308 jump

[bobby]

hi
just wanting to know by the 308 gang what is their jump to lands with what ever bullets they using and if the notice a big difference in accuracy and velocity is notice between close and further away from lands .

i've got 2 308s a howa and a cz . the howa has a 1,4mm jump less than the cz but the cz has done 2500 rounds and the howa only 300 rounds . when do you recon a rifle is shot out , i mean how much free bore constitutes to a shot out barrel ?

cheers
bobby

[James Wilson]

Jump will vary from rifle to rifle, even in the same product range. The presure and speed should change with AOL length. Anyway,a 308 with 2500 rounds through it should be very far from being shot out

[LUAN]

Also rifling twist rate plays a role. Seems like the 1:12 like a longer jump then say a 1:10 but its not a rule.

[Carlo]

a large jump does't always mean that the barrel is shot out. and depending on the knox, a long jump can be fixed by having a gunsmith rethreading it a bit more and rechambering it, thats if i'm not mistaken. there are a bit more cleaver guys on the site that can give you more info.I shoot my 308 with a 0.5mm jump and using Lapua brass, nosler Ballistic tip in 150gr and S335 @ 44.2gr it works QUITE well!

[bobby]

only 3 replys and there was like 100 guys who said the owned 308's of is dit omdat dit in engles geplas is?

thanks for the replys james , 303 and carlo.

[Hein M.]

Bob

Ek laai 42.5gr S335 agter 'n 150gr Nosler BT. Die jump is 2.5mm en die geweer groepeer baie mooi daarmee. Ek het hom gezero op 200m en my plank gooi pragtig op daardie afstand. Ek soek glad nie 'n plat trajek nie, net basiese akkuraatheid en dit is wat ek kry.

Ek moet sê - Nosler maak moerse goeie kwaliteit koeëls My geweer smaak hulle 100% so ek glimlag al die pad!

My 308 is glad nie so vol nonsens soos my 243 as dit kom by afstand van die lands nie. My 308 en 223 is BAIE vergewensgesind wat herlaai aanbetref.

Jy kan ongeveer 5000 akkurate skote uit 'n 308 loop kry as jy mooi kyk na hom.

Mooiloop!

Hein M

[LUAN]

Bob my .308 has a 2.9mm jump with 150gr nosler bt luckily it works cause my guns got a bit long freebore and loading against the lands will mean the cartridges won't fit in the mag. I also have a long jump with the nosler 155gr cc. .308's are renonwed for long barrel life so don't worry about the freebore that's just how it was cut.

[Fanta300]

Hi Bobby, nee ons is nie bang vir die Engels nie!

I used to do a lot of Bisley shooting with a .308 with a Ferlach 27.5" 1:14 twist barrel. In those days we all had to use standard PMP 143gr. military ammo so nobody worried about TPL or Max TPL to lands etc. Having recently switched to bench rest shooting and reloading myself and hearing all the talk about TPL and jump and so on, I decided to measure the jump in my Bisley rifle.

I removed the bullet from one of the 143gr FMJBT and tried to measure my max TPL but the bullet falls out of the front of the casing before it touches the lands! That would give a jump of more than 4mm I guess.

The next question is how accurate is this rifle. Well my best score was a 49 out of 50 over 300, 500 and 600m for a total of 147 out of 150.

My Howa .308 Varminter is still awaiting a license so I have not been able to play with it yet. I did try and measure max TPL with the PMP ammo but with the same result. I used some Sierras just to get a max TPL and this came to 73.8mm. My magazine has a limit of 72mm, so that is where I will have to start playing with TPL.

I can't wait

Fantie

[bobby]

thanks for the replys

clears some thoughts up . i'm going to try load some sierra's up again funny thing is that those sierras always play the game .

on another note who's got stock of 165 gr sierra game kings spbt bullets ? i can't find any in cape town and why are the sierras not appearing on the shelves ?