| Posted: Sun Aug 30th, 2009 03:45 AM |
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21st Post |
Mastiff54
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| Joined: | Fri Aug 28th, 2009 |
| Location: | Northwood, Ohio USA |
| Posts: | 2 |
| Photo: | | | Are you a handloader?: | Yes | | Favorite type of cartridge to load?: | I load everything! | | My favorite chambering is:: | 17 Mach IV, 223 Rem, 308, win, 460 Rowland, 45acp, ... |
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Hello Gunnut,
Glad to see your post, for all of the AR based 308 auto's that have been selling, either no one is reloading for them or they are not willing to share. Your results are unbelievable and I am very envious. That is much better shooting than I could ever do. But I will enjoy every pull trying !!!
My brother and I built a pair of LR-308's with JP Super match Barrels (22in 11.25 twist). We are now through the break in process and are trying to develop loads that will shoot better than factory. Our current recipes are:
Hornady New Dimension Dies
Lee Factory Crimp
- Bullet: 155 Hornady SST
- Powder: 44.0 Varget
- Brass: Winchester, primer pocket uniformed, flash hole deburred, case trimmed to 2.005
- Primer: Fed GM210M
- COAL: 2.735
If we tried to go anywhere near the lands the cartridges would not fit the magazines.
- Bullet: 165 Hornady SST
- Powder: 44.0 Varget
- Brass: Winchester, primer pocket uniformed, flash hole deburred, case trimmed to 2.005
- Primer: Fem GM210M
- COAL: 2.745
A couple of questions and comment on the neck turning and thickness:
- What tool do you use to check your brass?
- What tool do you use to turn your brass
- What variation do you get and what is your bogey?
I spent 35 years in quality for precision products. Our first venture into precision reloading was for a matching pair of 17 Mach IV's. We fought neck thickness for years turning, reaming, 2 stage turning etc. The assembled neck dia rarely equaled the bullet dia + 2x the neck wall.
We were using a Sinclair neck thickness gauge and I felt the brass was not uniform enough for a reliable reading using such small point of contact as the ball on the Sinclair tool. Having spent 35 years in quality and mechanical inspection I brought some work home and performed a GR&R study which proved that I had more error in the measurement than the tolerance I was checking for. I built a neck thickness gauge using my RCBS flash Hole Pilot stop as a mandrel. That was better, then I saw the Redding Case Neck Gauge with the flash hole locating mandrel. It was nearly sexual, but at over $100 way out of my price range (I am one of the casualties of the automotive industry collapse). I bought a Lee trim mandrel and used a dial indicator I already had for a total cost of $7. Once I built this fixture I found that neck thickness I measured finally correlated to the neck OD after loading, so I knew I was now reading the functional neck thickness and our accuracy significantly improved and we scrapped much fewer cases.
Moving ahead to the 308, we found the current lot of Winchester brass was .001 within each case and .001 between cases. To keep maximum case neck thickness we decided not to turn the first group, but did turn a second group for comparison. Using a Forster case neck turning lathe I found we really did not make the brass that much more uniform, just thinner. I'll know the results once we hit the range.
On our 223 DPMS AR15's with a 20" bull barrel we went through the same routine and ended up using Lapua brass to get uniformity. Against all rules we 3/4 neck size the 223's and have had no problems. Our intention is to do the same with the 308's.
Unfortunately we do not have a 300 yd range available and are anxiously awaiting some calm weather to shoot these for groups.
Thanks for your post and sharing, we'll add what we learn as soon as we can.
____________________
I have had the privilege of traveling the world and meeting those who envy us. Our freedom is precious, but is not free. Thank every veteran you see and pray for the families of those who gave all.
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| Posted: Mon Sep 14th, 2009 11:06 PM |
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22nd Post |
Jason308
member
| Joined: | Mon Sep 14th, 2009 |
| Location: | |
| Posts: | 4 |
| Photo: | | | Are you a handloader?: | Yes | | Favorite type of cartridge to load?: | I load everything! | | My favorite chambering is:: | .308 Winchester and .300 Winchester Magnum |
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For me...
Rifle: Fabrique Nationale Patrol Bolt Rifle, 24" barrel
Load:
Bullet: 168gr A-Max
Powder: 42gr Hodgdon Benchmark
Casing: New Remington brass
Primer: CCI 400 LR
Data:
Velocity: 2685 (avg, chronographed)
Grouping Results:
All-time Best: .208" @ 100 yards, 3-shots
Average: .300"~.500" @ 100 yards, 3-shots
Seating depth is .310" and that is .010" off the lands for me. Just where she likes the A-Max's.
-Jason
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