Reloading CMMG 308

[BayouBob]

Are any of you guys reloading for your CMMG Mark 3?  I am now wondering about the chamber deminsions.  I have never experienced brass so hard to re-size.  (Federal and Remington)  I use Hornady Unique lube and I literally have to beat the arm of my Rockchucker to get the brass in and out of the die.  I have tried dipping the neck in mica but it didn't help.  I even sent a note to Hornady asking if I had a bad set of dies but I tried a set of RCBS dies and the same thing happens.  The brass isn't deformed in any way so the only thing I can figure is the chamber is badly oversized.  Any thoughts? 

By the way I have been reloading for over 40 years and have loaded countless 308 rounds fired out of other rifles.

[BayouBob]

Put the first few rounds down range with the Burris Electro Dot scope mounted just to get it on paper.  (I make notes of all my loads in my book and while I am working up I write on the case what the load is.  I forgot to mark the cases of this batch so I don't know which load was which.)  Just shooting at 50 meters to sight in and shot about a 1" composite group of a dozen shots.  Nothing to brag about but I'll go back with the loads marked and start looking for magical combinations.  Right now I'm focusing on Hornady A-Max and SST's and Nosler Accubonds.  Varget and IMR-4895 with Federal cases and primers are on the menu for starters.

The JP muzzle break just makes the recoil go away completely.  If there had been anyone else at the range they might not have enjoyed it as much as me; it is loud! 

Anyway, it was a fun day at the range.  Finished sighting in my fiance's little 5 lb AR-15; sighted in a Kimber in 325 WSM, Started working with 55gr. bullets on my Sig Sauer AR-15 heavy barrel and fired some more pairs out of my Chapuis double rifle.

[survivalshop]

Are any of you guys reloading for your CMMG Mark 3?  I am now wondering about the chamber deminsions.  I have never experienced brass so hard to re-size.  (Federal and Remington)  I use Hornady Unique lube and I literally have to beat the arm of my Rockchucker to get the brass in and out of the die.  I have tried dipping the neck in mica but it didn't help.  I even sent a note to Hornady asking if I had a bad set of dies but I tried a set of RCBS dies and the same thing happens.  The brass isn't deformed in any way so the only thing I can figure is the chamber is badly oversized.  Any thoughts? 

By the way I have been reloading for over 40 years and have loaded countless 308 rounds fired out of other rifles.

Try a different lube , but anything made with" CMMG "in front of it would not surprise me.

Have the chamber cast & head space checked if you want to make sure of the chamber dimensions.

Could be a couple of other things , how does the brass look ? Pull marks from the extractor .

[BayouBob]

Brass looks okay.  No noticeable distortion or marks.  I am going to try some Winchester brass.  I have been using just Federal.  It could be that the case necks have really thick walls.  I am also digging around in my bottomless pit of a brass pile to find some brass fired in a different rifle to run through the die just for comparison.  I've been using the Unique lube for several years and it is absolutely the best I have ever found.  Thanks for the advice.

[98Z5V]

...sighted in a Kimber in 325 WSM,...

Much due to my personal affliction, I really need to see pics of this beast.  I love Kimber bolt guns, and have one of the old Clackamas guns in .308 Win.  Hook me up, man...  :o <laughs>

[BayouBob]

It's a Montana from the New York bunch, not one of the original Oregon rifles.  (Stainless synthetic)  I bought it and a mate in 270 WSM.  They are light and sweet and pretty well cover anything a guy would want to hunt in North America.  Good triggers on both; the 325 came from the factory a shooter.  The 270 took 6 months of work to get to the point of 1 inch groups.

[BayouBob]

For 98Z5V, Here's a shot of the Montana 325 WSM.  It's wearing a Burris 3-9 with the 1 mil electro dot reticle and DNZ mounts.  It will keep 200 gr. Barnes TSX Bullets at 3,000fps in an inch at 100 meters if I am having a good old eyeball day.

[BayouBob]

Off the 308 subject but just for fun here is the latest project.  It's Colt LE with an AP Customs carbon tube, aluminum gas block, Burris LRS 1-4, a Tri-Dellta micro brake and a Streamlight TLR-1 HP.  With the AP tube the bare rifle weight was down to 6 pounds on the postal scale.

[BayouBob]

With everything settled but which load I am going to stay with long term I got down to some shooting with the CMMG 308.  With Federal Premium 168gr. Sierra Matchkings the rifle was staying in 3/4 inch at 100 meters.  If I can find a load with Sierra Game Kings that will do that I will be quite happy.

[BayouBob]

Here is the CMMG in its final form.  It has a PRI adjustable gas block, a JP stainless brake, a Burris 3-9 with the 1 mil e-dot, Nikon P-mounts, the CAA-UPG grip, a Sims large grind to fit pad, a Cheek-eze cheek pad, and the new Sims Kodiak sling.  With 10 extra mags and a soft case I've got a little over $2,200 in it.  The load development needs to proceed in short order; there are some hogs waiting for me in about 3 weeks.

[unforgiven]

Nice setup brother Bob. <thumbsup>

[Matt.Cross]

Nice setup brother Bob. <thumbsup>

Oh yes! I really like the looks of that stick! That UPG grip is the cat's ass, it just makes an AR look like a million bucks.

[BayouBob]

This project is never going to be finished.  I'm starting through the loads again.  After some pretty good groups with factory loads I started working with Hornady SST's, Nosler Accubonds, and Sierra GameKings.  My groups just kept opening up and I was back to an occasional FTE/FTF.  I kept adjusting the gas port screw and kept getting failures.  I finally realized the gas block had worked loose and was literally rattling out there on the barrel.  Might be why the groups went to hell.  After stripping out the tiny little cap screws CMMG has used red Loctite to hold the handguard on with, drilling them out and finding some stainless replacements everything is back together.  Tomorrow I'll go back to square one with the handloads.  More reports to come.