Just a background. I had a Remington 700 AAC-SD that I had shooting .67 moa consistently. My best 4 shot group was .12 moa. I say that so you understand this is not my first rodeo.

I have a Savage 12 LRP in 260 Remington. 1:8 twist. It is topped with a Vortex Viper PST 6-24x50 SFP scope. Everything was shot with front bipod and rear bag support. My components are as follows:

Lapua Brass with .002 neck tension on the bullets
CCI BR2 Large rifle benchrest primers
H4350 Powder
140g Sierra Matchking bullets
Bullets seated to 2.765 COL

I am not having great results and I'm not completely sure why. I have run multiple OCW tests. My first test is pictured below with 4 shots each of 41.5g, 42.0g, 42.5g, 43.0g, 43.5g.






This told me that my accuracy node was going to be in the ballpark of 43.5g of powder.

I followed this up with another OCW test of 4 shots each of 43.3g, 43.5g, 43.7g, 43.9g. I saw no pressure signs on any of these loads.
My results were less than stellar





So i cleaned the gun thoroughly with WipeOut to remove all carbon and copper fouling. I fired 2 fouling shots and then ran the same OCW test again. 43.3g, 43.5g, 43.7g, and 43.9g





Again, not stellar re****s. The only factor I am not 100% comfortable with is the COL. I measure base to tip but as you know SMK are not all 100% exactly the same lenght. I assume they are all the same length to the Ogive though. I am seating the bullet with Forster Competition seating die with micrometer so I think they are consistent.

I know for some, they would be perfectly happy with these results. This is going to be a 1000+ yard rifle so these results are not good enough. Any suggestions/ideas? Thanks OB!

What is the COAL relative to the lands on the Savage?

Is the scope a known shooter? Check bases and rings?

No flies on some of those groups. Still worthy of LR accuracy. And from a factory gun. But i know you're lookng for better.

I'm sure I will get blasted for this, its a Savage take what you can get, next time stick with the Remington.

GSS...I do not know. I do not have a way to test for distance to lands. Been thinking about getting something though.

PFG...the scope is a known shooter. It was on my AAC-SD. I have doublechecked torque on everything there.

Cledus...My FIL has the 260 Model 10 and it literally shoots under .25 moa at 100 yards consitently. But, it took a gunsmith to lap/polish the bore for that to happen. From the factory it apparently had chatter marks in the barrel. If I can't figure it out I may be taking it to him to scope the bore. I have seen countless videos and posts about the Savage 12 LRP though, I know it is capable of extreme accuracy at extended ranges. I'm talking balloons at 1200 yards.

My COAL is 2.800, and that was the shortest I even tested... seems like yours is way low. That's my first observation...

NM

Also, once you determine OCW, you then try new COAL's until you find the sweet spot. Your testing is only half done...

43.3gr looks to be dead on for weight. time to start varying OAL. Measure the bullets individually, or better yet get a bullet comparator and base your OAL off that measurement. even though you are using SMKs, they tend to vary a little bit.

Seems to me you are not following the OCW , rather just shooting for best group.

The OCW test is a way to determine the charge weight in the middle where the POI shifts the least from one load to another. So your trials should not be focused on groups until after you determine the OCW. Once the OCW is determined, Then do some COAL trials and one will have groups you want.

http://optimalchargeweight.embarqspace.com/ocw-test-example/4529811475

Here is my writeup from sniper's hide with my 260, but for berger hybrids.
http://forum.snipershide.info/showthread.php?t=247584

It was my first OCW test, and I messed up at first as well. I didn't share the COAL trials, but that is a pretty simple exercise.

Get you a Hornady Modified Case and gauge to determine the distance to lands for your rifle.

You may also need to look at different projectiles. Some rifles juat dont like a particular projectile for multiple reasons. Dont limit yourself - there arw a lot of choices out there.

Check the crown for a burr as well. How are you determining runout on your loads? Are you turning necks?

Case Guage is useful unless magazine fed, if it has a magazine, just start with mag length, make sure that isn't into the lands, and go shorter, stopping where you started for the OCW test. 5 shot groups Of each length.

The bullet comparator is the best way to determine coal, even though you don't get a "true" COAL, you get a more consistent number, the o-give is more important than the tip.

That Lapua brass should not need to be turned, but maybe if nothing else works... and yes different bullets may be the answer, but I really believe if you get closer to the lands you will find a sweet spot.

TXAG72: a basic but useful way to determine COAL at the rifling is to partially size a case, where the neck will provide minimal but sufficient tension to hold the bullet. Seat the bullet slightly, then slowly chamber the round using the bolt to push the bullet into the case till the bolt closes.

Remove the round, hoping the bullet did not stick in the rifling (it seldom happens, but can). Measure the COAL, rinse and repeat to obtain what should be a reasonable COAL to the rifling with THAT type of bullet.
0.010" to 0.020" from the rifling are common distances to start in loading, but every rifle has its own preference.

Savage magazines are generally generous in what COAL's they will accommodate.

Good to know, regarding the Savage mags.

By the way, cleaning the bore never helps my groups, rather the other way around from my experience. I see you fouled it first, but some barrels need more fouling shots, 10-20 even. I have yet to clean my bore since I shot it the first time, and at about 300 rounds in, shot my best 5 shot group the other day:

The magazine or box is one limiting factor. On a bolt gun, generally speaking, the box is not a limiting factor becauae they are usually significantly longer than any chamber. The only rifle i have ever seen that i could not load to the lands due to the box length is a Remington 1917 military gun that probably has 3" of throat. (Seriously, the projectile is completely out of the neck before it even touches the lands.)

Some guns like off the lands, some like right on, some like into. It also can depend on the projo - simple ogive and compound ogive usually like different jumps. Hybrid like yet different jumps as well, but are usually closer to simple ogive jumps. You need to figure it out.

My Winchester 70's like right on the lands - i set the ogive .003" to .005" off on both of those with Nosler CT pills. I have heard about some guns that like projos jammed into the lands before they shoot well.

And never, ever really clean the bore. Knock the big stuff out, sure, but cleaning all fouling out generally is counternproductive to good shoots.

You may want to lap the bore as well, could have some rough spots.

quote:

---

The magazine or box is one limiting factor. On a bolt gun, generally speaking, the box is not a limiting factor becauae they are usually significantly longer than any chamber.

---

Hmm. do you have any with AICS mags? They have been short of the lands for me...

quote:

---

Get you a Hornady Modified Case and gauge to determine the distance to lands for your rifle.

You may also need to look at different projectiles. Some rifles juat dont like a particular projectile for multiple reasons. Dont limit yourself - there arw a lot of choices out there.

Check the crown for a burr as well. How are you determining runout on your loads? Are you turning necks?

---

This is what I'd recommend. Here is a good video on it. Probably $20 worth of new gear to do this

Not related to this your 260....
But what was your best load for your 700 AAC-SD? I'm assuming it's the .308?!?!I just got one in the 16.5" barrel and I'm about to work on it next. Planning on using Varget powder and 208 Hornady amax for subsonic and probably Sierra 175 bthp. At least that Sierra seems to be the most popular. But I'd prefer a accubond type bullet for animals. Might try some noslers

Thanks for the info!

quote:

---

quote:

---

The magazine or box is one limiting factor. On a bolt gun, generally speaking, the box is not a limiting factor becauae they are usually significantly longer than any chamber.

---

Hmm. do you have any with AICS mags? They have been short of the lands for me...

---

Nope.

But that is why I said "generally speaking" and also differentiated between the box and a mag too.

10-4 yeah I've loaded for autos, this 260 (with AICS), amd ADL's so in my limited experience all have been magazine bound except for the ADL's.

quote:

---

10-4 yeah I've loaded for autos, this 260 (with AICS), amd ADL's so in my limited experience all have been magazine bound except for the ADL's.

---

Sounds like you have that aspect covered then. The good news is that head to ogive is only one of many factors.

I think you need to look at that 43.3-43.5 range and mess with the seating depth. As previously suggested, get one of those depth gauges. You will be amazed what moving the bullet in or out can do.

Aggiewhoop..mine was in 308 with a 20" barrel with 1:10 twist. I put in in a B&C stock and put a Timney trigger on. 44.5G of Varget with 175g SMK was a great shooter for me. I had some great groups with 190g SMK and R15 powder.

Thank you for the info...I now understand OCW. So my question is...do I need to go back and start over or is there enough info here to determine my OCW?

With what I see, I would guess the 43.3 with that flat group. But it's about half a set of data, so it's hard to say for sure.

Check your velocity as well. I've never had much consistency out of the BR2's. I've had better luck with the Federal 210m's. Also try the Berger 140 VLD'S and/or the Nosler 140 C/C's.

quote:

---

With what I see, I would guess the 43.3 with that flat group. But it's about half a set of data, so it's hard to say for sure.

---

judging from the pictures you posted, 43.3 seems to be the most consistent vertically. your first picture showed a very tight group w/ one flyer, then your 2nd group showed almost 0 vertical deviation. For finding optimal charge, that's the kind of data you want. It means 1) you are consistently throwing 43.3 2) with that given OAL, the projectile is obtaining similar flight ballistics, 3) Given your barrel length/twist/grooves this projectile seems to work. If there was a decent changing wind when you shot the 2nd group, that alone could almost justify the left-right deviation.

Well...I went back an analyzed a 4th target I had shot the same string. It appeared, based on my new understanding of the OCW method, that my accuracy node was 43.3g, 43.5g, and 43.7g.

So, I loaded up 20 rounds at 43.5g. I made 2 changes...maybe not advisable. I switched to 140g Hornady Match bullets, and I changed my COL to 2.800. Here are the results...what do y'all make of this?

Here are closeups. My biggest concern is shift in POI vs. POA. I did shoot 24 rounds within 30 minutes so the barrel was pretty hot.

I understand about 10% of this thread (mostly shoot shotgun), but it looks like ill be adding this the list of "what to pick up next"

Just shot 8 rounds through my Magnetospeed Chrono. Avg. velocity was 2878 with a S-D of 8. I am pretty happy with that velocity for a 140g pill. I was shooting at 325 yards in an 8mph crosswind, all shots were within 3" circle.

BCO07...I am not happy with these groups at all.

This is what I am looking for. This was a group I shot with my Rem 700 in 308.

Yup, looks like fun.