Which barrel profile would act stiffer?

[Rset]

That is not true. 30 shots 10 different charge levels most loads had a left or right POI.

Looks like you have already made up your mind. Go with what you believe.

 

[Rob01]

Yep thats what I did with my friends hunting rifle. That was a long time on the bench lol.

Yup but something you have to do with those lighter barrels. All the ones you listed are so close I doubt you would see much difference and you should still let them cool. Get a barrel cooler to speed it up.

 

[darkangel_r2]

Ten different charge levels aren't hugely different loads. If you find a node wide enough and the charge increment small enough, you can get what show. I have had a few different customer rifles shoot over a couple grain powder charge increment to the same POI.

Not every tune will give you that.

That was 3 grains between the high and low charge. Factory 12lrp.

 

[darkangel_r2]

Looks like you have already made up your mind. Go with what you believe.

I have no idea which would be better between LP and LV. I was hoping someone had owned both and could share some info.

 

[darkangel_r2]

If you are doing load work with lighter barrels you would need to give them more time between tests to cool down to help any possible POI shift due to heat.

I know. I don't let any barrel get too hot during load dev. I give them all plenty of time. Takes much longer to get hot with the big barrels though.

 

[INTJ]

That was 3 grains between the high and low charge. Factory 12lrp.

That is a good node for that barrel. While your question makes sense, the only guidance I can give is to go heavy on the barrel and work to find a wide tuning node.

Like I mentioned before, the straight taper of a BR type barrel is likely optimum. Palma contours tend to be lighter but still shoot well. I use heavy varmint contours of my light gun class 1K BR rifles, but on a heavy hunting gun I like a light palma contour. My LG BR rifle can weight 17 lbs, but I want my heavy hunting rifle to come in around 12 lbs.

 

[Stan Taylor]

Darn I totally forgot to get popcorn I can’t wait.

 

[KMart]

The light palma has more metal at the muzzle and its neck section is chubbier than the light varmint. So the first 4.5" or so of the light palma will be thicker than the light varmint making it less likely to flex there.

From looking at your choices and projected use, go with the light Palma. Larger muzzle diameter at 24" and 6 0z lighter than the light Varmint.
You will see no difference in performance

 

[Rob01]

I know. I don't let any barrel get too hot during load dev. I give them all plenty of time. Takes much longer to get hot with the big barrels though.

Yeah it does take longer and why people not hunting use them. Lol you are really over thinking this. Pick one and use it. I highly doubt any will be much different being similar contours.

 

[darkangel_r2]

Darn I totally forgot to get popcorn I can’t wait.

Do you have any experience with LV and LP contours? Notice any difference?

 

[jelenko]

If you read the edit in the OP I'm not talking about bullets with the same load walking around in the same string. I'm asking about which profile would produce the lowest POI shift between different loads. Which would act stiffer and make different loads group closer together.

Why?

 

[Stan Taylor]

Do you have any experience with LV and LP contours? Notice any difference?

Sorry not interested in a response I’m sure someone will point you in a good direction I just make rifle barrels.

 

[Coyotefurharvester]

Long/thin less "stable" than short/fat.

 

[darkangel_r2]

Why?

Because all else being equal its better than the reverse condition. Especially since I'm going to make ammo 100 rounds at a time. This isn't a br gun where I'm tailoring ammo for that days conditions. The closer all loads are to each other the better.

 

[darkangel_r2]

Long/thin less "stable" than short/fat.

Right. I've got the length pegged at 24". Its really light varmint vs light Palma. Palmas fatter at the action and muzzle end and light varmint is fatter in the middle. Not sure which one acts stiffer because they are similar in weight.

 

[joshb]

Do you have any experience with LV and LP contours? Notice any difference?

Do a search on Stan Taylor. See what you find.

 

[darkangel_r2]

Do a search on Stan Taylor. See what you find.

Is it an answer to the question posted in this thread?

 

[Cloudrepair]

It seems to me for an fairly accurate test you would need 3 as close to identical as possible load sets and then start with the largest barrel profile then turn that barrel to the next largest then the smallest profile to even come close to a conclusion.

 

[darkangel_r2]

It seems to me for an fairly accurate test you would need 3 as close to identical as possible load sets and then start with the largest barrel profile then turn that barrel to the next largest then the smallest profile to even come close to a conclusion.

I can bust out my mechanics book and do a moment of inertia calculation and throw it into a cantilever beam equation to get a mathematically accurate answer but I was kinda hoping there were some lads on here that have owned both that could just tell me how they act to save myself a few hrs of work.

But it would be really cool to see it done for real. In fact it would be really cool to do it from all the way from strait to sporter to see how much each walks around with the same load dev loads at each profile. Same chamber and length the whole time.

Would be really cool to see what that impacts.

 

[Tommie]

Silly question