300WM Question

[weazer]

I was getting things around to try loading for my 300Wm, then I ran into a slight issue. I had a bunch of 208 Amax put away so I was checking the chamber. I'm at 2.960 to the lands which puts me at 3.692 OAL. My mag length is 3.654.

I have a few of the 230 Berger Hybrids and I'm 2.967 measured to the Ogive, that gets me an OAL of 3.739.

Its an older GAP build and shoots good with factory BH 190's, I just wanted to try the Amax's or Bergers. I don't have any of the 190's to measure. Where should I be with either of those or will the jump be too much?

 

[isofahunter]

Do not get wrapped around "The Lands". Start as long as mag box then go shorter from there. If factory shoots good start with those dimensions and then tinker. My 6.5 I measured the factory dimensions and built my handload to replicate and it is lights out accurate.

 

[briang7511]

you should not have an issue with jump. hybrids are not sensitive. At first i single loaded my 230s cause .020 off was too good of a load. Then i experimented with jump and they shot just as good. had to back powder down a little. then i found the 215s fit better in a mag and i was able to get 100 fps more out of them. shot alot of 208 hpbt and amax as well. ran h1000 with everything.

 

[texastonk]

This is what I’ve done on 3 different rifles with no accuracy issues. All shoot great!

Do not get wrapped around "The Lands". Start as long as mag box then go shorter from there. If factory shoots good start with those dimensions and then tinker. My 6.5 I measured the factory dimensions and built my handload to replicate and it is lights out accurate.

 

[weazer]

Alright guys, thanks for the advice.

 

[918v]

People who believe in “too much jump” are stupid.

 

[rustyinbend]

People who believe in “too much jump” are stupid.

Question ... are people who believe in "minimize the jump if possible" also stupid?
Asked differently ... should I care at all about jump, or just size to the spec?

 

[isofahunter]

Question ... are people who believe in "minimize the jump if possible" also stupid?
Asked differently ... should I care at all about jump, or just size to the spec?

You should care about it but do not obsess with getting as close to the lands as possible in every case.
Some combinations like to jump more than others; start with what is the max length that functions in your platforms magazine and chamber.
From there try to go shorter and see what happens to groups. I have some loads much longer than SAMII spec and others are shorter, depends on what the bullets on paper tell me.

 

[918v]

Question ... are people who believe in "minimize the jump if possible" also stupid?
Asked differently ... should I care at all about jump, or just size to the spec?

Adjust the coal to an optimum length. If optimum length is .005” off the lands, great. If it’s .105” off the lands, great. If it’s .045” off the lands, great.

But to argue that being close to the lands is always going to yield better accuracy is stupid. One should adjust both the coal and the powder charge to tune the load to the rifle.

You know what’s really stupid? It’s people buying factory rifles and loading way past mag length into the lands, squeezing out an extra 100 FPS while running 70,000 PSI and telling everyone on the internet how crappy Federal brass is.

 

[Clark]

I hit a running buck with a 125 gr nosler ballistic tip bullets with a Krieger barrel on a Mosin.
The deer went bang flop.

I own a lot of 300WM rifles and have a lot of bullets. I am not convinced I need more than 125 gr for deer.

 

[Clark]

300WM 125 gr nos bal tip moly 66 gr IMR4166 3174 fps chrono 22" barrel