Need some help with throat depth & bullet choice

[gt40dave]

Ok, new guy with a question - go figure. (honest I've searched and I'm still confused).

Going to try the F/tr world of competition this coming year. Easing in gently (read low $$) so I've started with a Savage Mod. 12 F/tr rifle, 30 inch barrel, 1 / 12 twist - purchased in Nov. this year. I've read about varying chambers in this rifle (95 Palma or Obermeier (sp?). or ??) and can't find a definite answer on what is in this gun. I would like to run the Berger 185 Jug round to help with wind if I can. I've measured the chamber with a Stony Point / Hornady gage and come up with the following data: (measurements with gage were from "seating" bullet into the lands fairly firmly, but just below where the bullet would stick and have to be "pushed" out from the front - so if this is wrong, please educate me).

Oal base to Ogive
2.857 3.2
2.889 3.234
2.886 3.229
2.887 3.23
2.889 3.232
2.8885 3.231
2.8865 3.23
2.885 3.229
2.8835 3.226
2.889 3.231
2.888 3.23
2.888 3.231
2.888 3.2305
2.8885 3.2305
2.8865 3.23
2.8865 3.229
2.886 3.23
2.8865 3.229
2.886 3.23
2.886 3.229


Std Dev 0.006871901 0.0015714
Avg 2.887026316 3.230052632
Median 2.8865 3.23

Now for the question. Using the 2.8865 median or 2.887 average measurements along with the 3.23 for base to Ogive, this puts the boat tail almost into the case are (below shoulder). If I now set the bullet back 10 to 15 thou. the boat tail will be definitely encroaching on the case volume. From what I've read, that would hinder volume & ability to reach 2650 fps for this load without going over pressure???

Should I try the 185 and work up to see if I can make a load safely or just try to find a gunsmith here in No. Calif. to lengthen the chamber for me? Or, just go to the 155 gr. to learn on?

sorry for the lengthy post / question

thanks for reading

Dave H.

 

[gt40dave]

Opps, forgot to mention that the first measurement was tossed for the calc's as it was a measurement error on my part - gage slipped after removing from chamber and I did not notice until making more measurements.

 

[Dusty Stevens]

Seat a bullet where you want it guving yourself plenty of room to go back n forth and send it to a good gunsmith to lengthen the throat to your specs. That would be cheaper than buying a barrel or getting discouraged with a handicapping bullet. Or take off with the palma bullets and let it teach you the wind real good while you save for that custom barrel youll have to have after a while

 

[JohnKielly]

Seat a bullet where you want it giving yourself plenty of room to go back n forth and send it to a good gunsmith to lengthen the throat to your specs.

Dusty,

... only if the gunsmith had a throating reamer of the same diameter as or larger than the throat that Savage cut.

John

 

[gt40dave]

Ok everyone - I've finally been able to do some load work-up with the 185's but wound up having more questions than answers / results.

Testing conducted with Laupa Palma brass, BR4 primers, Varget powder & Berger 185 Juggs, seated 0.020 off of the lands.

Since I don't have the Berger load manual for Max load I read this forum and AccurateShooter and (still confused) started with 41.1 gr of Varget.

41.1 = 2480's fps
41.5 = 2560's fps
41.8 = 2580 fps +/-
42.1 = ~2598 fps
42.4 = ~2600 fps
42.7 = 2644 fps
43.0 = 2662 fps
43.3 = 2672 fps (only 1 round fired)
43.6 = 2675 fps (only 1 round fired)

I did not load up enough of the 43.3 & 43.6 to do the ocw test with these charges.

Ladder test showed

42.1 - 42.4 showed similar group position on the ladder test (2 shots each powder charge) but too slow to be competitive at 1000 yds.

42.7 & 43.0 have acceptable velocity (per berger ballistics calculator)but are not close enough together to believe they are in a node.

I think that 43.0, 43.3 & 43.6 may be starting a higher node, but not sure how high up I can safely go with powder charge (none of these loads showed any pressure signs during testing in 60 deg. ambient temps.

Could someone look in a Berger reloading manual and tell me what the max recommended load is for Varget & 185's ?

I can't seem to figure out how to insert a photo of the OCW targets for 42.1 thru 43.3 charge loads.

any help appreciated.

Dave H.

 

[gt40dave]

ok, think I figured out photo posting!

This test was done @ 200 yards (100 yard range not available today)

 

[Highpower-FClass]

... or just try to find a gunsmith here in No. Calif. to lengthen the chamber for me?

This would be my recommendation. I had a Savage action barrel with a short throat (a Shilen barrel), it shot the 155 noslers well but too short for the Berger 185s. I had it throated out for the 185s by Omar Alonzo (awesome gunsmith in Houston area) and it made a phenomenal difference. Once you are shooting the 185 juggernauts with an appropriate freebore you will never look back. From there the next step is the 200 hybrids and the 215s. The 185s juggernauts are great projectiles, very forgiving.

 

[Scott Harris]

This would be my recommendation. I had a Savage action barrel with a short throat (a Shilen barrel), it shot the 155 noslers well but too short for the Berger 185s. I had it throated out for the 185s by Omar Alonzo (awesome gunsmith in Houston area) and it made a phenomenal difference. Once you are shooting the 185 juggernauts with an appropriate freebore you will never look back. From there the next step is the 200 hybrids and the 215s. The 185s juggernauts are great projectiles, very forgiving.

^^^what he said, get it throated and you should have no problem getting 2750+ fps with great accuracy with the Juggs.

 

[Zero333]

As long as the boat-tail / bearing surface junction is NOT BELOW the case shoulder / neck junction, you're good to go.