6mm RAT powders for NRA HP

[Rtheurer]

I purchased the whole thing, Upper, Dies, Brass, bore guide, case gage ect ect from Lee. So far very happy.

Testing will begin soon. Powder valley just got an order from me for a mixed basket of bullets, Nosler 105gr CC, Berger 87gr VLD's, 90gr BTHP,Hornady 105gr BTHP Match and 500 87gr BTHP's for fire forming.
This on top of the 95gr Sierra Match kings, 107's Berger 95gr VLD's, 105 VLD's and what ever else I have laying around for testing. Should be able to find something that shoots bug holes.
If there is anyone bullet that I really hope shoots the best its the 95gr Sierra. Mostly do to the fact My home range isnt real tough and I think it would be a great bullet to shoot all the way back to 600yds. Plus i can shoot a bunch of seconds that i can pick up at the Sierra plant. They shoot just fine.
Yes Nate XBR 8208 will be tested as well. : )
RussT

 

[infantrytrophy]

... 87gr BTHP's for fire forming.

...

If there is anyone bullet that I really hope shoots the best its the 95gr Sierra. Mostly do to the fact My home range isnt real tough and I think it would be a great bullet to shoot all the way back to 600yds. Plus i can shoot a bunch of seconds that i can pick up at the Sierra plant. They shoot just fine.
...
RussT

Re the 87 gr BTHP for fire forming - These will probably work fine, but my experience was that flat-tail bullets in the 80- to 85-grain category worked better than boat-tail bullets for fireforming.

I initially used some inexpensive Sierra 80-grain soft point hunting bullets (boat tail) for fireforming. The case shoulders were blown forward OK, but the shoulders were a little rounded. I then tried some similar 85-grain Sierra SP bullets, but these were flat-base bullets. The resulting fireformed cases were better - the shoulders were not rounded. The powder charge was the same, 28.5 grains of RL-15.

This may have been a distinction without a difference, however. One the second firing, both batches were equally accurate. And, as mentioned, the shoulders were adequately blown forward for both batches. So, the rounded shoulders thing was just cosmetic, not a real problem.

I'm not sure which feature was responsible for the difference between the two batches of fireformed cases - 85 vs. 80 grain bullets or flat base vs. boat tail bullets.

My only additional comment would be that the SMK 95 grain bullets are very accurate in both the 6RAT and the 6BR.

Randy

 

[rminut]

I'm just wondering what kind of brass life you guys are seeing? any problems with cases stretching early and needing trimming more than a .223??

thanks,
Robert

 

[dfry]

I haven't fired enough yet to know for sure, but with a 40 degree (Ackley) shoulder streatching should be nonexistent. But as Steve said before, I kind of agree that neck turning, at least for long line loads is not a bad idea just because necking down thickens them a little. I know others are not turning necks, but I think (more time will tell) that pressure issues will be reduced with turning. Brass life for others I know has been good, especially with the Lapua AA brass. I was getting about 8-10 slow fire loads out of my R-P brass in the 6WOA, this brass should last much longer and all indications to me are that it will. 3-4 firings on the brass I have been loading so far with no indication of pressure issues or the pockets really loosening at all. This brass may go a little sooner than normal just because I have run some of the charges up to see what my top end is so I have put a little extra stress on some of the brass but it is doing fine. Dave

 

[Rtheurer]

Here is a picture courteous of my shooting buddy Doug who will be testing the ammo in my absence. ( pretty good buddy huh?)

These are the bullets that will be tested sooner or later, In the 6mm FAT RAT

RussT

 

[flatlander]

The last 6 RAT upper I put together used a Krieger blank that I contoured & chambered myself. I worked up the gas port dia. by starting out with a #50 drill, then checked for function to see if it'd lock the bolt back on an empty mag. I wound up with a .086" port (#44 drill).

Not sure how this compares to the port dia. that Holliger & Lee are using, but have found that function is marginal with 87s & H322, even though H322 gives significantly sharper shoulders on formed cases than 8208 at the same velocities. It'll always cycle good enough with H322 to give reliable feeding, but doesn't always lock the bolt back on an empty mag. Accuracy is also significantly better with H322 in my bbl.

Judging by primer appearance (either CCI 450 or Wolf SRM), I don't want to go with hotter 8208 loads in an attempt to get sharp shoulders. I did try RL15 & AR Comp for FF'ing with 87s, but neither give results as good as H322. So, since I've got a couple of 8lb jugs of H322, that's what I'm going with for now.

 

[bpm990d]

Dennis, did you have any problems getting a reamer from PTG? I've e-mailed them twice, and they are ignoring me. Is the 6 RAT available as a special order or do you need someones permission?

B

 

[Rtheurer]

Ask for reamer # 37387 Dated 8-29-11, 6mm FAT RAT, by accurate and reliable. Its the current set up that Lee uses for his costumers rifles.

Russ T

 

[NateG]

Yes Nate XBR 8208 will be tested as well. : )
RussT

How on earth did you know what I was thinking? :-X

 

[bpm990d]

Ask for reamer # 37387 Dated 8-29-11, 6mm FAT RAT, by accurate and reliable. Its the current set up that Lee uses for his costumers rifles.

Russ T

Thank you Russ!

B

 

[6brxdude]

Great thread fellas!
Any advice for fire forming a fat rat with a 10 twist in a 20 inch Kreiger barrel? I'm supposed to get my upper from Lee on Tuesday. i've got a lot of Varget on hand along with some 8208, n540, 4895 and 4350. I'm hoping to shoot Nosler 70grn bullets when all the fireforming is done so any advice on loads for this would also be greatly appreciated.


Thank You
Kevin

 

[flatlander]

bpm990d - I've never tried contacting PTG via e-mail - as busy as they usually are, I didn't figure I'd ever get a reply. Right now, they're probably loading up to head for SHOT in Vegas, so I'd say e-mail is a definite long shot. I just ordered a 6 RAT reamer - don't recall whether there were any questions about it or not. However, in reviewing my reamer print, I noticed that there's no drawing or print # on it?

All I've heard about the FAT RAT is that it's .001" larger than the original in both body & neck dia. Necks of my loaded, fully formed rounds measure .270", while the reamer print shows a .275" neck, so I'm not sure what advantages - if any - the FAT RAT would have.

I checked the neck dia. on the 6 HAGAR print, and see that it's only .2723". Don't have any loaded HAGAR rounds remaining, so I can't check neck dia. But, I did have to neck turn Jamison 25 Rem brass in order to use it in my HAGAR chambers. I've seen no reason to consider neck turning FF'd RAT brass, as its neck wall thickness checks out very consistent on a Sinclair neck gauge, and .005" is plenty of clearance in an AR.

 

[jscandale]

I just got some of the preliminary test brass for the Hagar. I'll post here what the final neck diameter will be, but there are still some bugs to work out at the moment. I can tell you that the reamer was designed for very thin Remington brass and was designed by a very good gunsmith that builds excellent bench rest rifles. The drawback of that is that gas guns need a bit more clearance than a bench rest bolt gun in order to be "trouble free".

JS

 

[bpm990d]

Thanks for the info.

I just checked some of my brass again with a ten thou blade micrometer and the necks of loaded ammo (AA brass) with a bullet is .2705. The print I grabbed from the web says the 6mmRAT chamber neck is .274 with a +- tolerance on the print of .001. The next barrel is going to be done with a reamer that has a little more room.

B

 

[jscandale]

Thanks for the info.

I just checked some of my brass again with a ten thou blade micrometer and the necks of loaded ammo (AA brass) with a bullet is .2705. The print I grabbed from the web says the 6mmRAT chamber neck is .274 with a +- tolerance on the print of .001. The next barrel is going to be done with a reamer that has a little more room.

B

B,
If you would like to remove the barrel and send it to me, I can open the neck up to .276" with a neck reamer in about a day or so and only cost you a $20 bill plus the shipping. Just a thought.

JS

 

[bpm990d]

John, thank you. That is a generous offer. I think what I might do is wait until I get the reamer from PTG and then have this one redone at the same time I get another one made up. That way everything is the same. Are you going to be doing other barrels besides the Tomahawk?

It seems to function alright now, and two of the guys here in the NE have WOP RATS that seem to function fine, but it makes me nervous with so little clearance.

B

 

[spclark]

I just got some of the preliminary test brass for the Hagar. I'll post here what the final neck diameter will be, but there are still some bugs to work out at the moment. I can tell you that the reamer was designed for very thin Remington brass and was designed by a very good gunsmith that builds excellent bench rest rifles.

You're speaking here of the 6HAGAR reamer, right?

Yes the R/P stuff is thin, the Jamison 25REM has to be neck-turned to function at all in my rifle & others I know of. Not a big deal when compared to the total time it takes to form a 6HAGAR case....

What's your opinion of the first test run? Any other metrics worth sharing, on or off-list? I know only one other who's received some, and one who I thought would be an obvious recipient who so far is empty-handed.

Sure hope this dreamtime project sees reality soon and that the result is as fine as it assuredly can be made to by Hornady! I just used up the last of my stash of Jamison brass for this coming and any future seasons.

 

[jscandale]

B,
Yes, I am doing all types of barrels and calibers including service rifles and SR sights. I know the website doesn't reflect that, but it's in progress. An FFL is in progress and will also be taking in bolt guns once I am legally allowed to take them in.

spclark,
The brass looks very nice as I knew it would coming from Hornady. Still a few issues to address, but endurance testing will be done this coming weekend. Overall, very nice! I will be very anxious to pump out some Hagars as it is an excellent cartridge for the AR. The Tomahawk looks like it has excellent potential, but I must give credit where it is due and the fact is the Hagar has many things going for it, not to mention a few championship wins.

John

 

[ctrickett]

Just got some 8208 in white jugs, the guy got out of shooting and had this from a few years ago. Does anyone know if this is early 8208, and what could be expected as it compares to current 8208. I have been happy shooting my RAT with 8208.

 

[dfry]

One other thing in regard to the buffer spring issue in slow prone. I don't believe that the buffer spring was my issue. I still had the issue last weekend after putting in a new Tubb buffer spring. I tracked it down to the lips on my single shot mag (10 shot with single round follower) getting compressed down over time. I have used this mag forever and it had always worked but I did remember there were a few times with my 6 WOA where it failed to lock back in offhand. I think the recoil impulse with the RAT is a little sharper and magnified the problem with the mag. a little tweak of the feed lips and it seems to be working fine again. Time will tell, Dave