looking for a sanity check. So here is all the pertinent data:
Gun: Larue OBR 18"
Bullet: 175 SMK
Case: Once fired military brass pulled off my range
Powder: RE-15
Primer: CCI#34
Chronograph: Competition Electronics ProChrono Digital
Wx: 80 deg, wind 10kts at about 1 o'clock. Scattered clouds
<span style="text-decoration: underline">Reloading steps:</span>
1) retrieved brass off the range.
2) Cleaned for 2 hours in walnut.
3) Using a Hornady head space gauge I was able to determine the average fired cases showed the shoulders were at 1.628, so my goal was to bump the shoulders back to 1.625. On most cases I was able to achieve this, but I was getting inconsistant results, with about (guessing) 30% showing closer to 1.621. This was done on a Dillon 650 with just the resizing die in the toolhead.
4) Swage the brass on dillon super swager
5) Re-clean brass
6) Trim brass on Girard trimmer
7) Insert a different toolhead containing the bullet seating die and crimp die (all dies are dillon dies. I also have a set of RCBS small base dies but opted to use the dillon dies instead for this)
8) Hand weighed the charges for a ladder test starting at 35.8g all the way up to 44.0g. The scale was the dillon electronic scale that I leave in the shop where I am reloading, but during this evolution I was having a heck of a time getting it to stay calibrated.
9) Seated primer, seated the bullet to an OAL of 2.80 and put a light crimp on the bullet
10) Headed out to the range for a ladder test. Performed the test at 200yds. First accuracy node was in the 41.3-42.8g (41.3,41.8,42.3,42.8) area giving me a measured spread of .826". Second was in the 43.1-44.0g (43.1,43.4,43.7,44.0)range measuring 1.064". The cases did not show any signs on overpressure, but on 43.7 and 44.0 range the bolt would not lock back and the magazine follower was pushed nose down into the magazine.
11) I had not heard of the bolt not locking back problem so I posted that question on here last week and the response was yes, that is overpressure. I also was advised to not load the military brass past 42.0g using RE-15
12) I worked up 5 cases each starting at 41.4, going up in .2g increments up to 42.2g and went out with a chronograph to check accuracy and velocity.
13) I went out to the range this morning to check and the numbers just seemed low to me and also sporadic. I did not take alot of time between shots, maybe 10 sec and maybe a minute to get set up for each new group.
<span style="text-decoration: underline">41.4g </span> (velocites listed in order shot)
2464, 2433, 2455, 2446, 2419. Average 2443
<span style="text-decoration: underline">41.6g</span>
2455,2446,2450,2469,2446. Avg 2453
<span style="text-decoration: underline">41.8</span>
2469,2501,2469,2469,2469. Avg 2480
<span style="text-decoration: underline">42.0</span>
2464,2469,2464,2487,2482. Avg 2473
<span style="text-decoration: underline">42.2</span> I only loaded 3 of these
2520,2492,2496. Avg 2502
I then shot some factory FGMM in the 7.62 w/ 175SMKs:
2567,2564,2569,2574. Avg 2569
My goal was to get up to 2600ish, but I dont think that will happen with the numbers I am seeing. What is the greatest limiting factor...an AR-10 platform, the 7.62 cases vs 308, the powder. Are these numbers that I am seeing consistent with what I should be seeing? The Sierra data book shows a max powder charge of 41.3 should give in the ballpark of 2500 fps, I only saw that number when I went a full grain over the max. I know the test gun probably has alot to do with it, a Savage in 26" barrel. Im starting to think its just not going to happen. Any help would be appreciative.
Gun: Larue OBR 18"
Bullet: 175 SMK
Case: Once fired military brass pulled off my range
Powder: RE-15
Primer: CCI#34
Chronograph: Competition Electronics ProChrono Digital
Wx: 80 deg, wind 10kts at about 1 o'clock. Scattered clouds
<span style="text-decoration: underline">Reloading steps:</span>
1) retrieved brass off the range.
2) Cleaned for 2 hours in walnut.
3) Using a Hornady head space gauge I was able to determine the average fired cases showed the shoulders were at 1.628, so my goal was to bump the shoulders back to 1.625. On most cases I was able to achieve this, but I was getting inconsistant results, with about (guessing) 30% showing closer to 1.621. This was done on a Dillon 650 with just the resizing die in the toolhead.
4) Swage the brass on dillon super swager
5) Re-clean brass
6) Trim brass on Girard trimmer
7) Insert a different toolhead containing the bullet seating die and crimp die (all dies are dillon dies. I also have a set of RCBS small base dies but opted to use the dillon dies instead for this)
8) Hand weighed the charges for a ladder test starting at 35.8g all the way up to 44.0g. The scale was the dillon electronic scale that I leave in the shop where I am reloading, but during this evolution I was having a heck of a time getting it to stay calibrated.
9) Seated primer, seated the bullet to an OAL of 2.80 and put a light crimp on the bullet
10) Headed out to the range for a ladder test. Performed the test at 200yds. First accuracy node was in the 41.3-42.8g (41.3,41.8,42.3,42.8) area giving me a measured spread of .826". Second was in the 43.1-44.0g (43.1,43.4,43.7,44.0)range measuring 1.064". The cases did not show any signs on overpressure, but on 43.7 and 44.0 range the bolt would not lock back and the magazine follower was pushed nose down into the magazine.
11) I had not heard of the bolt not locking back problem so I posted that question on here last week and the response was yes, that is overpressure. I also was advised to not load the military brass past 42.0g using RE-15
12) I worked up 5 cases each starting at 41.4, going up in .2g increments up to 42.2g and went out with a chronograph to check accuracy and velocity.
13) I went out to the range this morning to check and the numbers just seemed low to me and also sporadic. I did not take alot of time between shots, maybe 10 sec and maybe a minute to get set up for each new group.
<span style="text-decoration: underline">41.4g </span> (velocites listed in order shot)
2464, 2433, 2455, 2446, 2419. Average 2443
<span style="text-decoration: underline">41.6g</span>
2455,2446,2450,2469,2446. Avg 2453
<span style="text-decoration: underline">41.8</span>
2469,2501,2469,2469,2469. Avg 2480
<span style="text-decoration: underline">42.0</span>
2464,2469,2464,2487,2482. Avg 2473
<span style="text-decoration: underline">42.2</span> I only loaded 3 of these
2520,2492,2496. Avg 2502
I then shot some factory FGMM in the 7.62 w/ 175SMKs:
2567,2564,2569,2574. Avg 2569
My goal was to get up to 2600ish, but I dont think that will happen with the numbers I am seeing. What is the greatest limiting factor...an AR-10 platform, the 7.62 cases vs 308, the powder. Are these numbers that I am seeing consistent with what I should be seeing? The Sierra data book shows a max powder charge of 41.3 should give in the ballpark of 2500 fps, I only saw that number when I went a full grain over the max. I know the test gun probably has alot to do with it, a Savage in 26" barrel. Im starting to think its just not going to happen. Any help would be appreciative.
