Reply With QuoteI think you've nailed it!Originally Posted by Zero333
Exactly how we started out. Min to max, eliminated the max right away, and started working on seat depth. Got the groups down to sub moa and we're planning on adjusting load by tenths. All stop now and considering options.
I think you've nailed it!
I won't try to delve into the details, but when a chrono graph shows a sudden increase in speed for a given load, its gone over pressure.
So, if you want this to be relevant, you start low and work up and watch the speed.
Just targeting for a speed is totally the wrong approach, and shooting for a velocity is not the way to do it.
You take what the world gives you. If you want max velocity, you have to fine out what that is for YOUR GUN.
Not reading what load development process is or understanding it is a serious mistake.
Start off at least 10% below max, or start at the low end of listed and work up and take data.
And when its been pushed to the upper edge, then indeed a magnum primer can push you over as it can be good for upwards of 2 or 3 grains more powder.
There is a lot of variation in that due to powder speed, cartridge, gun etc.
Again the point is, start low, work up and monitor ALL the indicators going up.
There will be another one or two accuracy nodes below what you are at, take what the setup give you, not what you want.
I would like to have a million in savings, I sure don't have that. I have to live with that. If I live like I have a million there is going to be a sudden screeching stop to my world.
Thanks, RC, that's some good advise.
There's nothing less impressive than a fast miss, so I don't load for speed. I don't compete at long range, and i don't see any point in pushing my equipment to the breaking point. Typically I look for a node in the mid range as I find they usually shoot better. Sometimes a minimum load shoots the best groups and since I am mostly shooting paper at 300 yds and under, that's just fine. Uses less powder anyway so it costs less. I like that!
And I don't use my chrono for as a load development tool. If the bullets all go to point of aim and make small groups, that's all I care about. And unless I am working towards the higher end of velocity levels for hunting applications, as this load was being developed for, I am not so much concerned about absolute speed as I am SD and ES as that tells me something about ignition consistency, but so will vertical dispersion in the groups, and why I made the switch to a magnum primer. And yes, we reworked the load starting at min but dropped the previous max (44.5) by a grain.
If you'll go back and read post #19 you'll see that see that the Lee manual lists a bit over 48 grains as a max load, and several others in 44+, and we were only beginning to see a flattening of the primers and a small bit of cratering at 44.5 grains. With that i mind, and the load shooting sub MOA, it was only then that i put the chrono in use to make a drop chart and found the velocity to be rather high, which begged the question of why so fast? is it the powder? Barrel? Bullet? Bad chromo? Maybe there really was no issue, hard to tell.
To tell the truth, I only put 3 across the magneto speed. Not much of a test, but enough to tell us we were making unusually fast headway IF published loading charts are to be believed.
So you see, RC, I am not being hap-hazard or reckless, and I am pretty sure I'm not about to produce a mushroom cloud on the firing line. I do this as a hobby, not as a professional competitor. I've competed all my life and to be frank, I am quite tired of it. Tired of the egos, tired of the back stabbing, tired of the maliciousness and well, you get the point.
So I think this thread has reached it's conclusion. Most of the responses have been off course of the original question which was a mechanical fit nature, and although there is a lot of good information, I've come to the conclusion that the barrel needs to be re-throated and thats where we're going next.
My thanks to all for your fabulous ideas and input. You're a great group of friends ( I count you all as friends) with a wonderful amount of experience to share. I know I appreciate that tremendously , and I hope others will appreciate my experience and successes as well.
I have read this thread completely, and if I missed it I am sorry, but nowhere did I see brass mentioned.
For the 243 BRANDS of brass is important, and LENGTH. Make sure all brass is trimmed to specified recommended length. The 243 will really stretch brass and is reloading a lot for it and not paying attention you CAN end up with issues similar to what you are describing. Also, my early days of loading my 243 ammo, I used 308 brass and necked it down. Most of the time, it was zero issues but on occasion, the neck would come out too thick and cause a tight chamber issue.
In those days I had no idea what a neck turner was so I tossed the brass.
Check your brass for same brands, and length, in addition to the recommendations the others have given.
I just remembered this was for a friend, but please pass on this info to him.
You bring up a very good point, Handi, in fact, it was a THE point in the load development. You've read the entire thread so you know I was taking over load development on this particular rifle where mixed brass, poor headspace control and trimming issues were abundant. So I bought 100 pieces of new Winchester brass, of the same lot. I used a better (RCBS) FL die, tweaking it to only bump the shoulder as necessary to chamber, and of course trimmed to length. Neck tension=.002 as measured before and after seating the bullet. Runout down to .002 max. Neck wall thickness .015 to .016 for the most part. Plenty of chamber clearance as noted by shot brass.
Well said and we and good balanced take.My thanks to all for your fabulous ideas and input. You're a great group of friends ( I count you all as friends) with a wonderful amount of experience to share. I know I appreciate that tremendously , and I hope others will appreciate my experience and successes as well.
If there is a residual truth it is that the gun was telling you things and while you did drop back a few tenths from Hornady, you ignored Hornaday data and then justified it by using other data.
My Horndady book shows 43.8 as the maxium load.
That is a very narrow range powder, while that is sort of ok, again with a known problem gun, short throat I would drop it down to the very lowest I could find. That's a clear indicator (narrow powder range) that there is not a lot of latitude for powder variation, primer deviation and or barrel status.
You also have a magnum primer in the mix when the load is close to maximum and into the lands.
The characteristic of an overload is a more than normal velocity increase per a powder increment. The term is exponential, aka logarithmic. Say the books says 1/10 of a grain increase velocity by 50 fps per each added 1/10 grain, you put it into the lands and a magnum primer and it then increases by 300 fps. Your gun is screaming at you there is an issue.
Erratic ignition is also an indicator of too much powder for the load and in this case, caused by not enough distance to the lands before the pressure spikes.
You are close to or into the lands.
All those are red alert warning signs for a gun that has shown pressure signs let alone starting a load development. Ignoring what the Chrony is telling you is a mistake as its another tool in the set.
I have done the same at times (started at mid levels though not anymore) with a a new powder and a gun that had not shown any stress indications with higher level loads and plenty of deep throating.
Even with a short throat, loaded off the lands at no less than .015, it should not show any signs pressure with a much lowered load.
I would be more interested in going to the minimum loads, non magnum primer (looking at more than one re-load book) and specific bullet mfg recommended (which you have but not sure you read it?) and then see what happens.
Hornady shows 3100 FPS for a load 3/10 lower.
While others publish other results you have a bullet mfg that has published specific results and that is where I really draw a line (for myself and recommended to others)
At the maximum end of the spectrum, you go with the bullet MFG data.
Lower end you can debate via manuals but not the upper end to start with.
You may wind up past there at some point but you are likely not to as well.
Look at the lowest loads, come up with an average and if lower than Horandy go there, then try a few rounds.
A short throat is not a problem, it gives you more barrel to use (competitors do it often and after market barrel makers offers them ).
I don't see this as a barrel problem, I see it as an ignoring good load development that bit you as all the right moves for general as well as this specific gun were averaged out to justify an ill advised load.
Start at the very low end, your pressure signs will go away and then work up slowly to higher numbers but as you know that 43.5 is too much, keep off that by at least 2 grains.
You may just have the wrong powder for that gun. H4895 is more suitable.
On a couple occasions I have loaded a string and then re-did the upper ones as they were staring to get me a sticky bolt.
Been reading the thread as it developed, and as I am a reloader with less experience than the OP, learning stuff. I like the idea of taking the rifle to an experienced smith to have him check chamber dimensions. If it is out of spec, you'll have your answer right there. Good luck and let us know how it turns out.
If that is indeed the issue it should have been done long ago.
In this case its a quick easy and safe check to reduce the load, make sure its off the lands and drop the magnum primer.
He is pushing published data. Yes you cross check data in load development, but you use the most conservative not the most aggressive and he has a proven problem barrel.
His load he is in or engaged close to the lands, he is at the upper end of that bullet mfg, he is using a magnum primer in a powder that does not require it nor was the load developed with one.
The good news is he is honest with his figures and we can assess it.
I keep getting the sense he does not believe how load development should be done.
Conservative is not looking at the maximum load you can find for all 87 grain bullets and then using the lowest of those.
Its going with the very lowest load on the charts.
I don't understand where the claim of a tight throat comes from?
You stated that you trimmed the brass, so that was eventually covered in this thread, check it again to be sure. measure the OD neck on fully prepped brass, loaded brass (which you have), and fired brass (which you have not stated?). If you have a couple thou expansion after firing - then your throat should not be undersized. The brass neck thickness you listed is on the high end - and it's possible you have neck thickening - which may also be evident if your necks on fired brass are not larger in ever so slight measurement terms >@.002.
Other concern I have - many decades ago when first starting to hand load the base instruction was to never seat bullets to the lands due to pressure spikes. 40 years later it seems seating to the lands is just a standard practice in load development. Here's the deal - you friend is going to use these loads for hunting - which means he will often need to take a loaded round out of the chamber - so seating into the lands is pointless, other than to identify/verify where they are. Back off the lands to find your best grouping - because no good group into the lands is going to be effective for your friends intended usage.
Other concern - in determining max powder charge to work with with every specific rifle/barrel, adjustments in seating depth should then be moved farther away from the lands, not closer to the lands. Getting closer to or into the lands builds pressure. If seems you had a load, which you thought was not max if I understand your post correctly, and found signs of over pressure when moving the bullet into the lands. It seems well covered in this thread that what you thought to be under max load, proved to resemble a max or over max load once moved into the lands.
The hard chambering part would tempt me to get a body die (@$25), take comparator measurements of the brass, and move the brass back a couple thousandths at a time to see if prepped but unloaded brass chambers without resistance. Hard chambering brass is typically a function of where the shoulder is - not the neck. But you won't know until you move the shoulder back.
As far as primer selection question you asked - I've not seen a big spike in chronographed speed with Magnum primers when using extruded powders like the 4831 you are using. I have seen a 200 fps difference in chronographed speed when moving from a large rifle primer to a large rifle magnum primer with a ball powder, specifically H380. In that case - my velocity was running below book values by 200 fps when using a LR primer, I dropped charge, switched to a LRM primer, and with the LRM primer in a 22-250 with H380 - my handloads were right along side with the book values, and pressure signs were less. Point is - using velocity as a pressure sign is "just one consideration". I was 200 fps under book values, starting to see pressure indications of max pressure, switched to a LRM primer and built up the next load - which had no pressure signs but matched book velocities. Who woulda thunk... My H380 was a very old can of powder (50-60 year old powder), when/if I load more with a new can of H380 powder/different lot I have it noted to drop charge weight and build up/verify load recipe again. So I've seen primer selection have a big velocity difference with a ball powder, but I have not seen the same with an extruded. It can happen though I'm sure.
Given all you have done so far, the next things I would so:
- drop powder charge .5 gr
- get a body die and chamber prepped brass to see if that solves the hard chambering issue.
- Turn your necks to uniform thickness (sorry, Winchester brass is not impressive in this area in my experience)
- Seat bullets to vary bullet jump with the longest seating .005 off the lands. Your friend has no use for bullets seated into the lands.
- Shoot for an accuracy node.
If you don't find an accurate node with that recipe - change a component, drop charge weight, and build up again. Possibly a LR primer, possibly a different powder. I honestly don't have any issue with a LRM primer in a 243 - but I've never worked up an 87 grain bullet in a 243/6mm. For my use I've only been interested in 100-105 gr bullets in 6mm and my best loads all use CCI 250 LRM primers.
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