8208 xbr in 223 velocity variability-updated 06-08-14

[MildBill]

I cam curious as to if others have observed that 8208 xbr having somewhat wide velocity ranges until it gets closer to max.

I loaded up some 55 grain sierra 1360's in my 223 with 2nd fired, neck sized only brass, lit with Rem 7.5 primers. All powder charges individually weighed and trickled up.

Here are results
24.3 gr- 3100, 3088, 3117, sd 15

24.6 gr- 3119, 3073, 3148, sd 40

24.9 gr- 3153, 3121, 3176 sd 28

25.2 gr- 3218, 3174, 3234 sd 31

25.5 gr-3291, 3238, 3223, sd 32

25.8 gr 3324, 3300, 3318, sd 12

the 25.8 gr charge has grouped the best, approx. 0.5" at 100 yds on three different tests.

I know from past reloading that I get way tighter results in velocity and groups in my 223 using benchmark powder than I have observed with 8208 xbr. With Benchmark I have been able to consistently have sd's in the mid to low teens, and on the best charges get single digit sd's.

I figured that the 8208 would have been more consistent that it is showing.

Has anyone seen similar results?

 

[Steve Blair]

Re: 8208 xbr in 223 velocity variability

My experience is that faster powders for a given combination will produce low ES over a wider range than slower powders for the same combination. Also, the slower powders almost always produce best results just below max pressure. YMMV

 

[CJ6]

Re: 8208 xbr in 223 velocity variability

Try working up the load with Tula SR primers. 8208 and Tula primers have worked well together in rifles I use that combo in (regardless of caliber)

 

[MildBill]

Re: 8208 xbr in 223 velocity variability

I would not know where to even look for tula primers around here.

 

[CJ6]

Re: 8208 xbr in 223 velocity variability

PV has them.

 

[spclark]

Re: 8208 xbr in 223 velocity variability

I would not know where to even look for tula primers around here.

Where are you located? Yes, PV'S a great source unless there's somebody close by who might 'gift' you a few to try.

I use 8208XBR in three different cartridges with both large and small Tula / Wolf primers, SD's in the 10 or under range. You don't want the small rifle Tula KVB-223 as they'll pierce. The next up is the KVB-223REM which has the same charge but in a magnum-weight cup. Last is the KVB556 with the magnum cup and a higher charge.

I just acquired some of the 556 type for testing against the 223REM SR primers I've been using. I know folks who use them & say they're great too but in a 223 you may not need the extra Oomph they deliver.

 

[Steve Blair]

Re: 8208 xbr in 223 velocity variability

I just acquired some of the 556 type for testing against the 223REM SR primers I've been using. I know folks who use them & say they're great too but in a 223 you may not need the extra Oomph they deliver.

[br]
All of the Russian primers are mild. KVB556 are about the same as CCI 450, well below the brisance of primers like Fed 205M, Remington 7½ BR or Winchester 6½-116.

 

[MildBill]

Re: 8208 xbr in 223 velocity variability

In addition to the Rem 7.5's I do have small amounts of Fed 205 GM's, CCI BR4's and some winchester small rifles.

Does any one know if 8208 xbr likes any of those better than the Rems?

 

[spclark]

Re: 8208 xbr in 223 velocity variability

Does any one know if 8208 xbr likes any of those better than the Rems?

Try the BR-4's first & let us know what you see....

 

[CJ6]

Re: 8208 xbr in 223 velocity variability

I just acquired some of the 556 type for testing against the 223REM SR primers I've been using. I know folks who use them & say they're great too but in a 223 you may not need the extra Oomph they deliver.

[br]
All of the Russian primers are mild. KVB556 are about the same as CCI 450, well below the brisance of primers like Fed 205M, Remington 7½ BR or Winchester 6½-116.

But if the SD's are in the single digits and the target shows the performance does the lower briscence matter ?

 

[Steve Blair]

Re: 8208 xbr in 223 velocity variability

But if the SD's are in the single digits and the target shows the performance does the lower briscence (sic) matter ?

No, but my approach is to start with mildest primers because experience shows they are the most likely to produce low ES. That does not mean another primer will not work. My current 6BR load uses Fed 205M as they showed best results with my current lot of H4895. I have ample supplies of almost all available primers because one never knows what will provide best result in a given application. [br]
On another matter: I don't care about SD as I am not trying to extrapolate what a larger population will do. My goal is to ensure that all of my ammunition will hold single digit ES. The reason is that long range targets only show ES, not SD.

 

[CJ6]

Re: 8208 xbr in 223 velocity variability

Steve my thoughts were/are that the less disruptive the (primer) blast the better (as you say) as long as the results are of a positive nature. The Tula LR primers have dropped the ES's in the 308 155.5 full bore to 4 where as the best I was able to get with others Fed GMM or CCI BR's was in the teens (with 8208), with 77 gr bergers in the 223 the ES is 5 and I'm working on tension with this. I misspoke on the SD (should have been ES).

 

[Steve Blair]

Re: 8208 xbr in 223 velocity variability

Roger, [br]
The large majority of my loads are just as you describe. There are a few exceptions. Sometimes, the hotter primers do a better job, but it is not typical for my efforts. Primers are the one area we really cannot control. If they work, great. If they don't, try something else.

 

[MildBill]

Re: 8208 xbr in 223 velocity variability

Try the BR-4's first & let us know what you see....

OK

Probably will be next week before I get to burn some more powder....

 

[MildBill]

Re: 8208 xbr in 223 velocity variability-update

I was able to shoot some loads to day with the BR4 primers in them...

velocities were very similar to test with the Rem 7.5's lighting them however sd's were worse.

25.2 has sd of 16
25.5 sd was 21
25.8 sd was 50

also shot one group with the 25.8 gr of 8208 xbr with 7.5's and it was pretty good with an sd of 6
interestingly it was about 50 fps slower than the last time I shot that combination across the chronograph.

the bullets were from a different lot, do you think that might have influenced speed?

I have some more to try and I will likely give winchester primers a kick at the can, although the 25.8 with the Rem 7.5 has consistently grouped very good, and seems to have reasonable consistency, maybe I should play with seating depth with it?