Loaded my first batch ever. Would like a sanity check.

[little_scrapper]

First time loader. Asking the experienced loaders to check my numbers and let me know if there is anything amiss. Loading for my LaRue 308, 18", 1:10. Loaded up 15 rounds. LC M118 LR Brass, CCI 200, H4895 and 168 gr SMK.

Measured a bunch of fired LC M118LR that I shot a few months ago and headspace measured 1.626. The total range was 1.6255 to 1.6275.

Redding 3-die set. FL resized bumping shoulder back .003. Most all ended up right at 1.623" but a couple were under and a couple were over by .0005". Brass OAL measured between 2.001 and 2.005" with 90% either 2.002 or 2.003 so I didn't trim. I did put a very slight neck chamfer.

Hornady OAL gage says Shortest was 2.870 and longest was 2.8725 over 6-7 measurements. Calling it 2.871. However this is easily 20 thou longer than mag will hold. I decided to shoot for 2.850". Two dummy rounds that ended up 2.848 and 2.850. However, head to Ogive was 2.259" on both rounds. I also loaded the dummy rounds in the mag and verified that both would cycle through my rifle.

Powdering It: Hodgdon H4895 and 168 gr SMK's
Hodgdon web site, selected 308 service rifle, says starting load is 41gr of H4895 and 42.3 gr is max load.
Starting 1.0 grain lower than the listed starting load, I loaded 3 rounds at each of the following weights 40.0 gr, 40.5, 41.0, 41.5 and 42.0.

Weighting powder: ChargeMaster lite set to 0.2 gr low and used a pick to push one or two kernels at a time into the pan until it rolled over to the listed weights. The powder filled the cases up to the shoulder area but not quite up to the neck so definitely not compressed. I have about .200" of bearing surface in the neck.

Questions? Any issues with any of my numbers and Should I load a few more at an even lower powder weight to start. Say 39.0 and 39.5grains?

Thank you,

L_S

 

[ShtrRdy]

This sounds good to me. The only thing I would do different is space the charge weights by 0.3 grain to do a OCW sort of test.

The 168 SMK is considered to not be picky about seating depth so you should be okay.

Have you tried any Federal Gold Metal Match with the 168 SMK and wit 175 SMK?

 

[Doom]

As noted your charge increment should be reduced. Since you are loading for a semiautomatic I would load to 2.8” COAL. Also I would recommend CCI #34 primers or other magnum primers for reduced risk of a slam fire.

 

[little_scrapper]

Thank you for the feedback Doom,

I have one (you) start lower and one you could start lower just to be sure but 40.0 is fine. Most loads I was looking at people using are 42-43gr I may roll out a few more lower.

CCI 200 listed as safe for semi auto. Also I do not have a free float firing pin. The LaRue has a spring supported firing pin. Slams "should" be a non issue. However, I look into other primers.

The M118LR which is what I normally shoot is already loaded to 2.820". I just went 30 thou longer which puts me over 20 thou off the lands.

 

[little_scrapper]

This sounds good to me. The only thing I would do different is space the charge weights by 0.3 grain to do a OCW sort of test.

The 168 SMK is considered to not be picky about seating depth so you should be okay.

Have you tried any Federal Gold Metal Match with the 168 SMK and wit 175 SMK?

thanks shtr, If one load groups particularly better than the others I intend to do a 0.1 gr ladder to try to fine tune. And yes I have shot both of those loads. I have in fact shot about 10 different ammos from 125 gr Nozzlers to 175gr SMK FGMM and M118LR. Had failure to feed issues with the 125 grain (too light?) but got about the best group (lower recoil?). Being a new shooter and suxing immensely about the best I could do with ANY of the factory loads was about 2-2.5 MOA if I disregard the egregious fliers.

My understanding is most any half arsed rifle can shoot sub MOA; you just need to find the node. Seeing as most all ammo was 2.5 MOA either I just sux and the rifle will probably shoot most ammo well or I just need to find a node and tighten my skills. I can shoot .75 MOA all day with my AR15 if I have the right ammo and do my part. But the AR15 is a heavy for caliber setup and is a real marshmellow compared to the LaRue 308.

 

[Defender3]

This sounds good to me. The only thing I would do different is space the charge weights by 0.3 grain to do a OCW sort of test.

The 168 SMK is considered to not be picky about seating depth so you should be okay.

Have you tried any Federal Gold Metal Match with the 168 SMK and wit 175 SMK?

I was wrong - see mea culpa below.

 

[little_scrapper]

I have a 20" LaRue tOBR and tried shooting factory FGMM in both weights, it popped primers. A call to Federal and they confirmed their loads were not intended for gas guns, which also included some of their lighter bullet hunting rounds. Provided FWIW.

Wait a minute! How does gas gun vs bolt gun have any bearing on a blown primer. I still have contacts within Federal Ima have to ask about FGMM not being intended for AR platforms. You sure you don't work for Winchester or Hornady???

 

[Defender3]

Wait a minute! How does gas gun vs bolt gun have any bearing on a blown primer. I still have contacts within Federal Ima have to ask about FGMM not being intended for AR platforms. You sure you don't work for Winchester or Hornady???

I have to apologize, I was WRONG. It was my LaRue .260 gas gun that blew the primers and when I contacted Federal they stated their .260 loads were not gas gun appropriate. Very sorry for putting out the wrong info.

 

[Doom]

Saw yor correction after the post below. Thanks for posting the correction!

I tend to agree wuth little_scrapper. 308FGMM 168 and 175 SMK has been loaded with IMR 4064 in federal brass and 210M primers. The loads are nowhere near max. I see many AR10 platform guns and M1A’s fire it without difficulty. If its blowing primers then I would be looking at either an overgassing issue or a chamber/headspace issue with the rifle.

The OP is selecting a load and powder suitable for an M1A. He has lowered his weight account for his brass being different than the Winchester used in the Hodgdon load.

 

[FCS]

Wait a minute! How does gas gun vs bolt gun have any bearing on a blown primer. I still have contacts within Federal Ima have to ask about FGMM not being intended for AR platforms. You sure you don't work for Winchester or Hornady???

Bolt guns do not extract under pressure, gas guns do. Has EVERYTHING to do with blowing out a primer pocket. Port pressure and gas volume more so than peak pressure. Buffer weight, buffer spring K constant, port location....whole lotta variables coming into play when loading for a gas gun that do not come into play with a bolt gun.

Gas gun you really are going to want to keep loads at 2.820" OAL or shorter, there is zero advantage to running a longer OAL. ZERO. Creates a more issues than it solves. 168 SMK takes jump just fine.

Load data you used was derived from a 22", M1A with a longer gas system then is on the LaRue 18". All about time / pressure history curve, pressure at time case is extracted is the issue.
Win brass is about 1-1.5 gr more powder than Lapua, M118LR is usually about 1 gr less than Lapua so you'll need roughly 2.5 gr less powder in M118LR brass than Win brass.
2.800" OAL, best guesstimate is you'll max out at 40.0 - 40.5 gr of H4895 for pressure with a 168 SMK. Highest probability is between 39.5 and 40 gr for accuracy.

UUK 308 with fixed gas block or a PredatOBR / OBR with PST gas block? Buffer weight? Suppressed or unsuppressed? You didn't state but it makes a HUGE difference so it is an variable that needs to be defined, verified.

 

[little_scrapper]

Thanks gunny, makes sense and I appreciate the input.

I ran some 3x groups from 39.0 gr up to 42.0 grains. At 42 was starting to see some cratering but very minor and was told most likely just due to firing pin hole size. *shrug* Otherwise at 42.0 gr the primers were still nice and rounded off at the edge.

Thread with pics here: https://www.snipershide.com/shooting/threads/range-trip-results-from-first-time-loads.6956087/
As stated in that thread I think my biggest limitation is my own abililties. I am not consistent enough. Still working on lots of fundamentals.

I ordered the UUT with a PredatAR barrel with the mozillo brake. Shooting unsuppressed for now. Still waiting for the suppressor. I will be running a finer ladder in the near future

 

[FCS]

Based off pictures in thread you linked in post above, I’d be testing in that 39.5-40 gr range.
I’d also shoot groups @ 200 when testing.

How heavy is buffer?

 

[little_scrapper]

H2 buffer. RAT stock.

 

[RegionRat]

In case it helps... further down this page you will see .308 service rifle loads. It shows the general lay of the land with respect to M1A and Garand recipes that are pet loads.

NJ Highpower Reloading Page