260AI...picture heavy

[schnyd112]

2950... Getting interesting at those speeds. That group looks great, gotta shoot it out to 600 now, make sure everything is copacetic. You are a bigger man than I shooting these last 2 mornings, 15-20 degrees with 10-15 mph winds. I am skiing tomorrow, gotta take advantage of 20+" of new powder. Probably going to run my last .220 swift rounds on Sunday, hope to snag a dog to put the ol girl to sleep. Never know though, it's always a toss up trying to call around here.

[LongRange]

sounds like your the bigger man going skiing LOL...its only supposed to be 16degs this morning on the valley floor so that means single digits or minus up at the resorts...good luck with the dogs i have only seen a couple around here this year but theres food and water up higher this year.

[LongRange]

i went out this morning and shot some RL-17 and then some RL-19...the RL-19 was just a little bit slower than the H4831...48,5g RL-19 was 2920fps but was all over so im going to concentrate on the RL-17 for the rest of the barrel life and see what i can get it to do...im also going to clean up the necks on the win brass as some of it is .0015 to .002 from one side to the other and since ive done the primer pockets and the brass seems to be holding up well might as well go all the way.

my interest was peaked even further this morning....i shot 6 rounds with the 45g RL-17 load first..one over the magneto speed(2952)and then a 5 round group...im happy with that load...i should of shot a few rounds first as it took 3 for me to settle in and shoot...

http://i1239.photobucket.com/albums/ff515/LTT-/Mobile%20Uploads/1451160896.jpg (http://s1239.photobucket.com/user/LTT-/media/Mobile%20Uploads/1451160896.jpg.html)

i also loaded 5 rounds at 45.3 5 at 45.6 and 5 at 45.9...i shot 1 each of these over the magneto speed to see where the speeds were then pulled the bayonet off and shot the other 4 rounds of each charge at the same targets as groups...45.3g was ugly and all good clean shots

45.6g looks tune-able....and im liking the increased speed...

http://i1239.photobucket.com/albums/ff515/LTT-/Mobile%20Uploads/1451160890.jpg (http://s1239.photobucket.com/user/LTT-/media/Mobile%20Uploads/1451160890.jpg.html)

now this here is where my interest in this project really peaked...when i shot round 3 i thought where in the he!! did that one go...round 4 just broke enough so i could see this was going to be one of those high 2 to mid 3 groups and you know what happened to round 5 LOL....WAY over excited!!!

http://i1239.photobucket.com/albums/ff515/LTT-/Mobile%20Uploads/1451160897.jpg (http://s1239.photobucket.com/user/LTT-/media/Mobile%20Uploads/1451160897.jpg.html)

im going to load up 20 at 45g and 20 at 45.9g and shoot them at 500yds tomorrow and what ever one groups the best is the load ill work with and fine tune...im hoping its the 45.9g load LOL!

[Dewey7271]

Thought you'd see some speed w 17. Nice the accuracy is there also.
Nicely done, you having fun yet?lol

[LongRange]

If I'm shooting I'm having fun lol!

seriously though...I like the load development,tweaking things and seeing the out come just as much if not more than shooting...I also like pushing the things right to the ragged edge and that will most likely be my demise lol!
ive done a lot of things in my life and most of them can only go so far at which point I loose interest...shooting and load development is something that could go on for ever so It keeps me interested.

like tomorrow...I'm not expecting tiny groups due to the neck wall variances because as I was seating these 40 rounds earlier I could feel the bullet resist at the top of the neck and then just kinda slide in...this tells me the the brass has flowed into the neck/shoulder junction and the collet die isn't fully sizing the neck or should I say not sizing evenly.

i set my neck Turing tool up tonight so after shooting these 40 rounds I will turn all the necks,anneal and shoot the same loads again next weekend and I'm willing to bet they will shoot tighter groups.

see...it never ends lol!!

[Dewey7271]

Yeah, I'm kind of the same. Get a good load then get all ocd about other possibilities
Glad to see you found the speed you were looking for

[LongRange]

LOL...thats why its a good hobby if you like to tinker.

[LongRange]

so ive turned/cleaned up about 65 necks this morning and as you can see some where turned about 95% and others only about 40-50%...notice the 2 cases on the left where the cutter starts to cut the neck near the neck/shoulder junction...that distinct line is aprox .040 from where it starts to where the cutter just barely starts to cut into the shoulder...this is what i was talking about above where the necks are sized unevenly...this is why IMHO the lee collet die works 10xs better if the necks are turned...i should of cleaned the necks up after the first firing but like i said i was loosing interest until friday...

http://i1239.photobucket.com/albums/ff515/LTT-/Mobile%20Uploads/1451227797.jpg (http://s1239.photobucket.com/user/LTT-/media/Mobile%20Uploads/1451227797.jpg.html)

also ive fired 50+ pieces of this brass 2xs and it does stretch...i have 5 pieces that have been fired 3xs that ive been tracking for this very reason and each time fired they have stretched .002 which is just a little less than a standard 260.

[Burr]

Interesting thread and results so far Long Range. I enjoy reading most of your threads - I hope you continue to share, it's appreciated.

If I can - can I make a few comments/questions - looking for your thoughts on these items? I've been reloading and shooting for 40 years, but don't have near the depth of experience you shared, and only recently started taking on some of the more advanced reloading techniques.

Magneto Speed - I'm confused by the preference written by so many for the Magneto Speed over a Chrony because I can't get over the physical setup of the Chronograph. I see how you address it, and I also see your targets support my concern. We're so careful to free float a barrel, and tune these things to a load, and the Magneto speed straps directly onto the barrel? I would think that would change POI, and your targets have confirmed. I see your approach, chronograph 1 load of each recipe, and then remove when shooting for groupings - that makes sense. Can someone explain why the Magneto Speed is so preferred to a Chrony given the above? I have not purchased or used one, because it mounts to the barrel. How is it better? Since you are not taking a reading on all shots, a data piece that is missing is SD and ES of the recipe - have you found SD and ES are not that important, or just does not vary much with your reloading methods?

Primers - I noticed earlier in this thread you shot some CCI 250s, and then went to the CCI BR-2's. The limited data on the 250's showed a little tighter ES, and quite a fps increase. Are you going to do some primer testing on the load workup, or stick with the BR-2s - and why? I ask primarily because I DON'T know what the answer should be, but I've started to think and test different primers in my load workup. Historically I have not tested different primers at all, and only recently started really looking at them in my recipes. I would appreciate any thoughts you have on that.

I have worked with quite a few AI cartridges over the years. I was doing some calculations on what I thought you would be able to achieve with the data you reported, I thought you should get to about 2985 - was just my estimate, and I see you're close to that. Interesting to me anyway. Yes, the AI cartridges still stretch, just not as much. In my recent 250 AI build I trimmed the necks before fire forming - my thoughts were after fire forming some of the neck becomes shoulder - and that could help prevent the donuts for a while longer. I see you waited until after FF, is there a reason, or just did not want to put the case prep time into it until some results were on paper?

In my 250 AI build I settled on Hybrid 100 V with Federal 210M's - but I don't see many comments on that powder. Similar to RL17 in burn rate. I'd be thirsting to try the 100V in the 260 AI from your results. Is there a reason I don't see many posts about 100V that I don't know? I don't have much range time with RL17, and you have me thinking I should give it a try.

Interesting data on your case weights and H2O capacity. I've only recently started weighing cases - my Lapua brass for the 250 AI I got 90 out of 100 into 2 - 1/2 grain groups - the other 10 fell 1/2 grain outside the 1 grain variance. I had no idea what to expect since I had never weighed brass before, it was educational to see how wide the variance was on the WW brass you weighed. I have not measured H2O capacity yet, mainly because I don't have a digital scale. I don't have a digital scale because I've read too much about bad quality scales, and just don't know which digital scale would be good. So until I get over my fear of digital scales, I guess I'm stuck with my beam scale, with makes H2O capacity a little more than I want to tackle. Which digital scale(s) have worked well for you?

With some of the AI's the availability of loading tools get's tough. I'm going to get the LCD ordered, your comments on them is appreciated. That will be a custom order, but the LCD custom is still reasonable. Some of the other custom die sets get really expensive. At some point I'll probably spring for having them made up, but for now I'm getting by with neck sizing the 250 AI and using the less expensive Redding seating die. I see you like the Forsters, they seem to be on-again, off-again when it comes to custom die sets. I might be turning to Whidden's when the time comes. Any experience with them?

I do a lot of wood working, how the heck did you get the rows of holes in that wood so perfectly spaced and straight! lol...

[yobuck]

So if we sort brass by weight and volume, is a high shot then the fault of the shooter?
If we seperate out that piece, will the group improve?

[LongRange]

let me start by saying i am far from an expert on reloading...you have 32-33yrs on me but what i have done is a ton of field testing with different combos,brass prep and bullet prep 1 step at a time and then shot groups to see the effects...i set aside the things that IMO are not worth the extra work or just didnt have an effect at all and kept what i think works...when i first started reloaded like most ppl i searched around and bought what i thought was the best tools to get started and progressed from there.
its when i started searching for more/better accuracy that i got tired of all the conflicting info and set out on my own to figure things out for myself rather then what someone else says works but has 37,896 post on a shooting forum LOL!!


Interesting thread and results so far Long Range. I enjoy reading most of your threads - I hope you continue to share, it's appreciated.

If I can - can I make a few comments/questions - looking for your thoughts on these items? I've been reloading and shooting for 40 years, but don't have near the depth of experience you shared, and only recently started taking on some of the more advanced reloading techniques.

Magneto Speed - I'm confused by the preference written by so many for the Magneto Speed over a Chrony because I can't get over the physical setup of the Chronograph. I see how you address it, and I also see your targets support my concern. We're so careful to free float a barrel, and tune these things to a load, and the Magneto speed straps directly onto the barrel? I would think that would change POI, and your targets have confirmed. I see your approach, chronograph 1 load of each recipe, and then remove when shooting for groupings - that makes sense. Can someone explain why the Magneto Speed is so preferred to a Chrony given the above? I have not purchased or used one, because it mounts to the barrel. How is it better? Since you are not taking a reading on all shots, a data piece that is missing is SD and ES of the recipe - have you found SD and ES are not that important, or just does not vary much with your reloading methods?

the magneto speed is a MUCH better and MORE accurate chronograph as it uses magnetic sensors instead of photo sensors like a normal chrony so it is not effected by weather..and yes it does effect barrel harmonics..the thinner the barrel the more it throws it off...the shilen in this thread is 1" and the muzzle...my bartlien is aprox .930 at the muzzle and that small difference equals about another 1/2" to 3/4" higher at 100yds with the bayonet strapped on...the thing i find odd is that with the bayonet attached it throws high shots.
ESs and SDs are VERY important...50fps equals about a 10" POI shift at a 1000yds.
now even when i used a normal chrony i NEVER shot through it until i found a load that shot well and then id chrony the load to see where i was as far as speeds and ESs but i pretty much knew the ESs where low because id already confirmed the load at 4-500yds and i will do the same with these loads that i shot today at 495yds.
and yes brass prep does lead to lower and more consistent ESs and SDs.


Primers - I noticed earlier in this thread you shot some CCI 250s, and then went to the CCI BR-2's. The limited data on the 250's showed a little tighter ES, and quite a fps increase. Are you going to do some primer testing on the load workup, or stick with the BR-2s - and why? I ask primarily because I DON'T know what the answer should be, but I've started to think and test different primers in my load workup. Historically I have not tested different primers at all, and only recently started really looking at them in my recipes. I would appreciate any thoughts you have on that.

ive done a lot of primer testing and some day may do a little write up on my findings...its not all scientific with fancy equipment...just shooting the same loads over a chrony with different primers.
i started with the CCI250s because ive found they are the most mild of the mag primers and since i was packing 48.5-49g into a small case that maybe they would light it off more consistently...and they did with only a 16fps difference in speed as apposed to the BR-2 but(and im guessing here as i dont own pressure trace equip)the CCI250 was causing a crazy high pressure spike as i was getting a little seepage around the primers so thats the biggest reason i switched over to the BR-2s...ive also found that milder primers produce lower ESs and that the CCIs are the most consistent and second are the fed210Ms which i just recently started using in another rifle.


I have worked with quite a few AI cartridges over the years. I was doing some calculations on what I thought you would be able to achieve with the data you reported, I thought you should get to about 2985 - was just my estimate, and I see you're close to that. Interesting to me anyway. Yes, the AI cartridges still stretch, just not as much. In my recent 250 AI build I trimmed the necks before fire forming - my thoughts were after fire forming some of the neck becomes shoulder - and that could help prevent the donuts for a while longer. I see you waited until after FF, is there a reason, or just did not want to put the case prep time into it until some results were on paper?

you answered this question LOL....i didnt want to put a lot of time or money in this until i seen if it was going to pan out or not...and the reason ive turned the necks now is like i said above because they are sizing like an upside down v...tight at the top loose at the bottom..because of the brass flow into the neck/shoulder junction...i have 2-3 firing on this brass and no doughnuts...ive read that with domestic brass you usually do not get doughnuts with AIs as the brass is thinner but i think Dewey here on the forum is shooting lapua brass in his 260AI with no issues.


In my 250 AI build I settled on Hybrid 100 V with Federal 210M's - but I don't see many comments on that powder. Similar to RL17 in burn rate. I'd be thirsting to try the 100V in the 260 AI from your results. Is there a reason I don't see many posts about 100V that I don't know? I don't have much range time with RL17, and you have me thinking I should give it a try.

i shot a couple of LBs of 100V and didnt care for it as it gets squirrely real quick once you reach higher charges...ive had great luck with RL-17 and if you want fast in a small cartridge it will do that.


Interesting data on your case weights and H2O capacity. I've only recently started weighing cases - my Lapua brass for the 250 AI I got 90 out of 100 into 2 - 1/2 grain groups - the other 10 fell 1/2 grain outside the 1 grain variance. I had no idea what to expect since I had never weighed brass before, it was educational to see how wide the variance was on the WW brass you weighed. I have not measured H2O capacity yet, mainly because I don't have a digital scale. I don't have a digital scale because I've read too much about bad quality scales, and just don't know which digital scale would be good. So until I get over my fear of digital scales, I guess I'm stuck with my beam scale, with makes H2O capacity a little more than I want to tackle. Which digital scale(s) have worked well for you?

IMHO dry weight dont matter especially if the cases havent been prep'd...some ppl think it does but ive shot nosler brass that varied 20gs dry(if i remember correctly)but the internal capacities were within a grain and thats close enough for me and the type of shooting i do.
if you want a great scale...Gem pro...if you want a good scale the dillon D-terminator is what i use and is within 1/10 of a grain of my scott parker beam.


With some of the AI's the availability of loading tools get's tough. I'm going to get the LCD ordered, your comments on them is appreciated. That will be a custom order, but the LCD custom is still reasonable. Some of the other custom die sets get really expensive. At some point I'll probably spring for having them made up, but for now I'm getting by with neck sizing the 250 AI and using the less expensive Redding seating die. I see you like the Forsters, they seem to be on-again, off-again when it comes to custom die sets. I might be turning to Whidden's when the time comes. Any experience with them?

call redding they make custom dies...no experience with the high dollar customs and probable never will have as i was told by 2 record holding F-class and bench shooters that they dont hold up well because they are not heat treated AFTER they are chambered...if thats true or not i dont know but for $325 plus dollars ill take their word for it.


I do a lot of wood working, how the heck did you get the rows of holes in that wood so perfectly spaced and straight! lol...

a tape measure and a chalk line LOL!!

[LongRange]

So if we sort brass by weight and volume, is a high shot then the fault of the shooter?
If we seperate out that piece, will the group improve?

did we squeeze the trigger or did we pull the trigger?were we shooting prone?off a rest?off a bipod?off a bench?

will the group improve if we cull out a piece of brass that has 2gs less or more internal capacity? or are the pressures the same in all of the 5-10-20 cases with one odd case in the mix?

[LongRange]

well im all in at this point LOL....i shot groups at 495yds today and am interested enough that i think ill order a reamer tomorrow morning with a .296 neck since im turning necks anyway...

im posting this pic not for numbers but for the weather...and believe me it wasnt a 2.whatever wind LOL but it was 21-28degs

http://i1239.photobucket.com/albums/ff515/LTT-/Mobile%20Uploads/1451260508.jpg.png (http://s1239.photobucket.com/user/LTT-/media/Mobile%20Uploads/1451260508.jpg.png.html)

this was 6 shots...1 to the right then adjusted 1moa left and got off the other 5 as quick as i could because the with was changing faster than i could shoot...
45.9g RL-17....

http://i1239.photobucket.com/albums/ff515/LTT-/Mobile%20Uploads/1451254799.jpg (http://s1239.photobucket.com/user/LTT-/media/Mobile%20Uploads/1451254799.jpg.html)

this was actually the first group of the 45g load but second because i fired 3 rounds to get on target on another piece of steel and then 2 to verify i was good...the wind died a little on 5&6 but im happy with the vertical...

http://i1239.photobucket.com/albums/ff515/LTT-/Mobile%20Uploads/1451254791.jpg (http://s1239.photobucket.com/user/LTT-/media/Mobile%20Uploads/1451254791.jpg.html)

im not sure what happened here(well i know but im not taking the blame LOL)still a pretty nice water line...

http://i1239.photobucket.com/albums/ff515/LTT-/Mobile%20Uploads/1451254796.jpg (http://s1239.photobucket.com/user/LTT-/media/Mobile%20Uploads/1451254796.jpg.html)

im going to stick with the 45.9g load for now and see if i can tune it in a little better...ive got all the necks cleaned up,all annealed and in the tumbler now so im thinking it should get better...and if this load gets to hot when it start to warm up(if this barrel lasts that long)i will fall back on the 45g load as both shoot pretty well.

on a side note...these 142s are really moving...i can see the trace in my scope all the way into the target at 25xs so that tells me they are shooting very flat...im not exactly sure what the actual drop is as my scope is all outta wack and not zeroed but as close as i can tell at 500yds with the 45.9g load the drop is right at 36"s and if thats close then at 25degs thats pretty impressive...ill zero up next weekend and see what improvements i can make but im very happy with it as it is.

[upSLIDEdown]

I swear, between you and the other guy I know that shoots a 260AI, you guys are gonna make me build one. What's you OAL on those rounds? Wondering if it's feasible for it to fit in a short action mag. I know a regular 260 with a 140 can be too long depending on the bullet and chamber/throat dimensions. That was part of the reason I went with a Creedmoor instead of a 260 on my match rifle.

[LoneWolf]

I swear, between you and the other guy I know that shoots a 260AI, you guys are gonna make me build one. What's you OAL on those rounds? Wondering if it's feasible for it to fit in a short action mag. I know a regular 260 with a 140 can be too long depending on the bullet and chamber/throat dimensions. That was part of the reason I went with a Creedmoor instead of a 260 on my match rifle.
http://www.6mmbr.com/gunweek046.html

Some specs for you and info for everyone one the 260ai.

Terry Cross knows what he's doing!

[LongRange]

I swear, between you and the other guy I know that shoots a 260AI, you guys are gonna make me build one. What's you OAL on those rounds? Wondering if it's feasible for it to fit in a short action mag. I know a regular 260 with a 140 can be too long depending on the bullet and chamber/throat dimensions. That was part of the reason I went with a Creedmoor instead of a 260 on my match rifle.

2.906 touching the lands so yes they will fit in a short action box as the 142s like to be off the lands...or at least in every thing ive shot them in...ive had the best luck at .025+ off the lands. i may at some point shoot the 140g berger hybrids again through this barrel and see how they preform...they shoot great in my standard 260 at .035 off the lands so im curious to see how they shoot at 150-160fps faster.
i also would like to shoot some of the new 140g hornady bullets(and put those new tips to the test LOL)with the high BCs i bet they would really buck the wind and maybe drop a few inches off the elevation.


http://www.6mmbr.com/gunweek046.html

Some specs for you and info for everyone one the 260ai.

Terry Cross knows what he's doing!

terry is most definitely the man when it comes to the 260AI and he is also IMHO the guy that got the 260AI craze started...you know ive flip flopped back and forth on this for awhile and the only reason i did this was #1 it was a cheap way to see what was what and satisfy my curiousity and #2 for the added speeds...the speeds have actually exceeded what i thought was doable and accurate at the same time. the bonus is that ive found 2 loads that shoot very well that are almost a grain apart.

ill call and try to talk to Kiff this morning at PT&G and see if he thinks theres any improvements to be made to the reamer and order one...i have a 28" shilen match select with 700 or less rounds through it that will be perfect to set back,rechamber and finish at 27". this would also be a great barrel to see how the round count is going to be...Terry cross thinks 1500-2000 which sounds about right.

[yobuck]

did we squeeze the trigger or did we pull the trigger?were we shooting prone?off a rest?off a bipod?off a bench?

will the group improve if we cull out a piece of brass that has 2gs less or more internal capacity? or are the pressures the same in all of the 5-10-20 cases with one odd case in the mix?

I guess my shot went high lol. Ill be more direct in asking, (can we also sort brass by shooting)?
Or do the traditional methods as stated suffice, after which poor shots are to be considered shooter error?

[Dewey7271]

2.906 touching the lands
Jim is consistent with the reamer, mine is 2.905.:eyebrows:
Nice groups you shot. Nasty weather but I'll trade you. I'll need a boat to shoot here. Hasn't quit raining for three days with wind.
Really cool how this is working for you. Glad you like it. I kind of thought you would once you worked it up. I was trying not to " lobby you" on the earlier communications. LOL.
The COAL I'm shooting is 2.885 if it matters.

[stomp442]

Looks like you have found the sweet spot with your rig. Welcome to the .260 Ackley club. My current set up has a C.B.T.O. of 2.120" with 140 Bergers at .025" off the lands which should put me right around 2.841" overall length according to Bergers data sheet.

[LongRange]

I guess my shot went high lol. Ill be more direct in asking, (can we also sort brass by shooting)?
Or do the traditional methods as stated suffice, after which poor shots are to be considered shooter error?

99% of my shots are the shooter not the rifle or the brass so if sorted by shots fired id never have 2 frings on any brass LOL.

seriously though at what point do we consider the shooter is the error and how do we distinguish that from brass or rifle errors? i have no idea...and to add more questions to this...i have read that a few of the top BR guys do no prep work and set records so is that because they are better shooters or because they are shooting $15,000 dollar rifles?

all i do know is that the prep work i do was done 1 step at a time and only made small differences but when all combined equal a big difference for me...is that because all the prep work is masking the fact that my clunky old long action savage isnt really that accurate? or does it make me feel and warm,fuzzy and secure so that i shoot a little better? or does the brass being prep'd,primers seated consistently,powder weighed to as close as can be on a good scale,bullets sorted by baring surface and seated consistently to the same depth every round equate to consistent pressures and lower ESs?

im not really sure but i do know it all works well for me so i will keep doing what i do...


Jim is consistent with the reamer, mine is 2.905.:eyebrows:
Nice groups you shot. Nasty weather but I'll trade you. I'll need a boat to shoot here. Hasn't quit raining for three days with wind.
Really cool how this is working for you. Glad you like it. I kind of thought you would once you worked it up. I was trying not to " lobby you" on the earlier communications. LOL.
The COAL I'm shooting is 2.885 if it matters.

no thanks you can have that rain LOL...i had planned to try other combos with this if things were not working out and honestly i wasnt expecting it to all pan out the way it has.