Help with a .308 load

[CBB1]

I have a chrono but didn’t expect to use it until I found a good group. My thoughts are if it doesn’t shot it doesn’t matter what the numbers are. Maybe I was wrong. I’m using new hornady does and a rcbs powder throw and trickled into a digital scale (admittedly a generic one from amazon). Although I always calibrate it and it always seems to read true.


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[stanginthe11s]

a chrono will tell you a lot about why you're not grouping well and if a certain powder is worth using. if FGM is what you want to duplicate then chrono it so you have a baseline.

 

[CBB1]

Gotcha, thanks for the advice, that’s why I come here.


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[eod.tek]

A chronograph isn't necessary when you're having success, but it can definitely help paint a picture when you're not.
Reading the beginning of the thread, my initial thoughts go to potentially inconsistent powder charge or inconsistent neck tension/brass. But without knowing if you're getting good ignition, a story told by es/SD, it's hard to know for sure.
Sometimes a rifle just doesn't like a load, but you've tried a lot of things, I'd be interested to dive into how your brass prep looks as well as what your ES/SD look like to really get a better idea of what's going on.

 

[SDHNTR]

a chrono will tell you a lot about why you're not grouping well and if a certain powder is worth using. if FGM is what you want to duplicate then chrono it so you have a baseline.

Sometimes. I’ve loaded up plenty of great grouping loads with lousy ES/SD numbers.

 

[Weldor]

Change up your powders, could just be back pressure from your suppressor. I had a Sig Cross 308 didn't like anything, hard bolt, swipes the whole ordeal. Would show pressure signs with starting loads, benchmark, 4064, etc. ended up going with Exteminator, and reloder 15. problem went away. Most Chrono at mid 2400fps through mid 2700 fps at 16".

 

[stanginthe11s]

velocity can be important to look at also. in this case the OP has a good load in a sense, its FGM. duplicating a load is a little different than working a load from scratch. if FGM is showing say 2600 fps but your load with varget only gets 2500 with pressure signs then there are only 2 options, drop down to a slower velocity to get the lower node or change powders to get the higher node. without a chrono you will just make a bunch of loads till you give up never realizing why or that you were so close.
of course, none of this is set in stone, the gun may not like a certain thing no matter what you do.
also, for FGM I believe it was 4064 that was used and somewhere around 42 gn. but I could be way off on that as it's been quite a while.

 

[EdP]

Given that the 168 Sierra MK shoots well, I suggest you chronograph it and try to match the velocity using 165 gr GKs. Watching pressures of course, but being a slightly lighter bullet you hopefully can match. You might have to try a couple of different powders. If you can match velocity and have decent ES and SD, I bet you will have a useful hunting load. Then you can play with jump if you want to fine tune further.

 

[CBB1]

Feed back from some testing today:
I bought a box a 168elm match ammo yesterday just to see if the results I was getting were my hand loads or if the gun didn’t like the bullet. Turns out it wouldn’t even shoot the white box eldm loads inside of 2” at 100. I played around with some 168tmks I had loaded over varget and TAC and was still very disappointed and honestly frustrated. Frustrated to the point that I was ready to sell the gun. Is a last ditch effort I went home and grabbed the remaining box of Hornady American 150gr interlocks. Well wouldn’t you know they shot fantastic so much so that I just kept shooting them into one big hole. By the end I had 14 shots that were just over an inch.

That said I think this gun likes 150gr bullets. I know the easy thing would be to go buy a case of these and be done but I not interested in that. I plan to definitely buy a box of 150gr interlocks but is there a better terminal option out there worth looking at while I’m playing with this stuff? Again I’m setting up for whitetail and 400 yards is about the max of my ability at this time.


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[stanginthe11s]

what was your TAC loads/grouping and why haven't you bought a chrono yet?

 

[CBB1]

I have a chrono and it will be going with me next time. After the factory 168 eldm loads shot so poorly I figured it was the bullet weight. I shot the TMKs just to verify and they shoot roughly the same 1.75-2” group every other 168 load had. As for the TAC I shot one at 43 and it definitely had pressure. I then went to the 42gr and they were fine but did not shoot well. I’ll buy some 150gr bullets tomorrow and start over trying varget and TAC.


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[Harvey_NW]

I have a chrono and it will be going with me next time. After the factory 168 eldm loads shot so poorly I figured it was the bullet weight. I shot the TMKs just to verify and they shoot roughly the same 1.75-2” group every other 168 load had. As for the TAC I shot one at 43 and it definitely had pressure. I then went to the 42gr and they were fine but did not shoot well. I’ll buy some 150gr bullets tomorrow and start over trying varget and TAC.

Trying 150's is probably a good idea. Don't waste components shooting small samples of very small changes in powder and seating depth, nodes don't exist. Shoot a pressure test and load up to an acceptable velocity at a safe pressure, and shoot a large sample size. If it doesn't group acceptable, drop a couple grains and shoot another large sample size. If it's still not acceptable, swap a component.

Despite tons of reloading folklore, there are no such thing as nodes, and .003" difference on seating depth or .1gr on powder charge isn't going to make or break a load. If someone tries to convince you otherwise, ask them if they have a statistically significant sample size of a comparison proving so. You won't get proof.

 

[sdupontjr]

If your not dead set on that bullet, I would try Barnes 130 ttsx being you already have varget and Tac. I have 3-308's, 1 tikka, 2 Rem 700's, and they all shoot sub .5 moa at 100 yards. The tikka shoots the 130's with 49g varget damn near .25 moa. And they are not as sensitive to seating depth. My tikka has a Long action bolt stop and a Long magazine, But I load them all the 2.825" so they will feed in the Rem's.

 

[stanginthe11s]

here's the one thing I notice that you are doing. you are trying to stay near max for a given powder/bullet.
if you had signs at 43 gn with tac then only going to 42 may not be enough. same with varget, you stayed high. it seems like you're chasing velocity, which isn't a good idea with a 16" barrel, drop your load down to 41 gn with TAC or VARGET and see what happens. you only need 3 rounds to know if there's potential, compare the groups to see the trend on which way to go.

 

[CBB1]

Thanks for all the input, this has been a good learning experience for me. I have no experience with mono bullets and to be honest I’ve been pretty influenced by Forms inputs on terminal bullet construction though I have no experience using match grade bullets for hunting. I do know a lot of guys like that 130 TTSX in the 308.


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[SDHNTR]

Interlocts are a fine bullet. Especially at .308 velocities. If they work, don’t let perfect get in the way of good.

 

[stanginthe11s]

Interlocts are a fine bullet. Especially at .308 velocities. If they work, don’t let perfect get in the way of good.

+1 on that. the interlocs work just fine for what you have and want so if you find a load for them, use them.

the biggest mistake new reloaders make is thinking they can find a better load. while you might, it usually cost money, time and exp. if your rifle shot 3/4 moa with fgm, that may be all the rifle is capable of regardless of load. reloading takes time, and even if a load is too slow or shoots poorly its still a lesson and gives you notes to fall back on.
be honest with yourself when it comes to what you want, need and will accept. then understand that the rifle has its own needs and it may not align with yours, this is why I own too many guns lol.
if speed and accuracy is what you want, you will need to get 125-135 gn bullets and a few different powders. if you just want accuracy, then you have what you need but you have to play with charge weight. or try taking the can off and see what happens.

 

[CBB1]

Wanted to give a follow up to this. I worked through some 150gr SST and TAC this week. As of today I was able to get a 10 shot group at slightly less than 1.5” with 44.5gr. I’m using a Caldwell chrono so not sure how accurate the readings are. There was a lot more variation than I expected considering each charge is individual weighed on 2 separate scales. Velocities were:

TAC 44.5
2781
2717
2755
2784
2774
2720
2749
2764
2706
2776

I’m going to knock it back to 44gr tomorrow just to see how it does but right now I’m pretty happy with this load. Again it’s a Remington 700ADL 308 16.5” with suppressor. Scope is a Burris Fullfield E1 mounted in Talley LW. Mounted per Forms instructions. Thanks for the help everyone this has been a fun learning experience for me.


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[stanginthe11s]

little surprised by the velocity but glad to see you're getting there. what's your max load for pressure signs? also, try groups with the can off.

 

[CBB1]

45gr gave me this group with these velocities.

TAC 45gr
2766
2761
2802
2731
2744
2818
2791
2796
2793
2814

I fired one round at 45.5gr and had a heavy bolt lift. I haven’t shot it without the can because it will be used with the can.


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