.308 175 SMK

[Marksman_92]

Just wanted to get some opinions. I will be loading up my first handloads for my 308 and I will be using once fired federal brass bump sized .002 with overal length trimmed to 2.005. I will be using Sierra matchking 175 grn as I know they already shoot great out of the gun. My question is how far shoot I start my bullet seating I was thinking .030 off the lands to start or should I just start with the book recommended 2.800 COAL? Thoughts?

 

[308pirate]

The first question you need to answer is whether you intend those cartridges to feed from the magazine or do you plan on loading them into the chamber one at a time.

If you intend to have these round feed from the magazine, what is the longest oal (to the tip) that will fit in your magazine and how much jump does that work out to be?

If you don't care about magazine feeding, start at .01" jump and see what happens.

 

[Deleted member 113831]

Some interesting results here:

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[1J04]

If you're saying FGMM shoots great outta your gun, just go with cloning it. If you're looking to tweak it, have at it. As stated above, the only thing that really matters is if mag feeding is a big deal to you and know your CBTO to keep from jamming your Ogive into your Lands, well, you're good to go.



Self appointed mall cops of reloading stand down! This will be a STARTING LOAD using the powder mentioned. (so lighten up Francis)... Here we present extremely strong evidence that Federal's current (fall of 2013) Gold Medal Match long range load recipe is 41.7 to 41.8 grains of IMR 4064 with the 175 grain Sierra Matchking in Federal brass. This is the Mk 316 Mod 0 military long range load recipe as well, which Federal is assembling to replace the M118LR load. The M118LR load used (uses) Reloder 15 powder, and is less stable across temperature spreads than desired. The Mark 316 load addresses the accuracy and temperature stability issue using IMR 4064 as the propellant, at a specified 41.75 grains. COL is 2.800", conducive to fitting and feeding well from standard Remington 700 magazines.

 

[GIXXER2000]

Here is my Federal brass 175 SMK load used in an AI-AE 26 in barrel. I found for my AI chamber .020 of the land worked best with most 308 bullets I tried.

Brass Fed GMM .001 bump on the resize
Primer CCI BR2
Powder Varget 42.8 Very Temp stable powder
Bullet 175 SMK
COAL 2.840 This .020 off the lands
AVG FPS 2671
SD 8.4

 

[straightshooter1]

Here is my Federal brass 175 SMK load used in an AI-AE 26 in barrel. I found for my AI chamber .020 of the land worked best with most 308 bullets I tried.

Brass Fed GMM .001 bump on the resize
Primer CCI BR2
Powder Varget 42.8 Very Temp stable powder
Bullet 175 SMK
COAL 2.840 This .020 off the lands
AVG FPS 2671
SD 8.4

This is very close to what I've done, so here's mine:

Brass: Fed GMM .002 bump on the resize
Neck Tension: .002
Primer: Fed 210M
Powder: Varget 43.6
Bullet : 175 SMK
COAL: 2.850 ( = .020 off the lands)
AVG FPS: 2674 fps (from 24" SS barrel, using MagnetoSpeed v3)
SD: 9.1

Addendum (my measurements from factory's cartridges) :

Brass: Fed GMM
Neck Tension: .004
Primer: Fed 210M
Powder: 40.0 gr (their particular blend, whatever it is)
Bullet : 175 SMK
COAL: 2.800 ( = .055 off the lands)
AVG FPS: 2620 fps (from same 24" SS barrel, using MagnetoSpeed v3)
SD: 4.8 - 16.9 (on 10 shot groups)

 

[Marksman_92]

Thanks for the replys, I will be loading these from the magazine. Just wanted to see what everyone was getting. Mostly like to duplicate the FGMM load with hopefully lowering SD and ES. Im not looking to make these scream but want them to be at least as fast as GMM if not a tad faster.

Gun is a Blueprinted Rem 700 with 24'' Bartlein barrel.

I am using a Lee FL sizing die with the expander removed. Setting neck tension with LE wilson expander mandrel.

Curious how many firings are you getting from the Federal cases and what are your cleaning and annealing processes? I dont have an annealer at this time and not really interested setting down with a drill and blow torch.

 

[supercorndogs]

Yes, I would just start with book 2.8 if that puts you .030 off. What ever reamer LRI used on my 308 puts me right in that neighborhood also. I think I ended up .020 off at 2.81. I only ran across .01 in my length test because I didn't want to get closer than .020, and didn't want to push the bullet into the case past 2.8. 2.8 fits in an AI mag easily.

 

[stello1001]

I would either start at 2.8 or mag length. Chances are, you'll likely still have to tweak some more after that. Flip a coin to see which of those two will be your starting depth.

 

[straightshooter1]

Thanks for the replys, I will be loading these from the magazine. Just wanted to see what everyone was getting. Mostly like to duplicate the FGMM load with hopefully lowering SD and ES. Im not looking to make these scream but want them to be at least as fast as GMM if not a tad faster.

Gun is a Blueprinted Rem 700 with 24'' Bartlein barrel.

For making them "scream" I got good results using 42.0 gr of H4895 (~ 2750 fps with really low single digit ES's and SD's).

Using 42.5 gr of 4064 produced average of 2676 fps with low SD's

Using 39.6 gr of AR Comp produces averages around 2585 fps with SD's in the mid single digits.

So . . . pic your poison.

I am using a Lee FL sizing die with the expander removed. Setting neck tension with LE wilson expander mandrel.

Curious how many firings are you getting from the Federal cases and what are your cleaning and annealing processes? I dont have an annealer at this time and not really interested setting down with a drill and blow torch.

If you use mild loads, the Federal cases should last quite a while (I've heard people getting 20-30 . . . yes, with Federal cases). I used the Federal cases for moderate loads for the most part and have gotten 11 firings from the one batch that I've used, then they started to show case head separation signs, so I finally dumped them.

I anneal all my cases after each firing then dry tumble them. But then after 7 firings I'll wet tumble with SS pins to get them really cleaned up and dry tumble again after that. My annealing process is what has really helped me get consistently low SD's, which goes along with consistent neck tension. I use an Annealeez for my annealing as it fit nicely into my budget.

 

[918v]

How are you getting 2600 FPS with only 40.4grs of 4064?

 

[straightshooter1]

How are you getting 2600 FPS with only 40.4grs of 4064?

Good question! And good catch.

It's NOT from a 175 SMK. My error , as that was from 168 SMK's.

Correcting that.

 

[918v]

Even with 168SMK it doesn’t make sense. What is your rifle barrel length, coal, jump, and chrono?

 

[straightshooter1]

Even with 168SMK it doesn’t make sense. What is your rifle barrel length, coal, jump, and chrono?

Barrel: 24" SS Krieger
COAL: 2.807
Jump: .030
Chrono: MagnetoSpeed v3

Throwing my number's into my QuickLoad app it shows an MV of about 2592 fps.

 

[918v]

I need 42.8 to get 2680 in a 26” barrel. When I plug your numbers into QL I get 2492 FPS.

 

[Kevins750]

42gr of imr4064 in lapua brass, fgmm primer 2.830 gets me 2654 avg out of a 26" 5r savage.

 

[straightshooter1]

I need 42.8 to get 2680 in a 26” barrel. When I plug your numbers into QL I get 2492 FPS.

Using QL's default burn rate, I pretty much get that 2680 fps for 42.8 gr of 4064 out of a 26" barrel. But I've had to tweek the Burn Rate as well as the Weighting Factor for QL to give me consistent numbers that match the MV's I gotten on several different occasions with my chrono. And to my surprise, I've even had QL virtually match other people's chronoed MV's using the adjustment settings I've made, which has given me a little more than my own anecdotal evidence that my setting are given me results I feel I can depend on for my barrel.

Confusing to me though is how I can plug in 42.8 in and QL will be at your 2680 with 26" barrel (my QL saying: 2675 which is pretty close), but when I plug in 40.4, QL shows 2537, which I'd say is substantially more that 2492 you're getting. In fact, when I look at my records, my old 20" factory barrel chronoed 2485 - 2510 fps with 40.4 gr of 4064 (COAL= 2.850 and neck sized only FC brass). So . . .????

 

[918v]

Here is my QL. And with the default settings it matches my 24” and 26” actual velocities. I have used multiple lots of 4064 and have never seen the kind of speed you’re getting. Further, I have never read about the kind of speed you’re getting in my 20+ years on the internet.

 

[straightshooter1]

Here is my QL. And with the default settings it matches my 24” and 26” actual velocities. I have used multiple lots of 4064 and have never seen the kind of speed you’re getting. Further, I have never read about the kind of speed you’re getting in my 20+ years on the internet.

Attached is a pic from my QL. Note: I've got the newest version and apparently there's some differences (see Bullet Length). You may want to update yours???

 

[918v]

I used 1.200 for the bullet length because that’s what they are. They aren’t 1.215” and the additional .015” of bullet length isn’t going to affect the velocity that much anyway.

 

[straightshooter1]

I used 1.200 for the bullet length because that’s what they are. They aren’t 1.215”

OK. Well, the one's I have measure 1.209 - 1.217. Go figure.

and the additional .015” of bullet length isn’t going to affect the velocity that much anyway.

True. But that wasn't the point.

 

[whatsupdoc]

Brass: Lapua Large Primer
Primer: Fed 210M
Powder: IMR 4064 42.5 grains
Bullet : 175 SMK
COAL: 2.847 .020 off the lands
AVG FPS: 2561 fps 20" Barrel
SD: 7.2

 

[mgrs]

You really can't go wrong loading to the 175 over 41.8 - 42.0 gr of 4064 at factory length (~2.800") and working from there. If it were my first time reloading, I would start with that to build confidence and then start tinkering with jump and charge weight. That load isn't a screamer by any means but shoots so well across a wide range of rifles that it is good to have in the data book. Also plays OK with gas guns, which is nice.

I find that Federal brass primer pockets get too loose before anything else about it fails. Using a tighter fitting primer like CCI stretches it out a bit longer. With WIN WLR primers, I can only get 3-4 firings before the primer seating feels effortless.

Attached is a pic from my QL. Note: I've got the newest version and apparently there's some differences (see Bullet Length). You may want to update yours???

Cool, I really need to get QL.

 

[pmclaine]

Dont use Winchester primers in Fed brass unless you like blown primers...........