6BR / 8208XBR RANGE RESULTS

[queen_stick]

Used my 1K bench gun....
Broughton 1-8 twist, 28" length.
Chamber cut with minimum spec PTG reamer, no-turn .272 neck. [Throated] for 105 class bullets.

Was loading at the range, so I could adjust things as I went...
To find the max charge, I loaded 1 round at a safe starting point, then worked up with 1 round at each charge weight, watching the velocity and the pressure signs.

Kept all components the same, just changed the powder charge...
Berger 105 target VLD jammed .015"
CCI 450 SRM Primers
Lapua 1x fired brass (fireformed), tumbled and neck-sized only.


Powder Charge Velocity
28.0 2760
29.0 2879
29.5 2911
30.0 2923 - very slight ejector mark. Primer looked good
30.5 2976 - heavy ejector mark, flattened primer, slight crater.

At that point, I loaded 30.1 and 30.2

Powder Charge Velocity
30.1 2930
30.2 2956 - pressure signs look similar to the 30.0gr noted above

I then loaded and shot 5 rounds with 30.2
Average velocity of 2950, but 2 out of the 5 shots were stiff on extraction. The group at 300 yards had .8" of vertical. Not too bad, but I had a load with RL-15 that printed 0.171" of vertical at 300 yards


My thoughts on the testing...
I was on the verge of too much pressure in order to get the velocity needed for 1K shooting (2950). I think I'd be more inclined to use this in my 6mmDasher varmint rig, which I will certainly will try at some point.

Please keep in mind that I did not have a large sample. I simply loaded one round at each weight, which certainly will not give completely accurate results on velocities. This test did give me a good idea of where I was, and where I needed to go. Hopefully someone can use this data for something?

Walt

 

[queen_stick]

Fouling!!!!!!!!!!!

I'm glad you brought that up. I almost forgot about...

I shot the entire session without cleaning, and went though 40 rounds. Those 40 rounds included the testing with 8208 and with RL15. (I have a good load with varget, where I've tested a dirty barrel and a clean barrel - the gun doesn't care. If it doesn't care, then I won't clean it until I'm completely done for the day). Anyway, that thing was unbelievably dirty! I did not get any copper fouling, but the carbon was ridiculous! I have never had to scrub the barrel the way I did yesterday. I even let the cleaner sit in there for 20 minutes before I started patching. I don't like using bronze brushes, but I busted that thing out yesterday and made 2 passes with it. Only after I ran that brush through there, and a couple patches, the barrel got clean. It really made me angry! LOL!!!

I shot RL-15 first, and 8208 second... It's the first time I tried either of them. I'm not sure if one or the other (or a combination of the 2) caused that fouling, but it was flippin horrible!

 

[25AI260]

q-stick if you wana bring up your velousity try H-414

Edit:
A Big O00000ps ! i tested H-414 but didn't settle on it it was H-322... Sorry
after a few tests.. i am using H-414 in my 25-260 [humdigger] an in my 243

 

[queen_stick]

I assure you Reloder 15 leaves a lot of black crud in the barrel. Varget will leave some if the load isn't hot enough. If I add a bit more powder it seems to get the pressure up to the point where the fouling is minimal. With Reloder 15 it's very dirty and at any same pressure it stays that way.

I'm hoping either 8208 XBR or Reloder 17 will be cleaner and less temperature sensitive without too much loss in velocity. If not I guess it's back to H4895.

I haven't tried 4895, but my gunsmith was playing around with a couple loads in his BR for a while. He couldn't find anything that was near as accurate as his Varget load. Even though my gunsmith and I have identical barrels, cut with the same reamer, I may try it for myself, and see If I can up with anything.

q-stick if you wana bring up your velousity try H-414

Never heard of anyone using that. Got any more info on it? (starting load, velocity #'s, what bullets you're using, primers, etc...)

 

[25AI260]

Q-stick... i edited my post.. sorry it was h-322 i settled on.. i did test h 414 but the load data is missing i believe it was over pressured ?
also i have 20'' 14tw barrel so my load data probably wouldn't do you any great doings... the load is 68gr bullet, 29.5/ h-322, w/ rem.7 1/2br ..lapua brass
its just a wee bit hotter then the varget load, the varget seems to push 70 an 75gr bullet better then the H-... but i can't get enough varget in the case to make it scream....

i was up at the last egg shoot in hickory,nc an the guys up there all said about the same thing 8208xbr... it gets good velocity But no accuracy to satisfy.. the fella i was with bought a #... so far hasn't liked it...!!


Edit: if i remember... H-414 is about the same burn rate as 4350 so i may have guestamated a load to try ? i'll keep looking

 

[skeetlee]

some of you fellas may feel different about this than i do but i think that if you have a 6mm 8 twist barrel thats shoots varget better than re15 then you have a dam good barrel. I like to call them varget barrels or better yet WINNERS!! Just my experience! Lee

 

[queen_stick]

hey Lee,

Thanks for your input.... always appreciated.

My gun shoots Varget pretty well. I'm not done testing yet, but 30.3gr of varget vs 31.5gr of Rl15 is where I stand right now. One of those (or close to it) will be my match load. As noted above, the RL15 gave me a vertical spread of .171" at 300yds. I'll take that any day! Though I had a very small sample of Rl15 (15 shots), I have yet to run the ladder test with Varget. Based on on my basic loads with Varget, the rig definitely likes it. It may like the Rl15 a little bit more though.... I have some more work to do at 300 yards to determine what might work best at 1K. I'm going up to williamsport for a 1k match in a couple of weeks. I need to figure it out soon, so I can at least have a chance at it...

It's interesting that you say that about Varget.... it's not the first time I've heard that.

 

[queen_stick]

30.3gr of varget vs 31.5gr of Rl15 is where I stand right now

That's a pretty hot load of Reloder 15. I get a stiff bolt opening if I go over 30.3 grains in either of mine with 105 VLD's and very stiff with 105 BT's.

QuickLoad says with either of my eight twists I'd be running over 63K PSI with 31.5 grains and VLD's. I'm just sayin'......

I'll double check my data when I get home today. I certainly don't want to post incorrect data (especially if it's a dangerous combo that someone may pick up and try to use). I'll edit the above post if it's incorrect.

Just curious... What temperature are you shooting in to get a max of 30.3 of RL15?

 

[queen_stick]

Just checked my notes, which I wrote as I was loading at the range... it states 31.5.

Something doesn't sit right with this.... ?????????????????????

Next time I go to the range, I'm starting over with the load. THANK YOU Gunamonth!!!, for pointing that out. I may have blown something up if I went out there and slapped the 31.5gr charge in there.

I'm pissed now! wtf is going on here?

 

[FroggyOne2]

It is good that you may want to go back and check your data again.. just remember not every rifle is the same either.. what one person's rifle limit is, is not the same for every rifle.. I used to shoot 31.6grs of RL15 in mine with a Berger 108 and SIE 107 and it was fine.. but it don't hurt to go back and check your load or data that you have wrote down. Just like in my .284.. I can't get anywhere near the same amount of powder that others are using because I have a tighter chamber in mine I have found out.

 

[queen_stick]

Thanks Froggy. I'll definitely restart from the beginning and double check myself before I load up a bunch small bombs

I'm glad you posted though... I thought I was loosing my mind when gunamonth posted the numbers. After he posted, suggesting I was a full grain too high, I went to the 6BR info page, and found most match loads were at (or around) 30.5. It just doesn't seem right to be a full grain higher than that.

 

[queen_stick]

I re-tested with RL15 loads today, because my numbers didn't 'sit right' with few forum members. (I mean that in a good way!)

I reached a max load of 31.7gr, which gave me 2980fps.

The most accurate load today was 31.3gr, which gave me an avg velocity of 2959fps, and an ES of 8 (5 shots on the chrono went 2956, 2956, 2964, 2964, 2956). The vertical spread on the target for those 5 shots was .510". (300 yards)

The last time I shot with RL15 (when I used 31.5gr) it was 73 degrees F. Today it was almost 90 degrees (88 F), and the 'sweet spot' was 31.3gr.

I had slight ejector marks at 31.5gr today, which I did not have when it was 15 degrees cooler.

So, it appears my gun likes a ton of Rl15 . Froggy had similar results (posted above), so I know I'm not the only one. I feel much better now that I've double checked myself. Now that I know the gun likes it, that's what I'm gonna feed it! (Although I'd still like to test some Varget loads, which looked promising as well).

Edit: I forgot to add... This was done with brass that was 1x fired (fireformed), neck-sized only, and neck-chamfered only. I did NOT measure, no trimming, no flash hole duburring, no primer pocket uniforming, etc... simply chamfered the inside of the neck, fireformed, tumbled, then shot it the second time today.

 

[FroggyOne2]

Glad to hear that everything is ok!

 

[queen_stick]

Went to Williamsport on Friday and tested the RL15 loads at 1K. It was 80 degrees F, and 31.3gr caused sticky bolt lift towards the end of a 10-shot string. It shot accurately though.

I ended up going with 31.1gr, which shot the smallest group I've ever done at 1K - 6.0" (8-shot group). The velocity is probably pretty close to 2920.

So, I was running a little high in the charge at first, but it was only evident in the last couple shots of a 10-shot string (plus a couple of sighters prior to the string). Now I know to test loads in long strings as well - the hot chamber makes a significant difference

 

[noload]

Queen, My son and Myself shot our br's thru a crony today. Son = 105 berger BT, 2900 Vel. with 29.4 XBR 15 shots @ 600yds= 2.4 group. After 2400 rounds of trials, thats his money round. He says + or - a tenth from 29.4 it won't shoot. Finiky stuff.
Me = pretty good, 105 VLD, RL15 29.8, 2856 Vel. 7 shots ,(Ran out of rounds for 15 shot group). 600y 2.25 group.
My gun likes varget more some days, but mostly RL. I haven't tried more than 31.0 of RL 15, It seems my 30" Shilen gets wild above 29.8. I do agree the RL will crud the barrel more than Varget. I'm going to try some of the XBR soon. See if I can keep the groups tight and get a little more Vel.