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Allrighty, I just got back from the range, and got my targets scanned in. Needless to say I was happy with the results, mostly because it's been quite a while for me, and getting back on the horse and shooting decently for me is acceptable. It was about 90 degrees and 70% humidity at 1000hrs when I got to the range. There was a 3-5mph breeze from 10 to 12 o'clock that was varying which contributed to opening up the groups a bit I believe. There were 20rnds in all, 2 variation of powder, and 2 of OAL's. I decided to try to duplicate Federal GMM as this discussion was originally about that. The groups are as follows;



This was my first group of all, as I said, it's been a while and my trigger control wasn't at it's best on this, and the wind was at 12 o'clock between 3 and 5mph. I shot 2 fouler shots into the berm before firing these groups just so that it wouldn't factor in.



I'm not sure how I got the 2 "flyers" at the same place, however if they are pulled shots than I pulled them both the same way. Still not too bad in my opinion, for this weapon.





The last one (Scan4) was the best group. By then I had settled into a grover of proper trigger control and breathing. I was also trying to shoot between the breeze gusts. That flyer wasn't really a flyer, I pulled the shot, and immediately called it after squeezing off the shot. So i'd prefer to exclude that round on that group. But .5 MOA'ish IMO is great for a Savage 10 tactical, and a knucklehead behind it that has been out of practice for a while.

All in all I though the Federal GMM clones actually fired very well. I'm going to try to tweak them a little more with the powder charge to see if I can get a little more out of 'em. Plus on the next batch i'm going to weight sort the bullets, and brass to get that extra little bit of consistency.

I'm happy with the groups for now, once I get a couple hundred more rounds downrange by fall I hope i'm constantly shooting .5MOA or better groups. Once I get the accuracy down, i'll borrow a chronograph and see what velocities are.

Branden
 

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Discussion Starter #22
Good work!!

You really need to fire more rounds to get a more meaningful statistical sample.

But your Gold Medel Match clones are well under MOA. Now let's just think about what happened here. With a minimum of load development and testing, Branden put together a load that will deliver sniper grade accuracy!!

It's really easy to do if you use some good components and proven combinations.

Mad.
 

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Also, another thing, my rounds only come out to about .50 cents per round, versus the close to $1.50 per round of factory GMM (depending on where you got it). So you can shoot about 3 times more ammo for the money! If you can only afford one box of GMM, now you can make 3 for the same price!

Branden
 

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I had just one round of Federal Gold Medal Match 168gr that I had kept from my last box purely for reference. I disassembled this round carefully and measured 43.2 grains of powder inside. I realize that looks do not count, but a pan of IMR 4064 is indistinguishable from the contents of Federal's load, supporting what I had heard of a Federal rep saying IMR 4064 is used in GMM. If anyone else could take apart and measure a round or two of their GMM to confirm what I found in mine, that'd be great.

So, from my measurements these are the necessary dimensions and components to duplicate Federal's Gold Medal Match 168 grain load:

Sierra Matchking 168 grain BTHP bullet
Federal 210M Large Rifle Match Primer
43.2 grains IMR 4064 powder
2.800" Cartridge overall length
Brass: Use quality brass, per madgunsmith's suggestion Lapua brass will do nicely. (also: Nosler, Winchester, other match quality)


I will load some of these and post results ASAP. I will be using once-fired Federal GMM brass that I have tumbled, full-length sized, and trimmed to length for testing. Gold Medal shot nicely from my rifle so this load should do as well or better.

-matt
 

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Monte make sure to watch when using different brass as the internal capacities will change the loads pressure and velocity. Federal and Lapua are close but Winchester has a larger internal and the load will give you less velocity. Not sure about Nosler as I never used them. Also if you put those loads in LC brass which has a smaller internal capacity it might be dangerous as the pressure will be higher. Just something for you or another reloader to think about.

Also some companies use non canister powders which are close to what we can buy but not exact. Just drop that load back a little to be safe if you plan to use 4064.
 

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No problem Branden. I would like to pull apart several more to check the consistency from one round to the next to make sure 43.2 grains is what they actually specify in each round. Ideally, one would take apart an entire box and measure the powder in each round (I reassembled my GMM after disassembling the round. Using an Inertia bullet puller there was no damage to any components and all powder was recovered) and use the average powder charge as the intended actual charge. My seating die is set for a 2.800" COL so all I did was pull the bullet, measure the powder, then refill the case and reseat the bullet. I may pick up a box of Federal GMM tonight after work. This would allow me to measure several more rounds to be be sure of measurements, and also be able to check my handloads directly against a proven standard.

-matt
 

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Rob01 said:
Just drop that load back a little to be safe if you plan to use 4064.
We must have been posting at the same time. Thanks for the advice Rob, that makes a lot of sense. What I plan to load tonight is my once-fired GMM brass with about 42.5 grains of 4064, this should put me in a safe range I believe since the case capacity should be on par (actually slightly larger because I had to trim for length to correct stretch from firing and sizing) and all other aspects should be identical. I will let you know how it goes.

-matt

Oh yeah, I worked up to a 41.5 grain charge of H-4895 in Nosler brass in my Winchester and could not get it to perform under 1.5 MOA where the 41.0 grain load was consistently between 1/2 and 1 MOA. What twist barrel are you shooting from? I have a 1:10 and I'm thinking from the loads I've shot that lower velocity is the way to go in my rifle.
 

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I'm using a 22" 10 twist Broughton barrel now which shoots 168s very well as I use some FGMM and GA Arms I have on hand for my close in practice so I don't waste my 178s. They are going out about 2670fps.

Usually you'll find nodes in different loads where they will shoot really well. You'll get good results at a slower speed but go up a little more and it will get worse. That said, if it's safe to do so, if you go up a little more I'm pretty sure you'll find the upper node at a faster speed that will give good accuracy again. Just keep a good eye for pressure signs.
 

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Ok, thanks Rob. The "node" concept makes a lot of sense, we see something similar in race motors with harmonics in tuned exhaust systems and valve springs, we call them "fuss points". I would logically follow that a rifle barrel would have similar points where it will or will not shoot well. Thanks for the advice, I will keep an eye on pressure signs and work up my load slowly. I am also going to load a bunch (read:500 or so for now) of 41.0 grain cartridges to keep around since they should be a good low pressure round that works in just about anything, like mad's intention with his initial load here.

-matt
 

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That's exactly it with the barrel harmonics. Same thing.

Any ideas what the velocity of the 41grn load is? Just asking because the 168s get really quirky after about 700 yards unless they are driven pretty fast. If you just plan on shooting them inside that then they should be fine but if farther than check them and make sure to push them or the better alternative is to use a 175/178 bullet as they will work great in your 10 twist. They will be just as accurate but you will be able to use them out to 1000+. I've shot my 178 load to 1300 yards without a problem. If you have a bunch of 168s onhand then use them for practice but when you reorder think about getting a heavier bullet with a better BC.
 

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I haven't chrono'd the load of 41.0 grains H-4895, but my guess is about 2600. I have about 300 rounds of 168 Match kings around new in the box. After reading your post, I think I will load these all to GMM specs after I test some to make sure the load works. I can pick some 178's up today to try loading some of them, I like the possibilities. What would be your suggestion for a COL with the 178's if I'm not seating them .005" off the lands? My current build is a long action 700 with a .308 barrel, so I could load long when that is completed.

-matt
 

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I'd load them to the normal length of your other rounds and see how they work. Unless you know the length to the lands then the 2.800-2.810 is a safe range. Each bullet will have a different ogive shape and measurement so you really should measure to the ogive to get the proper length as opposed to base to tip.

If you get a comparator you can do this easily. First check the length to the lands in your rifle by putting a bullet in a partially sizedunprimed with no powder case and so you have a little neck tension but not too much as you need the round to seat as you close the bolt. Now seat the bullet in your press until it's like 2.900 and stick it in your chamber and try to seat it the rest of the way using the bolt and the lands. Some people put black marker on the bullet to see the lands contact but you don't have to. If it won't go then seat the bullet a little deeper in your press and try again or if it goes to easily you might have a longer factory throat but it shouldn't be out that far.

Now with that round you take your comparator. It looks like this if you didn't know
and you can find them here for $17.50 http://www.sinclairintl.com/cgi-bin/cat ... type=store
Measure your distance to the ogive of the bullet and mark that number down in a log or somewhere where you can access it again for that bullet as it changes from bullet to bullet. Now when seating your actual loaded rounds seat them until they are .005" less than that and you will be .005" off the lands. It's easy to do and a much better way to know actual lengths as the tips of some bullets, especially SMKs, can be deformed and not give a good OAL measurement.
 

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Thanks Rob, that answered a lot of my questions. I'm going to get a comparator on order and do some more research on this to make sure I have a clear understanding before I load any "real" rounds. I'll also pick up some 178's when I can get in to buy some.

Thanks again for the help!

-matt
 

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Here's an interesting read regarding .308 match loads from Bart Bobbitt. Since it's referring to benchrest, some of the things don't apply to us, but many of the concepts are good to read and can be translated for our uses.

http://yarchive.net/gun/ammo/308_loads.html

-matt
 

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I was interested too, to see the recipe for 168 gr bullets. Oddly, while visiting my Dad, he gave me a package of 10 Nosler 168 gr bt fmj "Match" bullets. I had been shooting 165 gr btsp and found that to be a really reliable round..
but, I also discovered that I had only been shooting at 5-600 yds, and I want to reach out to 1000. When I bought the latest batch of stuff, I got 180 gr btsp, because it was my understanding that the lighter bullets go subsonic around 600 yds and then they can really drift. Also, I hunt Roosevelt Elk, and felt that the heavier bullet was the way to go there, as well.

As a side note, I just bought a pkg of 50 rnds '06 Brass from Winchester... the cartridge length was fine, but the mouth of all the cartridges was slightly deformed. Was it bent in handling and shipping, or is that standard from the production process?
Also, when measuring powder, are you guys using a volume measure or weighing each load? I have an old oil-dampened scale and I measure each load by hand... ultra tedious. But after getting the scale and doing a few test weigh-ins on the "scoop" loads, I would never trust the scoop again.
 

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My Win brass comes the same way. I just run it through a neck sizing die and it's fine. Pretty sure it comes from transport and not manufacture.

I throw each powder charge and weigh each and trickle if needed. I would never trust a scoop. Once you get in a good groove it doesn't take too long. I can load 100 rounds in about 75 minutes.
 

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My Winchester brass came the same way, since it's new it also goes easy through a full-length sizing die. Also, I chuck up each case in my case trimmer to make sure they're of uniform length. About every fifth case has some material removed to bring it to length. This also allows me to chamfer the mouths of my cases right off the bat since I do this while they're chucked up for trimming.

For loading, I run my Lee powder measure into the weigh pan on every charge and run them across the old 10-10 RCBS scale, a digital scale would save a lot of time in this stage. It doesn't take that much longer to check each charge when you're using a single-stage press anyway . . .

-matt
 
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