Finally .308 Success with handloads

[tarster]

So you are correct, I shot my last deer at 65 yards with a 270, 150gr nosler partition and it did great, but with my 308 I am looking to push it out and shoot some steel at 500+ yards, I can load just about anything under 175gr and get 2700fps out of it at the barrel and keep around 2350 - 2600 fps at 100 - 200 yards, I have a bunch of 150gr hornady softpoint that is a flatbase that I will be loading for deer and small game, and in which case shooting MOA would be fine with me. I know talking to Dyjital last night that he is in the same boat with wanting to push his 308 past the stock short range of 200 yards that they have here at the ARPC and would like to get to 350 - 500 yards and then beyond when we can hit that correctly. So looking for a nice tight group at 100 - 200 yards is a nice place to start to make sure your loads are solid before moving out to 350 plus.

 

[Member 5605]

so according to my app on android, strelok+ that load at 40gr should be something close to 2550 fps out of a max of 2650fps at the 41gr 3031 out of the barrel and according to strelok+ the retained velocity at 200 yd should be close to 2030fps so that sounds pretty right in line.

Yes.... To a degree. We have to remember that we just added case volume as well by extending the bullet beyond the 2.800" that they measured it at. Now I think if I punched these back to 2.800" and went shooting I would see less drop at 200y.

Theory unproven yet until I can chrono it.

 

[Member 5605]

@OutlawHoss
Since you helped a lot earlier...



I got out and used my new chronograph today. The results were interesting.
Hornady on their website shows a maximum of 41.3gr of IMR3031. Why then in the name of everything that's good did I exceed the maximum powder load by almost 1.5gr of powder? I only loaded to 43gr because I got lazy that night when I was loading and it was late. Didn't want to make any goof ups.

Quickloads. This program helped to assess the maximum PSI based on the bullet length, powder used, case length etc. The maximum that Quickloads busted out was 44gr at my bullet length and that was at 59K-PSI... something I wanted to stay away from. It also predicted the closeness of my target 2700fps to 43.5gr. Interesting eh?

Anywhoo... Finding everything out with verification, current load is well short using 40gr to achieve a 1000y plinking shot with .308... for clarification for internet armchair warriors, there is and will not be any accuracy shooting or hunting with this rifle out to that distance. Just for fun.

 

[OutlawHoss]

@OutlawHoss
Since you helped a lot earlier...

View attachment 281225

I got out and used my new chronograph today. The results were interesting.
Hornady on their website shows a maximum of 41.3gr of IMR3031. Why then in the name of everything that's good did I exceed the maximum powder load by almost 1.5gr of powder? I only loaded to 43gr because I got lazy that night when I was loading and it was late. Didn't want to make any goof ups.

Quickloads. This program helped to assess the maximum PSI based on the bullet length, powder used, case length etc. The maximum that Quickloads busted out was 44gr at my bullet length and that was at 59K-PSI... something I wanted to stay away from. It also predicted the closeness of my target 2700fps to 43.5gr. Interesting eh?

Anywhoo... Finding everything out with verification, current load is well short using 40gr to achieve a 1000y plinking shot with .308... for clarification for internet armchair warriors, there is and will not be any accuracy shooting or hunting with this rifle out to that distance. Just for fun.

Thanks for that. I'll spend some time looking at the data table. It looks like data I would geek out on. So the software is called "Quickloads", and where did you get it?

 

[tarster]

That sure is one pretty excel sheet! I will have to compare my numbers when I run my ladder which is almost identical.. But seeing your now.. I may load up some 43gr rounds, according to my rough guessing with the 175gr barnes matchburner bullets I should have enough case volume for 43gr of 3031 before I start to touch or compress the powder, which may not be a bad thing that may give more constant results with a flat powder face to the primer when the case is completely full.

 

[Member 5605]

I actually copied the data from the Caldwell sheet. I could have ran all the formulas myself but didn't feel like making a couple extra calculations. I used to make spreadsheets for a company years ago. This be easy stuff.

With this info and the info I have with data logging my shot placements and group size through the Ballistics AE application... I'm a cheater.


Do notice I'm using standard primers too. I didn't go Magnum because I'm wanting to see how this performs with the couple thousand standards I have here versus the couple hundred of magnum.

 

[Member 5605]

I'm thinking I like the program that works with the chronograph. I just wish I could export the data differently.



A little cast .40S&W, Berry's 9mm and a shot of the .308

 

[tarster]

Found some success shooting my ladder, I had a chance to take the chrono out and from what it looks like, 40gr of 3031 with a COAL of 2.980 (roughly .020 off the lands) and flying at 2350fps produced my tightest group at .428 and then pushing it up, 41.5gr of 3031 flying at 2600 fps didnt shoot to shabby also with a group at .534 with a flier not counted.. these are all 5 shot groups at 100 yd.. Time to take that load and push it out..

Bullet was a Barnes match burner 175gr
This was all shot suppressed from my 20in Rem 700 SPS Tactical using bipods and a rear bag.

 

[tarster]

Figured I would also throw up a shot of the excel sheet that Dyjital had sent me, was quite useful for tracking the rounds as I shot up the ladder. I think I will have to load some more above the 42gr mark because my groups starkly opened up between 41.5 and 42gr.. there might be something above that.

 

[Member 5605]

I have been working towards my magical number of 2700 ft./s. Today I loaded up and shot rounds out of my Remington 700. My average velocity was 2682 ft./s.



This is a four shot grouping I do not know why the shots went left to right that is a shooter error. These were shot at 100 yards. They are a 175 grain Sierra match King with IMR 3031 powder.

This group to me is significant because I am getting close to my target velocity, I am not seeing signs of overpressure, and I'm getting the same grouping that I got at my 40 grains of powder.

 

[v0lcom13sn0w]

man dyjital those .308 loads are about of those i would see from a 30-06. good job!

 

[Member 5605]

man dyjital those .308 loads are about of those i would see from a 30-06. good job!

Thanks buddy. While at the range there was a guy who was confounded because I was doing all of this on a 20" barrel.

I'm still keeping this on the lower recoil side as well. They have less punch than 180gr Remington CoreLok ammo.
Thinking I may pull the rounds I have made at 40gr and up them by another 3.6gr. No sense in shooting the lower loads when 43.6 does the same and I get the same results.

 

[Member 5605]

Actual chrono:
https://www.dropbox.com/s/6wv1xuy7gvoqdbm/Photo May 10, 4 33 05 PM.png?dl=0

@v0lcom13sn0w here is the actual chrono. I uploaded the wrong image earlier.

The good part is the SD of 12.x.

 

[tarster]

Thanks buddy. While at the range there was a guy who was confounded because I was doing all of this on a 20" barrel.

I'm still keeping this on the lower recoil side as well. They have less punch than 180gr Remington CoreLok ammo.
Thinking I may pull the rounds I have made at 40gr and up them by another 3.6gr. No sense in shooting the lower loads when 43.6 does the same and I get the same results.

I did this with the last set I loaded preemptively.. You know if we had 24in barrels we would be closer to the 2800 to 2900 fps.. But then we would have a walking stick.. And if we got those 32in Palma barrels we would have a fighting quarter staff with a stock but we could do 3200ish fps haha

 

[P7M13]

@Dyjital - that's some nice shooting!
Coming in late to this topic. I screwed up on my B2O measurements, set my press and loaded 50 168 SMKs at 2.752 OAL. I was going to pull them, and while working with my daughter on her trigger technique, ran out of "good loads" and started loading her mag with these.
The gun is a Savage 10 FCP-K in 308, muzzle brake removed.
Her first 5 shots produced a group very similar to yours.
I always try to be between touching to 15 mils off the lands - I still haven't wrapped my head around this one.

 

[Member 5605]

I'm a numbers guy and a visual creature..

Here is the final chart from the 175gr SMK's with 3031 Powder:



Graphing the maximum, minimum and average velocities produced interesting results: Excuse the low velocity round it's thrown that entire group off.



Standard Deviations vs shot spread (fps):


When I exclude some outliers my patterns start to look really good:




If my target is 2700 and I'm averaging 2675 right now I'd say I'm on track!

@tarster

 

[tarster]

so reading that graph it looks to me like 43.2 or if you can fit it, 43.7 gr might give you the best groups and MV with the least amount of spread in powder and groups.. hmmm sounds like more range time..

 

[Member 5605]

so reading that graph it looks to me like 43.2 or if you can fit it, 43.7 gr might give you the best groups and MV with the least amount of spread in powder and groups.. hmmm sounds like more range time..

Maybe so, but unlikely I will experiment more with this load. I've dropped enough change into it already.

Hodgdon states a maximum velocity of 2650fps online and speer claims in the manual #14 with a168gr (no 175's) a maximum of 2654fps. Both with 3031 powder. Hodgdon states 59,000 PSI at that velocity. I'm borderline right now along their numbers, even considering I'm pushing 2.3gr more than what they list as maximum at the same velocity but a 2.800" OAL.

43.6gr out performs the 43.2 all around.

 

[OutlawHoss]

That is some thorough work. The dip in performance of the second to last round is very telling (the 43.4 load, if I'm reading it correctly). If it were me, I'd go back to the 43 grain load (fourth data point back from the end of the graphs) as it would be the 'accuracy load/ocw' in this ladder. Having a goal of 2700fps is a good starting reference point in developing a load, ususally because it's a chief indicator of super-sonic speeds at 1000yards, but if the data supports a particular load as the most accurate, that would trump the 2700 fps benchmark. If the ballistics down range show the accuracy round (43gr) still at supersonic speed past 1000 yards (which I'd be surprised if it doesn't), then you have got the round, and the next step I would be taking is getting your d.o.p.e. and creating your most accurate range card, as well as getting as much trigger time with this load as possible.
Accuracy and precision is what you're after, I assume, so dialing your dope with the most proven round is going to be more beneficial than putting it at 2700 at the loss of accuracy and precision. 2700 becomes an arbitrary number when a particular round, like the 43 gr performs the best in your rifle, irregardless of fps.
If there's another reason for getting 2700fps that I'm not seeing, than it would mean trying a different powder, which is sounds like you're not wanting to do, and I don't blame you!
Also, if you aren't already, I'd take your two best loads, and shoot 10 rounds of each to get a statistically solid set of data, then choose the round that performs best.

Anyway, that's what I would do with your data, but that's just me.
Nice work!

 

[Member 5605]

Thanks @OutlawHoss, 2700 the bullet retains 1250fps @ 1000y.

I also have a 30MOA scope marks and 42 MOA of adjustment in my scope. I'd prefer to keep it under 30 so I don't have to dope the scope while taking shots. Though at this point if I'm only adjusting 5-6 MOA on turrets and using the full 30 inside the scope that would be fine.

2700 fps with the 175gr SMK papers out to 34.5MOA of adjustment.

I'm going out this weekend with Tarster and we are going to stretch some legs on our rifles. If I get bad performance I'll drop back down to the 43gr, but I think some of the error in velocities I have found.

The whole time I've been using mismatched brass. I've been noticing my powder charges are varying between brass and how one head stamp will fill the case and another will have .5" of air left.

I have more error right now in brass than anything else I suspect.