Range Report Range Report. Lot's of data and questions. UPDATE

Howie Feltersnatch · Sep 23, 2010

I am finally complete with load testing for the 168 gr SMK round in my rifle. I was happy with the results, but also disappointed. I'll explain as the post progresses. I tested on two seperate days. The first being the ladder test to find the node in my barrel, and the second shooting for groups after even finer tuning of my node groups from the first day. So here it goes.

My Rifle

DPMS "Hybrid" LR308
Noveske 20" 1x10 Poly Twist
2 stage match trigger
NFS 3.5-15X50

Day 1 (9/16/10)

Time: 1000- 1300
Temp: 88.0- 91* F
Alt: 91.9
Humidity: 52 RH
BP: 30.03
Wind was a steady 5-7 MPH with 12 MPH gusts from 9 oclock as well. Didn't vary direction hardly if any. (Leaves were breezy on trees and the flags were constantly waving. I dialed for wind today for the sake of the test and also I don't know much about hold overs just yet.)
Test Distance: 300 yards
Mirage: roughly a 40* angle from right to left and pretty thick
Bullet: 168gr SMK
Brass: IMI Match
Powder: IMR 4895
Charge Range: 39-41.5 (Sierra maxes out at 42. However no pressure signs at 41.5. Could have went to 42)
**During the test I had to sit through a couple of cold range sessions. It got hotter so you'll see Velocity slightly increased through the 3 round robin rounds. ***

39- 2,426, 2,430, 2,452. Average is 2,436 with a ES of 26.
39.5- 2,430, 2,432, 2,440. Average is 2,434 with a ES of 10.
40- 2,446, 2,456, 2,503. Average is 2,468 with a ES of 57.
40.5- 2,508, 2,528, 2,536. Average is 2,524 with a ES of 28.
41- 2,544, 2,563, 2,545. Average is 2,550 with a ES of 19.
41.5- 2,588, 2,607, 2,637. Average is 2,610 with a ES of 49.

So after I had all of my shots plotted I measured from the bottom of the page to the top of the hole for the highest shot of the charge weight and also the bottome of the hole for the lowest shot, and found my difference to find my vertical spread for each charge weight.

39- High was 5.25". Low was 2" for a difference of 3.25".
39.5- High was 7". Low was 5" for a difference of 2".
40-High was 4.75" and low was 4" for a difference of 0.75".
40.5- High was 8". Low was 7" for a difference of 1".
41- High was 8.25". Low was 4.5" for a differnce of 3.75".
41.5- High was 11.25". Low was 8.75" for a difference of 2.5".

It seems like based on the data the best load for me is between 40-40.5 which will yield around 2,400-2,500 FPS. However the velocity ES was the highest in these two load strings. This weight range has the smallest vertical spread of 1 inch and .75 inch. The high/low rounds were not in any specific order as in round 1,2, or 3. One thing I didn't understand was the ladder test went pretty much as planned however one of the least vertically spreading groups was actually shot lower on the target that the previous charge weight which I found weird.

Second Day (Today).

Time: 1000-1230
Round: 168gr SMK. IMI Match brass. FGMM Primers. IMR 4895 (Same as day 1)
Powder charge(s): 39.7, 39.9, 40.1, 40.3, 40.5, and 40.7
Distance: 100 yards
Altitude: 91.7 feet
Humidity: 77 RH
Temperature: 82.9* at 1000, and 88* at 1200
BP: 30.11
Wind: 8 mph consistent; 12 mph gusts

I loaded 5 shots of each charge and shot groups. I loaded the mag with 5 shots of a specific charge and threw in a sighter on top to eliminate the mysterious first shot flyer. I also shot a group with the sighters and they were pretty nice. In fact I thought they were going to be my load, but I never weighed the charges with these. The first two sighters were literally on top of each other, and then once I adjusted my scope mid test the group came down a little bit on the target. I threw 20 rounds together after I topped off my last 40.7 charge and didn't bother measuring it for exact powder charges. My cold bore shot was pretty much on, which made me happy. Any ways, here are the results:

39.7. It grouped ok and I was a little thrown off as I had a WTF flyer. It was all me. I definitely jerked the rifle and I called the shot correctly. I was pissed after I saw I called it right. The velocities of the shots were: 2,431, 2,400, 2,378, 2,378, and 2,387 which gives an average 2,394 and a ES of 53 FPS from high to low.

39.9. This was the best group of the day and I did not have any flyers so I see what the rifle is capable of (and me) with this group/load. It shot .442 MOA. Not much more to say. The velocities were: 2,430, 2,450, 2,403, 2,411, and 2,403 for an average of 2,419 and a ES of 47 FPS from high to low. This also was the least vertically spreading group from day 1.

40.1. This group was ok and I had a flyer caused by a car alarm going off as I was pulling the trigger and flinched. I yanked it bad low and to the right. The velocities were: 2,424, 2,429, 2,446, 2,414, and 2,465 for an average of 2,436 and a ES of 51 FPS from high to low.

40.3. I did an elevation error on my turret. I noticed the groups were starting to climb off the stickers so I meant to dial 1 MOA down, but I went up (DUH), which is why I missed the target completely. Any ways I pulled my last shot to the left, again it was me, not the rifle. The velocities were 2,461, 2,462, 2,488, 2,438, and 2,463 for an average of 2,462 and a ES of 50 FPS from high to low.

40.5. This group I was happy with. I had a slight flyer and I thought it was a good shot. The group measured .842 MOA. The velocities were: 2,484, 2,455, 2,482, 2,461, and 2,491 for an average of 2,475 with a ES of 36 FPS.

40.7. This was an awkward group, and I was excited to be done with this testing. The 5 shots measured .792 MOA. There were 2 "1 hole" groups, and then I had a flyer? that brought the group out to .792 MOA. I thought it was a good shot. The velocities were 2,497, 2,528, 2,535, 2,532, and 2,510 with an average of 2,520 with a ES of 38 FPS.

To Recap

39.7- 2,394 velocity on average.
39.9- 2,419 velocity on average and grouped the best at .442 MOA.
40.1- 2,436 velocity on average.
40.3- 2,462 velocity on average.
40.5- 2,475 velocity on average.
40.7- 2,520 velocity on average.

What should I go with as a load? Data tells me 39.9 (as it was the best ladder test load and also the best grouping load), but is there more to be desired with the velocity? Is there any other data that is needed that I didn't put?

==================================================================================================

Ok, so an update as I completed my load development for my rifle. I have reached pressure max, and also found a nice load(s) with a little higher velocity than 2,419 FPS. So let's begin.

Temp: 81* @ 1000, but rose to 86* @ 1700
Wind: 3-4 mph constant from all directions and gusted up to 8 mph
Humidity: 60%
Elevation: 91.7 feet
BP: 29.97
Rifle: LR308 Hybrid with Noveske 20" barrel 1x10 Poly Twist
IMI Match Brass @ 2.775 OAL
168gr SMK
IM$ 4895
FGMM Primers

First thing I did was the ladder test.

Test Distance: 300 yards
Charge Weight: 41.4-43.5 (42 being Sierra's max load for this powder)

41.5- 2,538, 2,526, 2,523 with an average of 2,455 and ES of 15
42.0- 2,570, 2,561, 2,560 with an average of 2,563 and ES of 10
42.5- 2,588, 2,584, 2,583 with an average of 2,585 and ES of 5
43.0- 2,654, 2,591, 2,611 with an average of 2,618 and ES of 63
43.5- 2,672, 2,660, 2,663 with an average of 2,665 and ES of 12

Vertical Spread

41.5- 2 inches
42.0- 2.25 inches
42.5- 3 inches (I really threw a shot here (lowest shot (low right) on target)
43.0- 2.5 inches
43.5- 1.1 inches

So according to this test I wanted to take the 43.5 and also I wanted to try the 42.5 load because I know I threw the shot. I was happy my ES shrunk quite a bit compared to the first few days of testing. After I got done with the test I wanted to test the pressure capabilities, so afterwards I put a 43.7 and it fired at 2,672 with no pressure signs. So I put a 43.9 charge in and it shot 2,694 but I saw primer expansion and extractor marks on the case. No need for me to go another charge up was useless. So around 80 degrees my max safe charge would be 43.7. So I learned something here.

So for the next part I shot 5 shot groups within the increment range of the two selected charges from the ladder test.

41.9- 2,563, 2,567, 2,591, 2,541, 2,571 with an average of 2,562 and ES of 30
42.1- 2,564, 2,577, 2,571, 2,564, 2,584 with an average of 2,572 and ES of 20
42.3- 2,568, 2,606, 2,600, 2,581, 2,576 with an average of 2,586 and ES of 38
42.5- 2,567, 2,594, 2,602, 2,583, 2,593 with an average of 2,587 and ES of 38
42.7- 2,614, 2,622, 2,608, 2,617, 2,605 with an average of 2,613 and ES of 17
42.9- 2,643, 2,619, 2,637, 2,635, 2,615 with an average of 2,629 and ES of 28
43.1- 2,640, 2,643, 2,627, 2,647, 2,633 with an average of 2,638 and ES of 20
43.3- 2,678, 2,640, 2,654, 2,645, 2,610 with an average of 2,645 and ES of 68
43.5- Fired one shot and noticed primer expansion and extractor marks so I ceased testing as I've reached it's max for a little hotter temperature than earlier's 43.7 weight. It was 1630 and by this time it was 86* so it definitely cause a pressure spike where earlier I was able to get away with this charge weight because it was cooler outside.

Grouped at:

41.9- .902 MOA
42.1- .402 MOA
42.3- 1.192 MOA (IDK WTF I was doing...DEE DEE DEEEEEEE)
42.5- .602 MOA
42.7- .602 MOA
42.9- .692 MOA
43.1- .842 MOA
43.3- 1.692 MOA (I was just wanting to get done. I rushed, but oh well)
43.5- DNF due to pressure signs.

So as the results show it seems as though another node is somewhere between 42.1 and 42.9 which would give me a new velocity of somewhere between 2,572-2,629 FPS which obviously is a big difference from 2,419. So here are a few questions:

1) Should I load at the 42.1 weight and have around 2,575 FPS or should I give up a few tenths of MOA and go for a little higher velocity?

2) Will the extra 50 FPS (+/-) make a lot of difference at the range of 800 yards (800 yards is all I want out of this round. When I get 175' I'll want 1000 yards)?

3) Would it be safe to say that I should not exceed 43 grains? I didn't have any problems shooting 43.7 in the AM/noon time, but as the heat increased I was unable to shoot the 43.5 weight. Not to mention I group better below 43 anyways, but to be on the safe side don't exceed 43?

4) Is there anything else I need to do/know about?

Thanks for any advice.

ReaperDriver · Sep 24, 2010

Re: Range Report. Lot's of load data and questions.

I would agree, that out of the list you posted, your 39.9 seems to be ONE of the accuracy nodes. The velocity is definitely on the VERY low side for 168 SMKs. But it all depends on what you plan to do with the rifle as far as max ranges you will be shooting. If you're going to be 300 yds and less - low 2400s might be fine. However, with a 20" barrel and 168 SMKs - I'm betting you'll find some additional accuracy nodes between 2600 and 2700 fps. Maybe even 2750. Granted these are two totally different animals - but I've comfortably gotten 168 SMKs up into the the low to mid 2700s in a 20" bolt gun.

I would suggest you keep working up your loads, because with 168 SMKs, you should not be getting pressure signs until well into the high 2600s or low 27s. 2419 is REALLY slow. But again, if its a short range gun - then that will work fine. Just work up carefully if you choose to keep going.

Caveat all the above with the fact that a gas gun may react completely different to higher pressure loads. I don't have a lot of experience with .308 gas guns, so take what I wrote with a grain of salt. BUT..... keep in mind that most of the better factory match rounds (FGMM, BH, etc) are probably in the 2550 to 2650 range for that bullet.

Grump · Sep 24, 2010

Re: Range Report. Lot's of load data and questions.

I'd suggest a final test with 40.5, 40.7, 40.9 AND 41.1.

If tight enough on all, it may confirm a good node for that barrel at 40.7 or 40.9. IF 41.1 is 1.25 MOA or less, I'd be more comfortable with a node at 40.9, especially IF the points of impact are closer than I see between your last 40.5 and 40.7.

THEN load 10 rounds, two each of the four load levels I suggest, plus a third one each for 40.7 and 40.9. Shoot those into two five-round groups for an *intentional* charge weight variation test (one will have two at 40.7 and the other will have two at 40.9). IF *that* group looks good, AND your powder measure will throw IMR 4895 to +/- 0.2 grains for a total spread of 0.4, you could then use thrown charges for 200 or maybe even 300-yard work...depending on the targets and purposes. It would be worth another 30 rounds to me.

Howie Feltersnatch · Sep 24, 2010

Re: Range Report. Lot's of load data and questions.

Thanks for the replies gentleman. Ideally I want this to be an 800 yard rifle with the 168's because that's what I understand is pretty much their limit. I want to get to 1000 and will do so after I shoot these and start buying the 175's. Well I'm glad that I'm not the only one to think that 2400 is slow as shit. I was just taken on how that grain range was the best for 2 different days.

Initially when I loaded for the ladder test the Sierra manual gives a powder range of 39.0-42.0. So I figured since I am using match brass I should back the max load off to 41.5 to be safe, and of course watch for pressure signs reaching up to that. After I shot all the rounds there were NOT any pressure signs in any of the 41.5 rounds. I very easily could have went up to the 42.0 charge I believe.

I'd like to be around the velocity of factory ammo so if I need to grab it in a pinch it will be very minimal adjustments needed to be made.

Sierra has the 2,419 round staying supersonic to about 850 yards. Which would be within my desire of this rifle. More than likely the wind would create havoc for the round at that distance. I was messing around with the program and at 2600 FPS it has the round going another 97 yards. So is it going to make THAT big of a difference?

I see what you're saying Grump. I've already done all this work already. So if I find something I like in there then that should put me in the mid 2500's. Is that going to make it a night and day differnce for stability?

ReaperDriver · Sep 25, 2010

Re: Range Report. Lot's of load data and questions.

Erik, I've found the Sierra manual to be pretty conservative on max loads. I'm NOT telling ou to exceed the printed manual, but I am telling you that many people do safely as long as they work up and pay attention to what the rifle is telling you.

IMHO, yes 2600+ WILL make a difference, particularily as you said with wind. And I'm not trying to say that speed is everything - just that most rifles have several accuracy nodes throughout the safe range of loads. I went back and looked at my load data for both my 168 SMKs and 168 AMAX (20" bolt gun, sloppy factory chamber) and I see that I had a good accuracy node at about 2590, 2640, 2705. I got as high as 2760 before pressure signs, but accuracy really fell off after 2700.

To give you a frame of reference that 2600-2700 is not unsafe.... factory Hornady 168 TAP loads chrono about 2650 in my 20" gun. AND they are extremely accurate at that velocity node.

eta: Again caveat that with those hot loads may not be ideal in a gas gun. Folks with more .308 gas gun experience than I have will give you better answers.

Howie Feltersnatch · Sep 27, 2010

Re: Range Report. Lot's of load data and questions.

Reaper. I know what you're saying regarding max loading, and it's not the first time I've been told that.

You do have a point about factory ammo. I was talking with a buddy of mine today and I want to be close to factory ammo if I can for the sake of my drop data. If in a pinch and I need to use factory ammo I'd like the data to be similar, at least in the same ball park. With the velocity I have now it's a whole different ball game compared to factory ammo velocities.

We'll see what happens as I redo do all this crap..haha. I already have all the data/drop/wind cards for this load of 2419 velocity, so now it's time to see if I can find a node at a higher velocity.

Like I said Sierra gives a 39-42 load range with 4895. What I'm going to do is pick up with 41.5 since I didn't see any pressure signs at that . Load up 3 rounds at each charge working up to the 43 range and redo the ladder test. Then for the sake up it load 1 round of each grain weight up to 44. Try to see what charge weight I start to see pressure signs (primer cratering/extractor marks on the case, etc) and that way I'll have an idea of what my rifle will handle. So I guess I'll answer 2 unknowns for the time being right now (another safe node and finding out what my rifle can handle) so I can close the book on this rifle so I'm not wondering if it can perform better. If not, the 39.9 it is.

Sound good?

artee · Sep 27, 2010

Re: Range Report. Lot's of load data and questions.

Erik, nice report. Lots of data to consider. Did the "weird" group that "shot lower than the previous group" on day one reoccur on day 2? Just interesting...

I've seen lots of rifles have their group POIs 'wander' in unexpected fashions and attribue it to a change in barrel vibrations that has the barrel pointing to a radically different point at the bullets muzzle exit.

Howie Feltersnatch · Sep 27, 2010

Re: Range Report. Lot's of load data and questions.

Artee, thank you. No it didn't. In fact after re-looking to answer your question it was my "node" group (the 40.0 charge). On Day 2 the groups were climbing slightly with each incremental increase (as it should) and I had to adjust my scope 1 MOA down in order to stay on the orange target. I was just surprised because if you look at the numbers from day 1 all the other charges climbed as expected, except for that one. I had the same POA, so what gives? I don't know...haha.

As far as my groups wandering. I fully believe it is partly me. I've only been doing "precise" shooting and reloading for all of 5 months now so I have A LOT more to learn and also need more time behind the trigger. After I saw my rifle is capable of sub .5 MOA, and noting the few flyers I had, I believe the groups that spread were partly me, and partly the frequency node being "off."

Howie Feltersnatch · Oct 15, 2010

Re: Range Report. Lot's of load data and questions.

Ok, so an update as I completed my load development for my rifle. I have reached pressure max, and also found a nice load(s) with a little higher velocity than 2,419 FPS. So let's begin.

Temp: 81* @ 1000, but rose to 86* @ 1700
Wind: 3-4 mph constant from all directions and gusted up to 8 mph
Humidity: 60%
Elevation: 91.7 feet
BP: 29.97
Rifle: LR308 Hybrid with Noveske 20" barrel 1x10 Poly Twist
IMI Match Brass @ 2.775 OAL
168gr SMK
IM$ 4895
FGMM Primers

First thing I did was the ladder test.

Test Distance: 300 yards
Charge Weight: 41.4-43.5 (42 being Sierra's max load for this powder)

41.5- 2,538, 2,526, 2,523 with an average of 2,455 and ES of 15
42.0- 2,570, 2,561, 2,560 with an average of 2,563 and ES of 10
42.5- 2,588, 2,584, 2,583 with an average of 2,585 and ES of 5
43.0- 2,654, 2,591, 2,611 with an average of 2,618 and ES of 63
43.5- 2,672, 2,660, 2,663 with an average of 2,665 and ES of 12

Vertical Spread

41.5- 2 inches
42.0- 2.25 inches
42.5- 3 inches (I really threw a shot here (lowest shot (low right) on target)
43.0- 2.5 inches
43.5- 1.1 inches

So according to this test I wanted to take the 43.5 and also I wanted to try the 42.5 load because I know I threw the shot. I was happy my ES shrunk quite a bit compared to the first few days of testing. After I got done with the test I wanted to test the pressure capabilities, so afterwards I put a 43.7 and it fired at 2,672 with no pressure signs. So I put a 43.9 charge in and it shot 2,694 but I saw primer expansion and extractor marks on the case. No need for me to go another charge up was useless. So around 80 degrees my max safe charge would be 43.7. So I learned something here.

So for the next part I shot 5 shot groups within the increment range of the two selected charges from the ladder test.

41.9- 2,563, 2,567, 2,591, 2,541, 2,571 with an average of 2,562 and ES of 30
42.1- 2,564, 2,577, 2,571, 2,564, 2,584 with an average of 2,572 and ES of 20
42.3- 2,568, 2,606, 2,600, 2,581, 2,576 with an average of 2,586 and ES of 38
42.5- 2,567, 2,594, 2,602, 2,583, 2,593 with an average of 2,587 and ES of 38
42.7- 2,614, 2,622, 2,608, 2,617, 2,605 with an average of 2,613 and ES of 17
42.9- 2,643, 2,619, 2,637, 2,635, 2,615 with an average of 2,629 and ES of 28
43.1- 2,640, 2,643, 2,627, 2,647, 2,633 with an average of 2,638 and ES of 20
43.3- 2,678, 2,640, 2,654, 2,645, 2,610 with an average of 2,645 and ES of 68
43.5- Fired one shot and noticed primer expansion and extractor marks so I ceased testing as I've reached it's max for a little hotter temperature than earlier's 43.7 weight. It was 1630 and by this time it was 86* so it definitely cause a pressure spike where earlier I was able to get away with this charge weight because it was cooler outside.

Grouped at:

41.9- .902 MOA
42.1- .402 MOA
42.3- 1.192 MOA (IDK WTF I was doing...DEE DEE DEEEEEEE)
42.5- .602 MOA
42.7- .602 MOA
42.9- .692 MOA
43.1- .842 MOA
43.3- 1.692 MOA (I was just wanting to get done. I rushed, but oh well)
43.5- DNF due to pressure signs.

So as the results show it seems as though another node is somewhere between 42.1 and 42.9 which would give me a new velocity of somewhere between 2,572-2,629 FPS which obviously is a big difference from 2,419. So here are a few questions:

1) Should I load at the 42.1 weight and have around 2,575 FPS or should I give up a few tenths of MOA and go for a little higher velocity?

2) Will the extra 50 FPS (+/-) make a lot of difference at the range of 800 yards (800 yards is all I want out of this round. When I get 175' I'll want 1000 yards)?

3) Would it be safe to say that I should not exceed 43 grains? I didn't have any problems shooting 43.7 in the AM/noon time, but as the heat increased I was unable to shoot the 43.5 weight. Not to mention I group better below 43 anyways, but to be on the safe side don't exceed 43?

4) Is there anything else I need to do/know about?

Thanks for any advice.

kyreloader · Oct 15, 2010

Re: Range Report. Lot's of load data and questions.

1. I would not due to it looking like that is a narrow accuracy node for you. I would load at 42.7g and be done. You have a node with similar accuracy from 42.5-42.9 and the 42.7g load had the lowest ES of the 5 shot groups that were shot.

2. JBM states that the 2572 fps load at 800 yards with 100 yard zero has 9.3 more inches drop(1.4MOA), 2 inches more drift (0.2MOA), and is going 28 fps less. Is that enough difference for you?

3. Luckily you node is less than that.

4. No

ReaperDriver · Oct 16, 2010

Re: Range Report. Lot's of load data and questions.

Erik, you might want to look at a less temp sensitive powder like Varget or RL-15 so you're not running into the am/pm thing.

CST · Oct 20, 2010

Re: Range Report. Lot's of load data and questions.

Forget everything....use 44.7 re15...win brass.. BR2 or 210 primer and 175smk.
Shot this load at 2540fps at 55 degrees 1/2-3/4" groups out of my 18" noveske...800YRD gun

This load shot 2640 our of my noveske 20" at 80 degrees

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Range Report Range Report. Lot's of data and questions. UPDATE

Howie Feltersnatch

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ReaperDriver

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Grump

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Howie Feltersnatch

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Howie Feltersnatch

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artee

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Howie Feltersnatch

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