Bullet Jump

[JoeBUtah]

Today I ran three different powder charges in two different bullet jump scenarios in my Remington Milspec 5R in .308. I had no preconceived notions of of what to expect, although I was hoping to see something. I really didn't.

Bullets were 175 SMKHP
Varget powder; 42, 42.5 and 43 Grains
Jump as measured with an RCBS tool: 0.015 and 0.010

Shot each combination with 5 round groups at 100 yards. With the exception of one group that was a little bit spread, every group had at least three shots touching and ended up sub moa.

My typical go-to load for the 175 smkhp is 42 grains Varget to the 'book' 2.80 OAL. I shot a number of them as well to warm up, and they did very well.

The question "is it worth the extra work" can't be positively answered. However, what do you any of you guys suggest as the next step? Should I drop the jump to .005 and then touch the lands?

 

[.50 Cal Cow]

If all three are touching what would you be trying to achieve? Sounds like a nice load with forgiving charge range.

Might need more drastic change to show any significant difference. From my short experience different bullets exhibit different characteristics. Some, SMK's include, I seated at different lengths with no effect. Some I've tried, A-max's and Interbonds, the 0.005" was enought to throw their accuracy off.

Recommend reading Berger's Seating Depth test as they have some background included on how to approach seating depth testing.

 

[gvanhyning]

It would help if you had pictures to post. Personally, I load my test rounds at .3 grain increments and seat bullets to the longest OAL that will fit in the magazine. Once I have identified a shot group to work with then I use that charge of powder for the next round of testing. I load all rounds with the same charge and vary the seating depth stepping down at .005 increments. When I have that seating depth identified then I take it to shoot to a minimum of 600 yards for load verification. Good luck.

 

[Highflyer]

My experience is that they like a jump of about .030. 175 SMK, 43gr BL-C)2)
100yds 5 shots of which was one was a choke on my part.
My rifle built on a Remington 700.

 

[JoeBUtah]

A few pics

Here is a collage of today's groupings. I can't shoot 5 without at least one flier...

 

[Highflyer]

Welcome to the club.

 

[jkonzal]

For what you are trying to do, I don't think 100 yards is enough to tell you what you need to know. I would try at least 200 yards and I think you might see a different story.