.338x.284 Win* Load Workup

[gitano]

I put an asterisk on the .284 Win because the 7.5x55 Swiss case works just as well because the action is a Ruger No.1, meaning that the extractor rim thickness on the Swiss case is irrelevant as is the rim diameter. :)

Turns out that the actual fireformed cases are smaller in volume than the paper-whipped ones.  The average volume of five .284 Win cases is 67.45 grains of water. (One FF Swiss case is 68.7 grains.) Armed with that info, I've been paper-whipping some loads in QuickLOAD. No surprises really. I won't bore you with the details until I get some rounds shot at targets. At the moment, I'm still out of 225 Accubonds - the bullet I would prefer to use. However, I have lots of .338 bullets. At the moment, I'll probably start with 200-grain Accubonds, OR, Nosler's "E" bullet in 200 grains. Neither is ballistically as good as the 225 AB, neither do I have the experience on game with either that I do with the 225, BUT... I do have plenty of each of those.


Paul

[Paul Hoskins]

Follow Catlin's choice in deer rifles. Go with what you have confidence in. It always works well for me too. .......Paul H .....

[gitano]

Copied from the "Project" thread:

Beginning to feel a little snake-bit on this thing.


Seeing as how this rifle  wasn't going 'off somewhere' for inletting a new stock, I was looking  forward to doing some precision reloading and shooting while working up a  load for it. Did my normal 'thing' and took precise measurements of the  chamber, including length from breech to lands. Hmm... Kinda short.


I told the people at PacNor  specifically what bullet I would be using in this rifle: The Accubond  225 with the shank seated 1 caliber deep. Since I don't have any of  those 225s that aren't in either the .338 Win Mags (Ruger and Sauer)  ammo, or the .338 MAI ammo,  I was going to use the Nosler 200-grain  E-Tips for sighting in and load workup, of which I have "plenty".


At 1.427" nominally, the  200-grain E-Tip, while "lead free" and therefore longer than the same  200-grain lead core bullet, is still shorter than the 225-grain Accubond  at 1.550". Therefore, it should 'fit' the chamber with room to spare,  when seated a caliber deep. Au contraire.  The chamber is about 65 thousandths too short. That in itself is too  much to 'live with', but it's also created another problem. Even if I  wanted to seat the bullet as deep as the chamber requires, I couldn't,  because the case's shoulder hits the bullet seating die's internal  shoulder before the bullet can be seated that deep.  That's with the seating plunger screwed ALL the way into the die. So...
 
I've ordered/rented, a .338 throating reamer. $44.85 including shipping  TO me. (A new one purchased from Pacific Tool and Gauge is $180 plus S&H.) At least I'll get it EXACTLY the way I want it for the 225-grain Accubond. Nevertheless, I'm a little disappointed that I have to wait some more to load and shoot this rifle. I'm hoping there aren't any more surprises.

Paul

[gitano]

Hokay...
Finally got a moment away from "the Counter Project", and the dog, and everything else, and got the throat reamed. I'm finally prepared to "make bullets" for this rifle and start the load workup process.

I extended the throat sufficiently (about 0.100") that a 225-grain Accubond, seated 1 caliber deep (on the bearing surface, meaning, not counting the boat-tail), is 0.05" off the lands. Were I to extend the OverAll Length (OAL) by 0.05" to put the bullet "on the lands", seating depth (0.288") would still be more than 0.226", which is 67% of a caliber, which is the minimum I am willing to seat a bullet "out".    

sakorick gave me an almost full box of the 225 Accubonds, AND, while I was visiting him, I ordered a box from a FISHING GUIDE IN CANADA. Possibly the only people in North America with some to sell! However, they expressed some concern over getting them past Canadian customs. They said, "It's not illegal, but stupid Customs agents, (really... whodathunkit? I'm still P.O'd.), might confiscate them. You are accepting the risk." I told them I would. $85 Canadian plus $35 Canadian shipping :frown plus $5.98 Canadian GST :frown :frown, for a grand total of $96 American. $2 a bullet. That hurt psychologically. Grrrrrr....

I now have 90 225-grain, .338 bullets with which to work up a load. I'm still going to use the 200-grain E-Tips to start load work-up. (The 225s are too precious.) Once I get those shooting straight and hitting where I want them to, I'll move to the 225 ABs and tweak them in.  I'll load 20 (at least) for the Missouri deer season. I'm a happy camper. :D

The "Counter Project", will keep me occupied til the coming weekend, but next weekend I should be able to get to the range and shoot some paper. I've already got QuickLOAD paper loads worked up, so sometime this week I'll get those loaded and be ready for the range on the weekend or the first of next week.

News at 11...


Paul

[gitano]

I've decided to try a new  method of "load work up". Instead of changing the charge and powder, I'm going to pick a powder and a charge that yields a 'modest' max pressure, and adjust seating depth. Only.

I dislike the number of combinations created by the permutations of powder type, charge, pressure, timing, and seating depth. By picking one powder, one charge, and one 'center' pressure, I can adjust the seating depth until I either run out of chamber length or the pressure gets too high. Or, of course, I find a precise load.

At this moment, I'm not sure what the increment in seating depth will be, but I'll start with one that produces the same change in barrel exit timing that a 0.3-grain change in charge produces. (0.3-grains is the charge increment I use when working up a load.)

I'm sure everyone will be happy to hear:

More paper-whipping to come! :D

Paul

PS - I forgot to mention that the seating depth increment will not be LESS than 0.010", and that's 'pushing' it. People that think they can adjust seating depth finer tha 0.010", are fooling themselves. And given all the variables associated with seating depth, 0.010" is, as I said, 'pushing' it.

Paul

[gitano]

So...
Per my previous post:
The bullet is the Nosler 200-grain E-Tip.

The powder is RELODER 17.

The charge is 58.1 grains. That's 105.7% of case capacity when the bullet is seated one caliber deep - 0.338"; the starting seating depth.

Predicted MV is 2868 f/s, at an estimated max chamber pressure of 53,919 PSI.

Estimated exit timing is on node 4 for the 28" bbl at 1.279.

Moving the seating depth out 0.019" to 0.319, results in the following changes:

Percent case capacity drops to 104.9%

MV drops 10 f/s to 2858.

Max pressure drops 979 PSI to 52,940.

Exit time increases to 1.287 msec, almost 1% longer than original.

Moving the seating depth out another  0.019" to 0.300, results in the following changes:

Percent case capacity drops to 104.1%

MV drops another 10 f/s to 2848.

Max pressure drops 967 PSI to 51,973.

Exit time increases to 1.296 msec, almost 2% longer.

Each of those increments was equivalent to reducing the charge by 0.3 grains but keeping the seating depth at 0.338". HOWEVER, muzzle velocity stays higher when the seating depth is changed. For example, in the first step 'down', changing the seating depth lowers the MV by 10 f/s. Lowering the charge reduces the MV by 15 f/s. The second step down again lowers MV by only 10 f/s when changing seating depth, but lowers the MV 16 f/s more when reducing the charge, for a total loss of 31 f/s when lowering the charge, but only 20 f/s when changing seating depth. (Keep in mind that max pressure reduction at each step down is the same for seating depth as it is for charge reduction.)

Hmm... It would be difficult to find someone less concerned with MV than I, but I do find this interesting.

The proof is in the pudding, as they say, so we'll see how this little exercise works out at the target butts.


  Paul

PS - I cautioned against reporting seating depths to a precision of 0.001" and yet I did that exact thing above. However, those measurements above were "paper-whipping" in QuickLOAD for the sake of ESTIMATING pressure changes. In reality, I'll move the seating depths in increments of 0.02" and report COALs to 0.01".

Paul

[gitano]

By the way... This seating depth exercise once again gives me an opportunity to demonstrate the value of Optimal Barrel Timing Theory. Once I find the TIME  of the most precise load for the 200-grain bullet, "moving" to the 225 bullet will be child's play, because, the harmonic timing of the barrel is INDEPENDENT of the bullet. Meaning, that best timing for the 200-grain bullet, will be the best timing for the 225-grain bullet. While I won't be able to hit the same faster node with the 225 as I can with the 200, it doesn't matter because I just step "down" a node to the next slowest node. Once I find the 'real' value of a timing node, because it's harmonic motion, all other node timings are equally spaced. You can see the practical value of this especially given the scarcity of the 225-grain bullets. I can develop a load with less expensive, AVAILABLE bullets, and when the rifle's characteristic TIME is determined, ALL other bullets "work"! This ain't theory. I've proven it several times with my own firearms, and once each with sakorick and davidlt89. It works.

Paul

[davidlt89]

Very interesting Paul. So I have been thinking about switching bullets in my 7mm mag due to two things...1. availability, the bullet I am currently using is a 160gr accubond and as you know, they are no where to be found right now, and I have no idea when they might and I am "low". 2. Price. The accubonds are expensive and I can  shoot hornady SST's for half the price!
You helped me develop the initial load in that rifle with quickload. was not long after that I purchased quickload and got in the game!
I am assuming that I can enter the data for that load into quickload, and that will give my "true" barrel timing for that rifle?

[gitano]

That is correct, David. HOWEVER... You need to enter data for your rifle and load that are as accurate as you can be. Case capacities, case lengths, barrel length, and seating depth, are critical to getting the correct exit time from QL.  That value should be very close to the "right" timing value for the SSTs. Armed with that, you should be able to "search" QL to get a load with that exact timing. If you need assistance doing that search for the first time, gimme a call.

Paul

[davidlt89]

Yes, that is most of the data I am referring to. All the same data I use when working up an initial load. I also actually measure out 10 bullets and take and "average" of the bullet length, since not all of them are all the same length and definitely are not the length quickload has them at.
I am also assuming using the actual chronographed velocity would help.

[gitano]

Absolutely, to everything! Sounds like you've got it figured.

You'll find the bullet lengths get more consistent if/when you use a Hornady (used to be Stoney Point), bullet comparator, https://www.hornady.com/reloading/precision-measuring/precision-tools-and-gauges/lock-n-load-bullet-comparator#!/ which measures the bullet from the base to the ogive where the bullet becomes 0.008" smaller than  caliber. (This is where the bullet has bore diameter, not groove, or caliber, diameter.) Still, they won't be exactly the same from bullet to bullet. This is part of the reason that claiming seating depths with a precision of 0.001", or even 0.005", OR, "I'm 0.057" off the lands", is... let's just say, 'not realistic'.

Looking forward to seeing how things work out!

 Paul


PS - The picture in the Hornady link above shows the whole, finished cartridge being measured. That's good for getting the Cartridge OverAll Length (COAL) value, but in order to use that COAL value, you'll have to adjust for NOT using the "tip to tail" length of the bullet. SO...

First, using the bullet comparator, you measure the length of the bullet from base to bore diameter.
Second, you seat the bullet to the depth that you want it to be for YOUR loads.
Third, you measure the COAL again using the comparator.
Fourth, use that COAL for your calculations in QL.

I "create" a "new" bullet in QL when I get its length based on the bullet comparator length. I call it the "SPOAL" length (Stoney Point OverAll Length). For example: Using the 225 Accubond, I create a "new" bullet in the QL library of bullets called the ".338 225 AB MINE SPOAL".

Furthermore, I have a "new" SPOAL cartridge. This cartridge's OAL is from the head of the case to the bore diameter of the bullet. Usually the "SPOAL" cartridge is "THE" load determined after load workup and when I've decided on THE load - bullet, powder, charge, and seating depth - of the most precise load I can find.

Paul

[gitano]

PS - One kink you may find is when you enter all the parameters, and the charge, you don't get the muzzle velocity that you MEASURED. This is a function of the actual characteristics of the powder you are using being different from the ones QL has. This requires 'fiddling' with the powder parameters. This is one of the most esoteric things you can do with QL, and requires keeping one's thinking cap on - with chinstrap. If you run into this problem, let me know and we can discuss solutions.

Paul

[gitano]

Well, finally got to the range. (Got shed of the "big project" monkey on my back.)


As days at the range go, it was "good". Wasn't too crowded. No jerks. Weather was good. I didn't forget anything, coming or going. Got some 'preliminary' data.

These were the first bullets down the bore, so my expectations weren't too high. My expectations were met.

You may recall that I have decided to choose a single load, and instead of 'fiddling' with the charge, I'm fiddling with the seating depth.

As mentioned in post #6 of this thread, the powder is Reloder 17. The charge is 58.1 grains. The bullet is the Nosler 200g E-Tip. This gives a predicted MV, with the .338" seating depth, of 2868 f/s.



I started with four rounds loaded to the following seating depths, and their associated MVs.

0.25" - MagnetoSpeed set wrong - .284 brass
0.29" - 2801 - 7.5x55 Swiss brass

0.31" - 2818 - ditto
0.34" - 2835 - ditto


Pretty close to the predicted drop per step, but the top step is a little lower than predicted. Don't really care, as 2800-ish is fine by me. Remember that I'm going to be hunting with the 225g Accubonds. Once I get the powder/seating depth dialed in, I'll shift to the ABs and tweak as needed.

As I was reading my notes on the .416x348 Win on the No.3, I was reminded that I had addressed the forearm 'issue' on that rifle. See here: http://www.thehunterslife.com/forums/showthread.php?t=19959. I have not on this rifle. After this range session, I may have to do the same for this rifle. I'll run another 25 or so rounds through it before I decide whether the forearm hanger needs "adjustment".


The seating depths with associated data are listed below. (All groups are 3-shots. Next time will be 5, but I have to preserve powder for sure, and bullets to a certain degree.)

.338" - Group size = 1.99"
.310" - Group size = 3.15"
.290" - Group size = 4.51"
.270" - Group size = 4.77"
.250" - Group size = 1.38"
.230" - Group size = 3.36"

As you can see, only one is "OK", and the rest are poor to bad. That's OK. That's what I was looking for: One batch to stand out. While the .338 group at 1.99" is marginal, the .250 group at 1.38" is 'tolerable' and warrants subsequent attention.

Of course the .250" seating depth used for MV measurement is the ONE that didn't get caught, but I think it's clear that it's going to be close to 2800. I'll check it at the next range session. (I don't like the MagnetoSpeed on the rifle when shooting for group size. I'm CERTAIN that it affects Point of Impact. It simply has to.) As long as the 225g AB can get to 2650 f/s, I'm fine, and I have no doubt this cartridge will get to that MV.

Here's an image with all of the groups, with each shot for a given seat depth the same color.



Not too much there, but "it is the data". Next step is to load some more at .240", 250,and .260" seating depths. I'll do some paper-whipping to check timing and relationships. With this 'far out', I may try to stuff some more powder in the case, but keep the timing by changing the seating depth. Of course, I'll stick to the 58.1 grain charge for the .240" - .260" test.

I'll be checking the fired case capacities to see if the fireformed .284 Win brass is different from the fireformed 7.5x55 brass.



Paul

[gitano]

To wrap up the analysis of the previous range event and because I used two different kinds of brass - 7.5x55 Swiss and .284 Winchester - here are the last of the data.

This first table has the weight and volume data for the Frontier 7.5x55 Swiss brass. I think the labels should make the table values clear.


This table is the data for the Winchester Western .284 Win cases. You can see that here are significant differences between cartridges. Within cartridges, there is fairly good consistency, especially for the 7.5x55 brass.


This table is the percent differences in those cumulative stats. For example, the first column "Case With Primer" is the % difference in the average weight of the 7.5x55 cases compared to the .284 Win cases.


These graphs are the case weight graphs for each cartridge (7.5x55 and .284 Win).


These two are for the case volumes before the cases are resized.


And these are the case volumes after resizing. Note the consistency after resizing. The variance is only half a grain for the .284 brass, and less yet - one third of a grain - for the 7.5 brass.


Since the Swiss cartridge has greater volume by about 2%, and, less variation between cases, looks like I'll be using 7.5x55 Swiss brass instead of .284 Win brass. There's "good" in that because the Swiss cartridge's brass is easier to get my hands on AND it's cheaper. So, should I change the name to .338 Swiss? That rolls off the tongue a lot easier than .338x.284 Win. Hmm... :undecided: Unfortunately, it's already etched on the barrel.


 Paul


PS - By the way, the CH4D neck resizer doesn't resize the neck small enough to hold a .338 bullet. I'm going to have to have speaks with the folks at CH4D.


Paul

[gitano]

By the way... The timing of the bullet's exit from the barrel for the smallest group, (.250" seat depth), is 3% down from the theoretical node. That is where almost every precise load I have ends up; about 3% down from the predicted node.


Paul

[gitano]

I've been doing a lot of analyzing and paper-whipping. (Always happens after a range session. Especially when I'm working up a load.) As a result, I've decided to combine the "change-the-charge" method with the "change the seating depth" method.

Since I have at least a preliminary idea about this rifle's 'native' harmonic timing, and mostly because that preliminary data fits well with almost all of my previous timing data for precise loads, I decided that I could use both timing and seating depth to get where I wanted to get with regard to precision and delivered energy.


To reiterate my personal ballistic standards:
1) Precision of one minute of an angle or better at 100 yd.
2) For calibers .308 and smaller, deliver at least 1500 ft-lb to 300 yd; and for calibers larger than .308, deliver at least 2000 ft-lb to 300 yd.
3) Total vertical deflection of the trajectory 12" or less over 300yd.
4) Ideally have muzzle energy of less than 3500 ft-lb. This can go up to 4000 ft-lb if necessary to meet #s 2 & 3 above.  (This criterion is more flexible than the others because perceived recoil depends on the weight and stock shape of the rifle almost as much as muzzle energy.)

I was also looking at my stock of powders and .338 bullets and found some red-plastic-tipped 225-grain boat-tails I bought from MidWayUSA when I was still patronizing MidWayUSA. (They were sold under the MidWayUSA brand, but I'm positive they're Hornady's.) I have 100 of those. I also found, again from MidWayUSA, some flat-based 250s that look like Partitions with a graphite coating. (I'll post a picture later.)

Now consider the myriad possibilities if you're gonna fiddle with charge and seat depth. However, things get at least a little simpler when you start to put constraints like those above (1-4), and you constrain the bullet's barrel exit timing to one or two.



To spare you lots of the gory details, I settled on two powders: I3031, and Bl-C2. The timing node I want to hit is 1.320 msec, which corresponds to the timing of the smallest group I shot the other day at the range. It's seat depth, (hereafter, SD), was 0.250", but I'm not concerned about a specific SD. I'm concerned about "hitting" a specific exit time. 1.320msec is 3% slower than the theoretical 4th node on a 28" barrel. Moving "up" to the next slower node 5, and dropping 3% down from it, yields an exit time of 1.474msec.




The reason I dropped down to the next slowest node is that I can't stay below max chamber pressure with the 225 bullet, (Accubond or other), at an exit time of 1.320msec at any seating depth. However, I can hit the 1.474msec mark with the 225s and keep the muzzle velocity up enough to meet the necessary criteria.


As it turns out, I'm using the I3031 at 1.320msec for the 200-grainers, and Bl-C2 at 1.474msec, for the 225s. About this time you may be saying, "I thought you were going to change charge too." Right. So for each powder I'm loading three different charges for three different seating depths, all of which yield exit timings of either 1.320msec for the 200-grainers using I3031, or 1.474msec for the 225s and Bl-C2.

The three SDs are: .34" (a caliber deep), .30", and .24" (minimum SD). Each of those SDs would yield a different exit time if the charge wasn't adjusted just a little. So there is the "change the  charge" component.

I'm loading 5 cartridges at each SD for each bullet, (3x5x2=30). Since I have 50 cases fire-formed, I'll load 3 each for each SD and each bullet weight, (3x3x2=18) to get statistically better MV data. Therefore, I'll be putting another 48 bullets down the bore for a total of 70, (last range session's 22 plus the 48 of the next one). That, (plus fire-forming 50 cases), should help get the bbl 'shot in', and hopefully, I'll find "The Load" amidst all of that.

News at ll.



Paul

[gitano]

Those that know me will know that I don't always "have a good day at the range". There have been some real disasters. Kinda goes with wildcat territory. However, yesterday was not 'one of those days'. It was great!

As I explained in the previous post, I had loaded 18 rounds of 6 different loads: 3 different seating depths, three charges for each seating depth for 2 bullets using 2 powders. These 18 for getting good muzzle velocity data. 'Caught' all 18. I also loaded 5 each for the same 6 different loads, (for a total of 30), for group size.


The six loads were:
1) Seating Depth - 0.24"; Bullet - 200g Nosler E-Tip; 50.4g I3031;
2) Seating Depth - 0.24"; Bullet - 225g MidWayUSA/Hornady; 56.6g BL-C2;


3) Seating Depth - 0.30"; Bullet - 200g Nosler E-Tip; 49.7g I3031;
4 )Seating Depth - 0.30"; Bullet - 225g MidWayUSA/Hornady; 55.8g BL-C2;


5) Seating Depth - 0.34"; Bullet - 200g Nosler E-Tip; 49.3g I3031;
6) Seating Depth - 0.34"; Bullet - 225g MidWayUSA/Hornady; 55.25g BL-C2;

Here are the MVs in f/s in seat depth pairs:
Load 1 - 2705, 2712, 2762. Average - 2726, (2780/+54*) Standard Deviation - 31
Load 2 - 2785, 2783, 2820. Average - 2796, (2741/-55*) Standard Deviation - 20


Load 3 - 2695, 2730, 2721. Average - 2715, (2771/+56*) Standard Deviation - 18
Load 4 - 2739, 2765, 2707. Average - 2737, (2732/-5*) Standard Deviation - 29


Load 5 - 2688, 2712, 2714. Average - 2704, (2768/+63*) Standard Deviation - 14
Load 6 - 2747, 2726, 2768. Average - 2726, (2725/-22*) Standard Deviation - 21
* - Quickload predicted/Difference.


Here are the MVs in f/s in bullet weight triplets:
Load 1 - 2705, 2712, 2762. Average - 2726, (2780/+54*) Standard Deviation - 31
Load 3 - 2695, 2730, 2721. Average - 2715, (2771/+56*) Standard Deviation - 18
Load 5 - 2688, 2712, 2714. Average - 2704, (2768/+63*) Standard Deviation - 14


Load 2 - 2785, 2783, 2820. Average - 2796, (2741/-55*) Standard Deviation - 20
 Load 4 - 2739, 2765, 2707. Average - 2737, (2732/-5*) Standard Deviation - 29
Load 6 - 2747, 2726, 2768. Average - 2726, (2725/-22*) Standard Deviation - 21
* - Quickload predicted/Difference.


Here's a screenshot of the part of the analysis spreadsheet with the MV data:

In the MV column, the background color denotes the case manufacturer.

As you can see, there were only two batches of three bullets with the same case: The 225 Hornady with 0.24" seating depth, and the 200 E-Tip with the 0.30" seating depth. There were some differences, clearly, but I wasn't after 'perfection', I was just after "what's the general MV". I didn't even shoot paper with these shots. On the other hand, all 5 of the cartridges for each load for "group" were the same manufacturer. Precision matters. MV, not so much.


Also note that QuickLOAD consistently overestimated the MV for the 200g/I3031 loads, and conversely, underestimated the MV for the 225g/BL-C2 loads. Although, it was essentially "right on", (missed by 5 f/s),  for the 225g, .030 seat depth load.


The next picture is the actual target shot for group size. The first one is the 200g E-Tip with 0.24" seat depth.

This one looks like it's all over the place, but in fact, I was adjusting the scope between shots. Since I noted the exact adjustments, I could later put a digital target together with the adjustments taken out. The digital target is below.

The max spread is 2.97". Nothing to write home about. A little disappointing to tell the truth, but I couldn't see how bad it was at the range because of moving the point of aim around. However, things were about to get much better.

Here's the next target I shot.

You can see the shot sequence. When I shot the second shot, I couldn't see the hole. Hmm... I was pretty sure I didn't miss the paper! Upon closer inspection, I saw that the two holes were almost one! Yeehaa! Next shot, #3. ALL RIGHT! Looking good! Took shot #4, and while 'away' from the first three, it was still inside MoA. Took the 5th and last shot of that load. Right as the trigger released, I saw that PoA was low. :frown @#$%^&*! However, I saw exactly where the crosshairs were, and knew I could adjust later. Even so, it still wasn't bad.

Here's the digital target. The red dot is the adjusted PoI for that 5th shot. You may choose the one you want, but I know what happened, so I'll take the smaller group as representative. Max spread for the unadjusted 5-shot group is 1.38". Adjusted max spread is 0.98".


Given the strategy of my loading, AND the "precious" nature of bullets and powder, as far as I was concerned, I had found my load. What I will do now, is load some 225 Accubonds, and tweak the charge to fine tune it. No need to fiddle with the seating depth unless the AB groups go completely south.

I packed up and went home. I'll pull the bullets and put the powders back in their respective canisters.

By the way, note the average MV for that 1 MoA load: 2796 f/s - for a 225g bullet! Assuming the 225 Accubond's speed is the same, it will deliver over 2850 ft-lbs to 300 yd, , and is 8.5" flat over that same 300 yd. (1.5" high at 120, and 7" low at 300.) Impact velocity at 300 is 2386 f/s. That 'beats' the .338 MAI by about 850 ft-lb and almost 400 f/s. (Frankly, it's equivalent to my .338 Win Mag loads. Of course I don't load my WM loads as 'hot' as this because they're not for a No.1 action.) The predicted max pressure is 'right up there' at 60835 PSI, but in the No. 1 action, that's no sweat. Theoretical rules of thumb aside, the reality is that the cases swelled only 0.006" max, and the primers were still "rounded".

Some days chickens, some days feathers. Yesterday was definitely a "chicken" day.

I'll be hunting with this rifle this fall.


Paul

[gitano]

I got to the range to check out the load that worked with the 225 Hornady on the 225 AccuBond. Same charge: 56.6g of BL-C2. Same seat depth: 0.24" of shank. Same case: Frontier 7.5x55 Swiss. Same primer: CCI 200, Large Rifle.  


No called fliers. Max spread 1.76 inches. :frown

You can see from the target that the rifle is stringing them vertically. This is the classic problem with the No. 1, and is a function of that blasted "hanger" in the forearm. I'll have to fix that if I want the groups to tighten up. Group size for first four was just over 1 MoA at 1.14", and first-and-second, and third-and-fourth, were very close pairs. I'll work on the forearm/hanger issue, and try again.

Muzzle velocity was a little slower at 2747 f/s, than the Hornady (2796 f/s). Standard deviation was a little worse at 33 f/s vs 21 for the Hornady. However, I think this is a function of neck tension. The bullets were not very tight in the necks of the five I used for MV measurement. I suspect MV will go up and std dev will go down when the neck tension is tighter and more uniform.

Were it not for the amazing terminal performance of the AB, AND the high (TRUE) BC of the AB, I'd be using the Hornadys. They're cheaper, and for the moment at least, they shoot straighter. Probably.

Paul

[gitano]

I didn't have the QuickLOAD-predicted muzzle velocity when I made the above picture. It is 2744 for the 225 Accubond. That's only 3f/s slower than the observed of 2747.

Paul

[gitano]

Just ordered 8 lb of BL-C2 at a cost if $248.50 delivered (to Missouri). That's $31.06/lb. Not a smokin deal, but $32.50 of that was shipping and PayPal fees.:frown

Such is the 'way of the world' these days.


Paul

PS - Used to be, you could transport small amounts of smokeless powder in your checked baggage. The fascist sons-of-bachelors at Homeland Security now say NO "gunpowder" of any  sort. So... I'm trying to cancel the above order as there is now NO WAY for me to get ANY amount of BL-C2 to Alaska.

Many of "us" are sitting quietly. Seething. It's going to be bad for politicians and other fascist sons-of-bachelors when the silent majority decides that enough is enough. I suspect it will make the aftermath of the French revolution look like a walk in the park.


Paul