New to Rifle reloading...OCW with 2000-MR

[391dave]

I'm new to metallic reloading but have done shotshell for many years.

I am planning on a OCW test, I have read the article, and wanted some confirmation that I am heading down the right path especially since there is not a whole lot of load information for the 2000-MR.

308, 1 in 12, 26" barrel
175SMK
Fed GMM Case
CCI BR2
2000-MR

Alliant lists a load at 47.7 for the 308 with 175 SMK. I was planning on backing off 7% and the adding 2% to each charge up to the 47.7 then adding 1% to each for two additional charges. My intention is to shoot these at 250 yes (my clubs max range) to determine the optimum charge weight. These will have an overall length of 2.8"

Does that seem reasonable? Am I taking too many charge increments? That gives me 8 strings I believe.

Thanks in advance for any input.

 

[JGorski]

Dave, Ive worked with 2000MR quite a bit in my SPSS & Classic sporter, I use the same components as you listed cept I used Win brass at first and I was shooting 178HPBTs Id load up 5 shots with 47.3 and work up to 47.5grs. This powder likes working near max pressures but I never saw any over pressure signs with it. I think we might have the same rifle as well, you gotta SPS, am I right. I noted another thing, my bullets liked to be seated deeper, those 175s will probably shoot better further from the lands as well from past experience. Id seat those 175 no longer than 2.830"oal. Best of luck!

 

[391dave]

Thanks! I am shooting a Savage 10 with a Shillen bull select match barrel in a AICS. I was able to get 5# of 2000-MR and only had 1# of Varget so the 2000 wins for the first load development.

 

[Aimsmall55]

Thanks! I am shooting a Savage 10 with a Shillen bull select match barrel in a AICS. I was able to get 5# of 2000-MR and only had 1# of Varget so the 2000 wins for the first load development.

Maybe this will help. I'm running the 175 smk out of a ga Crusader with a 22" bartlein 1:11.25 twist. I run 48.0 2000 mr fgm210m at 2.236 to the ogive. Lapua brass. 2770 fps and a tack driver. It's my ftr load and shoots very very well. With the br2s you'll lose about 25-30 fps but your Es and sd will almost certainly be lower. Power pro gives velocities with the heavys that varget never will. For example I was running 44.5 varget same data and getting 2680. I picked up 90 fps with mr. Never looked back

 

[Ishallbie O'Cullkillin]

Power pro is no joke. It doesn't stop there. In a 26" Rock Rem700 I've been using the 190's with 46.5gr in Fed brass, 2740 fps. Then stepped up to the Hornady 208hpbt using 47gr at 2650. I had to use Win brass with uniformed flash holes. Both loads are very consistent and accurate. Neither load shows pressure signs at 65deg. Smackin the steel at 1300.

 

[Bear24]

I don't have any chrono data as of right now but I have loaded some 2000MR in once fired fed GMM cases, f210m primers and 178g amax and BTHP. The A max shot great at 46.5g and had no pressure signs up to 47.5 (all I could fit in the case) loaded at 2.820"

 

[391dave]

I went ahead and loaded up 7% off of 47.7 and went every 2% to 47.7 and then every 1% for three more increments...the max was 49. The 49 and the one below it were tight for sure. I may not make it up to them if the lower ones show any pressure signs. I hope to get out this weekend and put it to paper. Thanks for all the advice.

 

[JGorski]

I dont think youll ever get to shoot anything past 48grs cuz you're going to have pressure issues, but once you get them you can take the shells you didnt shoot and pull the bullets and do some verifying loads. Im betting your best node will be at 47.8grs.

 

[391dave]

I dont think youll ever get to shoot anything past 48grs cuz you're going to have pressure issues, but once you get them you can take the shells you didnt shoot and pull the bullets and do some verifying loads. Im betting your best node will be at 47.8grs.

I was thinking the same thing on the higher end. I figured though, since I have to drive one hour to the range, better have more than enough rather than not enough to shoot

 

[391dave]

Well I finally made it out to the range today. I ran the OCW for 44.4 gr up to 49 gr of 2000-MR. No pressure signs. I pulled a couple, had a couple of primers that did not go off on a couple of the lower charges and had a couple that did not feed which was peculiar since they were all loaded at the same time, same die, same bullet lot but I could see where it was scraping.

Here's the photo of all the strings. Not sure what to make of it in all honesty. Thoughts?

 

[391dave]

44.4 gr

45.2gr

46.1gr

47.1gr

47.7gr

48.2

48.7

49.0 gr

 

[391dave]

I am thinking I need to work it tighter around 47.1 gr.

 

[Aimsmall55]

I am thinking I need to work it tighter around 47.1 gr.

Just an observation. But it seems to me that there is a trend there. The higher the charge the more the groups open up. What do you think??

 

[391dave]

Just an observation. But it seems to me that there is a trend there. The higher the charge the more the groups open up. What do you think??

True. I was looking mainly for the direction from the point of aim. I missed that. 46.1 gr might be better to work around then. If I do start there am I better off just taking 46.1 and working seating depth or change the charge by .2 and work two up and two down to see what happens?

 

[Aimsmall55]

True. I was looking mainly for the direction from the point of aim. I missed that. 46.1 gr might be better to work around then. If I do start there am I better off just taking 46.1 and working seating depth or change the charge by .2 and work two up and two down to see what happens?

The great thing about the bullet your using is it is so forgiving on seating depth. Yes it matters but not as much as say a Berger vld. What type of rifle are you shooting? If your shooting say a Remington your throat is very likely long. Do you have an oal gauge ?

 

[Jumper]

Good pics. Its pretty obvious to me that your OCW is between 48.2 & 48.7. Your groups poi get a little higher with each group and the tightest groups come immediately after the scatter node. Exactly what the OCW method predicts. I'd say its close to 48.7gr.

 

[391dave]

The great thing about the bullet your using is it is so forgiving on seating depth. Yes it matters but not as much as say a Berger vld. What type of rifle are you shooting? If your shooting say a Remington your throat is very likely long. Do you have an oal gauge ?

No, just ordered one from Midway. I had just been seating with the micrometer seating die and using calipers. I know that the meplat throws that off a bit but I was shooting for 2.800 overall length. The cases were all trimmed to 2.005 +/- .001.

I am shooting a Savage 10 in a AICS 2.0 chassis. It is the large shank with a shilen bull select match 1 in 12 barrel. 1" at the muzzle. 26" long.

 

[391dave]

Good pics. Its pretty obvious to me that your OCW is between 48.2 & 48.7. Your groups poi get a little higher with each group and the tightest groups come immediately after the scatter node. Exactly what the OCW method predicts. I'd say its close to 48.7gr.

Jumper, would you explain that a bit more please? When I read the OCW site it says I should look for groups that are on the same bearing and approximately the same distance from the point of aim. This is what OnTarget gave me

Charge X Y
44.4 0.098 0.137
45.2 -0.091 0.350
46.1 -0.149 0.685
47.1 -0.151 0.433
47.7 -0.147 0.451
48.2 -0.231 0.720
48.7 -0.305 1.055
49 0.079 1.125

If I take that then based on above I should be somewhere between 46.1 and 47.7? I think I did not have enough granularity in the loads. Am I reading this correctly? It seems that maybe between 47.1 and 47.7 I would get the same relative POI and possibly below 47.1? All the x shifts were close for the 46.1 to 47.7 the y shift on 46.1 is climbing.

Just for information wind was from my 4 steady at 12-15 gusting to 25

 

[Jumper]

Dave - the OCW method is a good way to find the ideal load for a powder and bullet combination that is tolerant of minor variations in production. But its easier to see the scatter nodes and changes in poi when the groups are shot at 200yds or more. At 100yds its real hard to see subtle changes in a group. But your 100yd groups showed a big difference in size and a subtle shift in poi that also corresponded with the increasing charge. Its subtle but its there . if you look at the bottom edge of the box around the group you'll see it get a little higher on the targets as charge increases. But the most obvious change is group size.

Continued...

 

[Jumper]

In the lower charge weight groups, there isnt a discernible change in group size until you get to 45.2 ~ 46.1 Then, as you progress, the groups get larger @ 47.7, then smaller at 48.2. 48.2 is a uniform group with the POI spread pretty even throughout the extent of the group. Then they tighten up nicely at 48.7. At 49.0 they again start to scatter. So your big at 47.7, getting smaller at 48.2 and smallest at 48.7. And, the poi is climbing with each of these 3 groups. According to the OCW theory, this means that as your barrel is vibrating the velocity of the bullet generated by a charge weight of 47.7 has the bullet exiting the barrel as the muzzle is moving between its high point and its low point, like the crest and trough of a wave. At 48.2gr, the bullet is leaving as the muzzle gets closer to the crest. And 48.7 generates the ideal velocity to have the bullet exiting the muzzle at the crest of a vibrational node. Notice how the group is tight and its POI is a little higher than the 2 groups preceding it. The crest and trough is where the muzzle is moving the least and is generally the best for accuracy.

To really do an OCW work up it should be shot at 200 to 300 yds and in round robin fashion so any shooter error or heat build up etc., is spread across all the groups. You did a good job of taking pictures and recording your charge weights so even though you only shot it at 100yds it was kind of easy to see. Hope this helps.

 

[JGorski]

Yes, I would like to see your groups at 300yds if possible, I think Itll show you more, I mean, all those 100yrd groups are pretty good, 300 would bring out the devil in some of those loads, so to speak.

 

[391dave]

I'll get it out to 250 this weekend if I can get back in the reloading room. I am going to try and load at both nodes. Lower and upper. The upper concerns me as it is above max loading recommendation and it was cool outside. I am not sure how temperature stable this powder is. I did not see pressure signs though. Also, jumper I did shoot round Robbin. Thanks for all the advice.

 

[Macmathews]

Not sure on the emphasis on group size for an OCW.
From what I have read and tried , group size while finding optimum charge with a given projectile , means very little

In my experience, some of my best 100 yard groups really didn't do well past 200

In you case take 48 grains back up to 250 and start shooting 5 shot groups with seating depths changing .005 at a time

Good luck

Kyle