ANATION
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Has any one had good accuracy using the AR load data for bolt actions? Couldn't find any bolt action information and was torn between using the data for the 80 gr or using the AR data.
Sierra 77 HPBT in bolt action question
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FROGO207
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I would think that the barrel twist rate would be more of a determining factor for a heavier/longer (boattail) bullet. I would use the charge for the weight of the bullet whether gas or bolt type.
I run my 77smk load that I developed in my AR through my bolt gun with similar results.
Suggested load data is a straight point for me. I stop when I find accuracy. Occasionally I stop when I get a sticky bolt, Or flat primers.
AJC1
Member
Ar data is 5.56 and would exceed chamber pressure for sami 223. There may be 5.56 bolt guns around but I have yet to see one. I would also run them longer than ar mag length and not crimp. The good part is that the 69 and 77s are very jump tolerant which should make tuning easy and afford larger seating depth windows. Good luck.
A lot of times 223 AR data stops at a lower charge weight than bolt action data.
There is a lot more than just peak chamber pressure that goes into loading for an AR.
OP
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ANATION
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My twist is 1/8 and it does a great job with the 69 gr. I normally would stick with those but I found some 77s.
What powder are you planning on running?
I found the best accuracy at 2680 with IMR4064 in a 16" barrel.
It's a compressed load seated at mag length.
8208 xbr gave similar velocity and accuracy.
H4895 trailed slightly behind on both counts.
Tac and cfe223 didn't work well for me.
I didn't try varget or r15 because availability is sporadic in my location.
When I was doing load testing for my then new Savage 10 PC, I found that my tried and true AR loads shot as well as anything. So why complicate things?
I have shot 77SMK's in a mid-range F-class match with that rifle and some of the guys with dedicated F-Class rigs were looking over their shoulders after the first string. They pulled away as the match progressed but I did OK. I'd think that any safe load in an AR would also be safe in a bolt gun.
I have shot 77SMK's in a mid-range F-class match with that rifle and some of the guys with dedicated F-Class rigs were looking over their shoulders after the first string. They pulled away as the match progressed but I did OK. I'd think that any safe load in an AR would also be safe in a bolt gun.
There's going to be as much variation from what one AR really likes to the next as from an AR to a Bolt.
You should easily get good results with a load that works in 2 guns but to get great results each gun may like a different load.
The 77 SMK is a great bullet for good results as it's not finicky the 80 SMK isn't as forgiving and may require more load development.
You should easily get good results with a load that works in 2 guns but to get great results each gun may like a different load.
The 77 SMK is a great bullet for good results as it's not finicky the 80 SMK isn't as forgiving and may require more load development.
AJC1
Member
I would tend to agree with that and even use it if the pressure of the load was listed and below sami spec limits for the barrel type I had.
And this is why I had concerns. Always going to the next level. That statement is not a safe mindset and exactly why I tried to be clear.
https://ballistictools.com/articles/5.56-vs-.223-myths-and-facts.php
You can always contact Sierra. They've always been helpful to me.
You can always contact Sierra. They've always been helpful to me.
Without going into the 5.56 v. .223 wormhole, which has been discussed ad infinitum and never ends with any useful conclusion, find loading data that gives chamber pressure numbers and use it. Hodgdon gives loads for the 77 Sierra HPBT. Start low and work up, as always.
You might try 24.0gr of rl-19 or varget.
Those are a common ar service rifle load with that bullet for mag length loads
As stated in a post below. RL-15 not RL-19. Got RL-19 on the brain lately
Been looking for more RL-19 for heavy cast bullet loads in a 308w.
Those are a common ar service rifle load with that bullet for mag length loads
As stated in a post below. RL-15 not RL-19. Got RL-19 on the brain lately
Been looking for more RL-19 for heavy cast bullet loads in a 308w.
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Reloadron
Contributing Member
My bolt gun has a 1:12 twist rate. Trying endless bullets and loads has never given me good results for anything above 55 grains. I just can't get the slow twist to stabilize the heavier bullets. This is all with a 26" barrel. Work from published load data. Hornady has three sections labeled 223 Remington, 223 Remington Service Rifle Data and finally 5.56MM NATO. The 223 Remington load data only goes to a 60 grain bullet and their test rifle was a 1:12 twist.
When it comes to 80 grain bullets Sierra does point out their 80 grain Match King bullets will chamber in a NATO chamber but the OAL is too long for standard magazines at 2.550" verse the standard 2.260 maximum OAL.
Working from published load data I doubt you will get any unwanted surprises with a good bolt gun. When looking at published data make sure you note the test rifle used and the twist rate. You mention neither barrel length or twist rate.
Ron
When it comes to 80 grain bullets Sierra does point out their 80 grain Match King bullets will chamber in a NATO chamber but the OAL is too long for standard magazines at 2.550" verse the standard 2.260 maximum OAL.
Working from published load data I doubt you will get any unwanted surprises with a good bolt gun. When looking at published data make sure you note the test rifle used and the twist rate. You mention neither barrel length or twist rate.
Ron
FLIGHT762
Member
The actual Alliant powder for service rifle loads with the 77 gr. bullet is Reloader 15, NOT reloader 19.
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ANATION
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4064 is my go to with 69 gr out of a 20 inch barrel with a suppressor. Probably will try Varget afterwards with the 77. I have a couple pounds of it and the 4064 I’ll save for the 69 gr until powder availability loosens up. Sometime around 2030 I’m thinking.
Well, if nothing else, at least I know I'm not the only one using IMR 4064 for heavier 223/5.56 loads. I had to Frankenstein the load together. Hornady bullets and OAL, powder charge from Hodgdens website and my Lyman manual, which dont match and neither tested the Hornady bullet. It's a wonder they don't come out of the muzzle and make a u-turn.
Thank you, had RL-19 on my mind for awhile now. Been looking for more RL-19 for cast bullet loads in a 308w.
Out of curiosity what charge did you settle on?
I ended up at 23.8 with the SMK. It's heavily compressed.
I've rang steel at 600 with it.
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