I did the Berger version with my 300wsm
Attachment 156739
I didnt fire the -130 as it was pretty obvious where things were working. Top right was comformation of -10 load and zero
Printable View
I did the Berger version with my 300wsm
Attachment 156739
I didnt fire the -130 as it was pretty obvious where things were working. Top right was comformation of -10 load and zero
After watching the Erik Cortina YouTube videos and following this thread, I thought I’d give it a go. Thanks DannyB for starting it up. I waste far too much time and too many components on load testing, so any ‘short cut’ that works is great. The test rifle is a Savage actioned ‘back-up’ 308 Winchester target rifle for F-TR and F-PR competition and practice.
Specs are:
Savage Model 16 stainless action with a Rifle Basix trigger, epoxy bedded in a Boyds laminate target-style stock. Barrel is 28” 1:10 twist stainless M24 profile (straight taper to 0.950” muzzle), made by Hugh Bradley. Chambered with a 308 Winchester tight-neck ‘Palma’ reamer by Les Grimsey. It has been showing some good accuracy potential. Scope is a Sightron SIII 8-32x56 in Leupold rings and I’ll be using an F-TR style bipod and rear bag.
I have some Sierra 155grn ‘Palma’ projectiles that haven’t been shot in this rifle before, to use for this test.
For the velocity test stage, my load specs are:
Lapua Small Rifle Primer 308Win brass (annealed with an AMP annealer), CCI 450 primers, Sierra 155 Palma projectiles, seated 20 thou off the lands (measured with a firm push into the lands with a Hornady seating depth gauge).
Load is 8208 powder, with four each of: 45.3, 45.5, 45.7, 45.9 and 46.1 grains (three for data, one extra in case the chronograph doesn’t register a shot). These loads are up to a grain over the maximum of the Sierra manual. It works for me, as the small rifle primer brass typically needs more powder to reach the same velocity/pressure as large rifle primer brass, and I’ve been shooting similar loads in this rifle with no pressure issues. It may not work for you, so it goes without saying to stay with reloading manual loads.
I’m a fan of small steps, as I think nodes can be quite small (and easy to miss with bigger steps).
Chronograph results (with a LabRadar chronograph):
45.3 – 3002, 3009, 2991 – ES = 18 – SD = 9.1
45.5 – 3005, 3006, 3006, 3011 – ES = 7 – SD = 3.0
45.7 – 3031, 3027, 3014 – ES = 17 – SD = 8.7
45.9 – 3050, 3033, 3042 – ES = 17 – SD = 8.4
46.1 – 3064, 3041, 3058 – ES =23 – SD = 9.7
45.5 looks like the clear winner. Given the ES of 2 after three shots, the fourth was fired and it is still very good. The bolt had very slight resistance to lifting for the 46.1 load, so I’m happy to be 0.6grn under that.
Forecast to rain tomorrow, so I’ll load up the length-test series, and hopefully test on Friday and report.
Any comments, questions or critique most welcome.
Good result with 45.5. Was that what you expected ? I am surprised that the loads either side didnt have a lower ES, putting you in the middle of a sweet spot rather than in the middle of some ordinary ES loads.
I have had similar and dont understand it fully
All nice results and I would be happy with any of them if I can tie it to a consistent good group at 500m. Shows excellent, consistent reloading procedures from you.
I recon the middle of the node will be before 45.5gr. Why? Look at the different increases of velocity per 0.2gr of powder for each group vs the ones below and above...
Soooo, some results...
"Inconclusive" would be the one-word summary. Maybe my expectations were a bit high, but I'll need to do a bit more testing. A couple of good groups, but not yet Cortina's 'wide-node' of two consecutive small groups. In the end I did 8 different seating depths, in 0.003" increments (one was a 0.004" increment). All were seated with a Forster press-mounted die (it seems to give me the lowest run-out) to 2.190", measured with a Hornady gauge thingy. Then I seated to depth with a Wilson micrometer hand-die at the range, and measured each one.
Attachment 157811
I'm thinking I'll now try two steps closer to the lands (2.193 and 2.196") and repeat 2.168" and do two more steps that way (2.165 and 2.162).
@JaSa - Yeah, I figure the velocity node is probably a bit below 45.5 given the trend. They are loaded with an RCBS Chargemaster, so +/-0.1grains is likely happening anyway.
@Moa Hunter - Yup, there is much I don't understand too. I think Litz is onto it when he says we read far too much into very small data-sets - statistically the the good groups above could be just random occurrences.
Couple of cracking groups there...if either proved repeatable I'd be very happy.
Certainly looks like 2168 is headed / trending into a wide node. Takes a lot of time this !
One thing I would like to do myself is fire one shot every morning from a cold barrel to give a five shot group at the end of the week. A chap on youtube explained he did that when he had his final hunting load
Looks like might be worth a group at 2.165 to see if you are at longer end of that node with first group, if it gave .7 or less I'd be thinking 2.168 is in the middle and good to go (provided it is repeatable)
Have done it in the past on a monthly basis and recently on a weekly basis when training or load development on other guns.Quote:
Originally Posted by Moa Hunter
Once I worked out the wind at our local range. I managed a 5 month 1.3" group @200 yrds but didn't run it over the Chrony.
I am 4 rnds into a similar test over the radar and although the group isint quite as good (waterline) the ES so far is 6fps.
If I fire another round within say 10mins my velocity jumps 40fps and ES stays within 10-16 fps for consecutive shots.
I was interested in determining my fouled cold bore consistency as it is a hunting load.
Apart from the 40fps jump ( has me a tiny bit confused ) when shooting consecutive shots on the cold bore I am pretty happy as the rifle never gets stretched beyond 500 yrds on game and the cold bore shot velocity hasn't so far, changed from winter to summer and that is using RL26 which is claimed to be temp sensitive.
As for the above. I can see an obvious node between 2.168 and 2.175.
Sent from my SM-T510 using Tapatalk
I’d say 2.165 is going to be about where you find your accuracy there.Quote:
Originally Posted by MMC3
Should pull it in nicely.
Attachment 157822
The area circled (including the shorter length not yet tested) looks hopeful
Thanks distant stalker for that extra analysis. I will let you know how I get on with the next test batch in a few days.
@R93 - the cold bore first shot velocity difference and clean bore vs fouled bore velocity difference is a common phenomenon. The long-range target stuff that I do is out to 900yds - you get two 'sighters', then (normally) 10 counting shots. The first shot of the day is pretty much always lower vertically, usually more so for a clean bore, due to that velocity difference.
I am aware of the clean bore cold shot. This barrel normally takes 3 rnds from clean to settle and hit POA. Just a bit surprised I am getting a 40fps jump after a fouled barrel cold shot.Quote:
Originally Posted by MMC3
I am assuming it is the same principle but have had excellent ES in this rifle over a 5 shot string from cold without a jump in velocity. I am a bit confused as to why it has come up now. However the cold fouled shot over the last year or so has been extremely consistent so no need to worry too much about it for a hunting rifle.
Sent from my SM-T510 using Tapatalk
This time the summary is two words: pleasantly surprised.
Given the first depth-seating test series indicated a narrow node within the range and strong hints of a node at the end (longest jump-to-the-lands tested), I loaded up 3 each of:
2.193 and 2.196 (closer to the lands – approx. 0.017” and 0.014”)
2.168 (repeating the good result at the end of the last test series)
2.165 and 2.162 (two steps further from the lands)
The results show:
(a) a pleasing repeatability of the 2.168 group
(b) a broad node from about 2.162 to 2.168.
Attachment 158034
Given the Cortina instructions, I should now pick 2.167” as my seating depth.
I put the chronograph back on for the last 9 and recorded an average velocity of 2995, with an ES of 19 and a SD of 5.5, so pretty happy with that.
Thanks to all for your suggestions, comments and likes. Cheers, M
Good stuff.
Nice!!!!! Looks like you have a very good load sorted
My F class rifles clean cold bore shots are 1 MOA low for my first sighter I add ! MOA elevation and take it off for the second if your wind call is correct you get 2 keepers very handy in the F disciplines.Quote:
Originally Posted by MMC3
Right finally have my new press installed and loaded up final load test and confirmation.
I loaded up 6 rounds a month ago on my old press and it was bloody diabolic trying to seat accurately.
I took those 6 rounds to the range and shot them.
The first 3 were seated at 2.834" ogive length and whilst the speed was consistent it was a bloody awful group
Which surprised me as I had already found this seating depth and charge weight to shoot very very well.
I also shot 3 at 2.831" ogive and this shot a half inch group which is what I expected from the first load.
My mate pointed out to me that when i shot the first group i was lying prone but nearly 70° to the rifle which would likely have thrown my parallax out and possibly the cause of the poor group.
So rather than suffer using my old press again I bought a new press off a forum member and waited for that to arrive before loading anymore rounds.
Fast forward 1 month.
Loaded up 3 more at 2.834" on the new press and what a delight it was to use a press that seated accurately every time.
Went to the range and put 3 factory rounds through just to check the rifle was all good and foul the barrel.
Then shot my 3 hand loaded Berger rounds.
I think I'm done.
But I'll let the pic do the talking.
Attachment 160523
Attachment 160524
Today's fps are circled down the bottom of the list and are consistent with the last lot that I made up at the same spec as per 2 lines above.
Attachment 160525
Fucked if I know why the last pic is upside down sorry guys
For the doubters here's the pic of the target with nothing in the way.
Attachment 160526
Hopefully fixed the upside down pic
Attachment 160527
now write that recipe with ALL its details on the wall above press with vivid.......tis a keeper mate.....
Tis in my load diary :thumbsup:Quote:
Originally Posted by Micky Duck
Ballistics for anyone interested.
Attachment 160551
So correct me if im wrong.
Start with powder load ladder. Take the load with best ES and SD, not necessarily the best ‘grouping’ on target.
Then proceed to seating depth ladder: work out ‘jam’ length… then ladder jam length-0.015-0.020”, then 3rounds at 0.003” intervals…. What are we looking at measuring with this? Just ES and SD, or target group size?
Ive done a powder ladder, but unfortunately the best group size and best ES didn’t marry up…. So do i go with the best ES and see if the group size comes in with the different seating depth ladder? Or just go with the powder charge with the best grouping, and see if i can improve group size and ES with the seating depth ladder?
My powder ladder was all done with the same Coal: 0.025” off jam length
Best es, then fiddle seating depth to tune group sizeQuote:
Originally Posted by micknz
👍Thanks…. I’ll be lucky to have any projectiles left after all the load development (6.5mm eld m) 🤔
Sad sign of the times unfortunately, currently developing a load for my 308 and I'm being extremely frugal just loaded to saami length and charge weight ladder, got 2 reasonable loads out of it, currently loading 3 more of each to confirm data and will pick the best and leave it at that.Quote:
Originally Posted by micknz
As luck would have it 1 is .5" 3 shot group at 100 yards the other is .7" the chrono was playing up so only got speed of 2 rounds at each of those charge weights but looks promising at around 12-15 fps spread for both loads.
Normally I would go hard and do seating depth ladders to really tune the load but I really don't have the luxury of components and am unlikely to anytime soon like the rest of us.
I found this to be quite helpful
Load Development Model XLS
Makes it easier for a simple person like me to interpret results visually
From here Load Development Analysis
I like Erics videos except the one where he criticizes neck sizing. The comments defending neck sizing were awesome and really wound up Eric.
Iv been watching his videos for a while now. Listening to those F Open guys like him and F Class John and Keith Glasscock.. their anti neck sizing thing seems to come from the super super custom super tight chambers they use. Even when they say they are shooting a standard 284.. they aren't, it's all cut on a custom made reamer just for them. Hence the full length sizing so that the bolt closes.Quote:
Originally Posted by Three O'Three
about 80% of the top shooters for fclass and or bench rest bump 1-2 thou its no more accurate then neck size and your no worse off on accuracy etherQuote:
Originally Posted by Three O'Three
but a 1-2 thou shoulder bump is far more reliable and consistent (you don't have to bump every 3-4 shots) as eric says he is 100% correct in those statements
for something like prs you would be stupid to neck size only
having a tight one that doesn't chamber smoothly could lose you a match
@dannyb; Thanks for starting this mate. Learn't a heap. Much like you I don't comp shoot, just want to get the best out of my gear and it's fun. I operate under the principle that there is no such thing as a stupid question, so here goes; I've read quite a few references to SD in this thread, I'm in the dark. The only SD's I'm familiar with are sectional density and seating depth. Can anyone assist? CheersQuote:
Originally Posted by dannyb
SD = standard deviationQuote:
Originally Posted by RugerM77
ES = extreme spread
Thanks mate.
Just spent a few interesting hours in the shed. I'm working with a long action Ruger M77, Shilen barrel in 7 x 57. @dannyb I see your seating depths and jam depth, in a .270. I used both the jam method and @mickyducks old school method. The curious thing, bearing in mind my calibre, with a Nosler BT 150, old school 3.188 held on lands. Jam approx 60 thou more. Tried several different brands, all had similar results. Example Rem coreloct @ 3.100 old school. I'm thinking I must have heaps of freebore, especially when I see your .270 seating depths. The good thing, though, long action magazine. Even jam measured Nosler, above, fits in mag well. Cartridge has a long neck which is going to help too. Don't know if I can manage seating adjustments in increments of 3 thou though.
I now use a different method of finding jam, take a fired case and paint some loctite on the end of the projectile that goes in the case mouth, put the projectile in the case mouth making sure to leave it longer than your freebore.
Chamber the round carefully closing the bolt then leave it for 30 minutes to let the loctite set.
Carefully eject the loctite round and measure it for your jam measurement.
Works well and once you have your jam you can soak the round in hot water to release the loctited projectile.
Great idea, thanks. I was a bit concerned about the difference between jam length and projectile toucjing the lands. Interesting that Cortana says back off 15 thou from jam. Projectile definately going to be touching lands still. What's hard case is; I shoot the old Norma 150 grn soft point spire point, under minute of angle easy. Using a cleaning rod its COAL length is 3.100. I've actually got it seated at 3.130. Absolutely no pressure. So I guess the lands jam is the way to go. I've only ever used the guesometer, close enough is good enough. I'd only accept MOA or less though. I wonder what's going to happen with a bit of science. Thanks dannyb
I have used all sorts of methods - split case necks and close on long seated bullet, Stoney Point (now Hornady OAL gauge) method, Sinclairs tool for measuring seating depth (lies in cupboard unused), measure to the bolt face from muzzle with cleaning rod then push a bullet into the bore and measure from muzzle again deduct one measurement from the other. The last method is fraught with inaccuracies due to differing bullet lengths even out of the same batch. The Hornady method can give differing measurements depending on how hard you push the projectile fwd. Can sorta work OK if you take many measurements and then average the results.
Now I just use Alex Wheeler's bolt click method only. Extremely accurate and repeatable. Also useful for tracking throat advancement.
Only thing it won't work on plunge ejector type bolts with the plunger in place. You must remove the plunger which is probably beyond the ability of the average guy. None of my rifles are plunger eject.
Just remember the measurement is only a starting point for optimum seating depth.
Have a look here https://www.wheeleraccuracy.com/videos
Have a look at "Finding your lands".
"Clickers" is similar but is dealing with tight brass.
There's some really competent guys out there, just some of them aren't always in your face.
