Any luck with 140gr nosler RDF in 6.5 Creedmoor?

[jetinteriorguy]

I’ve been fighting trying to make these work and am getting very frustrated. Shooting from my Savage 12FV, 26” varmint barrel with a 1:8 right hand twist. I have these powders available to try. RE 15,16,and 17,H4895,H4350,IMR4350,Varget, and Benchmark. I know the rifle is capable with Hornady ELD-M Bullets, no problem getting .25”-.5” groups all day at 100yds with H4350. But no matter what I try just can’t seem to break the MOA barrier with the RDF’s. Any suggestions? Thanks.

[hounddawg]

At .035 to .040 off the lands they shot ok groups but after messing with most of a box gave up because of flyers. You would have a 1 hole clover leaf then the next would go out in left or right field

I much prefer the Nosler 140 gn Custom Competition or at nearly twice the price the Sierra 142 gn or 140 Bergers. For my gun the 140 CC's are the best value out there, if have not already try a box

[Unclenick]

That bullet is longer than the others. I'll suggest it is likely a secant ogive bullet and they can be harder to get to shoot well. You should follow the approach Berger uses to getting their older secant ogive VLD designs to shoot. You want to use a concentricity gauge and make sure your ammunition is straight. You want to make sure your primers are firmly seated for consistent ignition.

[jetinteriorguy]

I did try the method Berger uses with basically no success. It didn't seem to make much difference where the bullet was seated. I don't have a concentricity gauge so it's about the only thing I haven't done. With the powders I've tried it seemed like RE16 gave the best results so that's the powder I've been using through all the seating tests. I'm mostly curious if one of the others I listed has worked better for people or if there is some other powder I should try.

[Road_Clam]

Spent some time experimenting with the rdf 140's and IMR 4350. My best load was 41.8 gr and got about .8 moa. Not sure if this is going to be a go to load as im struggling with consistency. My barrel is a high end McRees Precision 24" stainless 1-8 twist. I need to try some H4350 which is supposidly differenct from IMR4350 , and the H4350 is "THE" go to powder for 6.5CM. Need more money to buy more powder and more testing. 6.5CM is a new caliber to me, finally had to cave and buy a 6.5 as I was getting my butt handed to me at 600 yds by lousy shooters ! The 6.5 makes a crappy shooter shoot good ! LOL

[T. O'Heir]

Some rifles just don't like some bullets. It's very likely that vs anything you've done or not done. And not all rifles will shoot MOA, never mind sub-MOA, with all bullets.
You fighting with a No$ler for a reason? You have a load that works. Go shoot some matches.

[jetinteriorguy]

Yeah, I’m beginning to feel like this bullet just doesn’t work in my rifle. I know the rifle is capable since my ELD-M loads are consistently 1/4-1/2 MOA. I’ve shot up around 300 of the RDF’s and have about 400 Bullets left, plus I don’t give up on problems until I get them solved, which is why I’m looking for any hopefully positive input.

[hooligan1]

I can get decent groups with the RDF, but I'm using RL19 with them.

[jetinteriorguy]

I may have found my load, at least it's looking promising. Found a nice node between 39.5 and 39.8 gr of IMR4350. Here are the stats, Starline LRP brass bump sized .003 and neck sized with a Lee collet neck sizer. Bullets seated .015 off the lands and using CCI LRP#200. Muzzle velocity at 2620 FPS using my MagnetoSpeed. ES of 10 FPS. I'm going to load a dozen up at 39.6 and see if it pans out. Both of these groups were at .5" at a 100 yds so now I feel like I'm getting somewhere. I'll post future results.

[Unclenick]

Congratulations. Sounds like barrel timing was the main issue. Now that you've found it, try the other seating depths over again, if you haven't already. Until you get down to a reasonably tight group size, their effect can be difficult to discern.

After that, concentricity would be the next thing to tackle, as it is also more important to secant ogives than to tangent ogives. The reason is the tangent ogive starts with a zero angle of departure from the bearing surface of the bullet and it gets larger from there. As a result, some part of the tangent ogive always touches the leade angle into the rifling in the throat before the bearing surface does, so you tend to see some self-centering as that radius centers in the conically tapered leade. The secant ogive has an immediate angle of departure at the shoulder with the bearing surface, so the leading edge of the bearing surface usually makes first contact with the rifling at the groove diameter, so rifling marks start to be extruded into it before centering in the cone can occur. The centering forces are then not great enough to eliminate any tilt the bullet already has. The only cure is to have the bullet straight in the first place.

One thing you can do is get a Lyman M-die and set it up to expand only enough to put the small leading step into the case mouth (not the flare portion). If the cases will seat that way in your chamber without using a crimp die to bring the step back down again, the slight widening can actually help center the case mouth in the neck portion of the chamber. But even if it doesn't, if you don't have either the Forster or Redding competition/benchrest seating die, both of which tend to minimize runout, the step in the case mouth lets you seat a bullet upright in the case mouth so it starts straight into the seating die, and this cuts runout considerably. You already are using a good method to keep runout out of the case neck, so, between the two, you should get pretty straight ammunition.

[jetinteriorguy]

Thanks UN, this all makes sense. I'm in agreement, I think I'm getting much better results in this velocity range. My guess is while trying to find a node at a higher velocity I'd misread my original load workup and have been chasing my tail ever since. I do have the Forster micrometer seating die which is a very nice piece of equipment. Now I'm putting a concentricity tool on my Christmas list. Funny thing, this is the most accurate load with IMR4350 on the Nosler sight.

[Unclenick]

If you have their same barrel length the timing probably all works out the same. Or perhaps they found one of Dan Newberry's Optimum Charge Weights for it. I don't think it's ever a bad idea to chose the powder the load manual authors got the best results with and then work up to it from the starting load and check out its accuracy in your gun as a reference point.

[jetinteriorguy]

The test barrel was a 24", mine is a 26". I think it's mostly just a coincidence. Either way I'm happy with it and am looking forward to shooting it a lot more. I've been banging away with this rifle for about a year and a half now and feel like I'm just finally really beginning to click with it. The stock is set up just the way I like it, I love the new Timney trigger once I got it set up, and the scope is finally set just right so that it has all come together. I have two loads that work well enough that from now on I'm the limiting factor in accuracy and I know what to work on.

[Unclenick]

If you read about the Optimum Charge Weight (OCW) system, it's about loads that work out to do well in a wide variety of chambers and barrel lengths. Interesting concept.

[Rimfire5]

Unclenick,

I have been using Chris Long's theory (the basis for Dan Newberry's approach) and applied it to my loading for about 3 years and have found it to work really well as long as you identify the barrel steel in each rifle's barrel. Chris Long's original article was without any corroborating data so I had to do a lot of experimentation to verify the results. I eventually found out that even the temperature variation of the powder had to be included in the calculations in order to be able to notice the effect of his theory.

The theory is based on the concept that the shock wave created by the initial firing expands the barrel and that expansion travels down the barrel towards the muzzle at the speed of the reflection of the steel alloy causing the muzzle to expand at the crown. Then it reflects back to the chamber as the bullet is travelling down the barrel. The velocity of the bullet (effected by temperature, powder, and powder charge as well as trim length and seating depth) is crucial to determining the actual exit time of the bullet from the muzzle.

Obviously, accurate barrel length measurements are also crucial to determine the single reflection time. It is important to choose the right number of reflections to time the bullet exit from the muzzle.

Use of flash hiders, muzzle brakes or suppressors of different steel alloys add even more confusion to the calculation. While the bullet exits the rifling of the barrel and never touches the appendage on the barrel, the reflection still travels through the appendage and increases the reflection time.

I have found that the exit time in a 24 inch 3% carbon steel barrel is 1.256 msec. and that would require 12 reflections to occur to get the shock wave back at the chamber when the bullet finally exits the rifling.

But if you have a 2.125 muzzle brake made of 4150 steel on the same barrel, the target reflection time increases to 1.366 msec. because the reflection has to travel 12 more times through the muzzle brake as well.

Dan Newberry's estimate of 18,000 fps for the speed of the reflection in steel is inaccurate according to data for steel alloys in any materials handbook.

Most modern barrels that use 3% carbon steel with a reflection speed of 19,107 fps,
Older barrel steel is 18,916 fps because it was made with less carbon. Stainless steel varies too - 4140 & 4150 steel velocity is 19,979 fps and 416R steel used in my Les Baer barrels is 20,014 fps.

Based on about 3 years of using this approach, I find that loads that match the correct bullet exit time so that the reflection is at the chamber within +/- 0.010 msec. can yield improvement in accuracy of up to 0.050 to 0.070 inches in group size compared to loads that result in the reflection being closer to the middle of the barrel.

In my experimentation, if a rifle can't consistently shoot groups that are under 0.5 inches, it is very hard to see any difference.

But I have 8 rifles of different calibers that have shown the effects of using this theory in loading to get the reflection at the chamber when the bullet leaves the muzzle.

[Unclenick]

The reason I mentioned Newberry to Jetinterior guy was not the OBT theory but the chocolate ice cream load concept, wherein some charge weights seem to be tuned to cover a wide range of gun barrel lengths.

[jetinteriorguy]

I had read all this before, in fact it's saved in my favorites on my IPad. It's been a while though so it's nice to review it again, I should do it more often. Thanks for all the help guys.

[jetinteriorguy]

Headed to the range after work with this load, and wow am I tickled with the results. All four groups were under 1/2", and two were at 1/4" with one of those having two rounds making one slightly oblong hole and the third almost touching. Now I know a lot of people don't think much of three shot groups, but for me I've found if I shoot three then take a small break I can keep my concentration level up and shoot much more consistently. I also like to shoot four of these groups in a sitting since that takes about 30-40 minutes and then I can head home and still get home at a good time from work.

[Rimfire5]

jetinteriorguy,

While I normally quote accuracy based on 5 round groups, I also shoot 3 round groups when I am trying to see how loads perform without spending too much $ finding out some powder-bullet combination doesn't seem to work. You don't have to apologize for controlling costs during testing loads.

My good 3 shot group loads average under 0.25 inches at 100 yards with a Savage 12 LRP 6.5mm CM with a 26 inch barrel. It might be the big brother to your 12 FV but it doesn't seem to shoot much different. Mine likes Sierra 142 SMK and Hornady 147 ELD-M bullets with IMR4451 powder and it also shoots Hornady 140 ELD-M well with that powder. IMR4350 is a close second powder choice with those bullets.

I also shoot 5 round, 10 round and 20 round groups.
Of course, as you mentioned, lack of consistency in set up and other shooter induced variations produces larger groups the more you shoot.

For me, 5 round groups are about 50% larger than my 3 round groups, and I too have problems with consistency, primarily in set up between shots.

But even then, I have had 20 round groups under 0.6 inches, even including my screw-ups.

[hounddawg]

If I were testing for flyers I would definitely use more than three shot test groups. Ten at a minimum and fifteen or twenty if I was planning on using it in competition

I had excellent results with the 140gn bullets with 4831SC in a 26 inch barrel but my 20 inch likes Varget and light bullets (120 gn) and my 30 wants H4350 with the heavies

[jetinteriorguy]

I Know what you mean about consistent shooting. I feel like I'm just really getting the hang of this rifle. I never used to actually target shoot rifles, every year I'd pop off a couple rounds at a 100 yds to make sure I was sighted in. Then I'd shoot a deer and go home. In the summer I'd load up a few rifles and go out to a friends gravel pit and have a fun day probably 4-5 times and that would be it. But after messing with this rifle and trying to get consistently accurate with it everything is finally clicking, but without good consistent accurate ammunition it's hard to know if it's me or the gun. Now I have two loads that shoot very good for me and I'm also starting to get really good consistent results so I feel like I'm finally getting it right. It's a really good feeling and I'm loving it.

[Road_Clam]

My test criteria is to shoot 5, and calculate the best 4 shot groups for data. It's all about creating as much data as I can using averages. I'll always favor a 1.25 MOA consistent load vs. a "one day wonder" .3 MOA load that shot 1.75 MOA a month later.

[Phidelt208]

Man there is lots of good info here.
I couldn't get the 140 RDF to shoot well out of my 6.5 gas gun. I was using H4350 and Varget. 1 MOA is a must and the criteria I use. 10 shot group @ 200 yards.
3 shot groups can lie!
140 Bergers, 140 HPBT Hornady, and the ELD-M worked well.

[jetinteriorguy]

One of the reasons I prefer several three shot targets is because after so many rounds a 3/4" dot starts to get obliterated slightly off center. This then draws my eye off center on the target falsely opening up a group. But by shooting clean dots with three rounds, and then counting all of them as literally one collective target I feel I get a more accurate picture of both what I'm doing and what the gun/loads are doing. I don't just pick the best one and declare it the winner. So basically with my targets that have four dots each I'm essentially shooting twelve rounds per target. But for load development, I first shoot two rounds each using the MagnetoSpeed, then go back and shoot three rounds each without it. I then look for possible nodes using these two pieces of data. Armed with this I'll then shoot three sets of five rounds, one right in the middle of the node, then one going down a 3/10 of a grain, and one going up 3/10 of a grain. At this point if I feel I have a clear picture of a good load, I'll load up 20 rounds and shoot 4 groups of 5.

[Rimfire5]

I agree that a single 3 shot group or even an average of a few 3 shot groups isn't a dependable indicator of accuracy. I also believe that the average of a few of the best 5 shot groups isn't a dependable measure of accuracy either.

However, a 50 group average of 3 shot groups is a pretty good indicator of the performance of a powder-bullet combination.
The average of twenty 5- shot groups is a better statistical indicator of the combination of the shooter's performance as well as the powder-bullet combination's performance than the large sample, 3 shot group average.

If I am trying to find out what powder-bullet combinations to focus on, I want to try an eliminate the effect of shooter variations.
If I am trying to measure my performance, I use 5 shot, 10 shot, or 20 shot groups.

I look at group sizes as just tools to give you some idea of different types of performance.