SDand FPs problems

[Urmaker]

Hey fellow enthusiasts ....down the rabbit hole I go!

I am having issues with sd and consistent fps with my current reloading setup.....with 30 to 40 fps total swings.....here is my setup and reloading process.....my impression is something is wrong in the ignition process but I'm not sure....your guidance would be greatly appreciated

Ruger rpr 6.5 creed
Approx 2000 rounds on on barrel
No internal mods or smithing
Tuner and suppressor on when firing
Brass is SB....140 nosler custom comp at approx 2500 fps avg

Virgin Brass is neck turned ..pocket hole uniformed..flashhole uniformed...case capacity is confirmed With bison armory gauge of 51.6 to 52.4...I know this can give some fps difference but gordons relaoding tool I believe indicated around 18 fps....powder is h4350 at 37.1 grns .primer..is winchester WLR(only thing i could get a lot of during covid years)..round is consistently seated at depth and confirmed with calipers. I use induction heating after every firing. Between turning....bushing die of 2 thousands with spring back I get consistent 1 thousands neck tension. Seating the round with KM press and force pack I get consistent 18 to 24 lbs of seating force....

I'm at a loss....im trying to get in the teens for Fps variation and or SINGLE sd.

 

[Char'ed Cuterie]

I am having issues with sd and consistent fps with my current reloading setup.....with 30 to 40 fps total swings.....6.5 creed
Brass is SB....140 nosler custom comp at approx 2500 fps avg

powder is h4350 at 37.1 grns

37.1grns of H4350 for a 140grn in a 6.5 Creedmoor seems more than slightly lower than normal. The old standby is 41.5 grains of H4350 for 140's. Any chance we're missing something here? Are you significantly shorter than 2.800 COAL?

 

[Kickin45]

Your load is VERY low. Probably not in a node.
And maybe, and I emphasize maybe because it depends on your shooting style and barrel quality, your barrel may be getting close to giving up the ghost.

 

[FredHammer]

Typically too low a charge weight results in high ES/SD, then there is the sweet pot range of consistent ES/SD (Not always low) and then too hot a charge spikes the ES/SD again.

Granted, as handloaders, we always want to fine tune shit to the Nth degree, but all that really just induces anxiety. 98% of shooters can't shoot the difference between a single and teens SD load. Especially IPSC and steel shooting. 1000yd benchrest competition, maybe it matters more.

 

[supercorndogs]

30ES is not bad at all.

 

[DeathBeforeDismount]

Your load is VERY low. Probably not in a node.
And maybe, and I emphasize maybe because it depends on your shooting style and barrel quality, your barrel may be getting close to giving up the ghost.

There is no such thing as nodes but yea the load is way low.

Low case fill % results in inconsistent ignition. You tend to see groups tighten up at distance as your case fill % goes up due to a reduction is SD.

30 ES not not terrible and alot of peoples handloads shoot worse than that.

There are a ton of variables at play and anything from your gear to your reloading process could effect it. Change one thing at a time and test before changing something else or you will be chasing shit forever.

 

[Urmaker]

Hey there everyone...thank you for such prompt responses....

I did find velocity notes.at 37.1 long ago with a fps spread of 12 and then another at 38.2..with a diff of 26. Nosler data stated nothing over 41 gr. Additionally there reloading data stated and accuracy node at 37.

My length to ogive is 2.233 and over length of 2.746


My thoughts at the time was yes...it was a slower load but the sd and fps were low and that it wouldn't burn out the barrel as fast....


Thanks again. Folks for all your wisdom

 

[DeathBeforeDismount]

2.746 is very short. What is your jump?

You might be jumping them like .200. I would load close to mag length while being like .020-.050 off the lands. Im not sure what those Noslers like but bergers always seem to shoot well in that range. Most non binder plate mags you can load to like 2.950. Most of my 6.5C loads are like 2.925. Even most binder plate mags let you load to 2.875. The added benefit of loading longer is lower pressure for given charge weight.

 

[straightshooter1]

Hey fellow enthusiasts ....down the rabbit hole I go!

I am having issues with sd and consistent fps with my current reloading setup.....with 30 to 40 fps total swings.....here is my setup and reloading process.....my impression is something is wrong in the ignition process but I'm not sure....your guidance would be greatly appreciated

Ruger rpr 6.5 creed
Approx 2000 rounds on on barrel
No internal mods or smithing
Tuner and suppressor on when firing
Brass is SB....140 nosler custom comp at approx 2500 fps avg

Virgin Brass is neck turned ..pocket hole uniformed..flashhole uniformed...case capacity is confirmed With bison armory gauge of 51.6 to 52.4...I know this can give some fps difference but gordons relaoding tool I believe indicated around 18 fps....powder is h4350 at 37.1 grns .primer..is winchester WLR(only thing i could get a lot of during covid years)..round is consistently seated at depth and confirmed with calipers. I use induction heating after every firing. Between turning....bushing die of 2 thousands with spring back I get consistent 1 thousands neck tension. Seating the round with KM press and force pack I get consistent 18 to 24 lbs of seating force....

I'm at a loss....im trying to get in the teens for Fps variation and or SINGLE sd.

Hmmmm??? If the "30 to 40" you're reporting is SD's, then that's pretty bad. But if this is ES's, that's not bad at all, though there could be some improvement. Don't expect you ES's to be in the teens, though that's just common for a series of 3 or 5 shots.

If it's an SD issue, the first place I'd look at is your powder measuring. You didn't mention how you throw your powder and what you measure it on. . . .???

As other's have mentioned, low case fills is a big factor in getting lower numbers.

Some other minor things that I see:
Your brass having .8 gr H2O spread in volume contributes to your variance. My brass tends to be .5 grs or less.
Your neck tension might be a little too light. Play with that and see what you get.
You didn't mention how your seating your primers. . . consistent seating helps with those uniformed pockets.
The primers themselves could be a big part of your issue. Like I recently bought and tried some Remington 9.5's in my .308 and my ES's and SD's went to hell. . .no matter what I tried (even with different powders).

Well, hope this give you some ideas to address and see what kind of improvements you might see. Just don't try to make a bunch of changes at once so that you can see what actually makes a difference.

Good Luck.

 

[Urmaker]

You guys are great

My jump is .032


My scale goes down to .001

I'm around .08 to .12 when trying to get 37.1

My throw is from a hornady powder measure bit I trickle on.my scale to those numbers

 

[RegionRat]

My scale goes down to .001

I'm around .08 to .12 when trying to get 37.1

My throw is from a hornady powder measure bit I trickle on.my scale to those numbers

Is the "My scale goes down to .001" in grams or grains?
If the scale reads down to 0.001 grams, then try to keep your powder charge tolerance down a little tighter.

Pay attention to the details in the posts above with regard to case prep and primer seating.
Go through the rig and double check the ignition parts to be sure you have no issues with consistent firing pin strikes.

Your ES stat is not bad at the level of 40 fps. Is that for 5 rounds or for 20?
A nominal ES of 40 fps in a 6.5mm accounts for an estimated 3.7 " at 600 yards, which would be less than that for a tuned load.

If you re-run the testing where you arrived at the 2500 fps recipe, does it repeat?
It does sound a little slow for a 6.5CM with 140 grain.
Does the suppressor load up and need cleaning?
If it accumulates soot and changes weight over time, you will need to track it and clean it before it changes your system.

Any time you try to get a rifle and ammo to hold under 0.5 MOA at over 600 yards, and in different places and weather, it will take attention to details. Good Luck and keep at it.

 

[Slides]

Hey fellow enthusiasts ....down the rabbit hole I go!

I am having issues with sd and consistent fps with my current reloading setup.....with 30 to 40 fps total swings.....here is my setup and reloading process.....my impression is something is wrong in the ignition process but I'm not sure....your guidance would be greatly appreciated

Ruger rpr 6.5 creed
Approx 2000 rounds on on barrel
No internal mods or smithing
Tuner and suppressor on when firing
Brass is SB....140 nosler custom comp at approx 2500 fps avg

Virgin Brass is neck turned ..pocket hole uniformed..flashhole uniformed...case capacity is confirmed With bison armory gauge of 51.6 to 52.4...I know this can give some fps difference but gordons relaoding tool I believe indicated around 18 fps....powder is h4350 at 37.1 grns .primer..is winchester WLR(only thing i could get a lot of during covid years)..round is consistently seated at depth and confirmed with calipers. I use induction heating after every firing. Between turning....bushing die of 2 thousands with spring back I get consistent 1 thousands neck tension. Seating the round with KM press and force pack I get consistent 18 to 24 lbs of seating force....

I'm at a loss....im trying to get in the teens for Fps variation and or SINGLE sd.

A friend had the same problem until he brought his average velocity up to around 2600fps, inconsistent burn of light charge.

 

[Doom]

I did find velocity notes.at 37.1 long ago with a fps spread of 12 and then another at 38.2..with a diff of 26. Nosler data stated nothing over 41 gr. Additionally there reloading data stated and accuracy node at 37.

Since you mention this is a velocity node it begs the question as to how many shots per charge weight were used. It is generally accepted that most "velocity nodes" are the results of sampling error and probability distribution. They tend to not be repeatable. Basically they do not exist. (Do let this comment derail this thread!!!)

Your 0.8 gr H2O case variance is huge. This is on the order of 6 to 7 grains of brass weight. While weight is not alway a good measure of case volume this kind of variance tends to indicate the cases are of mixed lots and are not uniform. I agree with the rough estimate of the effect on velocity of that difference is about 18 fps. That difference is equivalent to about 0.3 gr of powder.

A side note on powder. Your case fill appears to be on the low side, into high 70's to low 80's per GRT. Loads this low do tend to be inconsistent. Looking at Nosler data 37 gr case fill is 84%. I would think loads nearer 90% and higher will be more consistent.

 

[Chris1972]

I would think with that low of a charge your rifle is running very dirty and making your suppressor filthy. Without the suppressor you would be seeing black smoke out the end of the barrel. You may be anyway. H4350 will burn clean (ish) at proper case fill.

It is an ignition problem like you thought but not the primer, it’s low case fill.


You case volume numbers are a high spread but not insurmountable. I wouldn’t look at this until you’ve looked at 4 more grains of powder.

With H4350 you can load a ladder and actually hear when you reach proper ignition. (Probably not suppressed)

 

[clcustom1911]

Your charge weights with a 140 should be between 40-43gr with H4350. I've found 40.5, 41.5, and 42.5 (too hot for my tastes) are 3 spots which will give you good accuracy and velocity numbers.

I currently shoot 41.5 with a 142gr Sierra Matchking, Federal Gold Medal primer, and Hornady/prime brass. It's the easy button for tiny groups and, about 2700fps (2735 @ 95⁰f), 10-15 SD, and 35-45 ES.