Two Powders, Same Bullet; Do I clean between powders?

[minnesotamulisha]

Good Morning Everyone. I have some load development to do this evening. I am shooting 175 SMKs in a 308. I have two powders to try, IMR 4064 and 4166. If I were to shoot the 4064 first, is it necessary to thoroughly clean before shooting the 4166 if I am shooting the same bullets, or do I just clean powder residue and call it good?

Thanks,

Adam

 

[6mmcldasher]

how many rounds of each.

 

[minnesotamulisha]

15 rounds loaded with 4064, and 40 rounds loaded with 4166.

The last time I shot this rifle it was with the 175 SMK and IMR 4064.

 

[LHSmith]

I always have at least run a wet patch followed by a dry patch when changing powders. Probably more important when switching from a known "dirty" powder like from Reloder 10 to 4198 or from WW760 to Reloder 15.

 

[alf]

When doing load work, I don't clean when switching powders, but usually shoot two rounds of the different powder to "season" the bore, so to speak.

I'd shoot the 4064 load first.

 

[savagedasher]

It depend on what your doing the tests to find out. I always test with different powders with a clean bore. Larry

 

[6mmcldasher]

it may not make a difference , but just to eliminate one variable give it a scrub and re fowl.

 

[spclark]

With both propellants being the same brand, I don't think a thorough cleaning between loads would offer much of a change in performance. When propellant testing I'll start with a cleaned bore then fire five or six fouling rounds before starting my number-gathering.

Last Friday I was out with Benchmark, N150 & 8208XBR in a 308, didn't do anything between loads. Wondering now if I should have cleaned between 'em; numbers & groups with 8208 consistent with expectations, the other two not so much.

 

[LHSmith]

^^^^^ Yep, eliminate the variables....and we certainly can by just taking the time to clean between powders. Perhaps even more important now that some new powders have more unique additives, such as a copper fouling deterrent and temp. stabilizers, etc.

 

[RDavies]

It is not just when testing powders from different brands or types. In 3 different calibres, I got very bad accuracy for 6-8 shots when switching from AR2209 (H4350) to AR2213sc (H4831sc), but accuracy was great all the way through when changing from H4831sc back to H4350. Same powder, just different order, different results.

 

[minnesotamulisha]

RDavies, that's interesting that accuracy would suffer from one to the next, but not the other way around.

I really appreciate the info that everyone has offered.

When cleaning between powders, would a CLP suffice?

 

[RDavies]

RDavies, that's interesting that accuracy would suffer from one to the next, but not the other way around.

I really appreciate the info that everyone has offered.

When cleaning between powders, would a CLP suffice?

When switching powders, just a wet patch or two, then a few dry patches brought accuracy back after 2 fouling shots.

 

[amlevin]

give it a scrub and re fowl.

Is there a particular bird you prefer when you "re fowl"? 8) 8)

 

[243winxb]

I would clean. Checking the MSDS its shows different components. 5 vs 8, Double vs single base. http://www.imrpowder.com/msds.html I use Hoppes number 9