I asked but I really didn't think Jim would answer.  My intent was to try and determine the temp sensitivity of whatever powder they use versus load data, but I also understand liability. The reality is any powder left in those conditions would probably have exhibited the same results, higher pressures. The brass in the picture was the worst of the lot, again, higher pressures.

I may be able to head out again this weekend, but the conditions will be closer to spring weather with winds and temps in the low 60s. I had the labradar with me last trip but focused on having some fun instead of being too anal.  The data points will be a good addition to the data book.

There are several ballistic programs to choose from including Knights Armament's Ballistic Calculator, AB and Ballistic AE. I need to pick one and use it as another tool in the kit. I don't have a Kestrel, and probably won't spend the coin since at least two of those programs automatically import environmental data so if anyone has any thoughts you'd like to post about ballistic calculators (ease of use being a priority) please feel free to jump in and comment.

I've also decided to take my Mausingfield in .308 and have it rebarreled in .260.  I have a couple of Krieger barrels just gathering dust in the safe, one being a .264, 5R, Heavy Palma that will probably be the choice (cut to 24"). Long Rifles in SD originally built the rifle, so I'll be sending it back out to them to do the rebarrel as they also have the ability to chamber in .260. I spoke with them yesterday and their backlog isn't too bad so I can get it done quickly.

Here's a picture for the day, the gong at 600y and my shots to the left calculated to under 1MOA. Granted it doesn't track any misses, but it's not too bad for a first timer using a gasser.       My shooting buddy had to show off with that head shot.  

You might also want to check out Reloder 16. It's one of Alliant's 3 temp-stabilized powders (along with AR-Comp, which I love in the other AR calibers, and Reloder 23), and it's in the 4350 burn range. These powders also have the interesting property that at lower temperatures, they're actually inverse temp sensitive... I found that with AR-Comp in 7.62 with the 178 ELD-X, the velocity increased about .7 fps per 1 degree F decrease in temperature from 75 to 0 F, which kept my trajectory constant within 0.5" out past 600 yards across that temperature range. This review produced a similar but less dramatic result with RL16 and tested it against H4350 in 6.5. Worth a read and maybe a try. After struggling to get consistent and predictable results with Varget over temp swings in 7.62, I'm a convert, since the stabilized Alliant powders have done exactly what I expect every time and vary velocity with temperature such that trajectory stays constant for me (H4350 and Varget are siblings just as RL16 and AR-Comp are).

I've even worked up some obscenely compressed loads with RL16 in 7.62 (powder almost to the case mouth, huge pain in the ass to load) that are loud as shit, horribly inefficient, and trash the brass on unlock and extraction due to port pressure from RL16's sloooooow burn in that caliber, but are perfectly safe peak pressure wise and perform very well and consistently with great velocity (178 ELD-X @ 2540 @ 50 degrees from a 16.1" tOBR... I can go up to 2600 before primers get sporty but it falls off the node long before then).

That was kinda why I was asking about the powder, to determine if there was a better more temp stable powder option. I would tend to think that they would use a powder that would lean toward saving money and working well enough. Its like my buddy that works for honeywell says, "I can build a jet engine that wont wear out".

I have been using shooter as it is the same developer that wrote the android code for AB. AB has a lot more functionality and I will make the move over to that soon.

Good luck on the new rifle and that is some good chootin

I like AB Mobile and Ballistics AE if you're running an iPhone. Also, you might want to reconsider getting a Kestrel. The apps can only pull environmental data from the closest weather station. That might be 2 miles away, or it might be 20 miles away. Conditions could be completely different 20 miles away, which would make all your data invalid.

Thanks for taking the time to provide some great data as well as an excellent article.  Clearly I need to read a bit more about powder temp stability and the Reloader and H4350 powders.  Also, "sporty" is one of my favorite words.  

Thanks for the thoughts on AB!  

Now you did it!  I had just convinced myself to try some psychology on HH6 and you throw in a new parameter. I was going to order the Vortex Gen II HD by selling off the Gen 1 and then “adding” the money I didn’t spend on something I saw on EE.  Kind of the same theory the wife uses where she “saved” some money by buying something on sale.  Now I may have another tool I need to add to the shooting kit.  

My understanding is both AB and B/AE take date from a Kestrel, but I'll do a bit more reading.  

ETA - I just bought and downloaded the iOS version and will add data tonight.

No problem! I just wish I'd tried those powders earlier instead of banging my head against the wall with large temp swings, so I figured I'd put that out there and maybe try to save you some trouble and money, though every gun and cartridge is different. Alliant powders (particularly the older Reloders and the Power Pro ball powders) have a reputation for above average sensitivity, so I'd been exhausting my other options at great expense. I got some fantastic results with 4064, but relatively small temp swings would take me off node, and even at a given temperature, velocities and POI would vary inexplicably between shooting sessions... not to mention the most promising charge of 4064 was on the ragged edge of overpressure. Single loading was great, but mag-feeding blew a ton of primers, probably due to bullet setback or set forward. Varget wasn't performing in line with its reputation either regarding both sensitivity and accuracy.

I did contact Alliant with my temp test results (data acquired round-robin in one afternoon at 0, 40, and 70 degrees, with 56 degree data from the previous day falling right on the line), and they confirmed the inverse sensitivity of the Bofors-made TZ powders was consistent with their own testing. Neat trick that the decreasing muzzle velocity and decreasing air density with temperature increases largely offset each other from an external ballistics standpoint. Allegedly H4895 does the same thing, but it patterns rather than groups out of my tOBR with the 178 ELD-X, so I didn't test that behavior. 

Side note: I'm 95% sure 175gr 308 FGMM is using ~40gr of AR-Comp, and I will be testing soon to try to confirm. (7.62/175 and 308/168 I obtained last year are almost definitely loaded with a stout charge of 4064).

As for ballistic calculators, I've had good results with AB software and their custom drag curves. I second the Kestrel recommendation, though. I had a 4500NV with Bluetooth which got wrecked by a leaky battery, but the Bluetooth connection got so frustrating that I usually just entered environmental data manually, and juggling 3 pieces of gear (Kestrel, phone, and rangefinder) for ballistic solutions was aggravating. I replaced it with the Kestrel 5700 Elite with AB and Link, and it's soooooo much nicer. Download the drag curve in the Link app, enter the info for your gun and load, and fire it off to the Kestrel with Bluetooth, where it will be saved permanently. You can save several profiles as well. Voila, instant firing solution updated in real time wherever/whenever you need it, with an average/gust wind hold bracket on the Kestrel itself. All you have to do is enter the range. It can also generate a drop/windage table for various ranges and detailed ballistic info at your chosen range (time of flight, velocity remaining, energy remaining, max ord, total drop from muzzle, etc.) for when you're at the edge of the performance envelope or shooting at meatier targets. Yeah, it's pricey, but so worth it if you shoot a lot in varied conditions.

Well, I do have a bit of an issue with powder:



I did buy the iOS version of AB and have been playing with it a bit.  Thanks for the tip about profiles and drag curves.  As to the Kestrel, I'm just not ready to drop $700 on another toy (yet as my shooting conditions are still limited.  I'm going to have the Krieger 5R spun up for the bolt gun and the other Krieger made into a 6.5CM for the tOBR.  That should keep me busy through summer.

Tonight's picture shows some stuff that arrived today I ordered for the next range day (including a 10" gong not shown).  When I ordered the waterproof "tarp" I didn't think is was microscopically thin and with the magic ability to take a 5'x7' tarp and fold it into a palm sized package.  

Good post. I have not had the luxury of trying 10 different powders in medium rifle as time and (for a while) supplies were hard to come by. Have loaded a lot of 3031, 4064, and 2000mr in .308.

3031 is OK but not really worth talking about...some great results with 125gr bullets, but too slow with the heavies.

4064- node and "index load" of 42.0 with most brass (Winchester takes a little more) and 175gr sierras or noslers at 2.8". I have not tried to run it hotter as this load shoots very well (pretty much duplicates FGMM 175gr .308 ballistically with a little better SD) and goes well with gas rifles. Temp sensitivity is just less than .5FPS per 1 degree F in my use, but it may vary by cartridge or charge weight. It is a pain to throw, but IMO 4064 is pretty good for a versatile medium rifle powder. Also using it in .30-06, .270, .30-40, 8mm, etc.

Unless they have changed powders recently, FGMM 175gr in both flavors should be loaded with bulk 4064... about 41.8 grs.

2000mr- High velocities, exceptional SDs, and excellent groups. Have worked it all the way up to max and found a node with the 175s around 46.6gr at 2.8 (or 2.89 with TMKs). Velocity and accuracy then drop off just a bit until about .5gr from alliant's max, and then tightens up again. I do not use this powder in a .308 gas gun, seems to be a little more violent, but it is great in a bolt. Pushing 175gr TMKs or SMKs at close to 2800fps in a 24" barrel with no pressure signs. Temp sensitivity is just over 1 FPS per degree.

Rumor (and load data) would also indicate 2000mr and CFE223 are pretty much the same thing; possibly commercial variants of SMP842 out of the St Marks plant.

Re: Ballistic programs- Have used KAC bulletflight and now have a Kestrel elite with AB. Kestrel has more atmospheric data and is consistently more accurate. Drag models seem to be just a little better and have more complete G1 and G7 data that is easier to find and upload to the rifle profile in the app. You can also add velocity/temp data. Kestrel also gives you the option of not having your phone on all the time. I was initially resistant to the cost, but do not regret it at all.

I burned up the last pound of IMR 4350 that I have this past weekend. 24lbs of H4350 showed up yesterday and I'm going to start working on a load with that.

I'm not a great shooter but this is one of the better 10rd groups of the day. Fairly weak load that clocked around 2600 fps. It was 41.5gr IMR4350 under the 140gr RDF.

I switched over to the AB program about 6 months ago and am very happy with it. I use it in conjunction with the Kestrel pro meter. It simplifies things tremendously for me. I got the weather vane as well. Saves quite a bit of time inputting data that changes as the day goes on. I am coming from using aTrag and like AB layout better. I am trying to decide if I want to spend money on the Link Bushnell laser to complete the package.

As far as handloads go I am going to test 130 gr TMKs first. I have some testing to do with 4831 and Varget. I have IMR 4350 also. I would like to try some H4350 too but have not been able to source any lately. My plan is to follow the TMKs with Berger 130s and then Hornady 130s. I know my gun shoots the factory Hornady load at an acceptable level of accuracy. I also have an assortment of 140 class bullets but am worried I won't be able to get them going fast enough to make it worthwhile.

Another notable discovery is that all of the Hornady once fired brass I have from the Larue will only need a neck sizing to facilitate reloading. I was surprised because the 762 OBRs destroy brass in my experience. The Hornady stuff fits the case gauge just the same as the unfired Lapua.

Yeah, I've had some great results with 4064 and 2000MR, but Wyoming weather tends to thwart any attempt I make to stay on a node with either, so temp insensitivity or slight inverse sensitivity is kind of a must-have for me now. 2000MR was very predictable but too sensitive, and 4064 was definitely less sensitive but totally unpredictable for me for some reason. H4350 should serve Defender3 well in that respect, unless he gets the same kind of wonky behavior I did with Varget.

As for 308/175 FGMM, the last 2 lots I've shot from have been 39.8-40.1 grains of a short-cut extruded powder that looks like either RL15 or AR-Comp... no long sticks like 4064 has (which I do see in pulled 168 FGMM and also the 7.62/175 load, which I understand is Mk318 Mod 0 overrun... my lot is 43.1gr 4064 @ 2530 FPS from a 16.1" barrel). Velocity for the charge weight and observed inverse temp sensitivity strongly suggest the 308/175 is AR-Comp, and QuickLoad agrees (within a couple % burn rate allowing for lot variation). It's way too fast for that low a charge of RL15, and while it could conceivably be within lot variation of 4064, it would have to be a REALLY hot batch... it just matches AR-Comp way better (and looks like it to boot). I'm going to pull 10 rounds and replace them with the same charge of canister AR-Comp to compare velocity, groups, and POI.

And now I'm way out into the weeds talking 308 in a 260 thread... sorry about that!

Well shit....I have always been confused as fuck as to how those work.

You're a bit behind in the thread Brother.  

Very nice!  There's some consistency in that load and repeatability in the shooter. What rifle are you shooting?

Thanks for the thoughts on the Kestrel and AB. I think the lack of variety in my range choices (and them being with a few miles of each other) helps in the decision to not buy the Kestrel (just yet).  Our weather data is pretty solid so I’ll take the chance for now.

Please let us know your success with the handloads, especially the Bergers.  As the 260 has a shorter neck length, some of the projectiles could be particular to neck tension and it seems you may be the first to get out with differing loads.

Interesting about the Hornady brass as my 7.62 tOBR is also pretty rough on brass.  I assume your OBR has the older round ejector?   Which case gauge are you using, the L.E. Wilson?

All good info, concepts tend to transfer!

My shooting buddy was using the KAC program and it appeared easy to use and accurate.  I had put my velocity data into the Vortex LRBC and, given the conditions for the day, was 1/2MOA off elevation versus the LRBC.  I’ll be using the AB if we shoot this weekend and see how well it does versus my DOPE.

That was with 22" barrel and tranquilo attached. I ordered a 18" barrel and will compare velocities between the two once it shows up.

Yes I know. Got bored last night so I started reading this thread. I'm still only on page 7.

there are a lot of words and sentences and those things that are made up of words and sentences, I forget what they are called but there are a ton of words

Let me help you out - go get yourself a tOBR in .260 -

Mark is an evil genius:

I spent some of the day today fulfilling my volunteer obligation for the QCS by cutting grass at the shotgun range.  It was an overcast day in the 60's so it couldn't have been better for hanging out with the John Deere. Heavy rain is predicted for tonight and tomorrow, so it was perfect timing and with the Warrior Shoot upcoming, the range will look sharp.

Hummmmm, this is a pretty big range!  Four houses up top and one really long one below.



Steve backing my stallion out of the stable:



After a few hours, and on my second tank of gas, I was done!



To keep the thread on topic, these guys were waiting for me when I arrived home:

I mainly look at the pictures.

First, I'll need you to buy it for me. Then I'll need you to cover my hours at work so I can have time to go shoot.

I would like to see a direct comparison against processed 308 brass and this alpha stuff. See if the juice is worth the squeeze

What exactly do you want to see?  My intent was to weigh the empty cases for consistency, and do the same with the virgin Lapua.

I'm just curious to see if the same end result can be had with say LC brass that's been resized, neck turned, trimmed, all the normal accuracy processes.

Maybe a comparison between

Alpha
Lapua
LC
Fgmm

Fwiw 65 guys has a review on the alpha brass and the lapua brass, similar tests.

6.5 Guys for the Folks who Don't Know

The Friday afternoon update starts with some arrivals from Midway.

The Long Rifle folks will be cutting the chamber for the 260 bolt gun's barrel using PTG reamers, so I ordered PTG go and no-go gauges for the .260, as well as a go gauge in .223 wylde.



I also received my LaRue AR10 rifle buffer to carbine buffer conversion kit.  The PRS stock I'm using is Gen 1 and takes a rifle length tube. To use it with the carbine / buffer spring set shipped with the .260 you need a spacer to fit in the buffer tube so the BCG does not over-travel to the rear.  I installed a Midway buffer but it was actually too long and does not allow the bolt to lock to the rear.  Here's the kit along with some dust.  The normal swag arrived sans dillo, first time that's happened.

NOTE - The LaRue 7.62/.260 uses a slightly longer "carbine" buffer tube which will not fit the Gen 3 PRS. To use the Gen 3 you'll need a rifle length tube and the LaRue spacer.  



Here's a picture of the Midway rifle buffer insert:



And one of the LaRue insert (with O-ring no less).  It's clear the Midway insert is longer:



The result is the BCG doesn't move far enough to the rear to effectively engage the bolt catch.  

The first picture is the bolt locked to the rear and the second is the amount of travel using the Midway insert:





Here's a picture with the LaRue buffer spacer installed and the amount of rear travel, just a skosh more.  



Alright, a question for the thread faithful, to Radius or not to Radius?

I am always questioning the weapon mounted stuff...

Did I hit the right thing and get the right distance? You cant look through it so you never really know. I almost rather hit it with the kilo

Oh heck, power just went out.

Power just came back up, interesting in that we have all underground infrastructure and haven't lost power for years. oh well.  

I think one of the benefits is not having to come off the rifle for a follow-on shot to a differing target.  The Radius is basically "bore" sighted to you scope reticle and stays that way once engaged on the rifle's rail.  If I can get it setup in time, I'll take it out for the next range day.

You don't need no stinking power

So true, but how can I whore in my thread?  I have the modem and router on one UPS and my system on another, but this was an extended issue.  I jumped onto Dominion's outage page and we were right in the middle of something going on.  Anyways, I survived without having to pop the Pmags, but it was daylight.  

I'm at the end of the line, nothing built West of me, so it seems like mine goes out more often than normal... plus fun Texas weather.... I've got an iPad with AT&T service on it... which helps for whoring and whatnot

If it can go wrong it will go wrong

I have no experience with a weapon mounted unit...just a devils advocate thing.

Interested in how you like the Kilo. I have not had any experience with those.

The kilo seems to be a go to device with good features and at an aggressive price point.  Apparently if you want to spend the coin, you can even get one with Applied Ballistics.

Sig Kilo 2000

And of course (since the time I bought mine), the price on the Radius was dropped by 50% (at least by Brownells) as of yesterday.  

Radius on Sale

Okay, I puss'd out on today's ARC match at the club (just didn't feel like getting rained on) and am instead working with the Radius and getting ready for shooting tomorrow at 800/1000y at Quantico.  

Before we begin the technical portion of the post, I have sad news in my beloved Sony XBR 49" TV is about to die.    It has a tab bond failure problem which is too bad as it's served me well and has killer sound (no BS having to buy a sound bar that costs $300 and still sound like shitake). I guess I need to research a replacement, figure out who is making the best panels, and most likely have to break down and buy a darn sound bar.    Oh well, it's been flawless for 10 years.  

Today's technical update deals with bolts and BCGs.  I have three BCGs (LaRue and two JPs) and decided to do some weight and length measurements, and then do a Go, No-Go with the two bolts.

Here are the LaRue 7.62 BCG (15.9ozs), JP BCG (15.3ozs) and a JP Low Mass BCG (10.9ozs), all sans bolt:







I have two bolts, the LaRue and the JP HP:





Then I measured the length of the bolt lugs for the LaRue and JP HP:





Next was to take the bolts apart so I could test go and no-go.  The LaRue bolt stripped down, note the super beefy ejector:



The JP HP bolt, notice the rubber O ring for the extractor:



I used the PTG Go and No-Go gauges, which are for multiple calibers, including the .260:



With the LaRue bolt disassembled, I reinstalled it in the BCG and then placed the Go gauge into the chamber, then let the BCG close on the gauge. It closed easily on the Go gauge.  Sorry for the crappy pics, I was trying to add light to show the bolt lugs properly locked but it looks like the extra light was too much.  However, you can see the BCG's shoulder is just about to impact the chamber.



Next I removed the Go gauge and replaced it with the No-Go gauge and again dropped the BCG onto the gauge.  It would not close, which you can see by again looking at the position of the BCG's shoulder vice the chamber, and as shown in the rear receiver picture showing the BCGs position with the no-go gauge:





I then repeated each step using the LaRue BCG and the JP HP bolt, with the same results, no issues go and not closing on the no-go.







As with anything on the internet, this is worth what you paid for it and YMMV.  

Next up will be some Radius setup pictures, but they will have to wait until it stops raining as I want to walk across the street and hang the target on the neighbor's fence and "shoot" it from my yard so I get a longer focal plane and hopefully less induced error.

Thanks for the brownells sale link.

FYI discount code "L9Q" will get you $30 off plus free shipping  = $469.99

You can also get 4% cash back shopping at Brownell's using Active Junky.

You just had to rub it in...

You too...

I think after going to Quantico, you still had a good week

The 2000 is small light and very fast. It will range stuff way off, and it's accurate. You get your readings right now.

The 2400 is improving on that unit and will be my next purchase.

My only wish is that they had a pocket clip similar to how vortex does it on their range finders.

Well, at least someone is paying attention to the thread.  

Time to go downstairs and get the gear and targets ready for tomorrow's range trip.

Just trying to help save $$$ for more ammo, tools, rifles, scopes.

Not to change the trajectory of the thread, but does anyone have experience with Double Tap Ammo?  Just came across them looking for factory loads for hunting rounds.  Looks like Ted Nugent likes them....

First off: Major Thank You to Defender3. The amount of information that you have posted for us has been amazing. You are an awesome individual!

Second: Took a family PIC of the LT Pew-Pew Collection.  (Still on the bench when it comes to some of you all) But my wilfey keeps granting wishes for my obsession - she's a keeper.

New .260 in 18" is sitting there with it's Cartridge Combo 14.5 p/w 7.62 and 12.5 Handguard. ((correction .260 barrel is out)
sorry for the crappy phone pic


Still haven't shot it (insert shame face here).

That's a nice collection you have there!

Thanks for the kind words. We're all learning with the .260s and there have been great contributions along the way from the people following.

It was mentioned earlier in the thread so many of us have rifles, but we don't always have time to get out an shoot. I was hoping more folks would have time to get out with these .260s, but it's still spring. I'm also hoping to keep the thread alive long enough so people do have time to get out and do some shooting.

So I trotted off to Best Buy (after looking over some reviews on Amazon, etc.) to look at TVs since my XBR is slowly dying.  There's some nice stuff out there and while I liked the Samsung, I didn't like the idea of having an external hub for the HDMI connections and some of the reviews mentioned there were less features for the price against others in it's class.  I ended up getting one of the Sony 4K UHD 900e's in 55" with a Zvox 3.1 sound bar (TV speakers just stink, downward firing and 10/20 watts at best). Of course the TV was out-of-stock and I didn't feel like driving to another store to get one, so it will arrive at the store later this week.  This is a major step in managing my OCD as I'm a I want it now guy, so this is a step forward.  

Here’s a tech update for the day as I get ready to head out to Quantico for 800 & 1000. The weather will be in the 50's, overcast with high humidity and winds up to 10mph, sounds like a great day for shooting!  My shooting buddy can't make it so I'm flying solo for the day.  I'll report more either late tonight or tomorrow.

I mounted and sighted the Radius so I could use it at Quantico.  It comes in a nice box with a magnetic cover latch no less:



It includes a sighting target and a pressure switch:



The Radius has a built in mount that attaches to a rail with a single lever:



The display can be easily changed from horizontal to vertical by removing two screws.  The buttons control the brightness of the display, meters or yards and the ability to have a constant on for the laser.



The Radius has elevation and windage adjustments that aids in sighting the Radius to the rifle's bore.  You use the supplied target and reflective tape to begin the process. You place the strips on the target and then you measure offsets to align the laser to the bore.

 

First measure the center of the scope to the center of the bore, it looks like 70mm to me.



Then measure the offset from the center of the bore to the center of the laser, which looks pretty close to 55mm.



Then you mark the offsets on the target and install a reflective dot.





The laser should be very close to the bore, but you need some distance to give it a test.  I decided not to be shooting a laser in the hood since the neighbors can be finicky, so I tried it in the backyard and taped the target to the Tacoma.  





My fancy seat and rest.  You center the crosshairs on the target's center and then activate the laser to see how close it is to center.  Using the elevation and windage adjustments, you move the laser to the center of the crosshair.  It was raining so I was doing this quickly and didn’t take a picture of the laser on the target, but it was clear.



The visible laser is pretty bright so I was lasing the neighbor's sat dish to fine tune it over a longer focal plane.  A pretty easy process and I'll validate it at Quantico tomorrow.

Unfortunately I've only been out with mine once.  Between weather, other weekend commitments and now a stomach bug this weekend, getting to the range has been difficult.

I need to get some range time here in the next 2 weeks. On 5/22 I really get to stretch the 260 at an all day 500yd training and want to ensure the scope is dialed in before that.

Thank you again Defender3 for all your insight in this thread.