Thread: Stupid Question. bare with me please

Originally Posted by Mroach

Newish reloader, have done alot of study and have had some success..Am reloading for 6.5 creedmoor Tikka T3x rifle, have been getting reloading data off XXL reloading am now looking at the New Hornardy 11th edition.. Am impressed by no.s however I am using Lapua brass and either wind river or federal primers the Lapua brass seems to be quite short 48.5 mil. I am looking at throwing the 147g Eld-m using Alliant 16/26. Hornardy manual says 71.12 mil COAL whereas I have been loading other ammunition to 70.1 mil ( 129 SST) I quess my question is, I don't know the Max cartridge length my rifle can handle, am I safe using the published COAL using different brass/primer as long as I start at the low end? and observe pressure signs ?!?!

Greetings @Mroach,
About now you are likely wishing you never asked the question. Simply the cartridge must fit in the chamber, preferably without the projectile touching the lands, and the cartridge must also fit in the mag. 70.1mm clearly meets these requirements with the SST and should with the ELDM as well. A lot of current projectiles shoot just as well with a bit more jump if not better so no need to try and fix what aint broke. I work with a minimum clearance to the lands of 1mm where the mag allows. The Creedmoor data is pretty good being quite new is right up there so I would work with that preferably chronographing a start load to validate the data before mong up closer to the top loads. The chronograph will give you a better indication of pressure than anything else. PM me if you have questions.
Regards Grandpamac.

Originally Posted by Taranaki Shooter

I haven't worked out how to print my QL data and post it here. I think once you guys understand what I'm doing you will be find it interesting. QL is the back bone of the solution. I could not get the low ES I do with out it. Or maybe I could if I was prepared to buy 1 of each powder and test it.

The right powder will have 100% case fill and 100% burn. Using QL alone I have had crazy first test load results. Its a good tool. I'm trying to be respectful here but some of the stuff I'm reading is a bit unfortunate.

That said without QL using your powder of choice and assuming it is not too slow for the projectile you can sneak up your pressure till the ES settles down. If the powder is too slow it will go over pressure before your ES settles. If it is too fast it wont settle. your ES will be shit and stay shit. QL nails that calculation every time!! A fair amount of experience would be needed to do this safely.

My WSM posted a 3 shot ES of 1.4 and an SD of .06. Garmin Chrony, Over 15 shot preceding it was ES 6. My .284 is also ES 8 over 10 or more shots I can't remember the total now. My system works.

Get what you are saying, at a practical level I would think you are via QL eliminating several possible variables in case fill and from there possible variations in powder column surface area for the primer gas jet to work on and ignite. What you are saying seems to me to agree with the stuff I've looked at on the topic where to sum it up consistency of ignition is what gives low ES and SD velocity figures. In other words, the bullet does the same thing every time from chambering to departure... We run into that more and more at the weird ends of reloading, like reduced loads and subsonics where case fill is so light that you run almost intentionally into these issues and then have to work around them like with crimping for consistency.

Originally Posted by Pommy

I'm saying that 10 thou is not far enough away from being jammed to aleviate the potential pressure spike from the bullet not having that run up. So we're in agreement, no?

Thanks, from your further explanation yep we are. I think that if you are careful in your load development, it doesn't matter where the pill is in relation to the lands - other factors can be more influential like tight carbon rings etc. I did read articles about load development where they do 'rough development' with the pill jammed and once at the velocity and basic group they want they then tune the load by adjusting seating depth deeper. In most cases this seems to slightly lower the pressure and adjust the harmonics. I find as we mentioned earlier that this is kinda a BS way to go for the average factory rifle - nice academic argument but in reality if the round won't fit in the mag it is really not much use for the majority of people's hunting use. Mental note - must try those subs again (my .308 sub load uses the 175gr Sub-X pill seated to cannelure, which has most of the pill in the case taking up volume and about a 6Km jump to the lands for 3-shots touching at 50m).

FFS it has been a thing forever.pick the powder that gives you the most full case.it should be best.... That's been a thing for fifty years or longer.

I can't seat the Nosler Ballistic tips and SAAMI spec in my M18 .308 as the magazine isn't long enough to allow it but it certainly hasn't affected accuracy with the 165Gr ones I've been loading.

Originally Posted by No.3

Get what you are saying, at a practical level I would think you are via QL eliminating several possible variables in case fill and from there possible variations in powder column surface area for the primer gas jet to work on and ignite. What you are saying seems to me to agree with the stuff I've looked at on the topic where to sum it up consistency of ignition is what gives low ES and SD velocity figures. In other words, the bullet does the same thing every time from chambering to departure... We run into that more and more at the weird ends of reloading, like reduced loads and subsonics where case fill is so light that you run almost intentionally into these issues and then have to work around them like with crimping for consistency.

YES! You get it! you need to be very careful with load around 90% and less case fill. They can cause a pressure spikes with a flash burn. I tried W760 in my 6.5-284 once and my ES was extremely bad and I had some really hot loads. I was pretty new to it all at the time and Mitch Maxbury put me right. It's all of these experiences over the years that point you in the right direction. And you have to think a bit.

I'd say on QL there are 3-4 possible powders for any given load but only 1 powder will give you the extreme low ES! That is my observation so far. ADI 2217 was slightly too slow for the WSM I was borderline for pressure and had ok ES around 15. I say around 15 because it would fire one randomly 30-40 over. I knew I had to go up but I was topped out on pressure so I was done with 2217. So shifted to RE25 it was better on QL but I only had a small amount to test, then a mate gave a bottle. I fired 4, 3 shot groups. First group was 68 of RE 25 nice group about .6moa I guess ES was 30. I upped it 2% to 69.4 10 thou off and the ES was 1.4 with a lovely 3 shot clover all touching. I then tuned it with 2 more groups to a bug hole. 12 shots fired in total.

This an F Class gun in a A5 stock. Your gun is the most important component to this whole thing. As Tracy Short said to me once " good ammo won't make a shit gun shoot" He is dead right I struggled with the 308 because it did random shots. I think it's a bedding issue but its some 3 piece stock thing. I have no idea. Not interested in it in the least. My point is if its a factory gun just do what Pommy said and make it go bang. You will chase your tail with this crap I'm talking about here.

Originally Posted by Micky Duck

FFS it has been a thing forever.pick the powder that gives you the most full case.it should be best.... That's been a thing for fifty years or longer.

LOL Yep! I bet you know the rest of the story to get these things to go through one hole too. I really am not reinventing the wheel here. Just refined it a bit.

Yip...get closer lol.

Originally Posted by Micky Duck

FFS it has been a thing forever.pick the powder that gives you the most full case.it should be best.... That's been a thing for fifty years or longer.

It's "conventional wisdom". This is often a way of saying "something that someone told us, that we have never tested".

However - Bryan Litz appears to have tested it, and the results appear possibly different to the "conventional wisdom".

https://www.facebook.com/photo.php?f...13289461288027

I have not tested this nor looked into it sufficiently. I select a powder based on:

1. Is it ADI, and therefore actually available and affordable?
2. Does it give the highest or close to highest MV out of the ADI book?
3. Is it widely and successfully used in the relevant cartridge?

Using these criteria eliminates the problem.

I have yet to see any genuine evidence that once an appropriate powder is selected, different charge weights actually produce a different velocity SD, all else being equal. If anyone has any, please post it.

I have data sets that suggest the opposite.

Any process that purports to allow one to select "the best load" by default also should allow one to deliberately select "the worst" and demonstrate that they are different. I am keen to see people provide evidence of this. Without evidence, we're all just another bloke with an opinion.

Don't look at me....I won't use a chronograph. If a load is accurate that's good enough for me...how accurate is a personal thing. Other than my open sighted single shot all rifles in my cabinet are capable of very tidy groups/ plucking heads off hares at hundy yards. They are let down if I haven't taken to range to sight in properly all the same.

Originally Posted by gimp

It's "conventional wisdom". This is often a way of saying "something that someone told us, that we have never tested".

However - Bryan Litz appears to have tested it, and the results appear possibly different to the "conventional wisdom".

https://www.facebook.com/photo.php?f...13289461288027

I have not tested this nor looked into it sufficiently. I select a powder based on:

1. Is it ADI, and therefore actually available and affordable?
2. Does it give the highest or close to highest MV out of the ADI book?
3. Is it widely and successfully used in the relevant cartridge?

Using these criteria eliminates the problem.

I have yet to see any genuine evidence that once an appropriate powder is selected, different charge weights actually produce a different velocity SD, all else being equal. If anyone has any, please post it.

I have data sets that suggest the opposite.

Any process that purports to allow one to select "the best load" by default also should allow one to deliberately select "the worst" and demonstrate that they are different. I am keen to see people provide evidence of this. Without evidence, we're all just another bloke with an opinion.

Read what I wrote above. Believe me, don't believe me I really don't care.

Originally Posted by Taranaki Shooter

Attachment 256701Read what I wrote above. Believe me, don't believe me I really don't care.

I've got dozens of strings where I can pick 3 shots with that SD. Please read my post above regarding 3-shot velocity strings and let me know what you think this tells you about the true SD of the load.

Ok you win.

Originally Posted by Taranaki Shooter

Ok you win.

This isn't about winning at all. I've been contemplating what to contribute to this thread today when I haven't been distracted by work demands. The single biggest thing I've learned about reloading in recent times is statistical significance. Thanks to YouTube and some excellent content creators this is now more widely known about. Here's a particularly good podcast/video that elaborates in a way that's digestible to a fairly wide audience:
https://youtu.be/QwumAGRmz2I?si=NjPt2qRQ5nlQ6YMN

There's been a lot of fantastic discussions on here recently around statistical validity by a lot of people who are interested in the technical aspects of shooting and reloading.

Originally Posted by Taranaki Shooter

Ok you win.

It's not a competition. If we want to learn more collectively and get to the "right answer" we need to question conventional wisdom and use data in meaningful ways.

You may have a process that works genuinely wonderfully. That might be useful to all of us. However I'm not going to accept that just cos you say so. Provide some meaningful data and we can have a look at it.

I've put up plenty of data showing that 3-shot SD doesn't mean anything.