6.5 Creedmore seating depth

[tom unler]

Hello all.
I just started shooting 6.5 Creed in my AR-10 build this weekend, 24" Shilen heavy barrel.
Breaking in the barrel at this point. I've researched components and boiled down that 140gr Nozler RDF and 31.5gr IMR 8208 XBR most likely to be accurate, (my result was 5 rounds touching at 100 yds with an occasional flyer, 100yds, 2.865" COL).

My seating depth is 2.865" = 020" short of the Lands. A few of my rounds accidentally got seated to 2.630", but I wasn't in the mood to pull and re-seat. In the spirit of laziness, I randomly put them down range and they seemed to preform BETTER than -.020". Thats a .055" jump to the rifling.

Does anyone here have insight/experience with the 140gr RDF for optimal seating/jump?

I'm thinking about doing a test run with 2.830"-2.860" COL rounds to explore potential

 

[Varminterror]

The RDF isn’t jump sensitive. 55thou is pretty long, but not unheard of. I’ve jumped them 35tho and saw minimal difference between 35 and 10.

 

[Blue68f100]

Hello all.
I just started shooting 6.5 Creed in my AR-10 build this weekend, 24" Shilen heavy barrel.
Breaking in the barrel at this point. I've researched components and boiled down that 140gr Nozler RDF and 31.5gr IMR 8208 XBR most likely to be accurate, (my result was 5 rounds touching at 100 yds with an occasional flyer, 100yds, 2.865" COL).

My seating depth is 2.865" = 020" short of the Lands. A few of my rounds accidentally got seated to 2.630", but I wasn't in the mood to pull and re-seat. In the spirit of laziness, I randomly put them down range and they seemed to preform BETTER than -.020". Thats a .055" jump to the rifling.

Does anyone here have insight/experience with the 140gr RDF for optimal seating/jump?

I'm thinking about doing a test run with 2.830"-2.860" COL rounds to explore potential

I've got a test planned for checking neck tension using the 140gr ELD-M and H4350. I always test for OAL after I have found my most accurate load. I normally step in 0.005" increments. But like said the these are not jump sensitive.

 

[tom unler]

My AR-10 doesn't seem to like IMR4350 all that much. VV-150 caused pierced primers with a moderately light load, (still trying to figure that one out). IMR 8208 @ 31.5gr seems to ring the bell.... This weekend will put the theory to the test. I'm going to set back .005" increments and see if there is any dramatic changes.
Surprising how much better the RDF performs over 142 SMK. Ive been a huge fan of SMK forever, but that may be a thing of the past, (at least with 6.5 Creedmore),

 

[MCMXI]

I just started shooting 6.5 Creed in my AR-10 build this weekend, 24" Shilen heavy barrel.
Breaking in the barrel at this point. I've researched components and boiled down that 140gr Nozler RDF and 31.5gr IMR 8208 XBR most likely to be accurate, (my result was 5 rounds touching at 100 yds with an occasional flyer, 100yds, 2.865" COL).

You show the average velocity on the target above to be 2,510 fps which is very, very slow for a 140gr from a 24" barrel. Factory Hornady is running around 2,700 fps for a 140gr from a 24" barrel. What was the velocity for the loads with an COL of 2.630"?

As for bullet jump in general, there are many bullets out there both secant and tangent that shoot lights out with "massive" jump to the lands. I have too many loads worked up that shoot incredibly well with as much as .250" jump to the lands so I think of bullet jump as final tuning and not something to worry about in terms of absolutes.

 

[mmatherne]

My savage 12 LRP bolt shoots the 140 RDF and the 130 RDF significantly better at around .09” - .13”, which I measure from the ogive. Discovered this through the Berger seating depth test. In fact most bullets in this rifle do their best in the .09”-.13” region across different powders as well.

Highly recommended looking into it. Saved me a bunch of load development work. Please use caution as always.

 

[rayatphonix]

I’ve been reloading 6.5 CM since about 2011 or so. Never thought to try 8208 which is my go to powder for Grendel. A web search seems to indicate it’s very accurate but velocity is slower than with many powders. RL 17 works very, very well for me. You may want to give it a try also..