BOLT LOCKING DOWN

[STUMPY]

ANY IDEAS? A FRIEND AND I HAVE BUILT A 300 TOMAHAWK AND THIS YEAR HAVE GOTTEN ALMOST ALL THE BUGS OUT OF IT BUT THIS ONE. ON FIRE-FORMING THE CASES WITH A 50%LOAD OF H-1000 AND 180-GRAIN SIERRA's IT DOES OK FOR ABOUT 15-16 SHOTS. THEN I WILL CLEAN IT AND KEEP SHOOTING. ON RELOADING THE CASES AFTER RESIZING AND LOADING WITH 100 GRAINS OF H-1000 AND BERGER 190 GGR. VLD's THE BOLT LOCKS DOWN. MY GUESS IS TO DROP DOWN 5 GRAINS OF POWDER AND TRY AGAIN?? THE CASES FORM VERY NICELY , THE RELOADS WITH FULL POWER LOOK GREAT ALSO. NO MARKS OR ANY OTHER SIGNS.

ANY IDEAS.
P.S. IT SHOOTS GREAT.null

 

[Brent]

If you're shooting with only 50gr?? of H1000 to fire form, that's scary ****! I would cease that and use a normal load or you could end up in trouble lickity split. Seconday explosions with that little powder could be lethal!!

I think you're TOO HOT.

Fire form with a reasonably warm load so the shoulder is blown out all the way "for sure", then measure the base to shoulder length with a Stoney Point headspace gauge or empty cartridge case located on the shoulders datum line. Record this length for reference. Make sure your FL die isn't shortening this length by any more than .002" at the very most. If you compare these cases to the ones you can't lift the bolt on now, I'll bet the headspace is less than zero on those tight ones, and more than likely "minus" .001" or more, indicating locking lug flex from excessive pressure.

Did you work this load up, or just start at 100gr?

 

[STUMPY]

THE INITIAL TESTING STARTED AT 95.5 GRAINS OF H1000. LIVE AND LEARN. WE HAVE ALREADY DECIDED TO GO DOWN IN FULL POWER GRAINS TO 95 OR 96 GRAINS. AND SEE IF THAT STOPS THE LOCKING UP. READING ABOUT DAVE & DARRELL USING 100+ GRAINS OF WC872 IN THEIR CASES ,BEING UNDER THAT WE DIDNT THINK IT TO BE A PROBLEM. I HAVE ABOUT 200 CASES WITH HALF LOADS TO BLOW YET. I WILL CHECK THE HEADSPACE LIKE YOU SAID. GUESS I WILL HAVE TO PULL THEM ALL AND ADD OR GO TO 4831 ABOUT 70 GRAINS. I WAS GETTING 3583FPS (CHRONY) WITH A 190 VLD BERGER ON TOP. I HAD 6 FULL POWER LOADS AND USED 4 OF THEM ON DEER THIS YEAR. I RUN A LEASE HERE IN SOUTH GEORGIA AND ONE SECTION HAS A 100 ACRE PEANUT FIELD. THIS WORKS GOOD ON IT. I TOOK DEER CLOSE AS 310 YARDS OUT TO 618 YDS. THE GUN SHOOTS PRETTY FLAT OUT THAT FAR. THE LONG SHOT I HELD 3" OVER THE BACKBONE.

I WANT IT RIGHT SO BACK TO THE DRAWING BOARD WITH THE LOADS. NO PROBLEM, SAFETY
THANKS

 

[Guest]

Yea , using reduced loads can get you troube just as fast a over power loads , personaly I would pull all that are loaded and fire form with a full case or use the cream of wheat method.
If you getting sticky bolt lift you should have alos been getting blown primers , extractor marks and other high pressure signs if the pressure is high encough to bind the locking lugs it is WAY to high.
Just because one guy get good results with one load in the same caliber that doesen't mean that you will , their are alot of things that play into it , chamber dementions , lot numbers on the powder.
I have seen two guys try to reach the same velocity as another fella and Gall their bolts shut , they came up short on the velocity due to the lot fo powder they had was two fast and their barrel was 4" shorter

 

[Brent]

Dennis,
Just a couple points -
Darryl uses rather long barrels to get the MV he quotes. He also uses a slower powder than H1000 to do it. He also doesn't care much about case life in his hunting rifles so he pushes the pressure limit too.

He used a 34" barrel in the Tomahawk the last I heard.

Darryl posted:
<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>3. 98.3 gr Retumbo---3348 to 3368 FPS---210 JLK and another group of Berger 210 gr. Results were almost the same. The older Bergers gave extremely tight groups.

4. 105 Grs of WC872----3326 to 3345 FPS---210 JLK and Bergers also.
<HR></BLOCKQUOTE>

I got a bit over 3300 fps in my 30-338 Lapua with the 210 JLK last time out, but pressure was real high with 96gr Retumbo vs the time before using it, real fouled barrel possibly contributed to it. Pressure was up by about 5-8k psi over the time before, so I'm doing a little more testing to determine why. I dropped the load to 90gr for some tests today.

I'd figure 85gr of H1000 with the 210 a good place to start, maybe 87 with the 190.

With a 220 SMK, 87gr RL25, and 90gr Retumbo were max loads in my 26" bbl 300 Ultra Mag. About 93gr Retumbo was max using the 200 Accubond.

Your 618 yard shot, I've got to ask - You were zeroed at 100 or 200 yards and held 3" over his back and made that hit? The 300 yard shot I could understand, 618 yards doesn't add up??

 

[STUMPY]

I WAS ZEROED 1" HIGH AT 100YARDS. THE BULLET HIT RIGHT AT THE TOP OF THE HEART. A BULLET SIZE HOLE GOING IN AND A LEMON SIZE HOLE COMING OUT. NONE OF THE BULLETS WERE RECOVERD. ALL PASSED THRU. THANKS FOR ALL THE INFO IT WILL BE LOOKED OVER AND USED. THANKS AGAIN.
D.

 

[STUMPY]

P.S. MY BARRELL IS A LILJA 30" FULL BULL. I WILL SEE IF I CAN POST A PIC OF IT. I USE AN OLDER NIGHTFORCE IN 5.5 X 22 X 56.
D.

 

[STUMPY]

correction it's a 32 inch barrell. i had to remeasure to be sure. if i can figure out how to post pics i made some of it!
d.