Short 7mm-08 length, 18"?

[Orchemo]

I cut a Tikka to 17 inches to host a suppressor.
Handles great!!
140 Accubonds at 2680 fps gives me 1500 ft-lbs at around 310 yds.
One dead bear this spring with the rifle.

 

[jjohnsonElknewbie]

What’s the real world numbers guys are getting with a 18” 7-08?

I finally chronoed mine the other day. Standard Tikka lite contour chopped to 18" with KGM R30 can.

Recipe was 46.7 gr SB 6.5 with 162 ELDX. Bullet was seated 2.25" base to ogive with an OAL of 2.930. I was using 1x fired Alpha brass and CCI LRP.

1. 2698
2. 2727
3. 2701
4. 2693
5. 2696

Avg- 2703
SD- 13
ES- 34

The second shot screwed up my numbers, and next time I'm going to fire 10 rounds to improve the sample size. Every case had ejector stamps as well, and I backed off .2 gr to 46.5 for the next 10 round group. This barrel is approaching 100 rounds, so "should" be stabilized by now or in the process.

These 5 rounds grouped well (3 touching and 2 in a ragged hole about 1" apart) but again, the next round will be a full 10 shot group, so we'll get a better indication of the cone.

 

[TxLite]

I finally chronoed mine the other day. Standard Tikka lite contour chopped to 18" with KGM R30 can.

Recipe was 46.7 gr SB 6.5 with 162 ELDX. Bullet was seated 2.25" base to ogive with an OAL of 2.930. I was using 1x fired Alpha brass and CCI LRP.

1. 2698
2. 2727
3. 2701
4. 2693
5. 2696

Avg- 2703
SD- 13
ES- 34

The second shot screwed up my numbers, and next time I'm going to fire 10 rounds to improve the sample size. Every case had ejector stamps as well, and I backed off .2 gr to 46.5 for the next 10 round group. This barrel is approaching 100 rounds, so "should" be stabilized by now or in the process.

These 5 rounds grouped well (3 touching and 2 in a ragged hole about 1" apart) but again, the next round will be a full 10 shot group, so we'll get a better indication of the cone.

Great velocities on that 18” with the SB 6.5.

If you can get them grouping I wouldn’t worry about a 13 SD or 34 ES. @ 5000’ your dope is identical out to 400 yards. Then you’re only off .1 mil out to 700.

 

[pods8 (Rugged Stitching)]

I finally chronoed mine the other day. Standard Tikka lite contour chopped to 18" with KGM R30 can.

Recipe was 46.7 gr SB 6.5 with 162 ELDX. Bullet was seated 2.25" base to ogive with an OAL of 2.930. I was using 1x fired Alpha brass and CCI LRP.

1. 2698
2. 2727
3. 2701
4. 2693
5. 2696

Avg- 2703
SD- 13
ES- 34

The second shot screwed up my numbers, and next time I'm going to fire 10 rounds to improve the sample size. Every case had ejector stamps as well, and I backed off .2 gr to 46.5 for the next 10 round group. This barrel is approaching 100 rounds, so "should" be stabilized by now or in the process.

These 5 rounds grouped well (3 touching and 2 in a ragged hole about 1" apart) but again, the next round will be a full 10 shot group, so we'll get a better indication of the cone.

Those speeds are cooking for a 7-08 that short, obviously few powders are gonna deliver that fast (most will be much slower). Being you're still likely at the top end be wary with hot temps, etc. Not sure how forgiving SB6.5 about pressure spikes being its already pushing a bullet notable faster.

Mainly pointing it out for anyone going short that your options are gonna be limited if you are wanting speeds like that from a 7-08. Those are the velocities I'm getting with a 19" 284WIN with the 162eldm and H4350.

 

[jjohnsonElknewbie]

Those speeds are cooking for a 7-08 that short, obviously few powders are gonna deliver that fast (most will be much slower). Being you're still likely at the top end be wary with hot temps, etc. Not sure how forgiving SB6.5 about pressure spikes being its already pushing a bullet notable faster.

Mainly pointing it out for anyone going short that your options are gonna be limited if you are wanting speeds like that from a 7-08. Those are the velocities I'm getting with a 19" 284WIN with the 162eldm and H4350.

This is the first focused round of chrono I've done with it, and I can't speak to the impact of heat on SB 6.5, but it's been in the 90s heat index every time I've shot with it this summer. I've also been on the max side and often saw ejector swipes on my 162 and 150 Fusion loads. I should've done a more complete job of developing these loads with chrono, etc..., and we'll see what happens to the numbers and groups this fall when it cools off some.

I'm also going to chrono the 120 NBT load over 44 grains of Varget. It grouped very well without any pressure and may be a good coyote load if what I've read about the thicker jacket is true re: reduced pelt damage.

 

[jjohnsonElknewbie]

Those are the velocities I'm getting with a 19" 284WIN with the 162eldm and H4350.

I have a .284 build planned for 2025. I did a bit of research on multiple bullets/powder combos. It seems like it is very underpowered in most of the tables I've reviewed, and there is little, if any, published SB 6.5 data. Becuase the 7-08 does such a nice job with the 162s, my .284 will be chambered for and focused on the 175 and 180 class bullets. I have a threaded 22" Tikka super lite barrel in 7-08 that I plan to have re-chambered in .284 and throated for the heavies. With careful development, i think 2800 MV could be the top end. It should be a fun project!

 

[pods8 (Rugged Stitching)]

I have a .284 build planned for 2025. I did a bit of research on multiple bullets/powder combos. It seems like it is very underpowered in most of the tables I've reviewed, and there is little, if any, published SB 6.5 data. Becuase the 7-08 does such a nice job with the 162s, my .284 will be chambered for and focused on the 175 and 180 class bullets. I have a threaded 22" Tikka super lite barrel in 7-08 that I plan to have re-chambered in .284 and throated for the heavies. With careful development, i think 2800 MV could be the top end. It should be a fun project!

Yes there is lacking SB6.5 data for that cartridge, I may play with it later (I have a jug) but in the short term for this season I hit the easy button with H4350. In general I think when picking a cartridge you need to plan for the velocities from common powders in terms of expectations and just be pleased if some of the "hot rod" powders work in terms of speed AND accuracy. Sometimes both don't show up.

Edit to add. BUT if they do it sure is nice!

 

[jjohnsonElknewbie]

Yes there is lacking SB6.5 data for that cartridge, I may play with it later (I have a jug) but in the short term for this season I hit the easy button with H4350. In general I think when picking a cartridge you need to plan for the velocities from common powders in terms of expectations and just be pleased if some of the "hot rod" powders work in terms of speed AND accuracy. Sometimes both don't show up.

Agree, and H4350 is by far the most ubiquitous for the .284 based on the F-Class guys and others. This is a "known" entity and certainly a superb starting point to build confidence.

On a similar note, I'm hearing more about the .284 Shehane, and it's very intersting. It has a little over 3 grains more capacity than the standard .284, and most load development has been focused on F-class and prone 1000 yard shooting. I don't like the idea of fire forming and am concerned with additional recoil, but the performance is pretty phenomenal for anybody curious about long range.

 

[pods8 (Rugged Stitching)]

Agree, and H4350 is by far the most ubiquitous for the .284 based on the F-Class guys and others. This is a "known" entity and certainly a superb starting point to build confidence.

On a similar note, I'm hearing more about the .284 Shehane, and it's very intersting. It has a little over 3 grains more capacity than the standard .284, and most load development has been focused on F-class and prone 1000 yard shooting. I don't like the idea of fire forming and am concerned with additional recoil, but the performance is pretty phenomenal for anybody curious about long range.

I got a 280AI and had it before there were good/reasonably priced brass for it so I fire formed brass. There is something nice about not needing to spend barrel life and burn up components on a temporary load. Sure you get "trigger time" during that phase but I'd rather get trigger time with final loads and/or lighter shooting guns.

So every time I get excited about a cartridge that requires fire forming again I talk myself back.

Now if you were a competition shooter and using the same caliber over and over its a different story, you likely could keep reusing brass (if the same reamer cut your barrels) and/or even keep a "shot out" barrel to put on for fire forming and switch to a fresh barrel for true load development and shooting.


Since we're on tangents, a 6-284 or 257-284 (like you have) are of future interest for me. I already got a 280AI, a 284win, and a 7-08 barrel, I don't need more 7mm options, haha.

 

[jjohnsonElknewbie]

I got a 280AI and had it before there were good/reasonably priced brass for it so I fire formed brass. There is something nice about not needing to spend barrel life and burn up components on a temporary load. Sure you get "trigger time" during that phase but I'd rather get trigger time with final loads and/or lighter shooting guns.

So every time I get excited about a cartridge that requires fire forming again I talk myself back.

Now if you were a competition shooter and using the same caliber over and over its a different story, you likely could keep reusing brass (if the same reamer cut your barrels) and/or even keep a "shot out" barrel to put on for fire forming and switch to a fresh barrel for true load development and shooting.


Since we're on tangents, a 6-284 or 257-284 (like you have) are of future interest for me. I already got a 280AI, a 284win, and a 7-08 barrel, I don't need more 7mm options, haha.

My 25-284 is awesome. Simple one-step neck down with 6.5-284 Lapua brass in my 25-284 Redding dies. I've only shot 20 rounds through the barrel (McGowen 22" #3) and they grouped so well I almost don't want to shoot any more and get disappointed! J/K, LOL!

54.5 grains of H1000 and 134 ELDM is the only load I've fired, and I plan to chrono this one soon. I'm hoping for around 2900 MV.

 

[swusaz05]

I finally chronoed mine the other day. Standard Tikka lite contour chopped to 18" with KGM R30 can.

Recipe was 46.7 gr SB 6.5 with 162 ELDX. Bullet was seated 2.25" base to ogive with an OAL of 2.930. I was using 1x fired Alpha brass and CCI LRP.

1. 2698
2. 2727
3. 2701
4. 2693
5. 2696

Avg- 2703
SD- 13
ES- 34

The second shot screwed up my numbers, and next time I'm going to fire 10 rounds to improve the sample size. Every case had ejector stamps as well, and I backed off .2 gr to 46.5 for the next 10 round group. This barrel is approaching 100 rounds, so "should" be stabilized by now or in the process.

These 5 rounds grouped well (3 touching and 2 in a ragged hole about 1" apart) but again, the next round will be a full 10 shot group, so we'll get a better indication of the cone.

Savage 116 Ultra light MT in Stainless
MAG V Crono
Elev 960
Temp 105
CCI 200
Lapua Brass 56 g H2O
150 ELD-X
Win 760
45.5g
COAL 2.880
CBTO 2.221
Vel 2884
ES 15
SD 6
Thumb hole @ 100
Other adjustments did not change results one hole suff at 100 great hunting viable for 600 easy.

 

[jjohnsonElknewbie]

Savage 116 Ultra light MT in Stainless
MAG V Crono
Elev 960
Temp 105
CCI 200
Lapua Brass 56 g H2O
150 ELD-X
Win 760
45.5g
COAL 2.880
CBTO 2.221
Vel 2884
ES 15
SD 6
Thumb hole @ 100
Other adjustments did not change results one hole suff at 100 great hunting viable for 600 easy.

Those are great numbers, and what's your barrel length?

 

[swusaz05]

Those are great numbers, and what's your barrel length?

Heck not sure stock gun think 20. Remember @ sea level almost and High heat load development. Pretty much extrapolate the numbers with alt / temps likely close to same for you. Quick Load numbers are crap though for complete powder burn in the 7-08 no matter what powder you use. Win 760 I scored at 36 per lb. so that's what gun eats. Only use LAPUA brass so brass is never the problem.