Sierra Gameking HPBT 7mm-08

[CptnAwesome]

Previously using 120gr Sierra Pro Hunter over 34gr H4895 seated to 2.70" (lighter load for my wife) wich gave me 1" groups at 100yds easily.

Just started experimenting with these. Sierra Gameking .284 140gr Hollow Point Boat Tail with H4895 for my 7mm-08 Rem. Started at 37.5gr and worked up in half grain increments to 39gr. Groups were horrible. 1 1/2" at 100 yds was the best I got at 38.5gr.
39gr started to flatten primers.

Rifle is Ruger American

Without changing my seating die (set for the 120gr) it loaded the HPBT's to 2.60.(did not test). If I were to seat to the lands with the HPBT would be at 2.79" (which would still fit in magazine). These tested were seated to 2.78.

I don't want to seat to the lands so only option I guess is to work my way back (or creep forward slightly) and maybe try a new powder if that doesn't work. 42gr H4895 has given me 1" groups with the 120gr.

Anybody have experience with these bullets?(any caliber)

This is my first experience with the Sierra GameKing HPBT.

Would you try to creep towards the lands more or back out? Try a new powder?

Any suggestions or input would be appreciated THR!

Side note: Posting this reminds me I miss rcmodel.

 

[627PCFan]

My Lee Data starts 140gn at 38.5gn of h4895 to a max of 40.5 @ 2769. Are you sure you started to flatten at 39 or were the primer edges just "crisp"? Also whats your brass type? 308 NATO Lake City necked down or commercial 308 necked down? I would try H-414 or H380 if you were going to make the jump to another powder. Also I tend to start at Max OAL that fits in my mags and don't focus on distance to the lands unless I'm single feeding them like Berger vlds. Too much to fuss with IMO.

 

[Patocazador]

H4895 is the most accurate powder with 120 gr bullets in my 16" 7-08 Model 7 rifle and my 14" XP-100 pistol. However, I don't load 140 gr. bullets in that caliber. If this is for a hunting load, I'd go back to the non-HP 120 gr bullets. If it's for bench shooting, try other powders with the 140 gr.

 

[George P]

With MY 7-08, which is a 18.5" Rem 7, Win760 gave me the best results, followed by 4895; but both of those were better with 140 grainers, Sierra and Nosler respectively

 

[horsey300]

Previously using 120gr Sierra Pro Hunter over 34gr H4895 seated to 2.70" (lighter load for my wife) wich gave me 1" groups at 100yds easily.

Just started experimenting with these. Sierra Gameking .284 140gr Hollow Point Boat Tail with H4895 for my 7mm-08 Rem. Started at 37.5gr and worked up in half grain increments to 39gr. Groups were horrible. 1 1/2" at 100 yds was the best I got at 38.5gr.
39gr started to flatten primers.

Rifle is Ruger American

Without changing my seating die (set for the 120gr) it loaded the HPBT's to 2.60.(did not test). If I were to seat to the lands with the HPBT would be at 2.79" (which would still fit in magazine). These tested were seated to 2.78.

I don't want to seat to the lands so only option I guess is to work my way back (or creep forward slightly) and maybe try a new powder if that doesn't work. 42gr H4895 has given me 1" groups with the 120gr.

Anybody have experience with these bullets?(any caliber)

This is my first experience with the Sierra GameKing HPBT.

Would you try to creep towards the lands more or back out? Try a new powder?

Any suggestions or input would be appreciated THR!

Side note: Posting this reminds me I miss rcmodel.

Me? I'd work back slowly with your best charge, hodgdon says 38-40.5 for charge weights coal at 2.75, Nosler says cousin Imr4895 worked best with 37 gr on the 140s. With that in mind, I'd even contemplate starting over with a shorter COAL, none of my sierras ever complained about a bit of jump (within reason) and I've never chased the lands, in my .243 I now run as many bullets as I can out to 2.68 (works for my charges but honestly still MILES from the lands) but with 2 different powders, I got gorgeous groups seated at 2.65 (even farther from lands) with the HPBT gk, so I'm thinking shorter wouldn't hurt any. Alternatively, considering the 140 ph may not be a bad idea. You never mentioned twist rate....

 

[Arkansas Paul]

I'm betting you'll like the results.
I shoot mainly 165 grain Gameking BTHP bullets in my '06 and they hit deer like Thor's hammer.

I just loaded them to the OAL listed by Sierra and it shot very well, so I didn't experiment with the seating depth. I am fortunate that my Weatherby Vanguard is not picky, and shoots most bullets well.

I feel that they are a great bargain at only $32/100.

 

[Bartojc]

Previously using 120gr Sierra Pro Hunter over 34gr H4895 seated to 2.70" (lighter load for my wife) wich gave me 1" groups at 100yds easily.

Just started experimenting with these. Sierra Gameking .284 140gr Hollow Point Boat Tail with H4895 for my 7mm-08 Rem. Started at 37.5gr and worked up in half grain increments to 39gr. Groups were horrible. 1 1/2" at 100 yds was the best I got at 38.5gr.
39gr started to flatten primers.

Rifle is Ruger American

Without changing my seating die (set for the 120gr) it loaded the HPBT's to 2.60.(did not test). If I were to seat to the lands with the HPBT would be at 2.79" (which would still fit in magazine). These tested were seated to 2.78.

I don't want to seat to the lands so only option I guess is to work my way back (or creep forward slightly) and maybe try a new powder if that doesn't work. 42gr H4895 has given me 1" groups with the 120gr.

Anybody have experience with these bullets?(any caliber)

This is my first experience with the Sierra GameKing HPBT.

Would you try to creep towards the lands more or back out? Try a new powder?

Any suggestions or input would be appreciated THR!

Side note: Posting this reminds me I miss rcmodel.

No experience with that bullet, but I shoot Sierra's in 3 different rifles/calibers. In my experience BT never grouped as well as a flat backed bullet like the Pro-Hunter. That has been my experience across the board not just with Sierra. I think that is common and I've heard it explained before (Maybe by rcmodel). You might try a flat backed bullet vs a boat tail, unless you need the boat tail for long distance.

I have used 125 gr Pro-Hunters and H4895 in a reduced recoil load for 30-06 and found an acceptable load with groups under 1". Good enough for deer hunting. Again though Pro-Hunter. FYI, I never push the lands.


-Jeff

 

[Blue68f100]

I have found that Sierra's recommendation on OAL is pretty good. In most cases I find that I end up with a 0.025"-0.035" jump to lands.

I do not have this caliber gun but use Sierra SBT GK 90% of the time. I do shoot flat base and boat tail through my guns to find what works best. Every gun is different. With my guns I end up using the BT for I get better grouping even at 100yrds. With loads being in the 95-98% of max with a few slightly over max.

Primers are a poor indications of pressure. Look for increased bolt lift or imprint on the case head. If your using S&B primers I find these to be softer and thinner than CCI's.

 

[Stumper]

FWIW. My wife's Mossberg Patriot 7mm-08 groups 140s better with H4895 than it does 120s 120s behave better with H380... Both bullet weights group better overall with various charges of H380....but I haven't found a stellar accuracy load apart from the familiarization loads we started her with.--Sierra 100 gr HP over 10.7gr of Red Dot (1750 fps and sub MOA).

 

[CptnAwesome]

Are you sure you started to flatten at 39 or were the primer edges just "crisp"? Also whats your brass type?

Primers aren't dangerous level flat, I guess more "crisp at the edges" like you said. I'd be comfortable going up another 1.5gr.

Brass is from factory Hornady 7mm-08 American Whitetail.

 

[CptnAwesome]

Me? I'd work back slowly with your best charge, hodgdon says 38-40.5 for charge weights coal at 2.75, Nosler says cousin Imr4895 worked best with 37 gr on the 140s.You never mentioned twist rate....

Twist rate is 1:9.5
Think I'm gonna try 2.78 with 39.5- 40.5gr and see how that goes. Also gonna start over and creep away from the lands a little. Gonna stick with H4895 for now.

 

[Blue68f100]

Pick your best grouping that's not near the max load , <0.2 gr max. Then start reducing the OAL by 0.005" steps. You will know pretty quickly once you get into the window your looking for.

 

[GooseGestapo]

H4895 is too fast for the 140GK in the 7mm08.
Switch to RL17, H4350, or IMR4350 for good accuracy.
I've gotten excellent results with H4895 and 120gr bullets for reduced loads, but not with full power loads.

Silhouette shooters in the mid '80's shot a lot of H380 and H414, but H4350 and RL17 didn't exist yet.
My Remington M-7 adores 47.0gr RL17 and 140gr GameKings. 150gr GameKing or Nosler AB over 45.0gr RL17 even better.

 

[.308 Norma]

I'm betting you'll like the results.
I shoot mainly 165 grain Gameking BTHP bullets in my '06 and they hit deer like Thor's hammer.

I'll second THAT! I use 165 grain GameKings BTSPs in my 308 Norma Magnum for mule deer (I don't believe in "overkill") with spectacular results. The bullets must hold together well because I've never recovered one, and the deer usually drop in their tracks. Besides that, I can shoot tiny, little groups at 100 yards with those bullets and my rifle.

1 1/2" at 100 yds was the best I got at 38.5gr.
39gr started to flatten primers. Rifle is Ruger American

On the other hand CptnAwesome, I hope this isn't the case, but one of my wife's 7mm-08s (an old, tang-safety M77 Ruger) absolutely hates boattail bullets. We tried everything - different powders and charges, different seating depths, even different primers, and the best she could do was about 2.5", 3-shot groups at 100 yards. Switching to plain-based 140gr Sierras immediately solved the problem - 3 shots in under an inch at 100 yards, with usually 2 of them touching.
But don't let our experience with that rifle discourage you. Because the fact is, my wife has another 7mm-08, a Winchester 70 Featherweight that does great with boattail bullets.

 

[Arkansas Paul]

1 1/2" at 100 yds was the best I got at 38.5gr.

I wouldn't call that terrible.
1.5" groups is plenty good enough for hunting deer. The bullet is landing within three quarters of an inch of where your crosshairs rest. When you think about it like that, it's pretty darn good.
But I also like to use the bullet that gives the best accuracy and am guilty of chasing smaller groups. There's just something about it.

I didn't read your post closely enough the first time, or I would have mentioned that sooner.

 

[MSgtEgress]

Capt Awesome, To begin with a GameKing is a SPBT and a great hunting bullet while a MatchKing is a HPBT and NOT suitable for hunting. See link Below:

https://www.sierrabullets.com/products/bullets/rifle.cfm/caliberID/8

That being said if you are dead set on using 140g bullets I would give IMR4064 a go. If you are open to try something different try a 120g

I found that a 120g is deadly on whitetail and I get better ballistics. I use 40g of IMR 4007SSC with a Nosler 120 Ballistic tip Hunting for 3100FPS at the muzzle. with a 200 yd zero it drops 6.7" at 300 and 19' at 400. I've dropped 5 deer in their tracks at up to 300 yds. The others didn't go more than 50 yds Ive attached pictures a typical wound

 

[azjohn]

My hunting bullet in my .270 is a Sierra140 grain HPBT . https://www.sierrabullets.com/resources/bullet-selection/index.cfm#gameking GameKing Bullets: All bullets in this classification are for hunting and all have boat tails. Their shapes include hollow point boat tail (HPBT), spitzer boat tail (SBT), and full metal jacket boat tail (FMJBT). The bullets in this classification have medium to heavy weights in each caliber. With their boat tail shapes, they have high ballistic coefficients, retain their velocities well, and resist crosswinds and vertical winds well as they fly. These bullets are designed for a combination of penetration and expansion in medium and heavy game animals for their calibers.

 

[horsey300]

Capt Awesome, To begin with a GameKing is a SPBT and a great hunting bullet while a MatchKing is a HPBT and NOT suitable for hunting. See link Below:

https://www.sierrabullets.com/products/bullets/rifle.cfm/caliberID/8

That being said if you are dead set on using 140g bullets I would give IMR4064 a go. If you are open to try something different try a 120g

I found that a 120g is deadly on whitetail and I get better ballistics. I use 40g of IMR 4007SSC with a Nosler 120 Ballistic tip Hunting for 3100FPS at the muzzle. with a 200 yd zero it drops 6.7" at 300 and 19' at 400. I've dropped 5 deer in their tracks at up to 300 yds. The others didn't go more than 50 yds Ive attached pictures a typical wound

Sierra makes a hollow point gameking, you should look into them, they're well worth it, they are NOT the matchking, the ogive and meplat are different, and they ARE designed for hunting, one heckuva good deer bullet!
https://www.sierrabullets.com/store/product.cfm/sn/1912/284-dia-7mm-140-gr-HPBT

 

[Biggs300]

I've had good results with several different 140 grain bullets (including SGK SBT) using both Varget and Ramshot Big Game powders. With heavier bullets, I use either H4350 or Ramshot Hunter. You might also want to check your case trim length. Sierra manual (edition 5) shows a trim length of 2.025 while Nosler suggests 2.035. My rifle is a Tikka T3 and I'm fortunate in that it is not too particular with regard to bullet weight with the right powder. I'm currently working up a new load for 160 grain SGK SBT using H4350.

 

[philip brousseau]

Captn.the way the hp game king is shaped the bore diameter on the ogive is closer to the point of the bullet meaning it is probably seated closer to the lands than your previous bullet. try seating deeper in small increments if you don't have a bullet comparator to match the 120 gr. loads distance to the lands. it's also possible your rifle just doesn't like 140s. i've had several rifles that were one weight only if i wanted the best accuracy the rifle would give.

 

[CptnAwesome]

You might also want to check your case trim length. Sierra manual (edition 5) shows a trim length of 2.025 while Nosler suggests 2.035.

Yeah I've been trimming to 2.035. I'll try 2.025 on the next batch