Thread: Testing a conventional approach to load development

Originally Posted by gimp

100m or 100y? @dannyb

yards, of note the targets are not to scale despite the PDF saying they are....

And here is the latest evidence this approach just plain works. A 6mm ARC barrel that I'd shot for 200 rounds or so, showed promise as an ARC with the 103s but never "properly tested". Rechambered to 6mm CM.

Taken to the range last night and a ladder shot up to book max. The results analyzed using GRT (calibrated to the resultant case capacity and actual velocity etc.). It suggested an additional 50-100 fps was still on the table. Not wanting to run this rifle "hot" I rounded the load up to an even number and confidently loaded 50 rounds.

At the range this arvo to test and here are the results, which include the cold bore shot - I got interrupted hence finished at 9 shots. All good for hunting to 500M

Note that the shot order is not as labeled, the cold bore shot is in the middle of the group, maybe #8

I did get humbled a bit later, we went to 571M to shoot some gongs and despite a solid zero from the above group I cocked up the settings between the scope and Strelok and couldn't hit the 6" gong to save myself . .,. It did eventually get sorted but shows how many things can go wrong in this LR game

I just found this thread. Its very interesting and a great practical example of the Hornady #50 and #52 podcasts I watched last week. Thanks @gimp for taking the time to do the test and share it.
I have a new rifle that I plan to load for using this method. Let's just say I settle on a load after 50 rounds. I understand that barrels speed up over the first 100-200 shots. Traditionally this would require retuning the load to get back to the "velocity node". In reality though, the velocity increase should be no real concern accuracy wise and I seem to recall the Hornady guys saying there is no correlation between velocity and accuracy. So it'll just be a matter of keeping an eye on velocity over time to make sure I'm making appropriate allowance in my ballistic calculator for long range work. Have I got the right take on that?
Cheers

I recently got a new rifle. I picked a load at book max of 2209. At 200 rounds it is 50fps faster than 0 rounds. The precision is no different.

Originally Posted by gimp

I recently got a new rifle. I picked a load at book max of 2209. At 200 rounds it is 50fps faster than 0 rounds. The precision is no different.

When I say I "picked a load", I mean -

I set the seating die so that the bullet is some distance off the lands and the COL is around the book max COL - not sure how far off the lands maybe 30 thou
I loaded 30 rounds, 10ea with 2209, 2208, and an old slow batch of 2209
I shot 3 10 round groups
All were fine for precision but the 2208 and the old slow batch of 2209 were a bit slower than my requirements

I then proceeded to select a max load of 2209 as my load at that random OAL, and use it.

Over the first 200 rounds it seems to have sped up around 50fps, precision hasn't changed.

As no-one else has repeated my "test of the test" - we can't say categorically that you should expect the same with every rifle, cartridge, bullet, powder combination - but I haven't seen any evidence to the contrary yet.

Cool, thanks. Coincidentally I will be using 2209 aswell.
Cheers.

Thought I’d come back and re-read. Definitely changed the way I do things

I managed to get to the range last night. Put 70 rounds of "load development" through the 223. Used a hybrid approach effectively a quick test of seating depth to see if I noticed any difference and to use the last bit of some old 4895 I don't trust. Then a quick exclusion test with various powders to exclude any options from further consideration (5 shots cant confirm a good group but inverse probability can highly suggest its not worth continueing with . I'm going to start a thread following this rifle as I have a few hundred bits of brass and intend to test a bunch of things for myself. I will try record it all to post on here. A summary was I shot 3+inch 5 shot groups as well as 4 consecutive submoa 5 shot groups with 4 different powders and charges that overlaid fall in 1.1moa for 20 shots. I think it's going to highlight the fastest reloading solution is to change components

Please post up the data! Very interested to see

Originally Posted by gimp

Please post up the data! Very interested to see

That's the plan. One thing I see straight of the bat is it doesn't like the 75s like the Tikka did.

A wee thought on this. The results are still a bit subject to "other factors". My 223 full length die has been on the same "setting" for years. My last two 223s didn't really perform as well as I expected. Then the latest one gave me a series of light primer strikes, no bang. Hmmm, it's a very well built rifle, everything should be good, what's causing that? I checked firing pin protusion, all good. Headspace is the next suspect, so a trip to the gunsmith, hmmm that's within tolerance as well, the"no-go" wouldn't drop.

A real big Hmmmm. So after some more thought I got a comparator and measured the should length of some fired, factory and reloaded rounds. The measurements are relative but most factory ammo hovered round 2.507" Fired cases from the last two 223s a very consistent 2.514. My sized cases, 2.505 to 2.507 ( including the light pin strike ones). So I dug through some old cases until I found some that were measuring 2.511+, neck sized them and presto, accuracy improved, and the light strikes vanished.

Funnily enough both current 223s have exactly the same chamber length, and both improved accuracy.

My dies must have been like it, potentially causing issues, for at least 5 years since I got a co-ax press.

Originally Posted by Tentman

A wee thought on this. The results are still a bit subject to "other factors". My 223 full length die has been on the same "setting" for years. My last two 223s didn't really perform as well as I expected. Then the latest one gave me a series of light primer strikes, no bang. Hmmm, it's a very well built rifle, everything should be good, what's causing that? I checked firing pin protusion, all good. Headspace is the next suspect, so a trip to the gunsmith, hmmm that's within tolerance as well, the"no-go" wouldn't drop.

A real big Hmmmm. So after some more thought I got a comparator and measured the should length of some fired, factory and reloaded rounds. The measurements are relative but most factory ammo hovered round 2.507" Fired cases from the last two 223s a very consistent 2.514. My sized cases, 2.505 to 2.507 ( including the light pin strike ones). So I dug through some old cases until I found some that were measuring 2.511+, neck sized them and presto, accuracy improved, and the light strikes vanished.

Funnily enough both current 223s have exactly the same chamber length, and both improved accuracy.

My dies must have been like it, potentially causing issues, for at least 5 years since I got a co-ax press.

Sure, a reloading process/quality error like that could mean that you'd struggle to "find a good load" at all. However tuings like that are a constant across all loads trialed and don't at all detract from the investigation of whether or not conventional load development methods work. It's a separate issue like whether or not your rifle is junk. I think right back at the beginning I recommend avoiding these issues by having a very high quality rifle system and using the best components.

Quite surprised theres not much focus on seating depth here. Remember watching a podcast with eric cortina and jack nerry (i think his name was) one f class the other benchrest for team lapua. Talking about seating depth has a direct relation on group size, testing in 3thou increments. A example of this is when people buy factory ammo to test what there rifle likes that is the seating depth of the different ammo that determines the better groups.
I think his way of load development makes sense, first stage over chony, no target to distract you, find lowest es
Once powder charge found on to seating depth testing

@Hunterdave
Get ready for the "Statistics only" crowd to get rev'd up again

Originally Posted by Roarless20

@Hunterdave
Get ready for the "Statistics only" crowd to get rev'd up again

Admin please remove me