46.0 Grains of Varget with 27 inch Barrel and SMK 175 Grain BTHP's
- Thread starter Dave Brown
- Start date
I soft seat the bullets so the ogive to base reading is about .005 longer than the ogive to lands reading.
I am not ignoring anyone. I just asked a question.
BoydAllen
Gold $$ Contributor
Putting aside the fact that we cannot feel posters' bolt lifts, and that no pictures of fired primers have been furnished, let me address one issue that has been discussed, and make a couple of suggestions.
Generally, the only thing that I have seen cause case head separations has been bumping shoulders back too far several times .
Another issue, that has not been discussed, is that of ejector marks on case heads. His action has a spring plunger type of ejector, and he has not posted that he is getting ejector marks.
What I suggest is that he go to the range with a goodly number of pre-measured charges and, starting with a new case, and only bumping .001 after it reaches its maximum shoulder to head dimension, that he repeatedly load and fire the same case, noting pressure signs, and the feel when seating primers.
As has been mentioned loads that do not loosen primers in the Palma brass may when fired in large primer cases of the same make. The inference that I would make from this is that those of us who shoot warm loads in small primer Lapua cases have greater latitude before pockets loosen, and that for the large primer cases, primer loosening will take place at a lower pressure, which makes pockets loosening a pretty safe pressure indicator as long as no big jumps of charge weight are made while testing.
Finally, useful information about pressure in rimless cases may be obtained by using a blade micrometer to monitor head diameter increases, measured at the bottom of the extractor groove. There are some guidelines out there, but you should probably do some careful testing, considering all signs, rather than blindly following. In the past, I have done something similar when doing a load workup with a belted case, starting low, and measuring as I went, with a regular 1" mic. I put a line across the case head with a permanent marker so that my measurements would all be positioned the same on the case.
Generally, the only thing that I have seen cause case head separations has been bumping shoulders back too far several times .
Another issue, that has not been discussed, is that of ejector marks on case heads. His action has a spring plunger type of ejector, and he has not posted that he is getting ejector marks.
What I suggest is that he go to the range with a goodly number of pre-measured charges and, starting with a new case, and only bumping .001 after it reaches its maximum shoulder to head dimension, that he repeatedly load and fire the same case, noting pressure signs, and the feel when seating primers.
As has been mentioned loads that do not loosen primers in the Palma brass may when fired in large primer cases of the same make. The inference that I would make from this is that those of us who shoot warm loads in small primer Lapua cases have greater latitude before pockets loosen, and that for the large primer cases, primer loosening will take place at a lower pressure, which makes pockets loosening a pretty safe pressure indicator as long as no big jumps of charge weight are made while testing.
Finally, useful information about pressure in rimless cases may be obtained by using a blade micrometer to monitor head diameter increases, measured at the bottom of the extractor groove. There are some guidelines out there, but you should probably do some careful testing, considering all signs, rather than blindly following. In the past, I have done something similar when doing a load workup with a belted case, starting low, and measuring as I went, with a regular 1" mic. I put a line across the case head with a permanent marker so that my measurements would all be positioned the same on the case.
Doesn't appear to be any ejector marks on the case heads
Attachments
This is a very common node for a lot of 308's. This will serve you much better!!
Also with RL-15.
Good Job Dave, enjoy.
I'm shooting SMK 175 grain bthp's
While it may be reasonable to consider multiple sources, I don't recommend taking the source with the highest powder charge and then using it for a heavier bullet.
The Sierra Manual lists a max load of 43.5 grains of Varget for the 168 SMK.
The Sierra Manual lists a max load of 41.7 grains of Varget for the 175 SMK.
My point exactly. At 46.0 grains the OP was already exceeding the published max by the manufacturer. Hodgdon's published max for a 175 grain bullet (Not SMK) is 45.0 grains.'
+1 for 43.0 grains of Varget. You don't need to kill your brass to find an accuracy node. I'm currently running 43.3 in Lapua brass, CCI 250, and the excellent Berger 175 grain OTM in a 24 inch Bartlein at 2620fps. Accuracy is stellar.
Danny
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.