Ocw confusion

[CAKustoms]

6.5 Creedmoor 22"
Hornady once fired
CCI B2
140gr ELD Match
IMR4350
OAL 2.80
100yd round robin
58 degrees

I'm not sure where to go from here. Most OCW tests I've seen have a more definite pattern of dispersion. I didn't have access to a chrono at the time I shot this. The IMR may not be ideal, but it is the most readily available in the area. No signs of any pressure.

Do I shoot it again starting lower and working even higher? (41.5 is recommended max) Make the switch to H4350? Stretch the distance to 200? I'm also thinking about using a sled for any further testing to minimize my errors.

 

[Yerman]

I would re-shoot but with a chrono. Not much can be evaluated from your group without some chrono results to compare too. I think you might need to speed them up a bit.

Also, I wasted a lot of time doing load development with Reloader 16 and Nosler RDFs even though I wanted to shoot H4350 and 140 Berger Hybrids. I learned my lesson and need to start over now that I found H4350.

If you are already having doubts with your powder, I would make the change. Confidence in your components goes a long way when your doing load development and H4350 is pretty widely known as the best for 6.5CM

 

[pell1203]

I'd go no larger than 0.3 grain increment size when first testing for loads with this amount of powder. If you were loading something that required 70+ grains, then a 0.5 increment is reasonable. In this case, jumping in 0.5gr increments could cause to altogether overlook an accuracy and/or scatter node.

There is at least one usable node in the range you tested. It is just hiding in the 0.5 increments.

Since you saw no pressure signs, I'd suggest retesting in 0.3gr increments starting at 40.7.

 

[lash]

I'd go no larger than 0.3 grain increment size when first testing for loads with this amount of powder. If you were loading something that required 70+ grains, then a 0.5 increment is reasonable. In this case, jumping in 0.5gr increments could cause to altogether overlook an accuracy and/or scatter node.

There is at least one usable node in the range you tested. It is just hiding in the 0.5 increments.

Since you saw no pressure signs, I'd suggest retesting in 0.3gr increments starting at 40.7.

^^^This^^^

 

[Juggerxxx]

I think your point of impact is very promising. I would explore as high as 43.0gr of IMR4350 but work your way up in 0.2gr increments. I bet you will find good results between 42.0-42.7gr. When I was using Hornady brass and IMR4350 I settled on 42.7gr and never saw pressure until 43.5gr. I bet you will tighten those groups up after a seating depth test as well.
I recently started doing my OCW tests at 200 yards. The data is much more clear.

 

[47guy]

id start at 41.5 and go up in .2g increments.

 

[Badfinger]

FWIW I found 43.5 IMR 4350, Federal M Primer, Lapua case, 140 ELD, Bartlien 5r 24" barrel, to be very accurate (.221) inch. I got lucky early in the process.

 

[CAKustoms]

Thanks for the info guys. The POI had me confused as it didn't show much of a shift. I've loaded up another round starting at 41.5 and went up in .2 increments. I'll see what happens when the snow clears a little.

 

[Darkside-Six]

hard to tell with .5 grain increments. you really need to go in .3 grain increments and should show better results.

 

[flashhole]

If you can shoot at 200 yards it will be better. 300 yards is better still. You're looking for minimum vertical dispersion over incremental charge weights. Also, don't take this the wrong way, but are you sure you have the rifle in the exact same position every time you pull the trigger. Minor variations in gun positioning can ruin the OCW test. I've done lots of OCW tests on my own rifles and friends rifles as well. Everything has to be exactly the same in the firing process to get useable results.

 

[CAKustoms]

Two more tests today, this time at 200yards..... Pretty sure my rifle doesn't like the IMR. With these tests I adjusted the COAL for a .002 jump, all componants were the same as before.

Top row is the IMR4350 and the bottom is the H4350. Looks to me the IMR would run at 41.7gr and the H at 39.1gr, although I'm sure there's a higher node. (Maybe around 41.3?)

Am I correct?

 

[pell1203]

CAKustoms, I noticed you are still trying to test H4350 in 0.5 grain charge weight increments. As stated before, you are not going to be able to discern where the accuracy nodes exist with that wide an increment. You won't get enough detail in your results to see the pattern and will skip over the accuracy nodes altogether with that wide a jump.

You are correct in believing other higher speed nodes exist beyond what you have discovered. You do not state what speeds you are presently getting out of your barrel so I would only increase charge weight if you have not experienced any pressure signs so far. As a reference, my 6.5 CM Ruger RPR (24" factory barrel/Hornady 140 ELD-M bullet) lives in an accuracy node of 41.2 gr. H4350 yielding 2690 fps at a COAL of 2.821" (0.050" jump). There is a faster node at 42.6 gr. H4350 @2770 fps. I typically load the 41.2 gr. node.

BTW, 41.7-41.9 gr. of IMR4350 looks promising.

 

[CAKustoms]

CAKustoms, I noticed you are still trying to test H4350 in 0.5 grain charge weight increments. As stated before, you are not going to be able to discern where the accuracy nodes exist with that wide an increment. You won't get enough detail in your results to see the pattern and will skip over the accuracy nodes altogether with that wide a jump.

You are correct in believing other higher speed nodes exist beyond what you have discovered. You do not state what speeds you are presently getting out of your barrel so I would only increase charge weight if you have not experienced any pressure signs so far. As a reference, my 6.5 CM Ruger RPR (24" factory barrel/Hornady 140 ELD-M bullet) lives in an accuracy node of 41.2 gr. H4350 yielding 2690 fps at a COAL of 2.821" (0.050" jump). There is a faster node at 42.6 gr. H4350 @2770 fps. I typically load the 41.2 gr. node.

BTW, 41.7-41.9 gr. of IMR4350 looks promising.

I think you looked at the first IMR test in the middle. The H4350 is the bottom and I did switch to .3gr increments for both tests this time. ?

 

[pell1203]

CAKustoms. got it! I agree with your evaluation regarding both powders given the test charges you ran. However, I'm wondering if you should perhaps explore the next higher velocity node with H4350 if you aren't seeing or experiencing any pressure signs.

Do you know what MV 39.1 gr. H4350 is giving you? My guess is closer to 2600 fps. It does seems like it will be plenty accurate for you if you are happy with velocity and should extend your barrel life appreciably. I am assuming those are 2" dots... looks good at 200 yards!

 

[CAKustoms]

I dont have any pressure signs with either powder and was also wondering about the next node. I haven't checked velocities yet. A friend has a chrono, so that's my next step. I think I'll chrono the 39.1, see what it does at 600 yards and go from there.