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Does anyone have a pet IMR 4064 .308 load?
- Thread starter dcmdon
- Start date
I'm NOT an expert, nor did I stay at a Holiday Inn Express last night. The following is My Understanding and My Imaginings...
Grainweight and shape of the projjie, barrel twist rate and length, headspacing on the case shoulder, distance from the cannelure curve of the boolit to the rifling lands (in general, the shape of the chamber) all add up to a VERY non-linear problem.
Minimums are intended to be safe in typical chambers (SAAMI or other standards bodies) but the "favorite" or ideal load is going to match the gun.
If you are reloading for hunting, I guess you would want to load for max energy without sacrificing accuracy... If reloading for benchrest, you are working for max accuracy regardless of energy.
Grainweight and shape of the projjie, barrel twist rate and length, headspacing on the case shoulder, distance from the cannelure curve of the boolit to the rifling lands (in general, the shape of the chamber) all add up to a VERY non-linear problem.
Minimums are intended to be safe in typical chambers (SAAMI or other standards bodies) but the "favorite" or ideal load is going to match the gun.
If you are reloading for hunting, I guess you would want to load for max energy without sacrificing accuracy... If reloading for benchrest, you are working for max accuracy regardless of energy.
dcmdon
NES Member
I'm aware of that, but thanks for contributing.
Some other food for thought. If you are reloading for long distance target shooting, you do want to push the upper limits of loads as long as they are accurate for 2 reasons.
1) faster bullets drift less in the wind.
2) faster bullets remain supersonic for longer distances. Bad things happen to accuracy when a bullet enters the transonic speed range.
With all that said, I found starting loads on the Hndgdon web site. I cross checked them for obvious errors with my Sierra reloading guide. I'm really curious how loads run for accuracy.
For example, do the 168 SMKs give the best accuracy at the upper end of the charge or lower end?
In case anyone cares. The min/max are as follows
168 gr SMK 41.5/45.9
175 gr SMK 41.5/45.6
Some other food for thought. If you are reloading for long distance target shooting, you do want to push the upper limits of loads as long as they are accurate for 2 reasons.
1) faster bullets drift less in the wind.
2) faster bullets remain supersonic for longer distances. Bad things happen to accuracy when a bullet enters the transonic speed range.
With all that said, I found starting loads on the Hndgdon web site. I cross checked them for obvious errors with my Sierra reloading guide. I'm really curious how loads run for accuracy.
For example, do the 168 SMKs give the best accuracy at the upper end of the charge or lower end?
In case anyone cares. The min/max are as follows
168 gr SMK 41.5/45.9
175 gr SMK 41.5/45.6
AllaSnackbah
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168 gr sierra match king
43.5gr 4064
2.831oal
br2 primer
i just shot60 of these out on my bolt rifle yesterday, i got 1/2 moa out of them consistently. they are very close to federal premium i believe.
43.5gr 4064
2.831oal
br2 primer
i just shot60 of these out on my bolt rifle yesterday, i got 1/2 moa out of them consistently. they are very close to federal premium i believe.
dcmdon
NES Member
Thanks.
I shot today with a bunch of different charge weights. 43.5 seemed to be the most accurate. Its interesting that its what you use. Average group size was .68" at 100 yards for three 5 shot groups. I'm very happy with today's results. 175 gr SMKs were almost as accurate at a .88" average. Although I threw a couple of flyers, that I blame on myself, they are figured into the average.
I am loading to a significantly shorter COAL. In the 2.810 range. I should start extending the COAL some. Even if it won't fit in magazines after that.
I shot today with a bunch of different charge weights. 43.5 seemed to be the most accurate. Its interesting that its what you use. Average group size was .68" at 100 yards for three 5 shot groups. I'm very happy with today's results. 175 gr SMKs were almost as accurate at a .88" average. Although I threw a couple of flyers, that I blame on myself, they are figured into the average.
I am loading to a significantly shorter COAL. In the 2.810 range. I should start extending the COAL some. Even if it won't fit in magazines after that.
+1 on this one. IIRC the Federal Gold match 168gr I took apart and measured had 43.5 of 4064.
Use the load data from your load data book, and "work up the load" that works best with the harmonics of your gun/barrel.
No one is going to be able to give you a magic recipe for that powder in your gun.
No one is going to be able to give you a magic recipe for that powder in your gun.
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4064 has fairly predictable accuracy nodes in commonly available brass.
Working up a Gold Medal Match equivalent for a Remington 700P I used Lake City 13 and Lake City Long Range 08 (full length resized/Federal GMM primers) and found accuracy nodes at 41.7 and 42.2--bullet was 175 grain SMK.
If you browse this thread you will definitely see some patterns emerging. There are pics of range results and recipes.
http://forum.snipershide.com/sniper...ral-gold-medal-match-load-mk-316-mod-0-a.html
Are you shooting an M1A, a bot gun, or some other?
Working up a Gold Medal Match equivalent for a Remington 700P I used Lake City 13 and Lake City Long Range 08 (full length resized/Federal GMM primers) and found accuracy nodes at 41.7 and 42.2--bullet was 175 grain SMK.
If you browse this thread you will definitely see some patterns emerging. There are pics of range results and recipes.
http://forum.snipershide.com/sniper...ral-gold-medal-match-load-mk-316-mod-0-a.html
Are you shooting an M1A, a bot gun, or some other?
dcmdon
NES Member
Thanks for all the input.
I'm shooting a Savage 10 FCP bolt gun. My last trip to the range, I averaged .86" group size. With pretty much the same results for 168 and 175 gr SMKs. This was just at a starting load of 4064 of 43.5 gr. I have not yet really worked up a load. It looks like my range time will be limited before my class at sig next week. So I'll probably load 400 of those in preparation for the class. I only shot 5 groups for theat average, but the best group was in the .6" range.
These were 5 shot groups. Not 3 shot "cheaters".
I'm shooting a Savage 10 FCP bolt gun. My last trip to the range, I averaged .86" group size. With pretty much the same results for 168 and 175 gr SMKs. This was just at a starting load of 4064 of 43.5 gr. I have not yet really worked up a load. It looks like my range time will be limited before my class at sig next week. So I'll probably load 400 of those in preparation for the class. I only shot 5 groups for theat average, but the best group was in the .6" range.
These were 5 shot groups. Not 3 shot "cheaters".
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I agree that 5 shot groups (minimum) are the gold standard for accuracy results.
Do consult the thread I linked, and look at the pictures with the load notes--there are clear patterns emerging from multiple rifles, and multiple headstamps of brass. I'm not a particularly impressive shooter, but a load of 41.8 grains under a 175 gr SMK was giving me multiple consecutive 5 shot groups of 4 rounds touching/overlapped and 1 round 1/4" away as a flyer. I think parallax error and (my) shitty marksmanship was contributing more to the flyers than the inconsistency of the load. I'll post pictures of the tests if you're interested in seeing them--going up in .3 grain increments you can clearly see the scatter nodes and the accuracy nodes.
Do consult the thread I linked, and look at the pictures with the load notes--there are clear patterns emerging from multiple rifles, and multiple headstamps of brass. I'm not a particularly impressive shooter, but a load of 41.8 grains under a 175 gr SMK was giving me multiple consecutive 5 shot groups of 4 rounds touching/overlapped and 1 round 1/4" away as a flyer. I think parallax error and (my) shitty marksmanship was contributing more to the flyers than the inconsistency of the load. I'll post pictures of the tests if you're interested in seeing them--going up in .3 grain increments you can clearly see the scatter nodes and the accuracy nodes.
AllaSnackbah
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I'm doing a couple batches of .308 tonight to feed my FN, i figured i would share.
CCI BR2 primer
43.1g of RL-15
175g SMK seated to 2.831
Im going to try this with Varget also since i have some.
I also want to try an M118LR clone, that stuff is pretty nasty supposedly, its been changed up a few times, mostly the powder, first it was 4064, then 4895, then RE15, now its 4064 again i believe because it is less sensitive to temp change than RE15.
I (think) this is pretty close to M118LR's current config: there are pages upon pages of discussion threads on cloning it on m14forum and SH
43.1gr 4064
175SMK
Fed GM210 primer
2.830
CCI BR2 primer
43.1g of RL-15
175g SMK seated to 2.831
Im going to try this with Varget also since i have some.
I also want to try an M118LR clone, that stuff is pretty nasty supposedly, its been changed up a few times, mostly the powder, first it was 4064, then 4895, then RE15, now its 4064 again i believe because it is less sensitive to temp change than RE15.
I (think) this is pretty close to M118LR's current config: there are pages upon pages of discussion threads on cloning it on m14forum and SH
43.1gr 4064
175SMK
Fed GM210 primer
2.830
dcmdon
NES Member
Grand,
I haven't yet chrono'd my 43.5gr loads. But 41.8 is below the starting load in my Sierra book. Is it correct that there would be another "node" that is above 41.8 gr? I guess the trick is to find if it is below maximums. I'm talking theory here. I realize that generally speaking things need to be tuned for my particular gun. However there is no denying that ammo like Federal GMM seems to shoot well in all guns.
Don
I haven't yet chrono'd my 43.5gr loads. But 41.8 is below the starting load in my Sierra book. Is it correct that there would be another "node" that is above 41.8 gr? I guess the trick is to find if it is below maximums. I'm talking theory here. I realize that generally speaking things need to be tuned for my particular gun. However there is no denying that ammo like Federal GMM seems to shoot well in all guns.
Don
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41.8 is for the 175 grain Sierra Match King.
You had cited both bullet weights in your original post.
Sorry for the confusion.
Last edited:
dcmdon
NES Member
Thanks.
41.8 is almost the starting load for a 175 gr SMK based on the IMR loading guide. So its certainly within spec.
Have you chrono'd it? I'm curious what you are getting.
Here is the IMR
BULLET WEIGHT
175 GR. SIE HPBT
MR IMR 4064 .308" 2.800"
Min
GR MV
41.5 2,500 45,200 PSI
Max
GR MV
45.6C 2,728 59,500 PSI
41.8 is almost the starting load for a 175 gr SMK based on the IMR loading guide. So its certainly within spec.
Have you chrono'd it? I'm curious what you are getting.
Here is the IMR
BULLET WEIGHT
175 GR. SIE HPBT
MR IMR 4064 .308" 2.800"
Min
GR MV
41.5 2,500 45,200 PSI
Max
GR MV
45.6C 2,728 59,500 PSI
