Specific Reloading Questions - 243win

[neutron619]

Maybe my rifle's a duffer?

 

I doubt that's the case and I can't fault your steps in case prep / loading assuming you're doing them right - I'm sure you are.

 

The only thing I'd say is check your FL die is adjusted properly. I once had a problem with a small number of rounds where the shoulder of the case wasn't being pushed back far enough when they went into the sizer. The rounds chambered, so the effect wasn't as noticeable as when I actually made the mistake of adjusting it in the wrong direction (not really sizing the brass at all; I ended up pulling and reloading about 90 rounds) but they were the wrong "shape" and I started seeing all sorts of pressure signs in a moderate load that I'd far exceeded in my "find the maximum" initial testing. It took me an age to work out that that was what was going on. I don't suppose that's what's happening here, but I mention it as the only thing I've ever seen to which I could attribute "not getting to maximum load".

 

Regarding the data, I've just run the Lee data through QL myself - it does seem to be an erroneous range and I would discount immediately it as being unsuitable. To be honest, they probably did find a chamber / barrel that would take that powder and bullet and stay under the maximum pressure, but it isn't going to be any hunting rifle, that's for sure. Their published maximum would supposedly give a velocity in the region of the 3500fps published, but the pressure curve is one ugly sonofabitch and I think even if you tried a ladder up to 44.5gr, you'd struggle to get there without risking your rifle and your life.

 

Looking at the other data: the Viht website data is the same as the Lee - I'd leave that well alone. The Viht published data is also a bit hot according to QL, even if I assume a max OAL of 2.700" (you didn't say above) and the Sierra data is really quite conservative indeed. I think that the ladder you proposed is a good plan, though I expect, based on what QL predicts for my own "known" loads, that you'll start to hit pressure signs around 40.5gr and certainly by 41.0gr. That's based on a OAL of 2.710", by the way.

 

My gut feeling here still says that N140 is too fast for .243, though I take your point about Varget. I think that feeling is based on expecting .308 loads to need faster powders than .243 because the case is the same size, but .308 has much more barrel volume to keep pressures down. Given that N140 is a reasonably good .308 powder, I'd expect something slower to work better with the smaller expansion volume of a 6mm barrel.

 

As far as this load, or the Varget alternative goes, I can only tell you what QL says, which is that Varget produces lower pressures for the same charge, which is probably why people like it (in general). What I don't understand however, is that the Lee published maximum and QL's prediction of the 70gr bullet / Varget load differ by 250fps, with QL the lower value. In fact, QL (and it would appear, your experience) seem to predict much lower velocities for most of the combinations I've tried - the (Lee) published data for .243 does seem to be generally rather "optimistic".

 

Not sure what I can offer beyond that. Given the choice, I'd still probably look for a pot of H414, but I realise that may not be practical. What I will do for you is go and run the 55gr bullet through QL and see what it says, if you can confirm the exact bullet you're planning to use. Perhaps we'll find that N140 is better suited to that one (it should be).

 

Sorry I can't think of anything more helpful / positive to say.

[mick miller]

I typed a thorough reply but it somehow got lost, so here goes again...

 

Firstly, thank you for your input. As regards, the shoulders of the cartridge, I'm not sure how you go about checking this. My die instructions (I use Hornady) simply state this in setting up.

 

To adjust the full-length size die, follow these steps:

1. Raise the press ram to highest position without camming over.

2. Thread the full-length die into the press until the base touches 
the shell holder head.

3. Tighten the lock ring against the press and tighten the set 
screw with the allen wrench.

(Note: Firearm action types and chamber dimensions vary causing excess headspace. To eliminate the headspace, adjust the full-length die upward.)

The Lee die states that I should turn the dies a 1/4 turn further and then lock down, so this is what I have done. Although, if the die is set correctly when the face of the resizing dies touches the face of the shell holder then I don't see how I could be getting that wrong? I cannot go any higher, only lower by not completing a stroke fully.

How do you find out if the shoulders are set too far back?

[malkiserow]

PM inbound

[Underdog]

May I add something.

You need a healthy pressure for the case to grip the chamber walls at peak pressure. If you are under that bolt thrust will be more than if you put far to much powder in!

I think I mentioned before but a good indicator of pressure is to measure the case head above the rim. Fire it and measure again. As long as you are under .004" growth you are well in.

 

U.

[neutron619]

How do you find out if the shoulders are set too far back?

 

I know your pain with the lost reply - it happens all too often on my dodgy WiFi!

 

We may be talking in opposite terms, but to avoid confusion, shoulders set too far back would mean to me that the shoulders had been pushed too far toward the bottom of the case (where the primer is). If that's what you meant, then generally, there isn't a problem with the case shoulders being further back than they need to be, providing of course, you don't have excess headspace. The only issue here would be that you would be making your brass under-sized, which would work it more as it expanded in the chamber on firing, shortening it's life. If you've set your die as above and trimmed your cases after sizing them (or at least measured them and checked they're within spec) this won't be your problem (if there even is one).

 

On the other hand, if the shoulders are too far forward, you'll have the problem I described above - the rounds won't chamber or will only chamber with heavy resistance. You'd tell this in the bolt closure / lift and it would be caused by the sizing die floating above the head of the ram - i.e. if you did what I did once and turned the die ¼ turn out rather than a ¼ turn further in. The result is that the shoulders haven't been pushed back to within ordinary spec and you're effectively trying to resize the case on the chamber walls, using the bolt as a press. I didn't discover my error until I'd sized a whole batch of cases and loaded most of them, hence the 90 rounds that had to be pulled, resized and then rebuilt.

 

I'm sorry that I haven't yet run the 55gr bullet data on QL. I'll try and get it done in the morning if I run out of time now.

 

As for the more general situation, I think that what you're experiencing is an excessive degree of optimism on the part of the powder / bullet manufacturers. I have to say that's unexpected, since in the past I've used a variety of data sources and found that real world experience and QL theorizing matches up pretty well with what's published. In this case, however, I'm struggling to find a way to reconcile what's in the manual in front of me and what I'd expect in real life. I know that people do sometimes have trouble getting .243's to produce the energy / velocities of which they're theoretically capable (i.e. approaching 2000ftlbs) but I'm surprised by how far short of that your experience and QL's predictions seem to be falling.

 

At this point I should defer to Muir of The Stalking Directory - if there is anyone who can make charge ranges, reloads and rifles match up, or explain why they won't, it's him. I would suggest that getting in touch with him and the other experienced reloaders on there may do you more good than listening to me struggle to work out the best way forward. Nonetheless, if you feel I can be of assistance, don't hesitate to ask - I'm happy to help if I can.

[neutron619]

Here's the QuickLoad data for the 55gr round - hope it's of some use.

 

Cartridge : .243 Win.
Bullet : .243, 55, Nosler BalTip 24055
Cartridge O.A.L. L6: 2.625 inch or 66.68 mm
Barrel Length : 24.0 inch or 609.6 mm
Powder : Vihtavuori N140

 

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

 

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-10.0 83 38.70 3303 1333 39560 8146 98.5 1.133
-09.0 84 39.13 3335 1358 40801 8210 98.7 1.117
-08.0 85 39.56 3367 1384 42079 8271 99.0 1.102
-07.0 86 39.99 3398 1411 43394 8328 99.2 1.087
-06.0 87 40.42 3430 1437 44746 8381 99.4 1.072
-05.0 88 40.85 3461 1463 46138 8430 99.6 1.058
-04.0 88 41.28 3492 1489 47571 8476 99.7 1.044
-03.0 89 41.71 3523 1515 49045 8517 99.8 1.030
-02.0 90 42.14 3553 1542 50562 8555 99.9 1.016
-01.0 91 42.57 3583 1568 52123 8588 100.0 1.003 ! Near Maximum !
+00.0 92 43.00 3613 1594 53730 8618 100.0 0.990 ! Near Maximum !
+01.0 93 43.43 3643 1621 55383 8644 100.0 0.977 ! Near Maximum !
+02.0 94 43.86 3672 1647 57085 8670 100.0 0.964 ! Near Maximum !
+03.0 95 44.29 3701 1673 58837 8695 100.0 0.952 ! Near Maximum !
+04.0 96 44.72 3730 1700 60640 8720 100.0 0.940 !DANGEROUS LOAD-DO NOT USE!
+05.0 97 45.15 3759 1726 62497 8744 100.0 0.928 !DANGEROUS LOAD-DO NOT USE!

 

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 92 43.00 3739 1708 63066 8337 100.0 0.923 !DANGEROUS LOAD-DO NOT USE!

Data for burning rate decreased by 10% relative to nominal value:
-Ba 92 43.00 3427 1434 44431 8697 97.5 1.078

[mick miller]

Thank you neutron, this is very handy!

[sonicdmb]

I used N140 with 55 sierra blitz kings and 58 vmax with very accurate results. I also used it for 75 vmax which i don't recall the exact load but Found two accuracy nodes and chose the lower of the two as it was fast enough and I tend to run all my loads that way you get more life from your brass and barrel.

I believe I used the Viht data that applied for the date on the powder tub (it does change always match to the correct year of manufacture).

[sixhills 69]

I have been using N140 with 70gr seirra blitzkings using 38.2gr powder rifle is a browning xbolt I get 1/2 inch groups I tested them a while back on a range they were pushing 2785ftps brass is trimmed to 10% lower than max lenght so 2.035 and OAL is 2.625 hope this helps a bit

[mick miller]

That's great info six hills, in that case I may start lower by half a grain and work up, it's unlikely I'll reach the upper end of the test charge scale anyway.

[mick miller]

Okay. I finally managed to chrono the first two loads I developed. Case and bullet specs are identical.

 

.243win Nosler 70gn Ballistic Tip. C.O.L (average) 2.680" Trim length 2.036" CCI Large Rifle Primers 1-10" twist 22" barrel

 

With IMR4350 at 43gns I get 2998 fps

With VN150 at 39.5gns I get 3287 fps

 

This second figure is way over the QL projected figure for this load, bullet and barrel combo although the first figure is very close to projected.

 

By the way, no sooty cases on either on extraction (I, um, cleaned my breech for the first time in 5 years , this may have helped somewhat)...

 

I will bother to develop a VN140 load for both the 70gns and 55gns too, but my feeling is that the VN150 is giving me bang on what I wanted, good speed, good groups.

Edited February 23, 2015 by mick miller

[Underdog]

Brother, that is very slow for those pellets!

 

U:-(

[mick miller]

 Brother, that is very slow for those pellets!

First one yes, second one not so bad - have a look here, it's in the ballpark.

 

I will be trying the N140 next, that's up there somewhere around Varget speed.

 

Nosler's states that maximum expansion occurs at 3000fps, so anything over 90 yards and I'm going to be under max expansion, so yes, there is room for improvement. But for now, very useable.

Edited February 23, 2015 by mick miller

[fizzbangwhallop]

Going sideways somewhat to Hodgdons........I use 70grn BalTips and 46grns of H414 with CCI Magnum primers (recommended for the ball powder H414 for better ignition) for my .243 Match and Sporter barrelled Blasers......speed was chrono'ed at 3463fps odd with the slightly longer Match barrel. Cases are either Lapua or FC's and neck-sized unless they won't chamber before prepping in which case they get a full length .

 

This load has worked really well in several different makes of .243* over the years, seated to between 2.225 and 2.233 on the ogive using a Stoney Point comparator depending on whichever rifle's sweet spot.

 

(*off the top of my head that's Tikka 591(?), 595, RWS, Sako A2(Mine), Remi 700, Ruger M77 and my Match and Sporter Blaser barrels)

 

I use Hodgdon H4831SC for the Nosler 95grn baltips but that's another story

 

Cheers

 

Fizz

Edited February 23, 2015 by fizzbangwhallop

[Underdog]

Going sideways somewhat to Hodgdons........I use 70grn BalTips and 46grns of H414 with CCI Magnum primers (recommended for the ball powder H414 for better ignition) for my .243 Match and Sporter barrelled Blasers......speed was chrono'ed at 3463fps odd with the slightly longer Match barrel. Cases are either Lapua or FC's and neck-sized unless they won't chamber before prepping in which case they get a full length .

 

This load has worked really well in several different makes of .243* over the years, seated to between 2.225 and 2.233 on the ogive using a Stoney Point comparator depending on whichever rifle's sweet spot.

 

(*off the top of my head that's Tikka 591(?), 595, RWS, Sako A2(Mine), Remi 700, Ruger M77 and my Match and Sporter Blaser barrels)

 

I use Hodgdon H4831SC for the Nosler 95grn baltips but that's another story

 

Cheers

 

Fizz

That sounds very close to what I loaded 414 to many years ago and I also remember it doing 3500 ish.

That was with Speer TNT 70 grn.

 

U.

[sixhills 69]

Mick I have purchased a new chrono I will re- test the load data I use and pm you the results using N140 give me a few days to sort a range day out and I will let you know I was also told the N150 is too slow for a 70gr ballistic tip ok for larger 95 gr bullets

[mick miller]

Thank you Sixhills, always good to have a cross reference to see if I'm in the ballpark. As I said, I think the N150 is just about useable, but no doubt there is room for improvement. I have some 90g Speer soft point that can make use of the surplus N150.

 

What chrono did you get?

Edited February 25, 2015 by mick miller

[malkiserow]

Mick I have purchased a new chrono I will re- test the load data I use and pm you the results using N140 give me a few days to sort a range day out and I will let you know I was also told the N150 is too slow for a 70gr ballistic tip ok for larger 95 gr bullets

 

I use 44.9 grains of N150 on 70grn Sierra blitzkings with great results accuracy wise and for fox lights-out-power. This load was "given" to me by another member on here as his favourite load. Not used a Chrono so no comment on speed but it does work well in the field even with my little 16 incher. I don't shoot beyond about 200yds for fox but the drop between 100M and 200 M is 1 inch. which I am OK with.

 

As it happens, I'd like to find a nice load with N140 as I have loads of it to use up!!! Sadly, all my previous experiments with this powder have ended in poor accuracy.

[mick miller]

Wow. I couldn't get anywhere near that when I tried. 42 gns of N150 was the absolute limit, and that was over pressure and grouped awfully. How odd.

[Underdog]

Wow. I couldn't get anywhere near that when I tried. 42 gns of N150 was the absolute limit, and that was over pressure and grouped awfully. How odd.

How do you know it was over pressure?

[mick miller]

Marks on the case head from the extractor pin. Heavy and stiff bolt lift. More recoil than usual.

[malkiserow]

Wow. I couldn't get anywhere near that when I tried. 42 gns of N150 was the absolute limit, and that was over pressure and grouped awfully. How odd.

 

For reference, the Vhit reloading guide (edition 10) for N150 in 70g is 45.5 max

Edited February 25, 2015 by malkiserow

[mick miller]

I know, I could barely get above their start load!

[Underdog]

Marks on the case head from the extractor pin. Heavy and stiff bolt lift. More recoil than usual.

That Mick is not a sign of over pressure!

It could simply be a sign of bolt thrust!

I will sincerely encourage you to measure the brass headabove the rim again. As long as it is under "004" growth after the shot you are good.

Do make sure the chamber is dry and free of oil or cleaning agents.

High pressure is needed for the case to grip the chamber at peak p, in fact the bolt does not hold peak pressure at all! Many experiments have proved this. Many automatic actions depend on this known fact!

 

Mick, if you had an over pressure situation that caused your issue with the bolt, believe me the brass would be trashed!

I have pushed brass so hard iI have had it come out looking like crazy paving all over the case! The action still opened though easily!

Measure the brass please.

 

U.

[sixhills 69]

Thank you Sixhills, always good to have a cross reference to see if I'm in the ballpark. As I said, I think the N150 is just about useable, but no doubt there is room for improvement. I have some 90g Speer soft point that can make use of the surplus N150.

 

What chrono did you get?

I bought the Caldwell ballistic precision chronograph from optics wearhouse and got the free iPhone app you just plug it into your iPhone with the cable provided enter bullet the weight ect and shot and it saves all data to you phone or ipad you can keep it then to help with load devolpment.

 

Did you try N140 with 38.2gr on a 70gr ballistic tip?