Playing with the Extreme .308

[Fur-n-dirt]

More 100 yard testing..  3 shot groups   No sugar coating..

I tested three types of bullets.

Lower left is my bullet design
Lower right unlubed /sized HP
Center is lubed/sized FP
Upper left is lubed/sized FP
Upper right is unlubed HP

I noticed after 20 shots my groups were opening up.  I guess the manual is serious about cleaning barrel after 15 to 20 shots!

Early indications is that the gun likes a unsized bullet rather than a sized .308 bullet.   Next step is to try a lubed unsized bullet.

Its nice to see that HP's are shooting slightly better than the FP since they are my hunting bullet.

[rsterne]

Good group on that unlubed, unsized HP.... My DAQ shot better with unsized bullets as well....

Bob

[Fur-n-dirt]

Good group on that unlubed, unsized HP.... My DAQ shot better with unsized bullets as well....

Bob

Bob, my Extreme is more accurate at 100 yards than the Rogue was at 50 yards!  lol

[11william]

That was a nice group on the upper right.   You will have to clean a lot until you get it broken in. I have a Haley 257 that I
Could not get 15 shots before I had to clean it. You could see the buildup with a light. Then I started lubing my bullets
That helped a lot. It made it easier to clean also. To start with I had to use solvent to get all the lead out.  I did not have
Near that problem with the two 45 calaber guns I have.  I did end up fire lapping the barrel to get it smothed out. Now I
Can shoot 60 lubed bullets or more before I pull a patch trough. 
People at the range are amazed that I shoot at 200 yards with this gun. I have a 6x6 metal targets I shoot at. I can see
Where it hits at that distance and I like to hear it ring.

[shamu25]

William....specifically how did you fire lap your Haley?  I am ready to do my new Condor 257 and plan to use Roachcreeks recommendations by using only the higher 2 grits the 320 and 600 .   Just very curious.
thanks Ray

[11william]

Hay Ray:   roachcreek or charlie had the same rifle I do except he had a extra barrel with a faster twist to shoot
Heavier bullets. He has some good advise on three or more forums. Unfortunate he has gotten out of airguns.
 I started out using jb bore paste with a tight patch. That did not get it done but it helped. Then I got the wheeler bore
Laping kit. I only used the 320 grit and 600.
15 shots with 320 grit. Clean after every 5 shots.
30 shots with 600 grit. Clean after every 5 shots.
That helped a lot. I ended up doing it again with 600 grit one more time.
40 shots with 600 grit clean after every 5 shots…
The good thing about my gun you can unscrew the barrel to clean it. No port whole to line up.
Ray I would shoot it first to see how it does.
Check out tofazou blogspot  he has a 257 on air force set up that he was hitting coke can at
450 yards.
Roachcreek has the longest shot made with a air rifle. He shot a coke can at 600 yards.
He called it the pepsi challenge 600 on ytube.

[Fur-n-dirt]

Hay Ray:   roachcreek or charlie had the same rifle I do except he had a extra barrel with a faster twist to shoot
Heavier bullets. He has some good advise on three or more forums. Unfortunate he has gotten out of airguns.
 I started out using jb bore paste with a tight patch. That did not get it done but it helped. Then I got the wheeler bore
Laping kit. I only used the 320 grit and 600.
15 shots with 320 grit. Clean after every 5 shots.
30 shots with 600 grit. Clean after every 5 shots.
That helped a lot. I ended up doing it again with 600 grit one more time.
40 shots with 600 grit clean after every 5 shots…
The good thing about my gun you can unscrew the barrel to clean it. No port whole to line up.
Ray I would shoot it first to see how it does.
Check out tofazou blogspot  he has a 257 on air force set up that he was hitting coke can at
450 yards.
Roachcreek has the longest shot made with a air rifle. He shot a coke can at 600 yards.
He called it the pepsi challenge 600 on ytube.

Hi William,  thanks for the info..  What's your favorite lube?

Oh yeah, I'm looking for .257 , wish I could find a haley

[shamu25]

Thanks for the info William.  I put 5 slugs with 320 grit down the pipe, cleaned then 5 more.  Then I did the same with 600 grit.  Sounds like I may need to do it over again using twice as many.  One thing I noticed is that when using soft cast slugs and rolling them on the steel plates they are reduced significantly in diameter so wonder if I need to use a harder slug that won't deform so much.  When they get reduced in diameter I am sure there is much less scrubbing action in the bore.  Will report more when I have time.

[Fur-n-dirt]

Thanks for the info William.  I put 5 slugs with 320 grit down the pipe, cleaned then 5 more.  Then I did the same with 600 grit.  Sounds like I may need to do it over again using twice as many.  One thing I noticed is that when using soft cast slugs and rolling them on the steel plates they are reduced significantly in diameter so wonder if I need to use a harder slug that won't deform so much.  When they get reduced in diameter I am sure there is much less scrubbing action in the bore.  Will report more when I have time.

Please  let us know your results!

It does make sense that more 600 grit is required to take out the scratches of the courser grit. 

[Fur-n-dirt]

Today I shot a coyote at 100 yards..  Hit it square in the chest , his legs stiffened, and tipped over..

Freakin awesome!

[Fur-n-dirt]

My buddy shot my extreme last weekend and did real well at 100 yards..

He shot two 3 shot strings.

If taking ctc of the first , second,  and third shots, the numbers are .35", .45", and 1.25".  That's pretty good consistency.

If taking the aggregate (all), the group is estimated to be around 2.5" ctc.

This lend to do more velocity measurements yesterday.  I wanted to fine tune my pressure for consistent velocity .  I had been using 3800 psi.

The answer looks like 3775 psi for the 115 HP , no size, no lube.

See the graph below.  Most shots are taken at 3700, 3750, 3775, and 3800 psi. 

I noticed during the session that some bullets slid in very easy and some needed to decent push.  I think its time to get serious and get very consistent lead in weight and diameter.  I am thinking of maybe using a .309 die to smooth out any edges.

I got to say, I really love this gun.  No leaks, works perfect, and is pretty darn accurate!  I got the cleaning of the barrel down to a science.  Lol

[Fur-n-dirt]

Had some more fun this morning...

This round, I cherry picked perfect bullets in .309 " in the 115 HP.  In addition, I used the optimal velocity of 3775 psi that gave the most consistent velocity from testing..

The overall results at 50 yards were a little disappointing.  I believe sizing down to .309" or form is the cause.

More testing will verify..

The pic below shows the grouping of the 1st, 2nd, and 3rd shots of each string.   So, the group on the right is the first shots of three strings and so forth..

Results are 1.4", 1.16", and 1" ctc for the first thru third groups, respectively.   If this was 100 , I would be happy, but it was at 50 yards.

I did recall that previous testing did not show as good for any sizing .   The next step is to shoot with more unsized bullets.

Best group of the day was .55", worst was 1.8"

I noticed that's my first shot groups differently than the 2nd and 3rd..  I need to figure out if it's form or the pressure since it's killing the group size.

[Fur-n-dirt]

I decided it was time to check out other mold designs..

I chose a spitzer bullet from RCBS.  It stunk that I had to buy a $40 dollar handle for it.  Lol

These puppies were coming out at an average of .313", so testing was done sized to .309". They are around a 130 grain bullet.  Extreme's are known to shoot long heavy bullets.   After receiving the mold, I decided to check the gyroscopic stability and it came in at ~1.1.  Cutting it close , huh?

Shooting from 50 yards, this was the first couple of shots..  First one was the HP to confirm it was sited.   The two grouped were the first couple of shots with these new bullets.   I got very excited!

However, after more testing, I started grouping at 1" to 1.5" with four three shot groups...   Not there yet! Did the barrel lead fast?  Probably not, it was just a fluke based on my other groups..  They seem to fly good, no tumbling yet..

In any case,  I need to do some more tweaks..

My plan is to up the velocity and resize ..  It's going to be sweet if I get these beauties to fly well..

[rsterne]

At a SF = 1.1 you could have a problem at high altitude on a hot dry day.... low air density could tip the scales against you....

Bob

[Fur-n-dirt]

At a SF = 1.1 you could have a problem at high altitude on a hot dry day.... low air density could tip the scales against you....

Bob

Right. ..  Good thing that I live in the desert in lower altitude..

Does anyone know of a good machinist that can take a .308 sizing die and increase ?   Thx

[rsterne]

Not that hard to do if you have a lathe and a Dremel.... I mounted my Dremel on the compound feed and set it at a few degrees to match the taper of the inside of the sizing die.... Using a 3/16" straight stone, like used for sharpening a chainsaw, I gradually opened up the hole until it sized a bullet to the size I wanted.... You have to go VERY slowly, just a fraction of a thou at a time....

Bob