enduron series, but even though the sales hype says go for it, the numbers in the manuals say that this is a ho-hum mid-velocity choice, no matter what the calibre.

I might also try a few loads with a 225gr SST, just to see what's what
18 Dec 2017
@ 06:32 am (GMT)

Thomas Kitchen

Re: Preliminary Range Results
hi Paul
Great to hear you got this up and running i know you have been working on it for a while.
any chance you got any pictures this is really an interesting round.

how much room have you got left in the case?
i have been using h1000 in my norma mag with 225gr so you could maybe try it in both of your calibers
18 Dec 2017
@ 10:09 am (GMT)

Nathan Foster

Re: Preliminary Range Results
Heck thats a great result for such a short magnum. The Lapua and Edge generally go 2735fps at 26" so this is outstanding.

Also interesting to see that the slow burn rate is working in this short case. I had wondered whether you would have to go faster at this case to bore ratio but by goodness it is showing some outstanding characteristics.

Left to right, 308 Norma Magnum, Paul's 338-585 S.P.L creation, followed by the 45-70 Govt.

18 Dec 2017
@ 08:47 pm (GMT)

Hamish Gibbs

Re: Preliminary Range Results
Paul how about a picture of a loaded round? it is a beautiful creation, I have dreamt of such a thing since the failure of the .338WSM to produce satisfactory results.
18 Dec 2017
@ 09:52 pm (GMT)

Mark Whitaker

Re: Preliminary Range Results
Don't know if you have come up with a name yet, but by the photos my suggestion would be "338 FAT LAP"

20 Dec 2017
@ 01:38 am (GMT)

Paul Leverman

Re: Preliminary Range Results
Thanks, guys. It was definitely a labour of love, well over a decade in development.

Thomas - I'll have to send a photo to your email, and if you could post it, I would appreciate it. For whatever reason, my security system won't let me do pics to hosts. It's probably me, I'm not real good with anything beyond a keyboard.

Nathan - I wasn't sure about the burn rates, but kind of used book info from the longer big boyz. Basically, made a guess, closed my eyes, reached into the powder keg and came out with 7828. Could just as easily been RL-25. I am hoping that the neck design is the strong point in this. If you look you will see that the shoulder angle (45*) guides the unburnt powder forward onto the neck wall, as opposed to the chamber wall. Theory says the brass will take the sandblasting instead of the barrel. Time will tell. The neck length also allows a lot of options for seating depth, ie, bullet choices. Not sure if you can tell in the photo, but the neck length is in over a calibre long. Just a theory, but I think the reason the slow powder seems to work is that the powder column is short, compared to conventional standards, in effect limiting the distance the primer flash has to travel to ignite the majority of the column. My thought was that this would bring more pressure to bear in a shorter time frame, hence the need for a slower powder. But I'm just a hick in the bush, not a ballistic engineer.

Hamish - if I can get one to Thomas, it will be here.

Mark - that's good, the first time I read it, I saw "FAT LIP". Guess I shouldn't try to read things without my specs on. "FAT" is right, as cases such as the Lapua, or Weatherby, fall right into it.

Presently, working on obtaining more brass from Bruce at Bertram. I lost half of the original purchase during the initial forming phases. Trial by fire. After the last loss, had finally figured it out, and didn't lose another. It's very frustrating at times to see hard work and a lot of thought go "squish". There were way too many expletives. Sometimes I just had to walk away.

Working up some accuracy loads now, but don't know when I will get to the range again. It's getting busy at work, this is a high volume time for consumerism. Maybe over the weekend. Will keep you posted as to what the results are. (Just fyi, when I was doing the incremental pressure loads, the first two were what you might call flyers, but I hadn't any idea where they would hit, so I just pulled the trigger. After I semi-zeroed the scope, the next eleven went into a ragged hole of 1-1/2"). This may not be fussy about it's diet. It will be fun finding the "one" load that does it.
20 Dec 2017
@ 06:33 am (GMT)

Thomas Kitchen

Re: Preliminary Range Results
This amazes me, i had enough trouble trying to form 6.5 rem mag brass from 7mm rem mag.
20 Dec 2017
@ 07:41 am (GMT)

Nathan Foster

Re: Preliminary Range Results
Image sized to 640 x 480 Web large:

20 Dec 2017
@ 05:36 pm (GMT)

Paul Leverman

Re: Preliminary Range Results
Thanks for posting that Nathan. It was the only photo of a loaded round that I could find this morning. I see now that it is an A-MAX, not an ELD-M, but close enough for illustrative purposes.

Twenty-one bushings, Thomas, and a full tin of Imperial sizing wax. That's what it takes to get it to the fireforming stage.
21 Dec 2017
@ 06:23 am (GMT)

Thomas Kitchen

Re: Preliminary Range Results
thank you Nathan.

you must be a very patient man Paul.

can i ask what action the rifle is built on and did you get get custom reamer made or use couple different reamers to make it?
21 Dec 2017
@ 06:05 pm (GMT)

Paul Leverman

Re: Preliminary Range Results
The action is a Barnard Precision, Model PL, right-handed, single shot.

I had two reamers made, a chamber reamer and a sizing reamer, as well as the go gauge for headspace.

The barrel is from Ted Gaillard in Saskatchewan, Canada. Inch and a quarter (+/-) diameter full length, 28" long, 1-10" right hand twist (6 lands/grooves), 11 degree target crown.

It came with the Barnard trigger, but it was misplaced along the way, so I replaced it with a Jewel, set at 2 oz. And wouldn't you know it, as soon as I had the Jewel mounted and set, a phone call stating the original had been found. Thank you, Murphy.

I have two scopes for it. The first is a Weaver T-36 with 1/8MOA turrets, the second is a Leupold 36X with 1/4MOA turrets. (I have both these scopes set up on Burris Signature Posi-Z rings and I interchange them when the fancy strikes. They are also set up to interchange on my Savage, Ruger, and P-14 rifles. Variety is the spice of life.)

The stock is a piece of sh*t that I ordered from a supposedly reputable family run outfit that is supposed to have benchrest in their blood. I think moonshine is more like it. I could have gotten a better finish using a putty knife and wall board paste. It is soon to be history. I got word today my new one is on the way.

I don't know if I'm what you would call patient. Finicky, anal, OCD maybe, but I don't think patient.
30 Jan 2018
@ 06:01 am (GMT)

Paul Leverman

Re: Preliminary Range Results
Made it to the range yesterday, finally. Almost a perfect day. Very little to no wind, steady temps (-12C), intermittent light snow.

Took twenty rounds with me. Two foulers that also doubled as pressure test loads for a different powder.

I've said this before, and it merits repeating: I am not a highly skilled target shooter, but I try. And thanks to Nathan, and all here, I am getting better. Having said that, I seriously doubt that the groups I was getting had anything in particular due to my skill.

So, these twenty loads were incremental in 0.2gr increases. Starting at 82.2gr of IMR 7828SSC up to 83.2gr (I had previously found 83.5gr to be max., but now I am doubting that figure, and will have to revisit to confirm).

Incredibly, the first group fired ended up as the best group of the day. I should have just packed up and gone home. Not that the rest were horrible, just not as good.

Results for the day:

#1 - #3 82.2gr .319"

#10 -#12 82.8gr .627"

#13 -#15 83.0gr .763"

I have serious misgivings about that first group. I almost think that one bullet didn't make it to the target.

The next round will be different seating depths. These were at .020", probably going to try .030" or .040".

I also have to find a way to control the neck tension. After measuring the fired case necks and correlating these numbers to the velocities, it became very apparent that when tensions are similar, so is velocity. The difficulty is in the fact that the case design does not allow for a standard crimp die to perform. Another custom from Lee is in order. In the same series of loads, I could get 2/3 within 4 - 9 fps, but the third could be as high as 50fps. I'm thinking that's a little outside of Nathan's guidelines.

One thing that was nice to find out was that the scope tracks flawlessly (at 100m, anyway). Instead of using umpteen target changes, I put one target up and use a large backer. By zeroing 12" high, I can move my POIs from one side to the other, dial in another 6" of up, and do it again. Six inch squares all over the backer (with some vertical dispersion from the increasing loads). Nice to know. And it really confuses the rest of the firing line when they look at my target, not one hole in it.

Round count to date: 54


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