Need help getting started with 7mm Berger Classic**OCW test added** Hunters

[JLDavid]

I have been working on a 280AI and I can't get 168 VLDs to shoot for a damn. I ordered 2 boxes of Classic Hunters to try. Where do you guys start seating them when you are starting your load development? I have a pile of 8133 so I plan on using it and doing a ladder test. I will moly these bullets as well. Any direction or advise is appreciated. Have a good weekend.

David

 

[JLDavid]

I shot a OCW test with IMR 8133 and moly 168 Berger Classic Hunter bullets. I set this up like Erik Cortina recommended. Bullets seated .020 off my jam point. Not sure I have enough different powder charges to see a definite node or not. Please look at it and tell me your thoughts. This rifle is a 280AI hunting rifle with 28" 8 twist 3B Bartlein barrel on a trued Reminton 700 with a PTG bolt and Jewell trigger bedded in a Christensen Arms sporter stock. I fired it off a bench with Harris bipod and rear bag. Temperature was 87° and I had a 4mph gusty breeze from about the 11 o'clock position. I did not wait for conditions to settle. Thanks.

 

[bozo699]

JL,
Was you shooting high or to the left?
Wayne

 

[bozo699]

JL,
Are you showing pressure signs at 66.5?… if not go up about 2 tenths at a time from there the group isn’t bad especially if your shooting left of bullseye and your numbers look great you haven’t flattened out yet as a matter of a fact quite a jump from 66 and numbers are looking good from 65.5 to 66.5 I’m betting your just starting in a node around 66.5 I’m not familiar with that powder so I would start another ladder from 66.3 and go 2tenths from there on up a ways then fine tune with seating depth that’s how Erik would tell you to do it I think. I think she’s gonna shoot for ya
Wayne

 

[JLDavid]

My 1st load was hittting high and right so I moved the scope 1" to the left to keep the groups over the dot they were shot at.

 

[JLDavid]

Thanks Wayne. That was my thought but I really didn't see a jump in height and a plateau in velocity like I was expecting. 66 is max but with moly I may have to go up a little higher to see pressure. The reason I am using 8133 is I have a pile of it and can't get much else. Thanks for the info.

 

[bozo699]

My 1st load was hittting high and right so I moved the scope 1" to the left to keep the groups over the dot they were shot at.

Ok perfect that 66.5 only has horizontal for the most part which was probably wind. I never like to shoot the bullseye either I want bullet impact on clean whit paper you can zero it when your done. I think your gonna get it I don’t think there crappy at all and especially if those are the first rounds through the new barrel
Wayne

 

[RegionRat]

I would punt, but if you are forced...

8133 is really slow stuff, so just be aware how far down on the charts you are going with that.

You are correct that the steps are too coarse and too few to call anything without lots of risk that the next time you shoot you would end up with more confusion.

There is no point to an SD when you have only three shots. Even with five to seven shots, it is risky to make a claim on an SD, so we look harder at the ES. A good one here prolongs the testing, but a bad one cuts that charge loose.

At least some of those are fair for the top end of your test, but with only three shots per step, this is very risky and forces you to take more shots there to see if the trend holds or falls apart.

I would either punt completely and trade for some H4350, or if forced to continue with 8133 I would explore those top two groups and see if a larger sample plays out. Maybe drop a point in between 66 and 66.5 to see if there is any hope for stability there, and then tune the seating depth.

Your odds at this point are only about 50/50 that the test shows anything at all. The 66.0 and 66.5 groups could actually be about the same size if you shoot more samples. The only saving grace is that you might then be able to play with seating to tune the group down since the velocity looks stable.




ETA: I would also suggest you run any follow-up tests at distance. If the steps from 66, 66.25, 66.5 show a POI node with your current jump 20, then the follow up with seating depth has hope.

 

[bozo699]

Thanks Wayne. That was my thought but I really didn't see a jump in height and a plateau in velocity like I was expecting. 66 is max but with moly I may have to go up a little higher to see pressure. The reason I am using 8133 is I have a pile of it and can't get much else. Thanks for the info.

I think your gonna find a sweet spot between sat 66.3 and 66.8 or so you may be in the middle right now but that group can’t be over 3/8” and you can play with seating depth to tighten the group further. If it will shoot like it is most every shot would be a outstanding hunting load in my opinion without improvement but your probably like me and want to ring the utmost out of it
Wayne

 

[JLDavid]

RegionRat thanks for plotting those shots. Took me a little bit to figure out what they meant but see what you are saying now.

Wayne I will load up some more test loads and shoot them to see what happens. Under really good light I do have a very light ejector mark at 66.5 grains. I have to have magnifiers on and hold the case just right to see it. The edges of the primers are nice and round still. I don't have any primer flow around the firing pin. These cases have 3 firings on them and they are Nosler brass, fyi.

 

[JLDavid]

Also not sure how much the 87° temperature had to do with anything in regards to the light ejector marks. The next time I shoot I will really pay attention to the temperature and see if the marks show up again. My bench is getting a little wobbly with age so the next round of testing I will shoot prone. I paid attention to bringing the rifle back to where it started before the shot and made sure I didn't change anything with my hold or trigger squeeze. I hate to change too many variables but will give it a go.

 

[JLDavid]

Also, yes, I really do want to get all the accuracy I can get. I built this rifle myself for my son to hunt elk with. He killed a cow at 425 yards with 1 shot last season with a 280AI I built for my cousin and her husband for their wedding.

 

[darkangel_r2]

Thats a really slow powder for that cartridge and bullet weight. You should try to swap some powder with locals for re 23, 7977 ,or h1000.

If you can't get a new faster burn rate powder try to add some neck tension as that can bring down es numbers in these scenarios.

Also if you are not limited by mag length you may want to try berger 195 eol hunters. A heavier pill may help too with that powder.

 

[RegionRat]

I don't have personal experience with 8133, so I won't comment on the 87 temps, but it is an Enduron that they call their stable powders.

I am familiar with ones close to it on the burn rate charts like H1000 and IMR 7977 that slow down just a little in cold weather, but not enough to ruin a tuning node.

If you think you can do like Wayne suggests and focus up there toward the top of your tests, there is a chance you will be happy once you test a little more. Don't run there if the bolt was stiff or the brass was showing signs.

I have developed loads for a few 280AI that did really well with H4350, so I usually start them there and only go to the slower powders if forced.

Good Luck and in for the range report.

 

[Idaho-Lefty]

Berger Classic Hunters, ARE very Depth Tolerant and "Jump Friendly" as, they are, a Tangent Ogive design.
I shoot them, in a 6 XC ( .025 to .060 Jump with, the 95's ) and in a .270 WSM, Tikka that, "Jumps", the 140 Cl. Hunt's .105 ( Bullet tip, is, just short of, Magazine Length ). Bullet going, 3,185 FPS and usually, Sub 1/2 MOA,..
IF, I can "do," MY Part ! Can't help with, the Powder charges but, my .30-06 W/ 165's used to LIKE,.. IMR 4350 !
IMR 4350 is, an amazing Powder but, you might try, H-4350 as, its better,.. in Cold weather.

 

[JLDavid]

I do have almost 2# of H4350 as well. I tried 8133 due to the increased velocity over both H4350 and H4831on the Hodgdon reloading website. I have had good luck with Retumbo in other cartridges with midweight to heavy bullets.

 

[Idaho-Lefty]

Accuracy, always Trumps Velocity in MY book and sometimes SLOWER burning Powders, don't produce, the "best" Accuracy ! Retumbo and RL-26 seem to work FINE in the WSM's / Saum's, .264's etc.,.. but "may" not be, a good "Fit" in, the Longer Powder column of, the .30-06 - .280's.
AGAIN, I'm not an expert on, the .280 AI But, I'd try the H- 4350,.. IMHO !
30-50 FPS "more" is,.. no big deal ! Never seen, an Elk "complain',.. YET !
Accuracy and a "good" Bullet + "placement', are more important than, a few FPS !

 

[JLDavid]

I agree that 30 to 50 fps isn't worth it but I was looking at an increase of 138fps over H4831 and 183 fps over H4350. I am not saying this to be an ass and I realize that published velocities don't mean a whole lot until you load up some and shoot them over a chronograph. I know I need accuracy over velocity no matter what as this rifle will be used to take game, not just shoot paper. If I can go through this test and get both I will have what I need.

 

[Idaho-Lefty]

Sounds like, you HAVE, "all" the RIGHT stuff, in that Rifle "Build" !
Should "shoot" those Classic's "well" IF, you can find, the "right", Powder !
A 24", .270 WSM is, "capable" of driving 140's,.. 3,300 FPS
But,.. Accuracy FADES quickly, past 3,200 FPS for, my Rifle,...

 

[JLDavid]

If there was a chance to find some VV powders I would try them. I am not saying that 8133 is the best choice, I thought I would give it a try because I have 16# of it. If my next test goes to hell in a handbasket, I will go to another powder I have, probably H4350.